Abstract:
A delivery system for selectively holding and deploying each end of an endoprosthesis includes a spindle having a spindle body. The spindle further includes proximal spindle pins and distal spindle pins extending radially outward from the spindle body. The delivery system further comprises a sleeve and a middle member sleeve. The endoprosthesis includes proximal spindle pin catches and distal spindle pin catches at proximal and distal ends of the endoprosthesis. The distal spindle pins extend into the proximal spindle pin catches and the sleeve radially constrains the proximal end of the endoprosthesis. The proximal spindle pins extend into the distal spindle pin catches and the middle member sleeve radially constrains the distal end of the endoprosthesis. Spindle pins may be omitted at one or both ends of the endoprosthesis, in some configurations.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    This invention relates generally to medical devices and procedures, and more particularly to a method and system of deploying a stent-graft in a vascular system and to the associated stent-graft. 
         [0003]    2. Description of the Related Art 
         [0004]    Prostheses for implantation in blood vessels or other similar organs of the living body are, in general, well known in the medical art. For example, prosthetic vascular grafts formed of biocompatible materials (e.g., Dacron or expanded, porous polytetrafluoroethylene (PTFE) tubing) have been employed to replace or bypass damaged or occluded natural blood vessels. 
         [0005]    A graft material supported by a framework is known as a stent-graft or endoluminal graft. In general, the use of stent-grafts for treatment or isolation of vascular aneurysms and vessel walls which have been thinned or thickened by disease (endoluminal repair or exclusion) is well known. 
         [0006]    Many stent-grafts, are “self-expanding”, i.e., inserted into the vascular system in a compressed or contracted state, and permitted to expand upon removal of a restraint. Self-expanding stent-grafts typically employ a wire or tube configured (e.g., bent or cut) to provide an outward radial force and employ a suitable elastic material such as stainless steel or Nitinol (nickel-titanium). Nitinol may additionally employ shape memory properties. 
         [0007]    The self-expanding stent-graft is typically configured in a tubular shape of a slightly greater diameter than the diameter of the blood vessel in which the stent-graft is intended to be used. In general, rather than inserting in a traumatic and invasive manner, stents and stent-grafts are typically deployed through a less invasive intraluminal delivery, i.e., cutting through the skin to access a lumen or vasculature or percutaneously via successive dilatation, at a convenient (and less traumatic) entry point, and routing the stent-graft through the lumen to the site where the prosthesis is to be deployed. 
         [0008]    Intraluminal deployment in one example is effected using a delivery catheter with coaxial inner tube, sometimes called the plunger, and outer tube, sometimes called the sheath, arranged for relative axial movement. The stent-graft is compressed and disposed within the distal end of the sheath in front of the inner tube. 
         [0009]    The catheter is then maneuvered, typically routed though a lumen (e.g., vessel), until the end of the catheter (and the stent-graft) is positioned in the vicinity of the intended treatment site. The inner tube is then held stationary while the sheath of the delivery catheter is withdrawn. The inner tube prevents the stent-graft from moving back as the sheath is withdrawn. 
         [0010]    As the sheath is withdrawn, the stent-graft is gradually exposed from a proximal end to a distal end of the stent-graft, the exposed portion of the stent-graft radially expands so that at least a portion of the expanded portion is in substantially conforming surface contact with a portion of the interior of the lumen, e.g., blood vessel wall. 
         [0011]    The proximal end of the stent-graft is the end closest to the heart whereas the distal end is the end furthest away from the heart during deployment. In contrast and of note, the distal end of the catheter is usually identified to the end that is farthest from the operator (handle) while the proximal end of the catheter is the end nearest the operator (handle). For purposes of clarity of discussion, as used herein, the distal end of the catheter is the end that is farthest from the operator (the end furthest from the handle) while the distal end of the stent-graft is the end nearest the operator (the end nearest the handle), i.e., the distal end of the catheter and the proximal end of the stent-graft are the ends furthest from the handle while the proximal end of the catheter and the distal end of the stent-graft are the ends nearest the handle. However, those of skill in the art will understand that depending upon the access location, the stent-graft and delivery system description may be consistent or opposite in actual usage. 
         [0012]    Many self expanding stent-graft deployment systems are configured to have the proximal end of the stent-graft deploy as the sheath is pulled back. The proximal end of the stent-graft is typically designed to fixate and seal the stent-graft to the wall of the vessel during deployment. Such a configuration leaves little room for error in placement since re-positioning the stent-graft after initial deployment, except for a minimal pull down retraction, is usually difficult if possible at all. Deploying the proximal end of the stent-graft first makes accurate pre-deployment positioning of the stent-graft critical. 
         [0013]    Attempts to overcome this problem generally fail to provide adequate control in manipulating the stent-graft positioning in both the initial deployment of the stent-graft and the re-deployment of the stent-graft (once the stent-graft has been partially deployed). 
         [0014]    Another problem encountered with existing systems, particularly with systems that have a distal end of a stent-graft fixed during deployment (or during the uncovering of the sheath) is the contact force between the retracting sheath and the stent graft contained therein make it necessary to use more retraction force to cause the stent-graft to axially compress or bunch up as the sheath is retracted. This bunching increases the density of the stent-graft within the sheath and can further increase the frictional drag experienced during deployment. 
       SUMMARY OF THE INVENTION 
       [0015]    A delivery system for an endoprosthesis includes a spindle having a spindle body and spindle pins extending radially outward from the spindle body. The delivery system further includes a tapered tip having a sleeve, the spindle pins extending from the spindle body toward the sleeve. The endoprosthesis includes a proximal anchor stent ring having spindle pin catches and anchor pins. The spindle pins of the spindle extend into the spindle pin catches and the sleeve radially constrains the anchor pins. 
         [0016]    A method of deploying the endoprosthesis includes radially constraining the proximal anchor stent ring of the endoprosthesis in an annular space between the sleeve of the tapered tip and the spindle. The method further includes radially constraining a graft material of the endoprosthesis in a primary sheath, the graft material being attached to a distal end of the proximal anchor stent ring. By radially constraining the graft material of the endoprosthesis by the primary sheath and radially constraining the proximal anchor stent ring by the sleeve, sequential and independent deployment of the graft material and the proximal anchor stent ring is facilitated. 
         [0017]    The primary sheath is retracted to deploy a portion of the endoprosthesis. As the endoprosthesis is only partially deployed and the proximal anchor stent ring is radially constrained and un-deployed, the endoprosthesis can be repositioned in the event that the initial positioning of the endoprosthesis is less than desirable. 
         [0018]    Further, as the proximal end of the endoprosthesis is secured and, in one example, the distal end is free to move within the primