Patent Publication Number: US-2021169668-A1

Title: Scaffold Loading and Delivery Systems

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 62/186,311 filed Jun. 29, 2015 and entitled SINUS SCAFFOLD DELIVERY SYSTEMS, U.S. Provisional Application No. 62/236,886 filed Oct. 3, 2015 and entitled SINUS SCAFFOLD DELIVERY SYSTEMS, and U.S. Provisional Application No. 62/314,239 filed Mar. 28, 2016 and entitled SINUS SCAFFOLD DELIVERY SYSTEMS, each of which is hereby incorporated by reference in its entirety. 
    
    
     FIFLD OF THE DISCLOSURE 
     This disclosure describes, inter alia, materials, devices, kits and methods that may be used for loading scaffolds into delivery devices and for the delivery of scaffolds into the body of a patient, including delivery of scaffolds to the sinuses for the treatment of chronic sinusitis, among other purposes. 
     BACKGROUND 
     Chronic rhinosinusitis (CRS) is a common condition defined by symptomatic inflammation of the paranasal sinuses lasting longer than 12 weeks. Up to 16% of the population is affected by this condition. Cavities associated with CRS include the maxillary, frontal, ethmoid, ostiomeatal complex, ethmoid infundibulum and sphenoid sinuses as well as the middle meatus location, or a combination thereof. Common symptoms of CRS include impaired nasal obstruction, facial pressure or fullness, nasal discharge, and olfactory loss; these symptoms likely arise due to mucosal inflammation, local infection, and/or impairment of mucociliary function. 
     While there is no approved therapy for the treatment of CRS, evidence-based medical management supports the use of a host of oral or topical corticosteroid therapies for the disease. High-volume, daily saline irrigation with adjunct application of a topical corticosteroid via nasal sprays is common as a first-line therapy. Second line agents for flare-ups and worsening disease include a short course of oral corticosteroids, although this approach can lead to unintended systemic side effects including glaucoma, osteoporosis and avascular necrosis of the hip and shoulder. It is estimated that up to 12-50% of CRS patients do not respond positively to this recommended medical regimen and are often candidates for Functional Endoscopic Sinus Surgery (FESS) and/or balloon sinuplasty dilation. 
     Avoidance of surgical interventions in the treatment of CRS would be ideal for patients since these procedures carry surgery-associated risks, cause post-operative pain and discomfort, and require burdensome and costly post-operative cleaning. Clinical data has demonstrated that topical corticosteroids are effective in reducing inflammation associated with CRS and thus, are a rational choice for the management of this condition. 
     An ideal treatment for CRS would provide local and sustained anti-inflammatory drug delivery in the sinuses of patients as an alternative treatment option to sinus surgery. Such a therapy would ideally establish safe and effective sustained drug delivery localized to the inflamed tissue and in some cases could prevent the need for surgery. 
     In this regards, FESS involves removal of bone and tissue to enlarge sinus outflow tracts, widen sinus openings or ostia and allow for ventilation of previously obstructed sinus cavities and restoration of mucociliary clearance. Currently, there are approximately 500,000 procedures performed annually in the United States. 
     By removing small pieces of bone, polyps, and/or debridement of tissue within the sinus cavities, FESS has proven to be an effective way to improve the drainage pathway of the sinuses. However, a significant number of postoperative complications such as inflammation, swelling, disease recurrence, need for repeat procedures and synechiae are often observed. Postoperative care is therefore an important component of FESS. Approximately 10-20% of FESS patients become refractory, do not respond to treatment, and may require additional surgical intervention or lifelong medical therapy. 
     Some form of sinus packing is generally conducted postoperatively to FESS. Examples of packing materials include simple dressings moistened with saline, foam dressings based on polysaccharide gel, PEG-based materials, and middle meatal spacers. Implantable sinus stents have also been devised and these scaffolds are intended to stabilize the sinus openings and the turbinates, reduce edema, and/or prevent obstruction by tissue adhesion. They also have the capability of being integrated with therapeutic agent(s) that may be delivered topically over time. This local delivery of therapeutic agent(s) may be superior to topical application in the postoperative setting. In this regard, the USFDA-approved PROPEL™ system (Intersect ENT, Menlo Park, Calif., USA) is a self-expanding, bioresorbable, steroid-eluting stent that is intended for use in the ethmoid sinus post-FESS. 
     There is an ongoing need for improved devices and methods for loading and delivering scaffolds to the sinuses. 
     SUMMARY 
     In accordance with various aspects of the present disclosure, scaffold delivery systems are provided, which are useful for the loading and/or delivery of self-expanding scaffolds that comprise a scaffold wall and have a scaffold lumen, a proximal scaffold end, a distal scaffold end, an inner luminal surface, and an outer abluminal surface. 
     In some aspects, the delivery systems may comprise a first assembly and a second assembly, wherein (a) the first assembly comprises (i) a loading member that comprises a tapered loading lumen having a proximal loading lumen end and a distal loading lumen end, wherein the proximal loading lumen end has a first diameter and the distal loading lumen end has a second diameter that is smaller than the first diameter and (ii) a delivery sheath having a delivery sheath lumen that is connected to the loading lumen and (b) the second assembly comprises (i) the self-expanding scaffold, (ii) an elongate advancement member having a proximal end and a distal end, (iii) at least one filament linking an end of the elongate advancement member to the scaffold, and (iv) an elongate inner member having a proximal end and a distal end, wherein the elongate advancement member and elongate inner member may be the same or different. The second assembly is configured to be inserted into the proximal loading lumen end of the loading member and advanced at least partially through the first assembly, such that the scaffold is moved through the loading lumen in a proximal-to-distal direction. 
     In additional aspects, the delivery systems may comprise (a) a loading member that comprises a loading lumen having a lumen axis and a luminal surface, a plurality of longitudinal pathways being formed in the luminal surface of the loading member adjacent to the loading lumen, said loading lumen comprising a tapered lumen region having a proximal tapered lumen end with a first diameter and a distal tapered lumen end with a second diameter that is smaller than the first diameter, (b) the self-expanding scaffold disposed within the loading lumen, said scaffold comprising a scaffold wall and having a scaffold lumen, a proximal scaffold end, a distal scaffold end, an inner luminal surface, an outer abluminal surface, (c) an engagement device comprising an engagement device axis and a plurality of elongate members, which taper radially outward from the engagement device axis, which have a shape memory that allows the elongate members to be radially compressed and to self-expand after upon removal of radial compression, and which teiminate in an engagement feature, wherein the engagement device is at least partially positioned within the scaffold lumen and loading lumen such that each engagement feature extends through the scaffold wall and into one of the longitudinal pathways and such that longitudinal movement of the engagement device is accompanied by longitudinal movement of the scaffold within the loading lumen. In various embodiments, the delivery systems further comprise (a) a delivery sheath comprising a delivery lumen in communication with the loading lumen and (b) an elongate inner member, wherein the elongate inner member and engagement device are configured such that elongate inner member engages and pushes the engagement device through the loading lumen and at least a portion of the delivery sheath. 
     In further aspects, scaffold delivery systems are provided for the delivery of self-expanding scaffolds that comprise a scaffold wall have a scaffold lumen, a proximal scaffold end, a distal scaffold end, an inner luminal surface, and an outer abluminal surface. The scaffold delivery systems may comprise (a) an elongate inner member, (b) a loading member that comprises a loading lumen having a loading lumen axis and a plurality of longitudinal pathways adjacent to the loading lumen, said loading lumen comprising a tapered lumen region having a proximal tapered lumen end with a first diameter and a distal tapered lumen end with a second diameter that is smaller than the first diameter, (c) the self-expanding scaffold disposed around the elongate inner member within the loading lumen and (d) a plurality of loading pins configured for engagement with the scaffold wall and for longitudinal movement along the longitudinal pathways, such that longitudinal movement of the loading pins along the longitudinal pathways is accompanied by longitudinal movement of the scaffold. In various embodiments, the delivery systems may further comprise a delivery sheath comprising a delivery lumen in communication with the loading lumen. 
     The above and numerous additional aspects of the present disclosure are enumerated in the following paragraphs: 
     Aspect 1. A crimping device configured to exert an inward radial force on a radially self-expandable scaffold and configured for detachable attachment to a distal end of a delivery sheath that comprises a delivery lumen, wherein the crimping device reduces an outer diameter of the radially self-expandable scaffold to a reduced outer diameter that is less than or equal to a diameter of the delivery lumen. 
     Aspect 2. The crimping device of aspect 1, wherein the crimping device comprises a collar band and a reducing mechanism that is configured to reduce the circumference of the collar band. 
     Aspect 3. The crimping device of aspect 2, wherein the collar-band-diameter reducing mechanism is a crank mechanism. 
     Aspect 4. The crimping device of any of aspect 1, wherein the crimping device comprises an inner lumen at least partially surrounded by an air bladder that is configured to be inflated to decrease a diameter of the inner lumen. 
     Aspect 5. A crimping system comprising (a) the crimping device of any of aspects 1-4 and (b) an elongate inner member having a shaft with an enlarged distal end or an elongate pusher member. 
     Aspect 6. A delivery system comprising (a) delivery sheath comprising a delivery lumen having a delivery lumen diameter and (b) a flexible tapered loading member comprising a first end which is larger than the delivery lumen diameter and which is configured to receive a radially self-expandable scaffold and a second end which is smaller than the delivery lumen diameter, wherein the flexible tapered loading member is configured to be inserted into the delivery lumen accompanied by a collapse of the flexible tapered loading member. 
     Aspect 7. The delivery system of aspect 6, wherein the flexible tapered loading member is a collapsible and expandable mesh. 
     Aspect 8. The delivery system of aspect 6, wherein the flexible tapered loading member is a funnel-shaped member. 
     Aspect 9. The delivery system of aspect 6, wherein the flexible tapered loading member is formed by cinching a filament at a distal end of a cylindrical member. 
     Aspect 10. A delivery system comprising (a) a delivery sheath comprising a delivery lumen, (b) a detachable funnel having a tapered lumen that is disposable at a distal end of the delivery sheath such that the tapered funnel lumen is in communication with the delivery lumen (c) a radially self-expandable scaffold and (d) an elongate loading member configured to transport the radially self-expandable scaffold through the funnel lumen and into the delivery lumen. 
     Aspect 11. The delivery system of aspect 10, wherein the elongate loading member is a flexible elongate member attached to an end of the radially self-expandable scaffold configured for pulling, the radially self-expandable scaffold through the funnel and into the delivery lumen. 
     Aspect 12. The delivery system of aspect 10, further comprising a flexible braided mesh, wherein the braided mesh is configured to receive the radially self-expandable scaffold and to be transported through the funnel and into the delivery lumen. 
     Aspect 13. The delivery system of aspect 12, further comprising a flexible elongate member attached to an end of the flexible braided mesh configured for pulling the braided mesh and radially self-expandable scaffold through the funnel and into the delivery lumen. 
     Aspect 14. The delivery system of any of aspects 12-13, wherein the flexible braided mesh is a double-layered mesh. 
     Aspect 15. A delivery system comprising (a) a scaffold, (b) a delivery sheath comprising a delivery lumen, (c) an engagement device comprising a plurality of radially contractible members, each comprising an engagement feature at its distal end, wherein the engagement features are adapted to engage a proximal end of the scaffold and reduce an outer diameter of the proximal end of the scaffold as the engagement device is transported into the delivery lumen due to radial contraction of the radially contractible members. 
     Aspect 16. The delivery system of aspect 15 further comprising a detachable funnel disposable at a distal end of the delivery sheath. 
     Aspect 17. A catheter configured for access to a sinus of a patient, wherein the catheter comprises a sheath having a lumen and a shape-memorized section that displays a curvature when the sheath is in an unconstrained state. 
     Aspect 18. The catheter of aspect 17, wherein the shape-memorized section has a curvature that ranges, for example, from 0 to 135 degrees. 
     Aspect 19. The catheter of any of aspects 17-18, wherein the shape-memorized section has a curvature that ranges from 1 to 50 mm in length. 
     Aspect 20. The catheter of any of aspects 17-19, further comprising a linear elongate member configured for insertion into and removal from the lumen, wherein the linear elongate member is of sufficient stiffness such that said insertion results in the substantial elimination of said curvature. 
     Aspect 21. The catheter of any of aspects 17-20, (a) wherein the catheter is a delivery catheter and the sheath is a delivery sheath comprising a delivery lumen that is configured to deliver a radially self-expandable scaffold or (b) wherein the catheter is a guide catheter and the sheath is a guide catheter sheath comprising a guide lumen that is configured to receive a delivery catheter. 
     Aspect 22. A system comprising the delivery catheter of aspect 21 and a scaffold, wherein the scaffold is configured to be delivered from the delivery lumen and into a sinus ostia. 
     Aspect 23. A system comprising (b) a delivery catheter configured for access to a sinus of a patient, wherein the delivery catheter comprises a delivery lumen configured for delivery of a scaffold and (b) an elongate member comprising a shape-memorized section that has a curvature when the elongate member is in an unconstrained state, wherein the elongate member is of sufficient stiffness such that insertion of the elongate member results in curvature of the delivery catheter. 
     Aspect 24. The system of aspect 23, wherein the elongate member is configured to be custom bent, depending on user preference. 
     Aspect 25. A delivery catheter configured for access to a sinus of a patient, wherein the delivery catheter comprises a delivery sheath having a delivery lumen and wherein the delivery catheter has a stiffness gradient wherein stiffness decreases in a proximal-to-distal direction or wherein stiffness increases in a proximal-to-distal direction. 
     Aspect 26. A catheter configured for access to a sinus of a patient, wherein the catheter comprises (a) a sheath having a curvature and a lumen and (b) a handle comprising a mechanism whereby the sheath may be rotated relative to the handle. 
     Aspect 27. The catheter of aspect 26, wherein the catheter is a delivery catheter and the sheath is a delivery sheath, or wherein the catheter is a guide catheter and wherein the sheath is a guide sheath. 
     Aspect 28. A delivery catheter comprising an elongate inner member and a flexible outer sheath, wherein a distal end of the outer sheath is folded into itself forming a region of double outer sheath thickness at a distal end of the delivery system that comprises an inner layer and an outer layer, wherein the inner layer is connected to a distal end of the elongate inner member, wherein the region of double outer sheath thickness forms a delivery lumen that is dimensioned to receive a radially self-expandable scaffold, and wherein proximal movement of the outer sheath relative to the elongate inner member shortens the region of double thickness and the delivery lumen formed thereby. 
     Aspect 29. A system comprising a delivery device, a radially compressible scaffold and a filament holding the scaffold in a radially compressed state. 
     Aspect 30. The system of aspect 29, wherein the filament is used to secure an outer sheath at a distal end of the delivery device, said outer sheath containing said scaffold, and wherein pulling the filament in a proximal direction releases the portion of the outer sheath secured by the filament allowing the scaffold to expand. 
     Aspect 31. The system of aspect 29, wherein the filament is in the form of a knit that secures and maintains the scaffold in a compressed state at a distal end of the delivery system and wherein pulling the filament in a proximal direction releases the scaffold. 
     Aspect 32. The system of any of aspects 29-31, wherein the filament secures the scaffold in a radially contracted state on an elongate inner member which is optionally disposed within a lumen of an outer sheath. 
     Aspect 33. A system comprising a delivery device comprising a delivery lumen, a radially self-expandable scaffold and a loading member, wherein the scaffold is configured to be flattened and wrapped around the loading member and inserted into a delivery lumen of the delivery device, after which the loading member is disengaged from the scaffold. 
     Aspect 34. The system of aspect 33, wherein the loading member comprises a pair of tines. 
     Aspect 35. A delivery system comprising (a) a spiral scaffold having a distal end and a proximal end and (b) delivery catheter comprising (i) an outer member having a distal end and an outer member attachment feature proximate the outer member distal end and (ii) an inner member having a distal end and an inner member attachment feature proximate the inner member distal end, wherein the inner member attachment feature is adapted to become attached to the scaffold distal end and the outer member attachment feature is adapted to become attached to the scaffold proximal end and wherein, upon attachment of the inner member attachment feature to the scaffold distal end and attachment of the outer member attachment feature to the scaffold proximal end, rotation of the outer member relative to the inner member in a first direction results in contraction of the spiral scaffold and rotation of the outer member relative to the inner member in a second opposing direction results in expansion of the spiral scaffold. 
     Aspect 36. The delivery system of aspect 35, wherein the inner member attachment feature and the outer member attachment feature each comprise hooks. 
     Aspect 37. An anchoring device comprising a distal inflation balloon which is configured for inflation in a sinus cavity and a proximal flexible tracking member that is configured such that a loaded delivery system comprising a delivery catheter and a scaffold may be routed over the flexible tracking member. 
     Aspect 38. A delivery system comprising (a) a catheter configured for access to a sinus of a patient, wherein the catheter comprises a sheath having a first lumen, (b) an elongate pusher member having a second lumen, said elongate pusher member being configured for insertion into the first lumen, and (c) an elongate inner support member configured for insertion through the second lumen and running through the length of the system. 
     Aspect 39. The delivery system of aspect 38, wherein said sheath comprises a shape-memorized section that displays a curvature when the sheath is in an unconstrained state. 
     Aspect 40. The delivery system of any of aspects 38-39, wherein the elongate pusher member is formed from a single material or wherein the elongate pusher member is formed of multiple materials thereby varying in stiffness between its distal and proximal end. 
     Aspect 41. The delivery system of any of aspects 38-39, wherein the support member is formed from a single material or wherein the support member is formed of multiple materials thereby varying in flexibility between its distal and proximal end. 
     Aspect 42. The delivery system of any of aspects 38-41, wherein support member comprises a third lumen dimensioned to receive a guide wire. 
     Aspect 43. A crimping assembly configured to exert an inward radial force on a radially self-expandable scaffold comprising (a) a loading member comprising a first end having a first inside diameter, a second end having a second inside diameter that is smaller than said first diameter, and a tapered region between the first end and the second end providing a transition between the first and second inside diameters (b) and a pusher member comprising a hollow cylindrical end having an unconstrained outside diameter that is substantially equal to the first inside diameter such that the pusher member can be inserted into the first end of the loading member, said pusher member having a plurality of slots forming a plurality of projections at the hollow cylindrical end and being configured such that the outside diameter of the hollow cylindrical end can be reduced from said unconstrained outside diameter to an outside diameter that is substantially equal to the second inside diameter when the cylindrical end is advanced from the first end to the second end through the tapered region. 
     Aspect 44. A delivery device comprising (a) an elongate delivery member having proximal end and a distal end that comprises a pocket having an inner width and configured to receive a scaffold in a contracted state, (b) an expulsion member having an outer width that is substantially equal to the inner width of the pocket and configured to be positioned in the pocket proximal to the scaffold when the scaffold is positioned in the pocket in the contracted state and (c) at least one filament having a first end and a second end, the at least one filament attached to the expulsion member at the first end and being routed out of pocket at the distal end of the elongate delivery member and proximally along or within the elongate delivery member such that proximally pulling the second end of the at least one filament causes the expulsion member to move distally in the pocket, leading to the distal expulsion of said scaffold when said scaffold is positioned in the pocket in the contracted state. 
     Aspect 45. A delivery system comprising (a) a braided scaffold having a distal end and a proximal end and (b) delivery device comprising (i) an elongate outer member having proximal end and a distal end and an outer member attachment feature proximate the elongate outer member distal end and (ii) an elongate inner member having a proximal end and a distal end and an inner member attachment feature proximate the elongate inner member distal end, wherein the inner member attachment feature is adapted to become attached to the distal end of the scaffold and the outer member attachment feature is adapted to become attached to the proximal end of the scaffold and wherein, upon attachment of the inner member attachment feature to the distal end of the scaffold and attachment of the outer member attachment feature to the proximal end of the scaffold, distally advancing the inner member relative to the outer member results in contraction of the scaffold while proximally retracting the inner member relative to the outer member results in expansion of the scaffold. 
     Aspect 46. The delivery system of aspect 45, wherein the inner and outer attachment features comprise hooks. 
     Aspect 47. A delivery system comprising (a) a delivery device comprising (i) an elongate outer member having a proximal end and a distal end and (ii) an elongate inner member disposed within the elongate outer member, said elongate inner member having a proximal end and a distal end and having a scaffold support segment positioned at or near the distal end of the elongate inner member and (b) a self-expanding scaffold disposed between the elongate outer member and the scaffold support segment, said elongate outer member maintaining the scaffold in a compressed state on said scaffold support segment, wherein a first force of friction between contacting materials of the scaffold and the inner support segment is greater than a second force of friction between contacting materials of the scaffold and the elongate outer member, such that distally advancing the elongate inner member relative to the elongate outer member leads to expulsion of the scaffold from a distal end of the elongate outer member and, optionally, such that proximally retracting the elongate inner member relative to the elongate outer member when the stent is partially deployed leads to withdrawal of the scaffold into the distal end of the elongate outer member. 
     Aspect 48. The delivery system of aspect 47, further comprising a guide catheter having a lumen through which the delivery catheter can be advanced to a target site in a subject. 
     Aspect 49. A delivery system comprising an elongate delivery member having a proximal end and a distal end, a scaffold disposed over the elongate delivery member at or near the distal end of the elongate delivery member, and a an elongate containment member having a proximal end and a distal end that at least partially extends around a circumference of the elongate delivery member, said elongate containment member disposed over the scaffold thereby maintaining the scaffold in a compressed state. 
     Aspect 50. The delivery system of aspect 49, wherein the elongate containment member is an elongate outer member that fully extends around a circumference of the elongate delivery member. 
     Aspect 51. The delivery system of aspect 49, wherein the elongate containment member is an elongate containment sheath that does not fully extend around a circumference of the elongate delivery member. 
     Aspect 52. The delivery system of aspect 51, wherein the elongate containment sheath comprises a pull tab at or near the proximal end of the containment sheath. 
     Aspect 53. The delivery system of any of aspects 49-52, wherein the elongate delivery member comprises a distal tip and a region of reduced diameter forming a recess immediately proximal to the enlarged distal tip, and wherein the scaffold is disposed within said recess. 
     Aspect 54. The delivery system of aspect 49, wherein the elongate delivery member is a balloon catheter comprising an elongate catheter shaft and a balloon. 
     Aspect 55. The delivery system of any of aspects 49-54, further comprising an elongate inner member, wherein the elongate delivery member and elongate containment member are configured to be advanced over the elongate inner member to a targeted delivery site. 
     Aspect 56. The delivery system of aspect 55, wherein the elongate inner member is configured to provide access to a sinus cavity. 
     Aspect 57. The delivery system of any of aspects 55-56, wherein the elongate delivery member is a balloon catheter comprising an elongate catheter shaft and a balloon. 
     Aspect 58. The delivery system of aspect 57, wherein the scaffold is disposed over the balloon. 
     Aspect 59 The delivery system of aspect 57, wherein the scaffold is positioned distal to the balloon and wherein the elongate containment member is configured to allow inflation of the balloon while maintaining the elongate containment member over the scaffold in a compressed state. 
     Aspect 60. A delivery system comprising (a) an elongate inner member having a distal end and configured to provide access to a sinus cavity and (b) a balloon catheter assembly comprising (i) an elongate catheter shaft, (ii) a balloon in the form of a hollow annulus having a proximal end, a distal end, and a central balloon lumen, (iii) an inner ring having a central ring lumen disposed in a proximal portion of the central balloon lumen, and (iv) a self-expanding scaffold disposed in the central balloon lumen at a position distal to the ring, wherein the balloon catheter is configured to be advanced over the elongate inner member to a target position, to inflate and deflate the balloon at the target position, and to release the scaffold at the target position. 
     Aspect 61. A delivery system comprising (a) a delivery member comprises an elongate inner member, a surrounding portion, and a distal tip, wherein the elongate inner member and the surrounding portion form an annular cavity having proximal and distal ends, (b) an elongate intermediate member disposed over at least a portion of the elongate inner member, a distal end of the elongate intermediate member disposed within the annular cavity and (c) a self-expanding scaffold disposed within the annular cavity between an outer surface of the elongate intermediate member and radially-inward-facing surface of the annular cavity of the surrounding portion, wherein proximally retracting the elongate intermediate member relative to the delivery member leads to delivery of the scaffold through the proximal end of the annular cavity. 
     Aspect 62. The delivery system of aspect 61, wherein the surrounding portion maintains the scaffold in a compressed state on the elongate intermediate member and wherein, as a result of a first force of friction between contacting materials of the scaffold and the elongate intermediate member being greater than a second force of friction between contacting materials of the scaffold and the surrounding portion, proximally retracting the elongate intermediate member relative to the delivery member leads to the delivery of the scaffold from the proximal end of the annular cavity and, optionally, distally advancing the elongate intermediate member relative to the delivery member when the scaffold is partially deployed leads to the withdrawal of the scaffold into the proximal end of the annular cavity. 
     Aspect 63. The delivery system of aspect 61, wherein the scaffold is attached to the elongate intermediate member by at least one temporary attachment feature such that that proximally retracting the elongate intermediate member relative to the surrounding portion leads to the expulsion of the scaffold from the proximal end of the surrounding portion. 
     Aspect 64. The delivery system of any of aspects 61-63, further comprising a delivery sheath having a distal end, wherein the elongate inner member and the elongate intermediate member extend proximally into a lumen of the delivery sheath. 
     Aspect 65. The delivery system of aspect 64, wherein retraction of the elongate inner member relative to the delivery sheath results in a proximal end of the surrounding portion abutting the distal end of the delivery sheath, and wherein advancement of the elongate inner member relative to the delivery sheath results in a gap between the proximal end of the surrounding portion and the distal end of the delivery sheath through which the scaffold is expanded and released. 
     Aspect 66. The delivery system of aspect 64, wherein the surrounding portion is in the shape of a hollow cylinder. 
     Aspect 67. A delivery system comprising (a) an elongate inner member, (b) a loading member that comprises a loading lumen having a loading lumen axis and a plurality of longitudinal pathways adjacent to the loading lumen, said loading lumen comprising a tapered lumen region having a proximal tapered lumen end with a first diameter and a distal tapered lumen end with a second diameter that is smaller than the first diameter, (c) a self-expanding scaffold disposed around the elongate inner member within the loading lumen, said scaffold comprising a scaffold wall and having a proximal scaffold end, a distal scaffold end, an inner luminal surface, an outer abluminal surface, (d) a plurality of loading pins configured for engagement with the scaffold wall and for longitudinal movement along the longitudinal pathways, such that longitudinal movement of the loading pins along the longitudinal pathways is accompanied by longitudinal movement of the scaffold, and (e) optionally, a delivery sheath comprising a delivery lumen in communication with the loading lumen, said delivery lumen having a delivery lumen diameter. 
     Aspect 68. The delivery system of aspect 67, wherein the first diameter is greater than or equal to an unconstrained diameter of the scaffold and wherein the second diameter is less than or equal to the delivery lumen diameter. 
     Aspect 69. The delivery system of any of aspects 67-68, wherein the longitudinal pathways comprise slots. 
     Aspect 70. The delivery system of any of aspects aspect 67-69, wherein the plurality of loading pins extend through the scaffold wall and into the elongate inner member, and wherein the delivery system is configured such that the longitudinal movement of the loading pins along the longitudinal pathways results in longitudinal movement of the elongate inner member and the scaffold. 
     Aspect 71. The delivery system of aspect 70, wherein the plurality of loading pins extend through a first aperture in the scaffold wall, through the elongate inner member and through a second aperture in the scaffold wall opposite the first aperture the scaffold wall. 
     Aspect 72. The delivery system of any of aspects 67-71, further comprising a removable packaging feature that engages the loading pins and the loading member such that the loading pins are held in place within the loading member. 
     Aspect 73. The delivery system of any of aspects 67-72, further comprising an inner member engagement member that is configured to reversibly engage and distally advance the elongate inner member. 
     Aspect 74. The delivery system of aspect 73, wherein the inner member engagement member at least partially surrounds the elongate inner member and wherein the engagement member is longitudinally moveable along a portion of the elongate inner member length. 
     Aspect 75. The delivery system of any of aspects 73-74, and wherein the elongate inner member comprises a stop that limits axial movement of the inner member engagement member relative to the elongate inner member. 
     Aspect 76. The delivery system of any of aspects 67-75, wherein the delivery system comprises a loading pin engagement member that is configured to reversibly engage and distally advance the loading pins. 
     Aspect 77. The delivery system of aspect 76, wherein the loading pin engagement member is a ring-shaped member. within the loading lumen, said scaffold comprising a scaffold wall and having a scaffold lumen, a proximal scaffold end, a distal scaffold end, an inner luminal surface, an outer abluminal surface, (c) an engagement device comprising an engagement device axis and a plurality of elongate members, which taper radially outward from the engagement device axis, which have a shape memory that allows the elongate members to be radially compressed and to self-expand after upon removal of radial compression, and which terminate in an engagement feature, wherein the engagement device is at least partially positioned within the scaffold lumen and loading lumen such that each engagement feature extends through the scaffold wall and into one of the longitudinal pathways and such that longitudinal movement of the engagement device is accompanied by longitudinal movement of the scaffold within the loading lumen. 
     Aspect 84. The delivery system of aspect 83, wherein the longitudinal pathways comprise grooves. 
     Aspect 85. The delivery system of aspect 84, wherein the grooves have a depth that gradually diminishes as one approaches the distal tapered lumen end. 
     Aspect 86. The delivery system of any of aspects 83-85, further comprising a delivery sheath comprising a delivery lumen in communication with the loading lumen, said delivery lumen having a delivery lumen diameter. 
     Aspect 87. The delivery system of aspect 86, wherein the first diameter is greater than or equal to an unconstrained diameter of the scaffold and wherein the second diameter is less than or equal to the delivery lumen diameter. 
     Aspect 88. The delivery system of any of aspects 86-87, further comprising an elongate inner member, wherein the elongate inner member and engagement device are configured such that elongate inner member engages and advances the engagement device through the loading lumen and at least a portion of the delivery sheath. 
     Aspect 89. The delivery system of any of aspects 83-88, wherein the engagement device further comprises an elongate shaft and wherein the plurality of elongate members extend from and taper radially outward from an end of the elongate shaft. 
     Aspect 90. The delivery system of aspect 89, wherein the elongate shaft is an elongate tubular shaft having a proximal end, a distal end, and a tubular shaft lumen, and wherein the plurality of elongate members extend through at least a portion of the tubular shaft lumen and taper radially outward from the proximal end of the elongate tubular shaft. 
     Aspect 91. The delivery system of aspect 90, wherein the engagement device further comprises a cap that is disposed over the distal end of the elongate tubular shaft and wherein an end of each elongate member that is opposite the engagement feature is attached to the cap, such that disengaging and pulling the cap from the elongate tubular shaft allows the elongate members to be pulled through the elongate tubular shaft and removed from the delivery system. 
     Aspect 92. A delivery system comprising, (a) a first assembly comprising (i) a loading member that comprises a tapered loading lumen having a proximal loading lumen end and a distal loading lumen end, wherein the proximal loading lumen end has a first diameter and the distal loading lumen end has a second diameter that is smaller than the first diameter and (ii) a delivery sheath having a delivery sheath lumen that is connected to the loading lumen, and (b) a second assembly comprising (i) a self-expanding scaffold, said scaffold comprising a scaffold wall and having a scaffold lumen, a proximal scaffold end, a distal scaffold end, an inner luminal surface, and an outer abluminal surface, (ii) an elongate advancement member having a proximal end and a distal end, (iii) at least one filament linking an end of the elongate advancement member to the scaffold, and (iv) an elongate inner member having a proximal end and a distal end, wherein the elongate advancement member and elongate inner member may be the same or different, wherein the second assembly is configured to be inserted into the proximal loading lumen end of the loading member and advanced at least partially through the first assembly, such that the scaffold is moved through the loading lumen in a proximal-to-distal direction. 
     Aspect 93. The delivery system of aspect 92, wherein the first assembly further comprises a handle having a handle lumen disposed between the loading member and delivery sheath, and wherein the loading lumen is in communication with the delivery sheath lumen through the handle lumen. 
     Aspect 94. The delivery system of aspect 93, wherein the loading member is in the form of a funnel and wherein either the funnel is detachable from the handle or wherein the funnel and handle are integrated into a single article. 
     Aspect 95. The delivery system of any of aspects 92-94, wherein the elongate inner member and the elongate advancement member are the same, wherein the scaffold is held in position over the distal end of the inner member by the at least one filament, and wherein the second assembly is advanced at least partially through the first assembly by pushing the elongate inner member from a proximal end of the first assembly. 
     Aspect 96. The delivery system of aspect 95, wherein the second assembly further comprises a press member that can be pushed by an operator, and wherein the proximal end of the elongate inner member is inserted into the press member. 
     Aspect 97. The delivery system of any of aspects 95-96, wherein at least one filament is looped from the distal end of the elongate inner member, through at least one aperture in the scaffold wall, and back to the distal end of the elongate inner member. 
     Aspect 98. The delivery system of any of aspects 95-96, wherein the elongate inner member comprises a lumen that extends from a proximal end of the elongate inner member to a distal end of the elongate inner member. 
     Aspect 99. The delivery system of aspect 98, wherein at least one filament is looped into the elongate inner member lumen at a proximal position, through the elongate inner member lumen, out of the elongate inner member lumen at a distal position, through at least one aperture in the scaffold wall, back into the elongate inner member lumen at a distal position, through the elongate inner member lumen, and out of the elongate inner member lumen at a proximal position. 
     Aspect 100. The delivery system of aspect 98, wherein at least one filament is looped from a filament holder, into the elongate inner member lumen at a proximal position, through the elongate inner member lumen, out of the elongate inner member lumen at a distal position, through at least one aperture in the scaffold wall, and back into the elongate inner member lumen at a distal position, through the elongate inner member lumen, out of the elongate inner member lumen at a proximal position, and back to the filament holder. 
     Aspect 101. The delivery system of aspect 100, wherein the filament holder comprises first and second portions that are separable from one another, wherein a first end of the at least one filament is connected to the first portion, and wherein a second end of the at least one filament is connected to the second portion. 
     Aspect 102. The delivery system of aspect 92, wherein the elongate inner member and the elongate advancement member are different, wherein the elongate advancement member is positioned distal to the elongate inner member, wherein at least one filament links the scaffold to the elongate advancement member. 
     Aspect 103. The delivery system of aspect 102, wherein the second assembly is advanced at least partially through the first assembly by pulling the elongate advancement member from a distal end of the first assembly. 
     Aspect 104. The delivery system of aspect 103, wherein at least one filament further links a distal end of the elongate inner member to a proximal end of the elongate advancement member. 
     Aspect 105. The delivery system of aspect 103, wherein at least one filament is looped from the proximal end of the elongate advancement member, through at least one aperture in the scaffold wall, and back to the proximal end of the elongate advancement member. 
     Aspect 106. The delivery system of aspect 105, wherein at least one filament is further looped through the distal end of the elongate inner member. 
     Aspect 107. The delivery system of aspect 103, wherein the elongate advancement member comprises a lumen that extends from a distal end of the elongate advancement member to a proximal end of the elongate advancement member. 
     Aspect 108. The delivery system of aspect 107, wherein the at least one filament is looped into the elongate advancement member lumen at a distal position, through the elongate advancement member lumen, out of the elongate advancement member lumen at a proximal position, through at least one aperture in the scaffold wall, back into the elongate advancement member lumen at a proximal position, through the elongate advancement member lumen, and out of the elongate advancement member lumen at a distal position. 
     Aspect 109. The delivery system of any of aspects 102, wherein the second assembly is configured to be advanced at least partially through the first assembly by applying force to the proximal end of the elongate advancement member. 
     Aspect 110. The delivery system of aspect 109, wherein (a) the distal end of the elongate inner member is configured to engage the proximal end of the elongate advancement member or (b) the elongate inner member is hollow and has a lumen, and wherein the second assembly further comprises additional elongate member having a proximal end and a distal end that is configured to extend through the lumen of the inner elongate member and engage the proximal end of the elongate advancement member. 
     Aspect 111. The delivery system of aspect 110, wherein a receptacle is provided at a proximal end of the elongate advancement member that is configured to receive the distal end of the elongate inner member or to receive the distal end of the additional elongate member. 
     Aspect 112. The delivery system of any of aspects 109-111, wherein at least one filament is looped from the elongate advancement member, through at least one aperture in the scaffold wall, and back to the elongate advancement member. 
     Aspect 113. The delivery system of aspect 112, wherein both ends of the at least one filament are adhered to the elongate advancement member. 
     Aspect 114. The delivery system of aspect 113, wherein the elongate advancement member comprises a groove and wherein one end of the at least one filament is positioned in the groove so that the one end can be cut and severed from the elongate advancement member. 
     Aspect 115. The delivery system of aspect 112, wherein the elongate advancement member comprises two portions that are configured to be reversibly joined. 
     Aspect 116. The delivery system of aspect 115, wherein the two portions are joined together, wherein one end of the at least one filament is adhered to one of the two portions, and wherein an opposite end of the at least one filament is trapped between the two portions. 
     Aspect 117. The delivery system of any of aspects 92-116, further comprising a delivery catheter having a proximal end and a distal end and configured for insertion into a patient, wherein the distal end of the delivery sheath is configured for attachment to the proximal end of the delivery catheter subsequent to insertion of the delivery catheter into a patient. 
     These and other aspects, embodiments and benefits of the present disclosure will become immediately apparent to those of ordinary skill in the art upon review of the detailed description and claims to follow. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  is a schematic side view of an implantable scaffold, in accordance with an embodiment of the present disclosure. 
         FIG. 2A  is a schematic end view of a crimping device, in accordance with an embodiment of the present disclosure. 
         FIG. 2B  is a schematic partial cross-sectional view of a system useful for crimping and loading a scaffold into a delivery catheter, in accordance with an embodiment of the present disclosure. 
         FIG. 3A  and  FIG. 3B  area schematic end views of a crimping device and scaffold, in accordance with an embodiment of the present disclosure. 
         FIG. 3C  is a schematic view of a system useful for crimping and loading a scaffold into a delivery sheath, in accordance with an embodiment of the present disclosure. 
         FIG. 4A  is a schematic side viewof a flexible tapered loading member and scaffold, in accordance with an embodiment of the present disclosure. 
         FIG. 4B  is a schematic side view of a scaffold being loaded into a proximal handle of a delivery catheter, in accordance with an embodiment of the present disclosure. 
         FIG. 4C  is a schematic perspective view of a process of forming a flexible tapered loading member, in accordance with an embodiment of the present disclosure. 
         FIG. 5A  is a side view of a delivery catheter in a process of being loaded with a scaffold, in accordance with an embodiment of the present disclosure. 
         FIG. 5B  and  FIG. 5D  are side views of delivery catheters that are with loaded scaffolds, in accordance with embodiments of the present disclosure. 
         FIG. 5C  is a side view of a delivery catheter and a partially deployed scaffold, in accordance with an embodiment of the present disclosure. 
         FIG. 6A  is an illustration of a delivery system in accordance with an embodiment of the present disclosure.  FIG. 6B  and  FIG. 6C  correspond to enlarged views of  FIG. 6A . 
         FIG. 7  is a schematic side view of a distal end of a delivery sheath, in accordance with an embodiment of the present disclosure. 
         FIG. 8A  is a schematic partial cross-sectional side view of a distal end of a delivery system, in accordance with an embodiment of the present disclosure.  FIG. 8B  is a schematic partial cross-sectional side view illustrating deployment of a scaffold using the system of  FIG. 8A , in accordance with an embodiment of the present disclosure. 
         FIG. 9  is a schematic side view of a delivery sheath in a process of being loaded with a scaffold, in accordance with an embodiment of the present disclosure. 
         FIG. 10  is a schematic partial cross-sectional side view of a delivery sheath in a process of being loaded with a scaffold, in accordance with an embodiment of the present disclosure. 
         FIGS. 11A  is a schematic partial cross-sectional side view of a scaffold within a loading funnel, in accordance with an embodiment of the present disclosure.  FIGS. 11B and 11C  are schematic side and end views, respectively, of a collapsible loading member, in accordance with an embodiment of the present disclosure.  FIG. 11D  is a schematic partial cross-sectional side view of scaffold partially compressed by a loading system in accordance with an embodiment of the present disclosure.  FIG. 11E  is a schematic end view of the collapsible loading member shown in  FIG. 11D . 
         FIG. 12  is a schematic partial cross-sectional side view of a delivery sheath in a process of being loaded with a scaffold, in accordance with an embodiment of the present disclosure. 
         FIG. 13A  is a schematic end view of a scaffold, loading member and delivery sheath, in accordance with an embodiment of the present disclosure. 
         FIG. 13B  and  FIG. 13C  are schematic perspective views showing a scaffold and a two-tined loading member, before and after winding of the scaffold on the loading member, in accordance with an embodiment of the present disclosure.  FIG. 13D  is a schematic cross-sectional view showing the scaffold and two-tined loading member after winding of the scaffold on the loading member. 
         FIG. 14  is a schematic view of a braided sheath, or braid embedded within a polymer sheath, in accordance with an embodiment of the present disclosure. 
         FIG. 15A  is a schematic view of a catheter and handle, in accordance with an embodiment of the present disclosure. 
         FIG. 15B  is a schematic view of a catheter (partial) and handle, in accordance with an embodiment of the. present disclosure. 
         FIG. 16  is a schematic partial cross-sectional view of a loaded delivery catheter in accordance with an embodiment of the present disclosure 
         FIGS. 17A and 17B  are schematic partial cross-sectional side views of a distal end of a scaffold delivery system, before and during deployment of a scaffold, in accordance with an embodiment of the present disclosure. 
         FIG. 18A  is a schematic view of a scaffold, sheath and filament, in accordance with an embodiment of the present disclosure. 
         FIG. 18B  is a schematic view of a scaffold and filament, in accordance with an embodiment of the present disclosure. 
         FIG. 19A  is a schematic side view of a scaffold and filament, in accordance with an embodiment of the present disclosure.  FIG. 19B  is a schematic end view of the scaffold and filament of  FIG. 19A , 
         FIG. 19C  is a schematic partial cross-sectional view of a loaded delivery catheter, in accordance with an embodiment of the present disclosure. 
         FIG. 19D and 19E  are schematic partial cross-sectional side views of a distal end of a delivery system during scaffold loading, in accordance with an embodiment of the present disclosure.  FIG. 19F  is a schematic end view of the scaffold and filament of  FIG. 19D .  FIG. 19G  is a schematic partial cross-sectional view of an alternate embodiment of the distal tip in  FIG. 19E  (filaments not shown). 
         FIG. 20A  and  FIG. 20B  are schematic partial cross-sectional side views of a distal end of a delivery system during scaffold loading, in accordance with an embodiment of the present disclosure. 
         FIG. 21  is a schematic view of a distal end of a delivery catheter and a spiral scaffold, in accordance with an embodiment of the present disclosure. 
         FIG. 22  is a schematic view of a delivery system including an anchoring balloon, in accordance with an embodiment of the present disclosure. 
         FIG. 23  is a photograph illustrating a scaffold delivery system, in accordance with an embodiment of the present disclosure. 
         FIGS. 23A, 23B and 23C  are schematic partial cross-sectional side views of a distal end of a scaffold delivery system, shown at three stages of deployment of a scaffold, in accordance with an embodiment of the present disclosure.  FIG. 23D  is a schematic end view of a containment sheath shown in  FIGS. 23A and 23B . 
         FIGS. 24A, 24B and 24C  are schematic partial cross-sectional side views of a distal end of a scaffold delivery system, shown at three stages of deployment of a scaffold, in accordance with an embodiment of the present disclosure. 
         FIGS. 25A, 25B and 25C  are schematic partial cross-sectional side views of a distal end of a scaffold delivery system, shown at various stages of deployment of a scaffold, in accordance with an embodiment of the present disclosure.  FIG. 25D  is a schematic perspective view of the containment sheath shown in  FIGS. 25A-25C . 
         FIGS. 26A and 26B  are schematic partial cross-sectional side views of a distal end of a scaffold delivery system, shown at two stages of deployment of a scaffold, in accordance with an embodiment of the present disclosure. 
         FIGS. 27A and 27B  are schematic partial cross-sectional side views of a distal end of a scaffold delivery system, shown at two stages of deployment of a scaffold, in accordance with an embodiment of the present disclosure. 
         FIG. 27C  is a schematic partial cross-sectional side view illustrating the loading of the scaffold delivery system of  FIGS. 27A-27B , in accordance with an embodiment of the present disclosure. 
         FIG. 28A  is a schematic partial cross-sectional side view of a scaffold delivery system, in accordance with an embodiment of the present disclosure. 
         FIGS. 28B and 28C  are schematic partial cross-sectional side view of select components within a portion of a scaffold delivery system, shown at two stages of deployment of a scaffold, in accordance with an embodiment of the present disclosure. 
         FIG. 28D  is a schematic partial cross-sectional side view of select components within a portion of a scaffold delivery system, in accordance with an embodiment of the present disclosure. 
         FIG. 28E  is a schematic partial cross-sectional side view of a distal end of a scaffold delivery system, in accordance with an embodiment of the present disclosure. 
         FIG. 28F  is a schematic cross-sectional end view of select components of a scaffold delivery system, in accordance with an embodiment of the present disclosure. 
         FIGS. 29A-29F  are schematic, partially transparent, perspective views of a portion of a scaffold delivery system, shown at six sequential stages of deployment of a scaffold, in accordance with an embodiment of the present disclosure. 
         FIG. 29G  is a schematic, partially transparent, side view of a portion of a scaffold delivery system, in accordance with an embodiment of the present disclosure. 
         FIG. 29H  is a schematic perspective view of select components within a portion of a scaffold delivery system, in accordance with an embodiment of the present disclosure. 
         FIG. 29I  is a schematic perspective view of a portion of a scaffold delivery system, in accordance with an embodiment of the present disclosure. 
         FIG. 29J  is a schematic perspective cutaway view of a portion of a scaffold delivery system, in accordance with an embodiment of the present disclosure. 
         FIG. 30A  is a schematic side view of a first assembly and  FIG. 30B  is a schematic side view of a loading assembly, which when combined form a scaffold delivery system, in accordance with an embodiment of the present disclosure. 
         FIG. 31  is a schematic side view of a scaffold delivery system, in accordance with an embodiment of the present disclosure. 
         FIGS. 31A-31C  are schematic perspective views of three press members, in accordance with embodiments of the present disclosure. 
         FIG. 32  is a schematic side view of a scaffold loading and delivery system, in accordance with an embodiment of the present disclosure. 
         FIG. 32A  is a schematic cross-sectional view of the ergonomic handle and valve of shown in  FIG. 32 . 
         FIG. 32B  is a schematic perspective view of an ergonomic handle, in accordance with an embodiment of the present disclosure. 
         FIG. 33A  is a schematic perspective view of a combined funnel and handle, in accordance with an embodiment of the present disclosure. 
         FIG. 33B  is a schematic cross-sectional view of the combined funnel and handle shown in  FIG. 33A . 
         FIG. 34A  is a schematic perspective view of a combined funnel and handle, in accordance with an embodiment of the present disclosure.  FIG. 34B  is a schematic cross-sectional view of the combined funnel and handle shown in  FIG. 34A . 
         FIG. 35  is a schematic partial cross-sectional side view an assembly for use in a scaffold loading and delivery system, in accordance with an embodiment of the present disclosure. 
         FIG. 36A  is a schematic partial side view and  FIG. 36B  is a schematic partial perspective view of a scaffold loading system, in accordance with an embodiment of the present disclosure. 
         FIG. 36C  is a schematic cross-sectional view of an engagement device, in accordance with an embodiment of the present disclosure. 
         FIG. 37A  is a schematic partial side view of a scaffold loading system, in accordance with an embodiment of the present disclosure.  FIG. 37B  is a schematic perspective view of components of  FIG. 37A .  FIG. 37C  is a schematic end view of components of  FIG. 37A .  FIG. 37D  is a schematic cross-section view of a component of  FIG. 37A . 
         FIG. 38  is a schematic partial cross-sectional view of a scaffold loading and delivery system, in accordance with an embodiment of the present disclosure. 
         FIG. 39A  is a schematic perspective view of a loading capsule, in accordance with an embodiment of the present disclosure. 
         FIG. 39B  is a schematic perspective view of a loading capsule, in accordance with another embodiment of the present disclosure. 
         FIG. 40  is a schematic cross-sectional view of a scaffold loading system, in accordance with an embodiment of the present disclosure. 
         FIG. 41  is a schematic cross-sectional view of an applicator, in accordance with an embodiment of the present disclosure. 
         FIG. 42  is a schematic cross-sectional view of the scaffold loading system of  FIG. 40  linked to the applicator of  FIG. 41 , in accordance with an embodiment of the present disclosure. 
         FIG. 43  is a schematic cross-sectional view of an applicator with a loaded scaffold, in accordance with an embodiment of the present disclosure. 
         FIG. 44  is a photograph illustrating a 32 filament scaffold having a diameter of 13 mm diameter and a length of 10 mm, in accordance with an embodiment of the present disclosure, following deployment in the native middle meatus of a human cadaver. 
         FIG. 45  is a photograph illustrating a 16 filament, 10 mm scaffold in accordance with an embodiment of the present disclosure following deployment in the frontal sinus ostia of a human cadaver. 
         FIG. 46  is a photograph illustrating a 32 filament scaffold having a diameter of 17.5 mm and a length of 10 mm, in accordance with an embodiment of the present disclosure, following deployment in the ethmoid sinus of a human cadaver following FESS. 
     
    
    
     DESCRIPTION 
     The implantable medical devices delivered by the delivery devices of the present disclosure are generally tubular devices, which devices are self-expanding devices in various embodiments. As used herein, “device,” “scaffold,” “stent” and “implant” may be used synonymously. Also as used herein, “self-expanding” is intended to include devices that are crimped to a reduced delivery configuration for delivery into the body, and thereafter tend to expand to a larger suitable configuration once released from the delivery configuration. As used herein “strands” and “filaments” may be used interchangeably and include single fiber strands and filaments (also referred to as monofilaments) and multi-fiber strands and filaments. As used herein a “tube,” “hollow member,” “catheter” and “tubular member” may be used synonymously. 
     As used herein, tei ins “sinus” and “sinus cavity” refer to both sinus cavities and nasal cavities, which include, for example, the maxillary, frontal and ethmoid sinuses, the ostiomeatal complex, the ethmoid infundibulum and the sphenoid sinuses as-well as the middle meatus (a sinus cavity). 
     Scaffolds for use in conjunction with the present disclosure are typically tubular devices which may be of various sizes, including a variety of diameters and lengths, and which may be used for a variety of medical applications including sinus applications. In the case of objects of non-circular cross-section, “diameter” denotes width. In certain beneficial embodiments, the as-manufactured (or unconstrained) diameter of the scaffold may range from 5 mm or less to 40 mm or more, for example, ranging from 5 mm to 10 mm to 15 mm to 20 mm to 25 mm to 30 mm to 35 mm to 40 mm (i.e., ranging between any two of the preceding numerical values), commonly ranging from 5 to 12 mm or from 15 to 30 mm. In certain beneficial embodiments, the as-manufactured (or unconstrained) length may range from 5 mm or less to 30 mm or more, for example, ranging from 5 mm to 10 mm to 15 mm to 20 mm to 25 mm or 30 mm (i.e., ranging between any two of the preceding numerical values), commonly ranging from 8 to 12 mm or from 15 mm to 30 mm. In various embodiments a drug or other therapeutic agent may be released from the scaffold for an extended period. 
     Various scaffold embodiments of the present disclosure are self-expanding in that they are manufactured at a first diameter, subsequently reduced or “crimped” to a second, reduced diameter for placement within a delivery catheter, and self-expand towards the first diameter when extruded from the delivery catheter at an implantation site. The first diameter may be at least 10% larger than the diameter of the bodily lumen into which it is implanted in some embodiments. The scaffold may be designed to recover at least about 70%, at least about 80%, at least about 90%, up to about 100% of its manufactured, first diameter, in some embodiments. Scaffolds in accordance with the present disclosure are provided with expansion and mechanical properties suitable to render the scaffolds effective for their intended purposes, including placement in the sinus cavities. 
     Scaffolds for use in the present disclosure may be formed from a variety of polymeric and non-polymeric materials. Scaffolds for use in the present disclosure may be biodegradable or non-biodegradable, or be a combination of both biodegradable and non-biodegradable materials. In various embodiments, the implantable scaffolds may comprise a generally tubular structure comprising scaffolding material. Scaffolds for use in the present disclosure may be fiber-based or non-fiber-based. 
     In various embodiments, the scaffolding material may be a biodegradable scaffolding material, typically, a biodegradable scaffolding material that comprises one or more biodegradable polymers. Non-limiting examples of biodegradable polymers for forming the biodegradable scaffolding material include biodegradable polyesters, polycarbonates, polyhydroxyalkanoates, polyanhydrides, and polyorthoesters. In various embodiments, the scaffolding material may be a non-biodegradable scaffolding material, typically a non-biodegradable scaffolding material that comprises one or more non-biodegradable polymers. Non-limiting examples of non-biodegradable polymers for forming the non-biodegradable scaffolding material include polyolefins, halogenated polyolefins, fluoropolymers, polyesters such as polyethylene terephthalate (PET), polyamides such as nylon, silicones, biostable polyurethanes (PU). 
     Scaffolds for use in the present disclosure may optionally comprise a coating formed of a coating material that at least partially coats the scaffolding material. Coatings may be applied for various purposes including mechanical property enhancement, degradation control, and therapeutic agent release and control. 
     In various embodiments, scaffolds for use in the present disclosure are braided scaffolds. For example, single-fiber strands and/or multi-fiber strands may be braided into a generally tubular structure.  FIG. 1  illustrates an embodiment of a braided scaffold  100 , which comprises at least one strand (e.g., a single-fiber or multi-fiber strand) woven to form a substantially tubular configuration having a length  130 , a width  131 , and first and second ends  132 ,  133  along the longitudinal dimension. For example, the tubular structure may comprise two sets of strands  110  and  120 , with each set extending in an opposed helical configuration along the longitudinal dimension of the scaffold. In certain embodiments, the number of helical strands forming the scaffold may range, for example, from 8 to 48 strands, among other possibilities. The sets of strands  110  and  120  cross each other at a braid angle  140 . The braid angle  140  may range, for example, from about 30 degrees or less to about 150 degrees or more, among other values. 
     The strands that form the braided scaffolds may vary widely in diameter, ranging, for example, from 10 to 1000 μm, among other possibilities. 
     In various other embodiments, scaffolds for use in the present disclosure may be in a spiral (e.g., helical) form. In some of these embodiments, a spiral form may be formed from a single strand (e.g., a single- or multi-fiber strand). In other of these embodiments, a spiral form may be formed from multi-stranded constructs. Examples of multi-stranded constructs include, for example, substantially two-dimensional structures (e.g., ribbon-shaped structures) which can be shaped into a spiral form. 
     Other examples of scaffolds include those described in “IMPLANTABLE SCAFFOLDS FOR TREATMENT OF SINUSITIS,” Attorney Docket No. 81354800001, Ser. No. 62/186,030, filed on Jun. 29, 2015, which is hereby incorporated by reference. 
     Scaffolds such as those described above, among others, may be loaded into a suitable delivery device for subsequent delivery to a patient by numerous methods, devices and systems as described in more detail below. 
     To facilitate low-profile aspects of the present disclosure (e.g., the delivery of the scaffolds into small diameter cavities, including small diameter sinus cavities), in certain beneficial embodiments, the strands used in forming scaffolds may have a diameter ranging from 100 to 500 μm, more beneficially ranging from 100 to 200 μm. The use of small diameter strands results in a scaffold with minimal wall thickness and the ability to collapse (i.e., to be crimped) within low diameter catheter delivery systems. In certain embodiments, the diameters of strands may be chosen so as to render the scaffold deliverable from a 18 French delivery catheter or smaller, from a 9 French delivery catheter or smaller, from a 6 French delivery catheter or smaller, or even from a from a 4 French delivery catheter or smaller, with a 6-9 French catheter being typical. 
     For instance, as one specific example, a scaffold ranging from 15 to 30 mm in expanded diameter, more typically 16 to 24 mm in expanded diameter, among other values, and 16 to 30 mm in length, among other values, may be implanted (e.g., using a 2-4 mm diameter delivery catheter, among other devices) into the vacated space that is formed during an ethmoidectomy. Where drug is released, in non-refractory patients the drug may be released over a period of 3 to 6 weeks, among other time periods, whereas in refractory patients the drug may be released over a period of 8 to 12 weeks, among other time periods. 
     As another specific example, a scaffold ranging from 6 to 20 mm in diameter, among other values, and 8 to 30 mm in length, among other values, may be implanted (e.g., using a 2-4 mm diameter delivery catheter, among other possible devices) into the middle meatus space. Where drug is released, it may be released over a period of 8 to 12 weeks, among other time periods. 
     As another specific example, a scaffold ranging from 6 to 10 mm in diameter, among other values, and 8 to 12 mm in length, among other values, may be implanted (e.g., using a 2-4 mm diameter delivery catheter, among other possible devices) into the sinus ostia (frontal, maxillary, or sphenoid) or the frontal sinus recess. Where drug is released, it may be released over a period of 6 to 12 weeks, among other time periods. 
     Thus, in various aspects, the present disclosure describes the use of delivery systems to provide access and positional placement of self-expanding scaffolds in the sinus space to treat patients. In various embodiments, this includes crimping and/loading the scaffold in a suitable delivery device, accessing the appropriate location within the anatomy via the delivery device, and deploying the loaded scaffold from the delivery device into the target location. In this regard, the following categories will be discussed herein: (a) crimping and loading solutions for the scaffold, (b) delivery system design concepts, and (c) combination/adjunct delivery concepts. 
     It should be noted that, although many embodiments are described herein in conjunction with loading and delivery of scaffolds to the sinuses, the present disclosure is not so limited, with many embodiments described herein useful in conduction with delivery to other body cavities and lumens including the vasculature, urinary tract, gastrointestinal tract, and lungs, among other applications. 
     With regard to crimping and loading solutions for the scaffold, and with reference to  FIGS. 2A-2B , in some embodiments, a crimping device  230  may be provided which is configured to exert an inward radial force on a radially self-expandable scaffold  220  and also configured for detachable attachment to a distal end of a delivery catheter  210  that comprises a delivery sheath having a delivery lumen. The crimping device reduces an outer diameter of the radially self-expandable scaffold  220  to a reduced outer diameter that is less than or equal to a diameter of the delivery lumen. 
     Turning in particular to  FIG. 2A , the crimping device  230  may comprise a collar band  232  and a diameter reducing mechanism such as a crank  234  or other mechanism that is configured to reduce the circumference of the collar band  232 . 
     In some embodiments, a system like that shown in  FIG. 2B  is provided, in which the delivery catheter  210  further comprises an elongate inner member  214  comprising a shaft with an enlarged distal end  214   d , wherein the enlarged distal end  214   d  has an outer diameter that is less than or equal to the reduced outer diameter of the scaffold  220 , while also being greater than an inner diameter of the scaffold  220  (so as to be able to engage the scaffold  220  without engaging the crimping device  230  upon retraction). In use, the enlarged distal end  214   d  of the inner member  214  is positioned distal to the crimping device  230 , which may be attached (not shown) to the delivery sheath  212 . When the inner member  214  of the delivery catheter  210  is retracted proximally, it engages a distal end  220   d  of the reduced diameter scaffold  220 . Upon continued retraction of the inner member  214 , the enlarged distal end  214   d  pulls the scaffold  220  proximally from the crimping device into the lumen of the delivery sheath  212 . 
       FIG. 3A  illustrates an alternative embodiment, wherein the crimping device  330  comprises an inner lumen  3301  at least partially surrounded by an air bladder that is configured to be inflated. Upon inflation of the air bladder as shown in  FIG. 3B , the diameter of the inner lumen  3301  decreases, thereby reducing an outer diameter of the radially self-expandable scaffold  320 . 
     In some embodiments, a system like that shown in  FIG. 3C  is provided, which further comprises a push rod  316  having an end  316   e , wherein the push rod end  316   e  has an outer diameter that is less than or equal to the reduced outer diameter or the scaffold  320 , while also being greater than an inner diameter of the scaffold  320  (so as to be able to engage the scaffold  320  without engaging the crimping device  330  upon retraction). In use, the end  316   e  of the push rod  316  is positioned distal to the crimping device  330  and attached (not shown as attached) delivery sheath  312  and pushed proximally to engage a distal end of the reduced diameter scaffold  320 . Upon continued pushing, the end  316   e  of the push rod  316  pushes the scaffold  320  proximally from the crimping device  330  and into the lumen of the delivery sheath  312 . In other embodiments, rather than a push rod  316 , the delivery catheter of  FIG. 3C  may be equipped with an inner member having a shaft with an enlarged distal end analogous to that shown in  FIG. 2B . 
     In other embodiments, a scaffold may be crimped and loaded into a delivery device using a flexible tapered loading member. With reference to  FIGS. 4A and 4B , a flexible tapered loading member  430  may be employed to load a scaffold  420  into a delivery catheter  410  comprising a handle  418  and a delivery sheath  412  having a delivery lumen with a defined delivery lumen diameter. The flexible tapered loading member  430  comprises a first end  430   f , which is larger than the delivery lumen diameter and which is configured to receive a radially self-expandable scaffold  420 , and a second end  430   s,  which is smaller than the delivery lumen diameter. When the second end of  430   s  of the flexible tapered loading member  430  is inserted into delivery lumen (either from the proximal end  410   p  or the distal end  410   d  of the delivery catheter  410 ) and the flexible tapered loading member  430  is advanced into the delivery lumen, the flexible tapered loading member  430  will collapse. As the flexible tapered loading member  430  collapses, a radially self-expandable scaffold  420  that is positioned within the flexible tapered loading member  430  will be compressed simultaneously and ultimately positioned within the delivery lumen. The lead-in taper of the loading member  430  facilitates compression of the loading member  430  (and scaffold  420 ). 
     In one embodiment, the flexible tapered loading member  430  is pulled into the delivery sheath  412  from a proximal end of the catheter  410  utilizing a flexible elongate component  436  (e.g., a filament such as a suture, string, thread or wire). Once the scaffold  420  is positioned in the handle  418 , flexible tapered loading member  430  can be pulled out of the distal end  410   d  of the delivery catheter  410 , leaving the scaffold  420  contained within the handle, to be delivered with an inner sheath or push rod (not shown) once the delivery sheath is placed into position for delivery within the sinus space. To maintain the position of the scaffold  420  during removal of the loading member  430 , a tool may be employed either grasp the scaffold from the proximal end or act as a stop for the scaffold from the distal end. 
     In other embodiments the flexible tapered loading member  430  and scaffold  420  may be pushed into the proximal end  410   p  of the delivery catheter (rather than being pulled by an elongate flexible component). In still other embodiments the loading member  430  and scaffold  420  may be pushed or pulled into the distal end  410   d  of the delivery catheter  410 . Once the scaffold  420  is positioned in the distal end  410 d, the flexible tapered loading member  430  may be pulled out of the proximal end  410   p  of the delivery catheter  410 , leaving the scaffold contained within the distal end  410   d,  to be delivered with an inner sheath or push rod. 
     In the embodiment shown the flexible tapered loading member  430  is funnel-shaped and may be formed from any suitable flexible material. In certain embodiments, the flexible tapered loading member  430  is in the form of an expandable and collapsible mesh (e.g., a braided mesh), which allows the flexible tapered loading member  430  to radially collapse without folding. 
     In another embodiment shown in  FIG. 4C , the tapered receiving member  430  may be formed by cinching a filament  437  that is associated with one end  431   e  of a cylindrical member  431 . In use, a scaffold  420  may be positioned in the cylindrical member  431 , after which one or both ends of the filament  437  are pulled, closing the end  431   e  of the cylindrical member  431 . At this point he now-formed and tapered receiving member  430  and scaffold  420  form an assembly which may be loaded into the delivery catheter as described above. In some embodiments, the filament  437  may be used to pull the assembly into the delivery catheter  410 . 
     In other embodiments a detachable funnel is disposed at a distal end of a delivery catheter and a radially self-expandable scaffold is inserted (i.e., pushed or pulled) into the delivery catheter via the funnel. 
     In one embodiment illustrated in  FIGS. 5A-5C , a delivery system may include a detachable loading funnel  530  and a delivery catheter  510  comprising a handle (in particular, a hub  518 ), delivery sheath  512  and a pusher member  514 . During loading, the loading funnel  530  is attached to the distal tip of the delivery sheath  512 . One or more filaments  531 . (e.g., strings, threads, sutures, wires, etc.) may be attached to a proximal end of the scaffold  520 , and strung through the funnel  530  and out the proximal end of the delivery catheter  510 . The scaffold  520  is drawn into the loading funnel  530  and ultimately transferred into the delivery sheath  512  by pulling on the filament(s)  531 . Subsequently, the loading funnel  530  is removed from the distal tip of the delivery sheath  512 , and the filament(s)  531  are removed from the scaffold  520  and delivery catheter  510 . In one embodiment, a filament  531  in the form of a loop that is strung through the scaffold  520  may be employed whereby the loop is pulled to draw the scaffold  520  into the funnel  530 , after which the loop is severed where it emerges from the proximal end of the delivery catheter  510 , thereby forming two ends, one of which is pulled to remove the filament  531 . 
     As illustrated in  FIG. 5B , a pusher member  514  is then inserted through the proximal end of the delivery catheter  510 , and advanced to the proximal end of the crimped scaffold  520 . The pusher member  514  may be formed, for example, of a single material or, alternatively, may be formed of multiple materials to vary flexibility along its length. 
     The delivery system may also have an inner support member inserted through the pusher member, running through the length of the system. The support member may be formed, for example, of a single material or, alternatively, may be formed of multiple materials to vary flexibility along its length. The support member may also have a lumen to accommodate a guide wire or illumination system. The support member may go through the center of the scaffold and the scaffold may be crimped over the support member. 
     A specific embodiment of such a system  600  is illustrated in  FIG. 6A  wherein a delivery catheter comprising clear outer sheath having a distal end  612   d  and a proximal end  612   p  terminating at a handle/hub  618 . Inserted into the delivery catheter is a pusher member having a handle assembly  619  and an elongate member having a proximal metallic portion  614   p  extending from the handle assembly  619 , through the delivery catheter handle/hub  618  and into the outer sheath, at which point the elongate member transitions to a polymeric distal portion  614   d , finally terminating at point  614 t. Finally, the system includes a polymeric support member extending through the entire system, which includes a clear proximal portion  622   p  with a first durometer extending from a proximal end  619   p  of the pusher member handle  619  transitioning within the system to a pigmented distal portion  622   d  with a second durometer extending from a distal end of the outer sheath  612   d . Enlarged views of the device of  FIG. 6A  are shown in  FIGS. 6B and 6C . 
     The loaded delivery system may be tracked into the intended sinus space, for example, either directly or over a guide wire (in which case the pusher member  514  may be provided with a lumen to accommodate the guide wire) or through an external guide member or catheter. Deployment may be accomplished by holding the pusher member  514  stationary and pulling back on the delivery sheath  512 , to unsheathe the scaffold  520  (shown partially unsheathed in  FIG. 5C ). Delivery may also be accomplished by pushing the pusher member or by a combination of pushing to initiate deployment, followed by pulling to maintain positional accuracy. 
     While the delivery sheath  512  shown in  FIGS. 5A-5C  is linear, in other embodiments, the delivery sheath  512  may be provided with a curvature. For example, the delivery sheath  512  may have a pre-formed shape-memorized section  512   s  with a curvature that improves access to various ostia as shown in  FIG. 5D . Such a configuration, wherein the angle of curvature of the delivery sheath  512  ranges from about 0° to about 45° may be useful, for example, to achieve sphenoid sinus access. In other configurations, the curvature of the delivery sheath  512  may range, for example, from about 45° to about 110° and may be useful to achieve frontal sinus access, for example. In other configurations, for example, such as that illustrated in  FIG. 7 , the curvature of the delivery sheath  712  may range from about 110° to about 170°. In such embodiments, the delivery sheath may provide may be useful, for example, to achieve maxillary sinus access. 
     While the delivery systems described immediately above are based on the use of a pusher to deliver a scaffold from a delivery sheath, in other non-pusher embodiments, the scaffold may be retained by compressive friction created by compressing the scaffold onto an inner member. For example, turning now to  FIG. 8A , a distal end of a delivery system  810  is shown that includes a scaffold  820 , an outer sheath  812 , and an elongate inner member  814  having an inner support segment  814   s . The scaffold is compressed onto the inner support segment  814   s  by the outer sheath  812 . Such a delivery catheter may be used independently or in conjunction with a guide catheter  811  as shown in  FIG. 8B , through which the delivery catheter has been advanced to a target site in a sinus  840 . The scaffold  820  has a higher force of friction when in contact with the material provided on the inner support segment  814   s  than it does when in contact with the material provided on the outer sheath  812 , allowing the support segment  814   s  to pull the scaffold  820  along with the support segment  814   s  as the support segment  814   s  moves in either a proximal or a distal direction relative to the outer sheath  812 , including allowing the inner support segment  814   s  to pull the scaffold out of the distal end of the outer sheath  812 . Examples of materials for the outer surface of the inner support segment  814   s  include biocompatible polymers including but not limited to polyethylene, polyethylene terephthalate, ultra-high molecular weight polyethylene, polytetrafloroethylene, expanded polytetrafloroethylene, polypropylene, silicone rubber, polycarbonate urethane, polyurethane, polyamide, polyether block amide, polyoxymethylene, polyetheretherketone, and aliphatic or semi-aromatic polyamide. Examples of materials for the inner surface of the outer sheath  812  include, but are not limited to, biocompatible polymers including but not limited to polyethylene, polyethylene terephthalate, ultra-high molecular weight polyethylene, polytetrafloroethylene, expanded polytetrafloroethylene, polypropylene, silicone rubber, polycarbonate urethane, polyurethane, polyamide, polyether block amide, polyoxymethylene, polyetheretherketone, and aliphatic or semi-aromatic polyamide. Both the inner support segment  814   s  and the outer sheath  812  may be of a composite of materials, allowing for a variable stiffness and frictional properties at various points in their lengths. At the time of delivery, a distal end of the delivery system  810  is advanced through the guide catheter  811  and out of its distal end  811 d. At the target position, due to the friction between the elongate inner member  814  and scaffold  820  that has been established by compression of the scaffold  820  onto the inner support segment  814   s , the elongate inner member  814  and scaffold  820  are advanced relative to the outer sheath  812  (e.g., by advancing the elongate inner member  814  while maintaining the position of the outer sheath  812  and/or by retracting the outer sheath  812  while maintaining the position of the elongate inner member  814 ) to an extent such that the outer sheath  812  no longer confines the scaffold allowing the scaffold  820  to expand into contact with tissue  840  as shown. In other embodiments, movement of the scaffold  820  may be coordinated with movement of the elongate inner member  814 , for example, by providing one or more retention features on the inner support segment  814   s , allowing the support segment  814   s  to pull the scaffold  820  along with the support segment  814   s  as the support segment  814   s  moves in either a proximal or a distal direction relative to the outer sheath  812 . Such retention features may include, for example, steps, bumps, hooks, barbs, or rings that engage at least a portion of the scaffold  820 , among other possibilities. 
     In another variation, and with reference to  FIG. 9  the scaffold  920  may be inserted into a collapsible braided mesh  935 , and the braided mesh  935  pulled into the loading funnel  930 , resulting in the compression of the scaffold  920  that is pulled into the loading funnel  930  along with the mesh  935 . One or more flexible elongate elements, for example, one or more filaments (e.g., threads, sutures, strings, wires, etc.), may be attached to the braided mesh  935  for this purpose. 
     In still another variation, and with reference to  FIG. 10  the scaffold  1020  may be inserted into a double-layer mesh  1035  having an inner layer  1035   i  and an outer layer  1035   o . By simultaneously pulling the inner layer  1035   i  and an outer layer  1035   o , the double-layer mesh  1035  can be pulled into a loading funnel  1030 , compressing the scaffold  1020  that is pulled into the loading funnel  1030  along with the double-layer mesh  1035 . Once the scaffold is properly positioned in the lumen of a delivery sheath  1012 , one can continue to pull either the outer layer  1035   o  alone, with the result being that the mesh  1035  is pulled off the scaffold  1020  and ultimately removed from the delivery sheath  1012 . Subsequently, a pusher member may be inserted into delivery sheath  1012  to complete delivery of the scaffold  1020 , among other methods. 
     In still another variation and with reference to  FIGS. 11A-11E , the scaffold  1120  may be initially inserted into a loading funnel  1130  having an enlarged diameter end  1130   e  and a reduced diameter end  1130   r  as shown in  FIG. 11A . The enlarged diameter end  1130   e  of the loading funnel  1130  may, for example, approximately match the uncompressed diameter of the scaffold  1120 . The reduced diameter end  1130   r  of the loading funnel  1130  may be configured to interface with a distal end of a delivery device (not shown), for example, by attachment to a distal end of a delivery device adjacent to a delivery lumen or by insertion into a delivery lumen at a distal end of a delivery device. During loading, the scaffold  1120  is advanced along the tapered portion  1130   t  between the enlarged diameter end  1130   e  of the loading funnel  1130  and the reduced diameter end  1130   r  of the loading funnel  1130 , thereby compressing the scaffold  1120  to a diameter suitable for introduction into a lumen of the delivery device. In the embodiment shown, a pusher member  1136  having slots  1136   s  forming protrusions  1136   p  is used to push the scaffold  1120  from the enlarged diameter end  1130   e  to the reduced diameter end  1130   r  of the loading funnel  1130 . As the pusher member  1136  is advanced through the tapered portion  1130   t  of the loading funnel  1130 , contact with the walls of the loading funnel  1130  move the protrusions  1130   f  of the loading funnel inward (thus reducing the width of the slots), thereby allowing the pusher member  1136  to continue to advance into the tapered portion of the funnel  1130  and thus continue to push the scaffold  1120  through the funnel  1130  and into the delivery device. 
     In certain embodiments, the slots  1136   s  may be tapered, for example, being larger at the tip of the member  1136 , and decreasing in width as one moves along the length of the device. 
     In certain embodiments, rather than having slots that extend longitudinally along the member  1136  (i.e., parallel to the axis of the member  1136 ), the slot(s) may include one or more spiral cuts of varying thickness in order to allow for the diametric compression at the tip of the member  1136 . 
     In another embodiment illustrated in  FIGS. 30A and 30B , a delivery system is shown which includes a first assembly  3001  and a second assembly  3002 . The first assembly  3001 , shown in  FIG. 30A , comprises a detachable loading funnel  3030  having a funnel neck  3030   n , and a delivery catheter comprising a handle  3018  (in particular, a Y-connector hub  3018 ) and a delivery sheath  3012 . The loading funnel  3030  is inserted into the handle  3018 , in particular, into one of the legs of the Y-connector hub, such that a portion  3030   p  of the loading funnel  3030  is positioned in the Y-connector hub  3018 . The loading funnel  3030  is detachable from the handle  3018  by means of a readily breakable connection point  3030   b  the funnel neck  3030   n  in the embodiment shown, although the loading funnel  3030  may be detached from the handle  3018  any other suitable mechanism that allows coupled components to be decoupled (e.g., male and female threaded portions, etc.). 
     The second assembly  3002 , shown in  FIG. 30B , comprising an elongate inner member  3014  having a distal end  3014   d  and a proximal end (not shown) and comprising an inner support segment  3014   s , an elongate pulling member  3016  having a distal end  3106   d  and a proximal end  3016   p , and a scaffold  3020  that is secured to the pulling member  3016  by one or more connecting members, for example, one more filaments  3031  (e.g., sutures, strings, threads, wires, etc.). For example, a filament  3031  in the form of a loop that is strung through the scaffold  3020  may be employed to secure the scaffold  3020  to the pulling member  3016 , whereby each of the ends (i.e., first and second ends) of the filament  3031  is secured to the pulling member  3016 . When it is desired to disengage the scaffold  3020  from the pulling member  3016 , a first end of the filament  3031  may be severed from the pulling member  3016 , and the filament  3031  may be removed from the scaffold  3020  by pulling the second end of the filament  3031  (e.g., by pulling the filament  3031  or by pulling the pulling member  3016  to which the second end of the filament  3031  is attached). Where desired, the proximal end  3016   p  of the elongate pulling member  3016  may be detachably secured to the distal end  3014   d  of the elongate inner member  3014 , for instance, any suitable mechanism that allows coupled components to be decoupled (e.g., by a readily breakable connection, for instance, one more filaments that may be severed, by male and female threaded portions, etc.). For example, analogous to the scheme described above in conjunction with the scaffold  3020 , in one embodiment, a filament  3031  in the form of a loop that is strung through the elongate inner member  3014  (e.g., a aperture in the distal end  3014  of the elongate inner member  3014 ) may be employed to secure the elongate inner member  3014  to the pulling member  3016 , whereby each of the ends of the filament  3031  is secured to the pulling member  3016 . 
     During loading, wherein the second assembly  3002  of  FIG. 30B  is pushed and/or pulled through the first assembly  3001  of  FIG. 30 , the second assembly  3002  may be inserted into the first assembly  3001 , for example, by first inserting the pulling member  3016  of the second assembly  3002  into the funnel  3030  of the first assembly  3001 . Where the pulling member  3016  is of sufficient length, the second assembly  3002  may be advanced through the first assembly  3001  exclusively by manipulation of the pulling tube  3016 , first from the funnel end of the first assembly  3001  until the distal end  3016   d  or the pulling member  3016  emerges from a distal end  3012   d  of the outer delivery sheath  3012 , at which point the pulling member  3016  can be used to pull the second assembly  3002  until the scaffold  3020  is positioned at a desired position in the delivery sheath  3012 . In other embodiments, the second assembly  3002  may be advanced at least a portion of the way through the first assembly  3001  by pushing the inner member  3014 . In any case, advancement of the second assembly  3002  into the first assembly  3001 , and more specifically, advancement of the scaffold  3020  and inner support segment  3014   s  through the funnel  3030  causes the scaffold  3020  to be compressed to diameter suitable for advancement though the second assembly  3002 . The scaffold  3020  may also be compressed onto the inner support segment  3014   s , in which case the scaffold  3020  may have a higher force of friction when in contact with material provided on an outer surface of the inner support segment  3014   s  than it does when in contact with the material provided on an inner surface of the outer delivery sheath  3012 , allowing the support segment  3014   s  to pull the scaffold  3020  along with the support segment  3014   s  as the support segment  3014   s  is moved in either a proximal or a distal direction relative to the outer delivery sheath  3012 , such that advancement and retraction of the inner support segment  3014   s  causes advancement and retraction, respectively, of the scaffold  3020 . In some embodiments, movement of the scaffold  3020  may be coordinated with movement of the elongate inner member  3014 , for example, by providing one or more retention features on an inner support segment  3014   s , allowing the support segment  3014   s  to pull the scaffold  3020  along with the support segment  3014   s  as the support segment  3014   s  is moved in either a proximal or a distal direction relative to the outer delivery sheath  3012 . Such retention features may include, for example, steps, bumps, hooks, barbs, or rings that engage at least a portion of the scaffold  3020 , among other possibilities. 
     Once the scaffold  3020  is advanced to a desired position in the outer delivery sheath  3012  (e.g., proximal the distal end  3012   d  of the outer delivery sheath  3012 ), the one more filaments  3031  may be removed from the scaffold  3020  to free the scaffold  3020  from the pulling member  3016 . For example, where the filament  3031  is in the form of a loop that is strung through the scaffold  3020  as described above, a first end of the filament  3031  may be severed from the pulling member  3016 , after which distal movement of the second end of the filament  3031  (e.g., brought about by pulling the filament  3031  itself or the pulling member  3016  to which the second end of the filament  3031  is attached), causes the first end of the filament  3031  to be pulled through the scaffold  3020  and out of the distal end  3012   d  of the outer delivery sheath  3012 . If attached, the pulling member  3016  may be detached from the inner member  3014  as well. In the embodiment illustrated, the loading funnel  3030  may be removed from the handle  3018  by snapping the readily breakable region  3030   b  of the funnel neck  3030   n , among other suitable methods. 
     In certain embodiments, where an inner member has sufficient column strength, the inner member and any associated components of a second assembly (e.g., scaffold, inner support segment, etc.) may be advanced at least a portion of the way through a lumen of a first assembly (which may include, for example, a funnel, handle, outer delivery sheath, etc.) by pushing a proximal end the inner member. In these embodiments, advancement of the inner member may be facilitated by providing a press member at a proximal end of the inner member. 
     For example, in one system  3100  illustrated in  FIG. 31 , a second assembly is provided that includes an inner member  3114 , a press member  3117  provided at a proximal end  3114   p  of the inner member  3114 , and a scaffold  3120  provided around a support segment (not separately numbered) positioned at a distal end  3114   d  of the inner member  3114 . The system  3100  also includes a first assembly that includes an ergonomic handle  3118 , an outer delivery sheath  3112  attached to and/or integrated with the handle  3118 , and an adaptor  3119  (e.g., check valve or a valve that can be opened and closed, for instance, Touhy Borst valve, etc.) attached to and/or integrated with an ergonomic handle  3118 . As illustrated, the inner member  3114  extends through the valve  3119 , handle  3118 , and through a majority of the length of the outer delivery sheath  3112 . At a subsequent point, the scaffold  3120  may be delivered from the outer delivery sheath  3112  by distally advancing the second assembly relative to the first assembly, for example, by applying pressure to a proximal surface  3117   p  of the press member  3117  such that the second assembly moves distally relative to the first assembly. For example, as previously noted, one or more retention features may be provided on the support segment, or the scaffold  3120  may have a higher force of friction when in contact with the material provided on the support segment of the inner member  3114  than it does when in contact with the material provided on the inner surface of the outer delivery sheath  3112 , allowing the support segment to pull the scaffold  3120  along with the support segment as the support segment moves in either a proximal or a distal direction relative to the delivery sheath  3112 . For instance, a proximal surface  3117   p  of the press member  3117  may be pressed with an operator&#39;s thumb while distal surfaces  3118   s   1  and  3118   s   2  are engaged by the operator&#39;s index and middle fingers (e.g., much like the plunger of a syringe is pressed by the thumb while the flange on the syringe barrel is held with the index and middle fingers) in order to apply pressure at a proximal end  3114   p  of the inner member  3114 . Since the second assembly can be advanced relative to the first assembly by applying pressure at a proximal end  3114   p  of the inner member  3114 , it is possible to load and advance the scaffold  3120  in the outer sheath  3112  without a pulling member, although in other embodiments, a pulling member  3117  may be employed to assist scaffold  3120  loading. 
     An embodiment of a press member  3117  that is similar to that of  FIG. 31  is shown in  FIG. 31A . Additional press members  3117  shown in  FIGS. 31B and 31C  may be engaged by placing an operator&#39;s thumb through an aperture  3117   a  (e.g., a loop) that is provided in the press member  3117 . 
     In an embodiment of a system  3200  illustrated in  FIG. 32 , a distal end of a second assembly is shown, which includes an inner member  3214  and a scaffold  3220  provided around a support segment (not shown) near a distal end  3214   d  of the inner member  3214 . The scaffold  3220  may be attached to the inner member, for example, one or more filaments (not shown). For example, a plurality of filaments may be looped through an aperture in the scaffold wall (e.g., a diamond-shaped aperture of a braided scaffold) and an aperture that is drilled or formed in a distal tip  3214   d  of the inner member  3214 . The system  3200  also includes a first assembly that includes a funnel  3230 , an ergonomic handle  3218 , an outer delivery sheath  3212  and an adaptor  3219  (e.g., a Touhy Borst valve with thumb screw closure). The scaffold  3220  may subsequently be pulled by the one or more filaments through the funnel  3220 , valve  3219  and handle  3218  and through a majority of the length of the outer delivery sheath  3212 , until the distal end  3214   d  of the inner member  3214  emerges from a distal end of the outer delivery sheath  3212 , allowing each of the filament loops to be cut and removed from the scaffold  3220  and inner member  3214 . As previously indicated, one or more retention features may be provided on the support segment, or the scaffold  3220  may have a higher force of friction when in contact with the material provided on the support segment of the inner member  3214  than it does when in contact with the material provided on the inner surface of the outer delivery sheath  3212 , allowing the support segment to pull the scaffold  3220  along with the support segment as the support segment moves in either a proximal or a distal direction relative to the delivery sheath  3212 . In certain embodiments, a portion of the inner member  3214  that is located distal to the scaffold  3220  may be detachably secured to a remainder the elongate inner member  3014 , for example, by any suitable mechanism that allows coupled components to be decoupled (e.g., providing a readily breakable linkage between the coupled components, male and female threaded portions, etc.). In some embodiments, the second assembly may be distally advanced relative to the first assembly by applying pressure to a proximal surface of a press member (not shown) as described above. A cross-sectional view of the ergonomic handle  3218  and valve  3219  is shown in  FIG. 32A . An alternative design for an ergonomic handle  3218  is shown in  FIG. 32B . 
     In certain embodiments, funnel and handle may be combined into a single integrated component. One example of such an integrated component  3301  is shown in perspective view in  FIG. 33A  and cross-sectional view in  FIG. 33B . Another example of such an integrated component  3401  is shown in perspective view in  FIG. 34A  and cross-sectional view in  FIG. 34B . 
     In an embodiment of a system  3800  illustrated in  FIG. 38 , a proximal end of a first assembly is shown, which includes a funnel  3830  and an ergonomic handle  3818  (which are integrated into a combined funnel and handle, analogous to those previously described, e.g., in  FIGS. 33A, 33B, 34A and 34B ), as well as an outer delivery sheath  3812  extending from a distal end of the same. Provided at the proximal end of the funnel  3830  is a funnel cap  3830   a,  which acts to ensure that scaffold  3820  is secured in place during shipping and storage, so scaffold  3820  is properly positioned within the system  3800  when it is desired to load scaffold  3820 . 
     Also shown is a distal end of a second assembly, which includes a hollow inner member  3814  having support segment  3814   s  near a distal end  3814   d  of the inner member  3814 . A stylet  3841  extends from a proximal end (not shown) of the hollow inner member  3414 , through the hollow inner member  3414 , out of the distal end  3414   d  of the hollow inner member  3414 , and into a capsule  3842 , which is described in more detail below. A scaffold  3820  is linked to the capsule  3842  via one or more filaments  3831  (one numbered). For example, one end of each of one or more filaments  3831  may be attached to the capsule  3842 , and the other end of each of one or more filaments  3831  may be looped from the capsule  3842 , through the scaffold  3820 , back to the capsule  3842 , and attached to the capsule. 
     By advancing the second assembly relative to the first assembly, and more particularly, by advancing the inner member  3814 , stylet  3841  and capsule  3842  relative to the first assembly, the scaffold  3820  may be pulled via the capsule  3842  and one or more filaments  3831  through the funnel  3820  and handle  3818  and through a majority of the length of the outer delivery sheath  3812 , until the capsule  3842  passes through the distal end of the outer delivery sheath  3812 . At this point, one end of each of the one or more filaments  3831  may be freed from the capsule and the other end of each of the one or more filaments  3831  may be pulled away from the distal end of the outer delivery sheath  3812 , allowing each of the one or more filaments  3831  to be removed from the scaffold  3820  and outer delivery sheath  3812 . 
     Capsule  3842  is shown in more detail in  FIG. 39A  and includes a top filament lumen  3842 t 1  that connects with a top glue port  3842   tp,  a bottom filament lumen  3842   b   1  that connects with a bottom glue port  3842   bp,  and a stylet receptacle  3842   r,  into which the stylet is  3841  is inserted in  FIG. 38 . One end of each of one or more filaments (not shown) is threaded through top filament lumen  3842   t   1  and glued through top glue port  3842   tp.  The other end of each of one or more filaments is looped through the scaffold  3820  (e.g., as shown in  FIG. 38 ), threaded through bottom filament lumen  3842   b   1  and glued through bottom glue port  3842   bp.  As noted above, during loading, the capsule  3842  passes through the distal end of the outer delivery sheath  3812 . At this point, the one or more top filament ends may be cut through the top slot along line L (the capsule  3842  may or may not be cut as well). This will free the top filament end(s) from the capsule  3842 . The portion of the capsule  3842  to which the bottom filament end(s) is(are) attached can then be pulled away from the distal end of the outer delivery sheath  3812 , allowing each of the one or more filament to be removed from the scaffold  3820  and outer delivery sheath  3812 . 
     In an alternative design shown in  FIG. 39B , a capsule  3842  is provided which can be manually split into a first portion  3842   p   1  and a second portion  3842   p   2 . One end  3831   e   1  of one or more filaments is attached (e.g., using a suitable adhesive) to the first portion  3842   p   1 . After being looped through the scaffold, the other free end  3831   e   2  of the one or more filaments may be physically clamped between the first and second portions  3842   p   1 ,  3842   p   2 . After the capsule  3842  is pulled from the distal end of the outer delivery sheath  3812 , the first and second portions  3842   p   1 ,  3842   p   2  may be separated (e.g., split apart), releasing the free end  3831   e   2  of the one or more filaments. 
     The first portion  3842   p   1  to which the end  3831   e   1  of the one or more filaments is attached can then be pulled away from the distal end of the outer delivery sheath  3812 , allowing each of the one or more filaments to be removed from the scaffold  3820  and outer delivery sheath  3812 . 
     In another alternative embodiment, one end  3831   e   1  of one or more filaments is attached (e.g., using a suitable adhesive) to the first portion  3842   p   1 . After being looped through the scaffold, the other end  3831   e   2  of the one or more filaments is attached (e.g., using a suitable adhesive) to the second portion  3842   p   2 . During advancement of the capsule  3842 , the first portion  3842   p   1  and second portion  3842   p   2  of the capsule  3842  are joined together. After the capsule  3842  is pulled from the distal end of the outer delivery sheath  3812 , the first and second portions  3842   p   1 ,  3842   p   2  may be separated, and the filament cut from one of the portions (e.g.,  3842   p   1 ). The other of the portions (e.g.,  3842   p   2 ) can then be pulled away from the distal end of the outer delivery sheath  3812 , allowing each of the one or more filaments to be removed from the scaffold  3820  and outer delivery sheath  3812 . 
     Once the stylet  3841 , capsule  3842  and one or more filaments  3831  are removed, the system  3800  will be ready for delivery of the scaffold  3820 , with the scaffold  3820  overlying the support segment  3814   s  in a distal section of the delivery sheath  3812 . As in other embodiments described herein, one or more retention features may be provided on the support segment  3814   s  and/or the scaffold  3820  may have a higher force of friction when in contact with the material provided on the support segment  3814   s  of the inner member  3814  than the scaffold  3820  does when in contact with the material provided on an inner surface of the outer delivery sheath  3812 , allowing the support segment  3814   s  to pull the scaffold  3820  along with the support segment  3814   s  as the support segment  3814   s  moves in either a proximal or a distal direction relative to the delivery sheath  3812 . 
     In this way, the scaffold  3820  can be delivered from a distal end of the outer delivery sheath  3812 . 
     For example, in some embodiments, the scaffold  3820  may delivered from a distal end of the outer delivery sheath  3812  directly into an implant location (e.g., a sinus) in a patient. 
     As another example, the scaffold  3820  may be delivered into an applicator  4100  (i.e., delivery catheter) like that shown in  FIG. 41 , which includes an ergonomic handle  4118 , a delivery sheath  4112  and an adaptor  4119  (e.g., a Touhy Borst valve with thumb screw closure). For this purpose, a delivery sheath  3812  of a system  3800  like that illustrated in  FIG. 38  may be truncated (shortened) to form a truncated loading sheath  3812   t  of a scaffold loading system  4000  such as that shown in  FIG. 40 , and a distal end of the truncated loading sheath  3812   t  may be inserted into valve  4119  or other suitable adaptor at the proximal end of the applicator  4100  of  FIG. 41  as shown in  FIG. 42 . The scaffold (not shown) may be loaded, either before or after the loading system  4000  and applicator  4100  are linked, such that the scaffold overlies a support segment  2814   s  of an inner member  3814  in a distal section  3812   s  of the truncated loading sheath  3812   t  as shown in  FIG. 40 . Once the loading system  4000  is linked to the applicator  4100 , the inner member  3814  can be advanced in order to pull the scaffold through the valve  4119  and into the applicator  4100 . For example, the scaffold  3820  may be advanced to a distal end  4112   d  of the outer delivery sheath  4112  as shown in  FIG. 43 . In addition, once the scaffold  3820  is transferred from the truncated loading sheath  3812   t  of system  4000  and into the applicator  4100 , if desired, all components of system  4000  may be removed except for inner member  3814 , as shown in  FIG. 43 , which can be used to deliver the scaffold  3820  distally from the applicator  4100  into an implant site within a patient. In some embodiments, the inner member  3814  may be configured such that a portion of the inner member  3814  lying proximal to the support segment  3814   s  may be disengaged and separated from the support segment  3814   s , and an additional elongate member may subsequently be used to advance the support segment  2814   s  through the outer delivery sheath  4112 . 
     Other loading systems described elsewhere herein, including those shown and described below in  FIGS. 36A-36B  and in  FIGS. 37A-37D , among others, may also be used in an analogous fashion with applicator  4100 . 
     In another embodiment illustrated in  FIG. 35 , a second assembly  3502  is shown that includes a hollow inner member  3514  having a lumen (e.g., in the form of a stainless steel hypotube), a press member  3517  (e.g., a molded member) disposed at a proximal end of the hollow inner member  3514  and having a lumen that provides access to the lumen of the hollow inner member  3514 , and a scaffold  3520  provided around a support segment (not shown) at a distal end of the inner member  3514 . The scaffold  3520  is held in position at the distal end of the inner member  3514  by a plurality of filaments  3531  such that the second assembly can be pushed through a first assembly that comprises a funnel, handle, and delivery sheath as described above (not shown). The plurality of filaments  3531  may be looped from a filament holder  3532  that is positioned at a proximal end of the first assembly  3501 , through a lumen in the press member  3517  lumen, through the hollow inner member  3514  lumen, through the scaffold  3420 , and back through the hollow inner member  3514  lumen and press member  3517  lumen to the filament holder  3532 . Whenever it is desired to remove the one or more filaments  3531  from the scaffold  3520 , one can simply sever one end of each filament where it attaches to the filament holder  3532  and subsequently pull the filament holder  3532  proximally to withdrawn the filaments  3531  from the scaffold  3520 , hollow inner member  3514  and press member  3517 . In certain embodiments, the filament holder  3532  may comprise first and second portions that are separable from one another, and one end of each filament  3531  may be connected to the first portion, while the other end of each filament  3531  may be connected to the second portion. Whenever it is desired to release the scaffold  3520  first assembly  3501 , one can simply sever an end of each filament where it attaches to the first portion of the filament holder  3532  and subsequently pull the second portion of the filament holder  3532  proximally to withdrawn the filaments  3531 . In certain embodiments, the filament holder  3532  may be provided threaded with threads, such that it can be screwed into a threaded aperture in the pusher member. 
     In other embodiments, a scaffold may be crimped and loaded into a delivery lumen of a delivery device using a delivery system that includes an engagement device that comprises a plurality of radially expandable and contractible members, each comprising a hook at its distal end. 
     One example of such a delivery system is found in  FIG. 12 , which shows a delivery system comprising an engagement device comprising a plurality of radially expandable and contractible members  1232 , each comprising a hook  1231  at its distal end. The contractible members  1232  taper radially outward and have a shape memory that allows them to self-expand upon removal of radial compression. The contractible members  1232  and associated hooks  1231  can be routed from the proximal end of the delivery system (not shown) through the distal tip of the delivery sheath  1220 . A funnel may be used to assist with the insertion of the hooks  1231  into the delivery system in some embodiments. The contractible members  1232  are associated with an elongate member  1233  by which the contractible members  1232  and hooks  1231  can be pulled proximally into a lumen of a delivery sheath  1212 . The hooks  1231  project radially outward and are configured to engage a proximal end of a scaffold  1220 . As the contractible members  1232  (which taper radially outward) are drawn into the delivery sheath  1212  (or funnel), the delivery sheath  1212  (or funnel) engages and radially compresses the contractible members  1232 , reducing an outer diameter of the scaffold  1220  at its proximal end such that the scaffold  1220  can be drawn into the delivery sheath  1212  (or funnel). The hooks  1231  may ultimately be disengaged from the scaffold  1230  by distally advancing a member with a suitably small diameter lumen over the contractible members  1232 , drawing the contractible members  1232  and associated hooks radially inward or, in the case where the hooks reverse direction (e.g., where the hooks are in the shape of a “U” or a “V”), by reversing the direction of the hooks  1231  (e.g., by pushing the elongate member  1233  distally, after which the engagement device may be removed from the distal end of the delivery sheath), among other methods. 
     Another embodiment of a delivery system  3600  illustrated in  FIGS. 36A and 36B  includes a loading member  3630  (e.g., a funnel), an ergonomic handle  3618 , an adaptor  3619  (e.g., a Touhy Borst valve with thumb screw closure), and an outer delivery sheath (not shown). The loading member  3630  comprises a loading lumen  36301  having a lumen axis, A, a luminal surface  3630   l s, and a plurality of longitudinal pathways, for instance, keyways (e.g., grooves, slots, etc.), not shown), which are formed in the luminal surface  36301   s  of the loading member  3630  and which extend longitudinally along a length of the loading member  3630 . The loading lumen  3630   l  comprises a tapered lumen region having a proximal tapered lumen end  3630   lp  with a first diameter and a distal tapered lumen end  3630   ld  with a second diameter that is smaller than the first diameter. This and other tapered lumens described herein may be provided with a variety of tapers, including linear tapers, curved tapers (e.g., bell-shaped tapers) and combinations of linear and curved tapers, for example as shown in  FIGS. 36A and 36B , where an initial linear taper is followed by a curved (i.e., bell-shaped). While  FIGS. 36A-36B  illustrate a separate loading member  3630  and ergonomic handle  3618  connected by a valve  3691 , it will be appreciated that in other embodiments, these components can be integrated into a combined funnel and handle, for example, like that shown in  FIG. 38 , if desired. 
     Also shown is (a) a self-expanding scaffold  3620  having a scaffold lumen  36201  that is disposed in the loading lumen  3630   l,  (b) an inner member  3614  having an inner support segment  3614   s , and (c) an engagement device  3603  having an engagement device axis, A, and a plurality of elongate members  3632 , which taper radially outward from the engagement device axis, A, and which have a shape memory that allows the elongate members  3632  to be radially compressed and to subsequently self-expand after upon removal of radial compression. Each of the elongate members  3632  terminates in an engagement feature  3632   e  (e.g., a hook), and the engagement device  3603  is at least partially positioned within the scaffold lumen  3620   l  and loading lumen  3630   l  such that each engagement feature  3632   e  extends through a wall of the scaffold  3620  and into one of the longitudinal pathways in the luminal surface  36301   s  of the loading member  3630 . When so arranged, longitudinal movement of the engagement device  3603 , and more specifically, distal longitudinal movement of the engagement device  3603 , is accompanied by distal longitudinal movement of the scaffold  3620  within the loading lumen, leading to compression of the scaffold  3620 . While the engagement features  3632   e  (e.g., hooks) engage the scaffold  3620  from an interior (luminal) side in the embodiment shown, in other embodiments, the engagement features may be provided which engage the scaffold  3620  from an exterior (abluminal) side. 
     One specific embodiment of an engagement device  3603 , shown in  FIG. 36C , includes a tubular shaft  3636  having a lumen  3636   l,  an axis, A, a proximal end  3636   p , and a distal end  3336   d . The tubular shaft  3636  serves as a detachment sleeve, which will be discussed in more detail below. A plurality of elongate members  3632 , each terminating at an engagement features  3632   e,  specifically, a hook tab, extend through the lumen of the tubular shaft  3636  and extend proximally from the proximal end  3636   p  of the tubular shaft  3636 , tapering radially outward from the longitudinal axis, A, of the tubular shaft  3636 . A removable cap  3636   c  is disposed over the distal end  3636   d  of the tubular shaft  3636 , and a distal end  3932   d  of each elongate member  3632  is attached to the cap  3636   c  by a suitable technique (e.g., adhesive, welding, etc.), such that disengaging the cap  3636   c  and pulling the cap  3636   c  from the tubular shaft  3636  allows the elongate members  3632 , and associated hook tabs  3632   h,  to be pulled through the tubular shaft  3636  and removed from the delivery system. 
     Turning again to  FIGS. 36A and 36B , it can be seen that by pushing a distal end  3614   d  of the inner member  3614  against proximal end  3636   p , the engagement device  3603  may be advanced through the loading member  3630  (with the keyways in the funnel acting as guides for the engagement feature  3632   e  (e.g., hook tabs), valve  3619 , handle  3618 , and through at least a portion of the length of the outer delivery sheath (not shown). 
     In an alternative embodiment, a hollow inner member  3814  may be employed and a stylet may extend from a proximal end (not shown) of the hollow inner member  3614 , through the hollow inner member  3614 , out of a distal end  3614   d  of the hollow inner member  3614  and into contact with the engagement device  3603 , thereby maintaining a longitudinal spacing between the distal end of the hollow inner member  3614  and the engagement device  3603 . A stylet interface (e.g., a receptacle) analogous to that used with capsule  3842  in  FIG. 39A  described above may be provided in the engagement device  3603  to ensure proper engagement between the stylet and the engagement device  3603 . 
     As the engagement device  3603  is advanced, the engagement features  3632   e  engage and pull the scaffold through the loading member  3620 , valve  3619 , handle  3618 , and a portion of the length of the outer delivery sheath (not shown). Advancement of the scaffold  3620  and inner support segment  3614   s  through the funnel  3630  causes the scaffold  3620  to be compressed onto the inner support segment  3614   s  to a diameter suitable for advancement into the valve  3619 , handle  3618 , and outer delivery sheath. As previously discussed, the scaffold  3620  may have a higher force of friction when in contact with the material provided on an outer surface of the inner support segment  3614   s  than it does when in contact with the material provided on an inner surface of the outer delivery sheath, allowing the support segment  3614   s  to pull the scaffold  3620  along with the support segment  3614   s  when the support segment  3614   s  is moved in either a proximal or a distal direction relative to the outer delivery sheath, such that advancement/retraction of the inner support segment  3614   s  causes advancement/retraction of the scaffold  3620 . Alternatively or in addition, movement of the scaffold  3620  may be coordinated with movement of the elongate inner member  3614 , for example, by providing one or more retention features on the inner support segment  3614   s  (e.g., steps, bumps, hooks, barbs, rings, etc.) that engage at least a portion of the scaffold  3620 . In some embodiments, the plurality of longitudinal pathways formed in the luminal surface  36301   s  of the loading member  3630  are in the form of grooves which have a depth that gradually diminishes as one approaches the distal end of the loading member  3630 , causing the engagement features to draw radially inwards, thereby facilitating distal movement of the engagement features  3632   e  from the loading member  3630 . 
     Once the distal end  3636   d  of the tubular shaft  3636  emerges from a distal end of the outer delivery sheath (not shown), the cap  3636   c  can be removed from the distal end  3636   d  of the tubular shaft  3636 . Because each elongate member  3632  is attached to the cap  3636 c, the elongate members  3632  can be pulled from the tubular shaft  3636  by means of the cap  3636   c,  while at the same time maintaining the position of the tubular shaft  3636  within the outer delivery sheath as the cap  3636   c  and elongate members  3632  are removed. After removal of the cap  3636   c  and elongate members  3632 , the tubular shaft  3636  can be removed from the outer delivery sheath as well. 
     In other embodiments, a scaffold may be selected which can be wrapped around a loading member and inserted into a delivery lumen of a delivery device, after which the loading member is disengaged from the scaffold. Referring to  FIG. 13A , a scaffold  1320  may be flattened and rolled around a loading member in the form of a solid or tubular elongate member  1330  in an overlapping folded manner, after which the scaffold  1320  and loading member  1330  are loaded into a delivery lumen in an delivery sheath  1312 . After the loading member  1330  and scaffold  1320  are loaded into the delivery sheath  1312  (from either the proximal or the distal end of the delivery system), the loading member  1330  may be removed. Upon deployment (e.g., using a suitable pusher member), the scaffold  1320  will unfurl, allowing controlled expansion at a targeted deployment location. 
     In a related embodiment, and with reference to the cross-section shown in  FIG. 13B , a scaffold  1320  may be loaded onto a loading member comprising a pair of tines  1330   t   1 ,  1330   t   2  such that one tine  1330   t   1  is placed in the lumen of the scaffold  1320  and the other tine  1330   t   2  placed on the outside of the scaffold  1320 . The scaffold  1320  may then be flattened and wrapped around the tines  1330   t   1 ,  1330   t   2  of the loading member, or the tines  1330   t   1 ,  1330   t   2  of the loading member may be rotated to wind up the scaffold  320 , such that the scaffold  1320  is wrapped around the tines  1330   t   1 ,  1330   t   2  in an overlapping manner as shown in  FIG. 13B . The scaffold may be subsequently loaded into a delivery lumen of a delivery catheter  1312 , after which the loading member may be removed from the scaffold. 
     Other aspects of the disclosure pertain to catheters and delivery systems that are useful in the deployment of scaffolds in a sinus cavity of a patient. 
     In various embodiments, an external guide catheter is employed for navigation and positioning of the scaffold. In these embodiments, the delivery system may include a) a guide catheter comprising a guide catheter lumen, (b) a delivery catheter comprising a sheath with a delivery lumen (e.g., associated with an outer sheath), where the delivery catheter is dimensioned to be inserted through the guide catheter, and (c) a scaffold that is adapted to be placed into and delivered from the delivery lumen. An external guide catheter may be useful, for example, in accessing the sinus space and providing cannulation and access to smaller or more difficult to reach regions of the sinus. In certain embodiments, the external guide catheter may be provided with increased stiffness to allow for manipulation of surrounding tissue and to provide an unimpeded channel for sinus access. A delivery catheter containing a scaffold may then be routed through this guide catheter lumen for direct access to the treatment area within the sinus. Such a system may enable access to occur with minimal tissue removal. 
     In various embodiments, catheters are provided which comprise a sheath having a section with a shape memory (referred to herein as a “shape-memorized section”) such that the section has a curvature when the sheath is in an unconstrained state. The shape-memorized section may have a curvature that ranges, for example, from 0 to 135 degrees, among other values. The curvature of the shape-memorized section may correspond to an arc having a length that ranges, for example, from 1 to 50 mm, among other possible values. 
     In certain embodiments, the catheter is a guide catheter and the sheath is a guide sheath that comprises a guide lumen through which a delivery catheter may be advanced. The guide sheath may be pre-formed to a specific curved geometry to allow access to challenging locations within the sinus. 
     In certain embodiments, the catheter is a delivery catheter and the sheath is a delivery sheath that comprises a delivery lumen from which a scaffold may be delivered. The delivery sheath may be pre-formed to specific curved geometries to allow access to sinus ostia. In this way, each ostium may have a dedicated form to support access. The delivery sheath may be provided with sufficient stiffness to allow for tissue manipulation and allow access without removing tissue. 
     One catheter of this type is shown in  FIG. 5D  (previously described), which illustrates a delivery catheter  510  having a delivery sheath  512 . The delivery sheath  512  has a shape-memorized section  512   s  that has a curvature when the sheath is in an unconstrained state. The curved shape-memorized section  512   s  in the embodiment shown is approximately 80 degrees. 
     In certain embodiments, delivery systems are provided that include a linear elongate member (e.g., a wire or rod) that is configured for insertion into and removal from a lumen of the sheath having a curved shape-memorized section. The linear elongate member is of sufficient stiffness such that, when inserted into a lumen (e.g., delivery lumen, guide lumen, etc.) of the sheath the curvature of the shape-memorized section is substantially eliminated. The elongate member may also be pulled proximally, thereby allowing the shape-memorized section to bend and provide access accordingly. 
     In various embodiments, catheters (e.g., guide catheters, delivery catheters, etc.) are provided which comprise a sheath that is configured to be custom bent to a curvature that is dependent upon user preference. For example, with reference to  FIG. 14 , a stiff, malleable metal braid  1412   b,  such as a braid formed from nitinol, may be incorporated onto and/or into a catheter sheath  1412 . The use of such a sheath  1412  allows the catheter to be bent and manipulated on demand by a health care provider. The metal braid  1412   b  may also act to resist kinking in the sheath  1412 . 
     In various embodiments, the above-described catheters may be provided with an additional lumen in addition to the lumen previously described (e.g., delivery lumen, guide lumen, etc.). 
     The additional lumen may be configured to receive, for example, a stiff elongate member (e.g., a wire or rod) such that insertion of the elongate member into the lumen changes the shape of the catheter. For example, insertion of the elongate member may straighten a non-linear/curved delivery catheter or guide catheter. Conversely, insertion of an elongate member comprising a curved section may be used to provide a custom bend in an otherwise substantially linear delivery catheter or guide catheter. In some embodiments, the elongate member may be configured to be custom bent, depending on user preference. 
     The additional lumen may be configured to receive, for example, an illumination fiber or a scope for direct visualization (e.g., a fiber-optic-based fiberscope, which may further comprise a suitable illumination system). 
     In various embodiments, each of the preceding catheters may be provided with a stiffness gradient. For example, the catheter may have a stiffness gradient wherein stiffness decreases in a proximal-to-distal direction. This may, for example, allow for atraumatic navigation of the delivery system to more challenging sinus locations, by allowing the end of lower stiffness to be advanced while reducing risk of tissue damage or perforation. As another example, the catheter may have a stiffness gradient wherein stiffness increases in a proximal-to-distal direction. For example, the catheter may include a malleable metal (e.g., in the form of a metal braid) to allow the user to bend and manipulate the distal tip geometry for customized access. 
     A stiffness gradient may be provided through multitude of means, including braid variation, variable extrusion, variable diameters, varying wall thicknesses, or by adhering varying stiffness materials (e.g., by heat bonding or using a suitable adhesive) along the length of the catheter, among other techniques. 
     In various embodiments, the above-described catheters may be provided with a mechanism whereby an outer catheter sheath (e.g., guide sheath, delivery sheath, etc.) may be rotated relative to a handle. For example, with reference to  FIGS. 15A and 15B , the outer sheath  1512  of a delivery catheter may be anchored to a handle  1518  in a way such that thumb manipulation can be used to steer the tip of the delivery system. Examples of thumb control mechanisms include a left/right toggle switch  1519   t  ( FIG. 15A ) or a rotating band  1519   b  ( FIG. 15B ) each of which can transmit rotational force to the outer sheath  1512 . In other embodiments, the thumb manipulation may be used to advance or retract inner support members or any layer of sheaths within the system. Systems of this type may be used, for example, in conjunction with catheters having a pre-formed curvature or an adjustable curvature to allow for navigational flexibility. 
     Other aspects of the disclosure pertain to catheters and delivery systems in which a distal end of an outer sheath of the delivery system is folded back over itself. 
     Referring to  FIG. 16 , a delivery system may be provided comprising an elongate inner member  1614  and a flexible outer sheath  1612 , a distal end of which is folded into itself forming a region of double outer sheath thickness  1612   r  at a distal end of the delivery system. The region of double outer sheath thickness  1612   r  comprises an inner layer  1612   i  and an outer layer  1612   o  and forms a delivery lumen that is dimensioned to receive a radially self-expandable scaffold  1620 . The inner layer  1612   i  of the outer sheath  1612  is anchored at point  1612   p  to a distal end of the elongate inner member  1614 , which can provide a mechanical stop for the expandable scaffold  1620 . By proximately pulling back the outer layer  1612 o relative to the elongate inner member  1614 , or by distally advancing the elongate inner member  1614  distally relative to the outer layer  1612   o,  or both, the sheath  1612  is rolled back such that the region of double thickness  1612   r  gradually shortens and the scaffold  1620  that is radially constrained within the region of double thickness  1612   r  is gradually released. In some embodiments, the outer sheath  1612  may not continue for the entire length of the delivery system. In this case, the outer sheath  1612  may be, for example, pulled back to release the scaffold by attachment to a member such as a collar which is then proximately pulled back by a wire or wires, an outer braid or other suitable means. Suitable materials for the sheath include flexible materials with a relatively low coefficient of friction, for example, a fluoropolymer such as polytetrafluoroethylene, among other potential materials. 
     Other aspects of the disclosure pertain to delivery systems in which at least one filament (e.g., a string, suture, thread, wire, tape, ribbon, strip, etc.) is used to deploy a self-expanding scaffold. 
     In some embodiments, and with reference to  FIG. 18A , a filament  1815  may be used to secure a rolled outer sheath  1812  at a distal end of the delivery device. The rolled outer sheath  1812  contains the scaffold  1820  to be delivered. Pulling on the filament  1815  in a proximal direction releases the portion of the outer sheath  1812  secured by the filament  1815 , allowing the scaffold  1820  to expand into the deployment space without pushing or pulling of either an inner member (not shown) or the sheath  1812  itself. 
     In other embodiments, the filament itself may be used to secure the scaffold in a radially contracted state. For example, and with reference to  FIG. 18B , a filament  1815  in the form of a knit may be used to secure and maintain the scaffold  1820  in a compressed state at the distal end of the delivery system. The ends of the knitted filament  1815  may be routed to the user, for example, along the outside of the delivery system, down a dedicated lumen within the delivery system, or inside an outer sheath of the delivery system, among other options. Pulling the filament(s) in the proximal direction releases the scaffold to the target space. 
     As another example, the filament may be used to decrease and/or crimp the diameter of a scaffold for loading in a delivery system and for eventual deployment in a subject. With reference to  FIGS. 19A-19B  (a schematic side view is shown in  FIG. 19A  and a schematic end view is shown in  FIG. 19B ), one or more filaments  1915  may be woven through the distal end and/ or proximal end of a scaffold  1920  allowing the scaffold  1920  to be collapsed uniformly. As shown in  FIG. 19C , the scaffold  1920  may be crimped onto an elongate inner member  1914  and the inner member  1914  and scaffold  1920  disposed within an outer sheath  1912 . At the time of deployment, the outer sheath  1912  is pulled back. The one or more filaments  2115  may, for example, be cut by a feature provided on the outer sheath  1912  as it is pulled back, or the filament(s)  1915  may be routed back through the delivery system such that an operator can pull on the filament(s)  1915  to release the scaffold  1920  from the inner member  1914  in a fashion analogous to that previously discussed. 
     Turning now to  FIG. 19D , a schematic partial cross-sectional side view of a distal end of a delivery system is shown during a process of scaffold loading. As seen from this  FIG. 19D , the system includes a scaffold  1920  disposed around an elongate inner member  1914  having a lumen  19141 . Two proximal filaments  1915 p are woven through the proximal end of scaffold  1920  and two distal filaments  1915   d  are woven through the distal end of scaffold  1920 . Proximal filaments  1915 p are routed through proximal apertures  1914   p  formed in the elongate inner member  1914  wall, into the elongate inner member lumen  1914   l,  and back through the delivery system. Similarly, distal filaments  1915   d  are routed through distal apertures  1914   d  formed in the elongate inner member  1914  wall, into the elongate inner member lumen  1914   l,  and back through the delivery system.  FIG. 19F  is a schematic end view illustrating the elongate inner member tip  1914   t,  scaffold  1920  and distal filaments  1915   d  of  FIG. 19D , and showing the distal filaments  1915   d  woven around nodes of scaffold  1920 . This allows for even tensioning of distal filaments  1915   d  while reducing the number of distal filaments  1915   d  employed. Turning now to  FIG. 19E , a schematic partial cross-sectional side view of the distal end of the delivery system of  FIG. 19D  is shown, after pulling the filaments  1915   p,    1915   d  proximally and placing the filaments  1915   p,    1915   d  in tension, which acts to elongate the scaffold  1920  and compress the scaffold  1920  onto the elongate inner member  1914 , thereby placing the scaffold into a configuration suitable for delivery. After being positioned at a target site in a subject, the scaffold may be allowed to self-expand by removing the tension placed on the filaments  1915   p,    1915   d  and delivery may be completed by releasing the filaments  1915   p,    1915   d  from the scaffold (e.g., as previously discussed) and withdrawing the delivery system from the subject. 
       FIG. 19G  is a schematic partial cross-sectional view of an alternate embodiment of the distal tip  1914 t for the elongate inner member  1914  in  FIG. 19E  (filaments  1915   p,    1915   d  not shown). 
     In some embodiments, one or more filaments may be employed to pull the scaffold out of a pocket formed at the distal end of the delivery catheter. In one specific example illustrated in  FIGS. 17A and 17B  a delivery device  1710  is provided having an elongate delivery member  1714  with a pocket  1714   p  formed in a distal end thereof. The scaffold  1720  is disposed in the pocket  1714   p  during delivery. An expulsion member  1717  (e.g., a movable component in the form of a disc, ring, etc.) is disposed proximal to the scaffold  1720  in the pocket  1714   p , and attached to the expulsion member  1717  are one or more filaments  1715  (e.g., strings, sutures, threads, wires, lengths of tape, ribbons, strips, etc.), which are routed out of the distal end  1714   d  of the delivery member  1714  where they reverse direction. In various embodiments, the filaments  1715  (or extensions thereof) extend to the proximal end (not shown) of the delivery member  1714 , allowing the filaments  1715  to be actuated (i.e., pulled) by a user. In the embodiment shown, by pulling the filaments  1715  in a proximal direction as shown by the arrows in  FIG. 17B , the expulsion member  1717  advances distally and delivers the scaffold  1720  from the pocket  1720   p  and into a targeted delivery area. The delivery catheter  1710  may be used independently, as shown, or may be used in conjunction with a guide catheter as previously described herein. The filaments  1715  extend along an outside surface of the delivery member  1714  in the embodiment shown. However, in other embodiments, the elongate flexible members  1715  may be routed through one or more channels or grooves that are formed in the surface of the delivery member  1714  or through one or more internal lumens that are formed within the delivery member  1714  (not shown). Although the one or more filaments  1715  are attached to an expulsion member  1717  in the embodiment shown, in other embodiments, the one or more filaments  1715  may be temporarily attached to a proximal end of the scaffold  1720  to affect delivery. 
     In another embodiment, a tubular membrane is substituted for all or part of the length of the filaments  1715 . The tubular membrane may be closed or open at the distal-most end. In one particular embodiment, the distal-most portion of the tubular membrane may be closed and may be folded back into the pocket  1720   p  and around the scaffold  1720 . The proximal end of the tubular membrane may be connected to one or more filaments extended to the proximal end of the delivery member. The user may deliver the scaffold  1720  by pulling on the filaments which in turn pulls the membrane out of the pocket  1720   p , thereby delivering the scaffold  1720 . 
     In other aspects of the present disclosure, elongate inner and outer members are employed to longitudinally lengthen, and thus radially contract a self-expanding braided scaffold. In one specific example illustrated in  FIGS. 20A and 20B , a delivery device  2010  is shown disposed within a guide catheter or other access sheath  2011 . The delivery device  2010  includes (a) an elongate outer sheath  2012  having an attachment feature (e.g., attached hooks  2012   h ) and (b) an elongate inner member  2014  having an attachment feature as well (e.g., attached hooks  2014   h ), the elongate inner member  2014  being at least partially disposed within the elongate outer sheath  2012 . An expanded scaffold  2020  is shown in  FIG. 20A , with hooks  2012   h  and  2014   h  reversibly attached to opposing ends of the scaffold  2020 . Hooks  2012   h  and  2014   h  are hinged or are flexible such that when the elongate inner member  2014  is advanced while maintaining the position of the outer sheath  2012  and/or when the elongate outer sheath  2012  is retracted while maintaining the position of the elongate inner member  2014 , the scaffold  2020  increases in length and decreases in diameter, such that the scaffold  2020  collapses onto the elongate outer sheath  2012  as shown in  FIG. 20B . The scaffold  2020  may be released by reversing the process (i.e., by retracting the elongate inner member  2014  while maintaining the position of the elongate outer sheath  2012  and/or by advancing the elongate outer sheath  2012  while maintaining the position of the elongate inner member  2014 ). Although the catheter  2010  is configured such that the scaffold  2020  collapses onto the elongate outer sheath  2012  in the embodiment shown in  FIGS. 20A and 20B , in other embodiments, the outer sheath  2012  does not extend distally beyond hooks  2012   h,  such that the scaffold  2010  collapses onto the elongate inner member  2014 . 
     Other aspects of the disclosure pertain to delivery systems in which a spiral (e.g., helical) scaffold is delivered. In some embodiments, and with reference to  FIG. 21 , the delivery system may comprise (a) a spiral scaffold  2120  having a distal end  2120   d  and a proximal end  2120   p  and (b) delivery catheter comprising (i) an outer member  2112  having a distal end and an outer member attachment feature  2112   a  proximate the outer member  2112  distal end and (ii) an inner member  2114  having a distal end and an inner member attachment feature  2114   a  proximate the inner member  2114  distal end, wherein the inner member attachment feature  2114   a  is adapted to become attached to the scaffold distal end  2120   d  and the outer member attachment feature  21  Ila is adapted to become attached to the scaffold proximal end  2120   p . Once the inner member attachment feature  2114   a  is attached to the scaffold distal end  2120   d  and the outer member attachment feature  2112   a  is attached to the scaffold proximal end  2120   p , rotation of the outer member  2112  relative to the inner member  2114  in the direction shown results in contraction of the spiral scaffold  2120  and rotation of the outer member  2112  relative to the inner member  2114  in the opposing direction results in expansion of the spiral scaffold  2120 . 
     Thus, the delivery system shown provides a means for anchoring and delivering a spiral scaffold  2120  design. In the design shown in  FIG. 21 , the inner member is in the form of an inner sheath  2124  and the inner member attachment feature is in the form of an anchoring hook  2114   a  which hooks a loop formed at the distal end  2120   d  of the scaffold  2120 . The outer member, on the other hand, is in the form of an outer sheath  2112  and the outer member attachment feature is in the form of an anchoring hook  2112   a  which hooks a loop formed at the proximal end  2120   p  of the scaffold  2120 . By turning the outer sheath  2112  in the same direction as the spiral wrap of the scaffold  2120 , the scaffold  2120  can be tightened around the outer diameter of the inner member  2114 . For deployment, rotating the outer sheath  2112  against the direction of the spiral will allow the scaffold  2120  to release in the target implant location. The hooks  2112   a,    2114   a  disengage after the outer member has been rotated to the point where surrounding tissue is contacted and expansion of the scaffold  2120  ceases. 
     Still other aspects of the disclosure pertain to delivery systems in which a distal anchoring device is used to assist with scaffold delivery. In these aspects, and with reference to  FIG. 22  a balloon  2218  may be inflated in a sinus  2240  on a distal side of a desired implantation site (e.g., distal to a sinus ostium). The balloon provides an anchor and a tracking point for implant delivery, and a flexible tracking member  2219  is routed to the exterior section of the nasal cavity. A loaded delivery system  2210  may then be routed over the tracking member  2219  for delivery of the implant near or at the ostia. A loaded delivery system  2210  may comprise a soft trackable distal section in some embodiments, After scaffold delivery, the unloaded delivery system may be removed, followed by deflation of the balloon and withdrawal of the anchoring device. 
     Other aspects of the present disclosure pertain to systems in which a scaffold is released, followed by balloon expansion within the scaffold. Balloons for use in conjunction with this aspectof the present disclosure may have an inflated diameter ranging, for example, from 4 mm to 25 mm, for example, ranging from 4 mm to 7 mm for smaller sinus spaces and ranging from 18 mm to 22 mm for larger sinus spaces (e.g., the ethmoid post-surgical space), among other sizes. In certain embodiments, (e.g., a scaffold is deployed in a post-surgical spaces of irregular geometry, for instance, the ethmoid post-surgical space), it may be desirable to employ a compliant balloon such that the balloon can better conform to the irregular geometry of the space. In other embodiments, it may be desirable to employ a non-compliant balloon, thereby allowing higher pressures to be employed. 
     In one specific example illustrated in  FIG. 23 , a delivery assembly  2310  is shown which includes an outer sheath  2312  having a distal end  2312   d , and a balloon catheter comprising a balloon  2318  having a proximal end  2318   p  and a distal end  2318   d  disposed within an outer delivery sheath  2312 . A scaffold  2320  is disposed on an outer surface of the balloon  2318  within the outer delivery sheath  2312 . While the length of the balloon  2318  is significantly greater than that of the scaffold  2320  in the embodiment shown, in other embodiments the length of the scaffold  2320  and balloon  2318  may be more closely matched. Also included in the embodiment shown is a stiff support tube  2312   r  which is provided within the outer delivery sheath  2312  and which provides stiffness support for the outer delivery sheath  2312  over a proximal portion of its length. In this embodiment, the scaffold  2320  has a higher force of friction when in contact with the material provided on the outer surface of the balloon  2318  than it does when in contact with the material provided on the inner surface of the outer delivery sheath  2312 , allowing the balloon  2318  to advance the scaffold  2320  out of a distal end  2312   d  of the outer sheath  2312 , followed by inflation of the balloon  2318 . In this regard, it is noted that the excess length of the balloon  2318  in the embodiment shown increases the tolerance of the system to any slippage that may occur between the balloon  2318  and stent  2310 . 
     In another specific example illustrated in  FIGS. 23A-23D , a delivery assembly  2310  is shown which includes (a) a balloon catheter comprising a balloon  2318  and an outer sheath  2312 , (b) an elongate inner member  2314  disposed within the balloon  2318  and the outer sheath  2312  of the balloon catheter, the elongate inner member  2314  having an enlarged tip  2314   t  and being used to provide access to the delivery site, and (c) a containment sheath  2319  disposed at least partially around a scaffold  2320  and maintaining the scaffold  2320  in a compressed state, when the scaffold  2320  is positioned on the balloon  2318  as shown. In order to assist with its removal, the containment sheath  2319  may be provided with a removal tab  2319   t  and may snap onto and extend only partially around the outer sheath  2312 , as shown in a side view in  FIGS. 23A and 23B  and in an end view in  FIG. 23D . 
     During a delivery procedure, once the tip  2314   t  of the elongate inner member  2314  is positioned at a desired target location, the outer sheath  2312 , balloon  2318 , scaffold  2320  and containment sheath  2319  may be advanced over the elongate inner member  2314 , at which point the containment sheath  2319  may be removed from the assembly  2310 , for example, by gripping removal tab  2319   t  and pulling the containment sheath  2319  proximally as shown in  FIG. 23B . By pulling the containment sheath  2319  upward, the containment sheath  2319  may be removed from the outer sheath  2312  if desired. Once the containment sheath  2319  is pulled from the scaffold  2320 , the scaffold self-expands (the scaffold  2320  is shown in a partially expanded state in  FIG. 23B ). After the containment sheath  2319  is pulled from the scaffold  2320 , the balloon  2318  may be inflated to maximize conformance between the scaffold  2320  and surrounding tissue  2340 , as shown in  FIG. 23C . Although the containment sheath  2319  in  FIGS. 23A-23D  does not completely surround the outer sheath  2312 , in other embodiments, the containment sheath  2319  may be configured to completely surround the outer sheath  2312 , in which case the containment sheath  2319  is pulled proximally to allow self-expansion of the scaffold  2320  and inflation of the balloon  2318 . 
     In simplified embodiment, a delivery assembly  2010  like that illustrated in  FIGS. 23A-23D  is provided, except that there is no elongate inner member  2314 , in which case the balloon catheter serves as the innermost member. 
     In a further simplified embodiment, a delivery assembly  2010  like that illustrated in  FIGS. 23A-23D  is provided, except that there is no elongate inner member  2314  and containment sheath  2319 . In such an embodiment, the scaffold  2310  may be crimped on the balloon  2318 , holding it in place. 
     Other aspects pertain to systems in which a balloon is initially used for dilation followed by scaffold release. 
     In one specific example illustrated in  FIGS. 24A-24C , a delivery system  2410  is shown which includes (a) a balloon catheter comprising a catheter shaft  2412  (distal-most portion shown only) having a central lumen and an annular inflation lumen, a balloon  2418  having an inner balloon surface  2418 s, and an inner ring  2417 , (b) a scaffold  2420 , which is expanded against the inner balloon surface  2418 s and is disposed distal to the inner ring  2417 , and (c) an elongate inner member  2414  positioned within the catheter shaft  2412 , balloon  2418 , inner ring  2417  and scaffold  2420 . During a delivery procedure, once the tip of the elongate inner member  2414  is positioned at a desired target location, the catheter shaft  2412 , balloon  2418 , inner ring  2417  and scaffold  2420  may be advanced over the elongate inner member  2414 , with the inner ring  2417  ensuring that the scaffold  2420  advances with the balloon  2418 , at which point the balloon may be expanded as shown in  FIG. 24B . The balloon  2418  is then deflated and the balloon catheter, including the outer sheath  2412 , balloon  2418  and inner ring  2417 , is withdrawn distally, resulting in deployment and expansion of the scaffold  2420  at the desired target location. The scaffold  2420  may be maintained at the delivery location while the balloon catheter is withdrawn, for example, by one or more retention features on the elongate inner member  2414 . Such retention features may include steps, bumps, hooks, barbs, or rings that engage the at least a portion of the scaffold  2420  (e.g., a distal end of the scaffold  2420 ) to maintain positioning during retraction of the balloon  2418 , among other possibilities. 
     In another specific example illustrated in  FIGS. 25A-25D , a delivery assembly  2510  is shown which includes (a) a balloon catheter comprising a balloon  2518  and catheter shaft  2512  (distal-most portion shown only) having a central lumen and an annular inflation lumen, (b) an elongate inner member  2514  disposed within the balloon  2518  and central lumen of the catheter shaft  2512 , and (c) a containment sheath  2519  disposed at least partially around the scaffold  2520 , which scaffold  2520  is positioned adjacent the balloon  2518  as shown. As best seen from the perspective view shown in  FIG. 25D , the containment sheath  2519  comprises a first portion  2519 s that corresponds to the position of the scaffold  2520  and maintains the scaffold  2520  in a compressed state, a second portion  2519 b that corresponds to the position of the balloon  2518  and a third portion  25190  that corresponds to the position of the outer sheath  2512 . As with the embodiment of  FIGS. 23A-23C , in order to assist with its removal the containment sheath  2519  may be provided with a removal tab  2519   t  and may snap onto and extend only partially around the outer sheath  2512 . 
     During a delivery procedure, once the tip of the elongate inner member  2514  is positioned at a desired target location, catheter shaft  2512 , balloon  2508 , scaffold  2520  and containment sheath  2519  may be advanced over the elongate inner member  2514  to the target location, at which point the balloon  2518  may be expanded as shown in  FIG. 25B . Due to the fact that the second portion  2519   b  that corresponds to the location of the balloon  2518  is of small cross-section, the balloon  2518  may be expanded in the presence of the containment sheath  2519  without disrupting the ability of the containment sheath  2519  to maintain the scaffold  2520  in a compressed state. Upon deflation of the balloon  2518 , catheter shaft  2512 , balloon  2508 , scaffold  2510  and containment sheath  2519  may be retracted by a length approximately equal to the length of the balloon  2518 , thereby aligning the scaffold  2820  with the sinus tissue previously expanded by the balloon  2518 . At this point, the containment sheath  2519  may be removed from the assembly  2510 , for example, by gripping removal tab  2519   t  and pulling the containment sheath  2519  proximally. As the containment sheath  2519  is removed from the scaffold  2520 , the scaffold self-expands as shown in  FIG. 25C  and is released, at which point all remaining components of the delivery system  2510  may be withdrawn from the subject. Alternatively, upon deflation of the balloon  2518 , catheter shaft  2512 , balloon  2508 , and containment sheath  2519  may be retracted, leaving scaffold  2520  in place for placement distal to the balloon dilation  2518 . 
     In still other embodiments, a containment sheath may be employed for delivery without an accompanying balloon catheter. For example, in one specific example illustrated in  FIGS. 26A-26B , a delivery system  2610  is shown which includes (a) an elongate inner member  2614  having reduced diameter region  2614 r and an enlarged tip  2614 t that may be used to provide access to a delivery site and (b) a containment sheath  2619  disposed at least partially around a scaffold  2610 , which is positioned in a recess formed by the reduced diameter region  2614 r in the embodiment shown. In order to assist with its removal, the containment sheath  2619  may be provided with a removal tab and may snap onto and extend only partially around the elongate inner member  2614  (e.g., as discussed previously in conjunction with  FIGS. 23A-23D ). During a delivery procedure, once the tip  2614 t of the elongate inner member  2614  is positioned at a desired target location, containment sheath  2619  may be withdrawn, for example, by gripping and pulling the containment sheath  2619  proximally. Once the containment sheath  2619  is pulled away from the scaffold  2620 , the scaffold  2620  self-expands as shown in  FIG. 26B . Although the containment sheath  2619  in  FIGS. 26A-26B  completely surrounds the elongate inner member  2614  in the particular embodiment shown, in other embodiments, the containment sheath  2619  may be configured to only partially surround the elongate inner member  2614 . Additionally, the elongate inner member  2614  may be flexible or rigid, and may be pre-shaped, for example, having a curve suitable for providing access to sphenoid, frontal, and/or maxillary sinuses. This embodiment may also be used in conjunction with an access sheath or guide catheter, among other possibilities. 
     In another embodiment illustrated in  FIG. 27A and 27B , a distal end of a delivery system  2710  is shown, which contains a delivery member  2714  that includes an elongate inner member  2714 e, a surrounding portion, for example, a hollow cylindrical portion  2714   c , and a distal tip  2714 t, wherein the elongate inner member  2714   e  and cylindrical portion  2714   c  together form an annular cavity  2714   a . The elongate inner member  2714   e  is positioned within a lumen of an intermediate elongate member  2718 , and a scaffold  2720  is compressed within the annular cavity  2714   a , with an inner (luminal) surface of the scaffold in contact with an outer surface of the a distal section of the intermediate elongate member  2718  and an outer (ablum nal) surface of the scaffold in contact with a radially-inward-facing surface  2714   c  r of the cylindrical portion  2714   c  of the delivery member  2714 . The system  2710  further includes a delivery sheath  2712  having a distal end  2712   d . The elongate inner member  2714   e  of the delivery member  2714  and the intermediate elongate member  2718  together extend proximally into a lumen  2712   l  of the delivery sheath  2712 . 
     As illustrated in  FIG. 27A , a proximal end  2714   cp  of the cylindrical portion  2714   c  is spaced from the distal end of the sheath  2712   d  thereby creating a gap  2710   g,  in order to facilitate delivery of the scaffold  2720  as described below in conjunction with  FIG. 27B . During delivery, however, the delivery member  2714  and the intermediate elongate member  2718  may be retracted relative to the delivery sheath  2712  (or vice versa) to a point where the proximal end  2714   cp  of the cylindrical portion  2714   c  abuts the distal end  2712   d  of the sheath  2712 , if desired. Once the delivery system is positioned at a target site, the delivery sheath  2712  may be retracted relative to the delivery member  2714  and intermediate elongate member  2718  to provide a gap  2710   g  between the proximal end  2714   cp  of the cylindrical portion  2714   c  and the distal end  2712   d  of the sheath  2712   d  as shown in  FIG. 27A . Subsequently, and with reference to  FIG. 27B , the elongate intermediate member  2718  may be retracted relative to the delivery sheath  2712  and delivery member  2714 , thereby pulling the scaffold  2720  from the annular cavity  2714   a  and allowing it to expand in the gap  2710  between the proximal end  2714   cp  of the cylindrical portion  2714   c  and the distal end of the sheath  2712   d.    
     The scaffold  2720  may be pulled from the annular cavity  2714   a  by various mechanisms. For example, the scaffold  2720  may be pulled from the annular cavity  2714   a  by providing one or more temporary attachment features on the elongate intermediate member  2718 . Such attachment features may include, for example, steps, bumps, hooks, barbs, or rings that engage the at least a portion of the scaffold  2720  (e.g., a distal end of the scaffold  2720 ), among other possibilities. As another example, the scaffold  2720  may be pulled from the annular cavity  2714   a  as a result of friction forces. For instance, the scaffold  2720  may have a higher force of friction when in contact with the material provided on the outer surface of the distal end of the elongate intermediate member  2718  than it does when in contact with the material provided on the radially-inward-facing surface  2714   cr  of the cylindrical portion  2714   c  of the delivery member  2714 . Examples of suitable materials for the outer surface of the distal end of the elongate intermediate member  2718  and examples of materials suitable for the radially-inward-facing surface  2714   cr  of the cylindrical portion  2714   c  are set forth above in conjunction with  FIGS. 8A and 8B . 
     An example of a method for a loading delivery member  2714  like that of FIG. 
       27 A is illustrated in  FIG. 27C , in which a scaffold  2720  is advanced distally through a funnel  2730  thereby reducing the diameter of the scaffold  2720  to that of the annular cavity  2714   a  of the delivery member  2714 . In some instances, the scaffold  2720  may be pushed from its proximal end  2720   p  through the funnel  2730  and into the annular cavity  2714   a , for example, using a pusher member  1136  like that described in conjunction with  FIGS. 11A-11E , among other possibilities. 
     In another embodiment illustrated in  FIG. 28A , a delivery system  2810  is shown, which includes a handle  2832  that comprises a thumb slide  2838  and a thumb wheel  2834 , as well as an delivery sheath  2812  (e.g., a guide catheter) extending from a distal end of the handle  2832  and having a curved section  2812   c,  which may be used to enhance access to a particular target site. The handle  2832  further comprises a loading lumen  2833  with a first region  2833   d   1  having a first diameter, a second region  2833   d   2  having a second diameter, and a tapered region  2833   t  (e.g., in the shape of a frustum) between the first region  2833   d   1  and the second region  2833   d   2  in which the diameter of the lumen  2833  is gradually reduced from the first diameter at a proximal end of the tapered region  2833   t  to the diameter of the second region  2833   d   2  at a distal end of the tapered region  2833   t.  The first diameter may be approximately the same as or greater than an uncompressed diameter of a scaffold  2820  to be delivered. The second diameter may approximately the same as or less than an inside diameter of a lumen  2812   l  of the outer sheath  2812 . In this embodiment, a plurality of loading pins  2836  are employed to advance the scaffold  2820 , 
     In some embodiments, the loading pins  2836  are inserted through openings in the wall of the scaffold  2820  (e.g., between scaffold braids) such that distal advancement of the loading pins  2836  results in distal advancement of the scaffold  2820 . The loading pins  2836  may be advanced, for example, using a suitable mechanism such as a thumb slide  2838  like that shown in  FIG. 28A  through a suitable interface (e.g., a ring) which engages the loading pins and moves them in tandem. One example of such a ring  2837  is shown in dashed lines in the end view of  FIG. 28F . In one alternative embodiment, the thumb slide may correspond to a portion of a sliding ring. To the extent that the loading pins  2836  do not engage ith the elongate inner member  2814 , the elongate inner member  2814  may be advanced independently of the loading pins  2836 , for example, by a thumb wheel  2834  as shown in  FIG. 28A . 
     In some embodiments, the loading pins  2836  are inserted through openings in the wall of the scaffold  2820  and further into the inner member  2814  at a distal end of the inner member  2814  such that distal advancement of the elongate inner member  2814  results in advancement of the loading pins  2836  and scaffold  2820 . 
     In either case, and as seen from the partial side views of  FIG. 28B  and  FIG. 28C  (which simultaneously show the system at two different points in time) and the partial side view of  FIG. 28D , distal advancement of the loading pins  2834  (i.e., in the direction of the arrows in  FIG. 28B ) results in distal advancement of the scaffold  2820 , including distal advancement of the distal end  2820   d  of the scaffold  2820  from the first region  2833   d   1 , through the tapered region  2833   t,  and into the second region  2833   d   2 , thereby compressing the scaffold  2820  onto a support segment  2814   s  that is disposed at the distal end  2814   d  of the elongate inner member  2814 . 
     It is noted that the pins  2836  may travel distally through a variety of longitudinal pathways provided in the handle  2832 . Examples of longitudinal pathways include pathways that comprise longitudinal slots, including simple slots and longitudinal pathways having a T-shaped cross section, among others. 
     After the scaffold  2820  is loaded onto the support segment  2814   s  of the elongate inner member  2814 , the pins  2836  can be removed from the scaffold  2820  and the elongate inner member  2814  by a suitable method. For example, the pins  2836  may be removed manually or mechanically. For instance, with reference to  FIG. 28D , the heads of the pins  2836  may slide through longitudinal pathways in the handle  2832  (the position  2832   p  of the heads of the pins  2836  as they pass through the pathways is shown), wherein the longitudinal pathways allow the heads of the pins  2836  to maintain a constant radial distance from the center of the lumen as the pins  2836  move distally over a first distance d 1  and wherein the longitudinal pathways cause the heads of the pins  2836  to radially diverge from the center of the lumen as the pins  2836  move distally over a second distance d 2 . The result of this divergence is that the pins  2836  become disengaged from the elongate inner member  2814  and scaffold  2820 , which can subsequently be advanced down the lumen  2812   l  of the outer member  2812 , for example, as shown in  FIG. 28E . 
     Advancement of the scaffold  2820  along with elongate inner member  2814  may be brought about, for example, by providing one or more retention features on the distal end of the elongate inner member  2814 . Such retention features may include, for example, steps, bumps, hooks, barbs, or rings that engage at least a portion of the scaffold  2820 , among other possibilities. Advancement of the scaffold  2820  along with elongate inner member  2814  may also be brought about, for example, by as a result of friction forces. For instance, the scaffold  2820  surface may have a higher force of friction when in contact with the material provided on the outer surface of the distal end of the elongate inner member  2814  (e.g., the material on the outer surface of the support segment  2814   s ) than it does when in contact with the material provided on the surface of the lumen  28121  of the outer member  2812 , allowing the support segment  2814   s  to pull the scaffold  2820  along with the support segment  2814   s  when the support segment  2814   s  is moved in either a proximal or a distal direction relative to the outer member  2812  as previously discussed. Alternatively or in addition, movement of the scaffold  2820  may be coordinated with movement of the elongate inner member  2814 , for example, by providing one or more retention features on the inner support segment  2814   s  (e.g., steps, bumps, hooks, barbs, rings, etc.) that engage at least a portion of the scaffold  2820 . 
     A particular embodiment of the disclosure will now be described in conjunction with  FIGS. 29A-29J . Turning to  FIG. 29A , a delivery system  2910  is shown, which includes a loading member shown in two sections,  2932   a  and  2932   b,  which can be used as a handle. Section  2932   a  includes a wheel  2934  whose teeth engage teeth on an elongate inner member  2914  and is used to advance the elongate inner member  2914 . Section  2932   a  also includes a wheel  2938  whose teeth engage teeth on an engagement member  2918  and is used to advance the engagement member  2918 . The engagement member  2918  includes a hollow shaft through which the elongate inner member  2914  extends, and the engagement member  2918  is longitudinally moveable along a portion of the elongate inner member  2914 . 
     Section  2932   b  includes a loading lumen comprising a first region  2933   d   1  having a first diameter, a second region  2933   d   2  having a second diameter, and a tapered region  2933   t  between the first region  2933   d   1  and the second region  2933   d   2  wherein the diameter of the lumen  2933  is gradually reduced from the first diameter at a proximal end of the tapered region  2933   t  to the diameter of the second region  2933   d   2  at a distal end of the tapered region  2933   t.  The distal end of the loading lumen terminates at a lumen of a delivery sheath  2912  (e.g., a guide catheter). Section  2932   b  further includes a plurality of longitudinal pathways in the form slots  2932   s  (better seen in  FIG. 29I ) that extend into the loading lumen in section  2932   b.  Loading pins  2936  are inserted through the slots  2932   s,  through the scaffold  2920  wall and into support segment  2914   s  that is positioned at a distal end of the inner member  2914  (see, e.g.,  FIG. 29J ). 
     As seen from  FIGS. 29A-29F  (which shows the system at six different points in time), distal advancement of the engagement member  2918  using wheel  2938  results in distal advancement of the elongate inner member  2914  (by abutment of the distal end of the engagement member  2918  with the proximal end of the support segment  2914   s  of the elongate inner member  2914 ), which in turn leads to distal advancement of the scaffold  2920  and loading pins  2936  to the distal end of section  2932   b.  Distal advancement of the scaffold  2920  results in radial compression of the scaffold  2920  as it proceeds through the section  2932   b.  Because the slots  2932   s  radially diverge from the central axis of the device  2910  and because the pins  2936  are configured to engage the slots  2932   s  (e.g., by engagement with grooves formed in the shafts of the pins  2936  or by engagement with heads of the pins), as the pins  2936  approach the distal ends of the slots  2932   s,  the pins  2936  also radially diverge from the central axis of the device  2910 , removing the pins  2936  from engagement with the support segment  2914   s  shown in  FIG. 29D . In an alternate embodiment, the pins may be removed manually or through a mechanical release mechanism. 
     Subsequent distal advancement of the elongate inner member  2914  using wheel  2934  leads to advancement of the scaffold  2920  through the delivery sheath  2912  and out the distal end  2912   d  of the delivery sheath  2912  as shown in  FIGS. 29E and 29F . Advancement of the scaffold  2920  along with elongate inner member  2914  may be assured, for example, by providing one or more retention features on the support segment  2914   s  of the elongate inner member  2914 , allowing the support segment  2914   s  to pull the scaffold  2920  along with the support segment  2914   s  as the support segment  2914   s  moves in either a proximal or a distal direction relative to the delivery sheath  2912 . Such retention features may include, for example, steps, bumps, hooks, barbs, or rings that engage at least a portion of the scaffold  2920 , among other possibilities. Advancement of the scaffold  2920  along with support segment  2914   s  may also be assured, for example, by as a result of friction forces. For instance, the scaffold  2920  surface may have a higher force of friction when in contact with the material provided on the outer surface of the support segment  2914   s  than it does when in contact with the material provided on the inner surface of the lumen of the delivery sheath  2912 , allowing the support segment  2914   s  to pull the scaffold  2920  along with the support segment  2914   s  as the support segment  2914   s  moves in either a proximal or a distal direction relative to the delivery sheath  2912 , as previously discussed. Alternatively or in addition, movement of the scaffold  2920  may be coordinated with movement of the elongate inner member  2914 , for example, by providing one or more retention features on the inner support segment  2914   s  (e.g., steps, bumps, hooks, barbs, rings, etc.) that engage at least a portion of the scaffold  2920 . 
     Yet another embodiment of the disclosure will now be described in conjunction with  FIGS. 37A-37D . Turning to  FIGS. 37A-37D , a portion of a scaffold loading system  3700  is shown which includes a handle  3718 , an outer delivery sheath  3212  provided at a distal end of the handle  3718  and an adaptor  3719  (e.g., a Touhy Borst valve with thumb screw closure) provided at a proximal end of the handle  3718 . The assembly  3700  further includes a loading member  3730  having a distal end  2730   d  that is configured to be inserted into the adaptor  3719  such that it is attached to the handle  3718 . The loading member  3730  has a tapered loading lumen  3733  (e.g., a funnel) wherein a diameter of the loading lumen  3733  gradually decreases as one proceeds from the proximal end  3730   p  of the loading member  3730  to the distal end  3730   d  of the loading member  3730 . Loading member  3730  further ncludes a plurality of longitudinal pathways in the form of slots  3730   s  that extend from an exterior of the loading member  3730  into the loading lumen  3733 . While  FIG. 37A  illustrates a separate loading member  3730  and ergonomic handle  3718  connected by an adaptor  3719 , it will be appreciated that in other embodiments, these components can be integrated into a combined funnel and handle, for example, like that shown in  FIG. 38 , if desired. 
     Each loading pin  3736  (three pins  3736  are provided in the embodiment shown) is inserted through a first slot  3732   s,  through a first aperture in the scaffold  3720  wall, around the inner member  3714  or through the inner member  3714  (e g through an aperture formed in the support segment  3714   s  of the inner member  3714 , through a sleeve disposed around the inner member, etc.), through a second aperture in the scaffold  3720  wall opposite the first aperture, and through a second slot  3732   s  opposite the first slot  3732   s.  The loading pins are typically formed from a relatively strong material such as a metal or a polymer of suitable tensile strength. The pins may be, for example, in the form of relatively stiff rod-like members or filaments, such as a sutures, strings, threads or wires. Where it is desired to employ a plurality of loading pins  3736 , in certain embodiments, each loading pin  3736  may pass through the same aperture formed in the support segment  3714   s , whereas in certain other embodiments, each loading pin  3736  may pass through a different aperture formed in the support segment  3714   s , in which case it may be desirable to stagger the loading pins  3736  and apertures at different longitudinal positions along a longitudinal axis, A, of the scaffold loading system  3700 . Also shown is a packaging feature  3739  which may be used to hold the loading pins  3736  in place in the loading member  3730 . 
     The loading pins  3736  may be advanced using any suitable mechanism that engages the loading pins  3736  and moves them in tandem, for instance, a movable ring  3738  in the embodiment shown. Although the loading pins  3736  pass through the ring  3738  at the same longitudinal position in the embodiment shown, in other embodiments, it may be desirable to stagger the loading pins  3736  such that they pass through the ring  3738  at the differing longitudinal positions as noted above. 
     When it is desired to load the scaffold  3720 , the ring  3738  is distally advanced along a length of the loading member  3730  (i.e., in the direction of the arrows in  FIG. 37A ), which in turn leads to distal advancement of loading pins  3736 , scaffold  3720  and inner member  3714  relative to the loading member  3730 , valve  3712 , handle  3718 , and outer delivery sheath  3712 . The ring  3738  is distally advanced along a length of the loading member  3730 , resulting in radial compression of the scaffold  3720  as it proceeds through the tapered loading lumen  3733 , until the loading pins  3637  reach distal ends  3732   sd  of the slots  3732   s,  at which point the scaffold  3720  has been compressed onto the support segment  3714   s  of the inner member  3714 . At this point, the pins may be removed manually or through a suitable mechanical release mechanism. 
     Subsequent distal advancement of the elongate inner member  3714  leads to distal advancement of the scaffold  3720  as previously described. Advancement of the scaffold  3720  along with elongate inner member  3714  may be assured, for example, by providing one or more retention features on the support segment  3714   s  of the elongate inner member  3714 , allowing the support segment  3714   s  to pull the scaffold  3720  along with the support segment  3714   s  as the support segment  3714   s  moves in either a proximal or a distal direction relative to the delivery sheath  3712 . Such retention features may include, for example, steps, bumps, hooks, barbs, or rings that engage at least a portion of the scaffold  3720 , among other possibilities. Advancement of the scaffold  3720  along with support segment  3714   s  may also be assured, for example, by as a result of friction forces. For instance, the scaffold  3720  surface may have a higher force of friction when in contact with the material provided on the outer surface of the support segment  3714   s  than it does when in contact with the material provided on the inner surface of the lumen of the delivery sheath  3712 , allowing the support segment  3714   s  to pull the scaffold  3720  along with the support segment  3714   s  as the support segment  3714   s  moves in either a proximal or a distal direction relative to the delivery sheath  3712 , as previously discussed. Alternatively or in addition, movement of the scaffold  3720  may be coordinated with movement of the elongate inner member  3714 , for example, by providing one or more retention features on the inner support segment  3714   s  (e.g., steps, bumps, hooks, barbs, rings, etc.) that engage at least a portion of the scaffold  3720 . 
     Still other aspects of the disclosure pertain to systems that incorporate a flexible fiberscope, for example, for primary navigation when the location cannot be directly visualized with a traditional scope and approach. In some embodiments, a small fiberscope (e.g., having a diameter of less than 0.30″) may be provided alongside the scaffold delivery system or in a lumen of the delivery system. In some embodiments, a fiberscope is inserted through a centrally located cannula, which provides for delivery of the scaffold around the scope system. This allows for direct visual confirmation and scaffold placement into the tight locations within the sinus and decreases the amount of instrumentation that must be inserted to complete the procedure. 
     Other aspects of the disclosure pertain to systems that incorporate fiber illumination systems, for example, through a center cannula (e.g., ˜0.020″) or other lumen of the delivery system, or along the side of the delivery system. The illumination can provide additional positional feedback to assist with navigation and confirmation of scaffold delivery without significantly impacting trackability. 
     Other aspects of the disclosure pertain to navigation and access that may be utilized during device use, including by not limited to, direct visualization, endoscopic imaging, fluoroscopic imaging, tactile feedback sensors, pressure sensing, or electro-magnetic sensing. 
     Still other aspects of the disclosure pertain to access to the nasal cavity via a short, large diameter introducer, minimizing the impact of anatomical variability that may interfere with ideal access conditions. The introducer may be, for example, in the form of a partial conic section, for example, one having a diameter ranging from 3 to 20 mm and one end and a diameter ranging from 3 to 9 mm at another end. An introducer can be used in conjunction with other access technologies by allowing an expanded access port for additional manipulation and orientation without causing damage or irritation to surrounding nasal tissue. 
     Potential benefits of various aspects described herein include one or more of the following, among others: (a) more controlled loading of scaffold through even application of force across the entire diameter of the scaffold, allowing for consistent crimping of a large scaffold in the delivery system, which translates to more consistent expansion upon delivery, (b) more controlled access and delivery location of the scaffold, resulting in superior control and more precise stent placement within the target location, (c) the use of a combination of both pull and push forces to provide flexibility during deployment, enabling a partial deployment to anchor the scaffold position, followed by controlled deployment into the target space. 
     EXAMPLE 1 
     A human cadaver study was conducted to assess the clinical performance of scaffolds and delivery systems in accordance with the present disclosure in the human anatomy. Device prototypes and delivery system prototypes were integrated to test multiple scenarios within the representative anatomy, both before and after functional endoscopic sinus surgery. Endpoints included visual appearance via endoscopy and clinical feedback. 
     Several small diameter scaffold prototypes are described in Table 1, while two large diameter scaffold prototypes are described in Table 2. These scaffolds are described in detail in “IMPLANTABLE SCAFFOLDS FOR TREATMENT OF SINUSITIS” supra. 
     
       
         
           
               
               
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                   
                   
                   
                 Filament 
                 Braid 
               
               
                   
                 Diameter 
                   
                 diameter 
                 angle 
               
               
                 Entry 
                 (mm) 
                 Filaments 
                 (in) 
                 (deg) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                 1 
                 8 
                 32 
                 0.006″ 
                 127 
               
               
                 2 
                 8 
                 16 
                 0.006″ 
                 127 
               
               
                 3 
                 10 
                 32 
                 0.006″ 
                 127 
               
               
                 4 
                 10 
                 16 
                 0.0065″ 
                 127 
               
               
                 5 
                 10 
                 16 
                 0.0065″ 
                 110 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
               
               
               
               
             
               
                 TABLE 2 
               
               
                   
               
               
                   
                   
                   
                   
                   
                 Filament 
                 Braid 
               
               
                   
                 Mass 
                 Diameter 
                 Length 
                 Fila- 
                 diameter 
                 angle 
               
               
                 Design 
                 (mg) 
                 (cm) 
                 (mm) 
                 ments 
                 (in) 
                 (deg) 
               
               
                   
               
             
            
               
                 2 filament 
                 60 
                 ~3.8 
                 20 
                 2 
                 0.0075″ 
                 50 
               
               
                 braid 
                   
                   
                   
                   
                 twisted 
               
               
                 offset 
               
               
                 4 filament 
                 77 
                 ~3.8 
                 20 
                 4 
                 0.0075″ 
                 70 
               
               
                 braid 
               
               
                 (monofila- 
               
               
                 ment) 
               
               
                   
               
            
           
         
       
     
     Scaffolds were placed in the middle meatus, using delivery systems in accordance with the present disclosure, thereafter providing mechanical force to displace the middle turbinate medially and demonstrating the potential to deliver scaffolds (and any associated drug) to the ethmoid sinuses. Five deployments were conducted: (a) a 16 filament, 8 mm scaffold, (b) a 32 filament, 8 mm scaffold, (c) a 16 filament, 10 mm scaffold, (d) a 32 filament, 10 mm scaffold and (d) a 32 filament, 13 mm scaffold. Although all devices conformed relatively well to the tissues, displacing the middle turbinate medially (MT) and providing outward force on the uncinate process (UP) laterally, the 32 filament, 13 mm scaffold appeared to provide the best fit for the particular space into which it had been implanted.  FIG. 44 , is a photograph illustrating the 32 filament, 13 mm scaffold (length of 10 mm) following deployment in the middle meatus of a human cadaver. The implant conformed well to the tissues with appropriate medialization of middle turbinate. 
     Scaffolds were also placed in the frontal recesses of human cadavers using a delivery system in accordance with the present disclosure. In a first cadaveric specimen, the frontal recess could not be accessed prior to surgical intervention. The ostia to the frontal sinus was approximately 1 mm in diameter and could not accommodate the delivery device. Functional endoscopic sinus surgery (FESS) was conducted to remove ethmoid cells and expand the passage to the frontal sinus. Following this procedure, 32 filament (Table 1, entry  3 ) and 16 filament (Table 1, entry  4 ) devices were deployed into the fontal sinus ostia. Although both devices conformed well to the tissue, 16 filament device appeared to exhibit enhanced conformance for the particular space into which it had been implanted.  FIG. 45  is a photograph illustrating a 16 filament, 10 mm scaffold following deployment the frontal sinus ostia. 
     In a second cadaver, the frontal sinus ostia was accessible prior to surgical intervention. 10 mm, 16 filament devices (n=1 from Table 1, entry  4  and n=1 from Table 1, entry  5 ) were deployed into the frontal sinus before and after FESS, respectively, using a delivery system in accordance with the present disclosure. These devices were appropriately placed from a delivery standpoint, conformed well to the sinus ostia, and were slightly undersized for the space immediately outside the ostia. 
     A 16 filament, 10 mm diameter scaffold, a 4 filament, 38 mm scaffold, a 2 filament, 38 mm scaffold, and a 32 filament, 17.5 mm scaffold were placed the ethmoid sinus of human cadavers following functional endoscopic sinus surgery using a delivery system in accordance with the present disclosure, with the 10 mm diameter scaffold appearing to be undersize for the particular space into which it had been implanted, the 38 mm scaffolds appearing to be oversize for the particular space into which it had been implanted, and with the 17.5 mm scaffold appearing to provide the best fit for the particular space into which it had been implanted.  FIG. 46 , is a photograph illustrating a 32 filament scaffold having a diameter of 17.5 mm and a length of 10 mm after deployment in the ethmoid sinus following FESS. 
     This study utilized 7.5 French and 9 French catheter systems. The 7.5F system was used to access all frontal sinuses, while the 9F system was used for device deployments into the ethmoid sinus. Both catheter diameters were acceptable, and devices functioned appropriately during use. A 90-degree bend was appropriate for reaching the frontal sinus. 
     Although various embodiments are specifically illustrated and described herein, it will be appreciated that modifications and variations of the present disclosure are covered by the above teachings and are within the purview of the appended claims without departing from the spirit and intended scope of the disclosure.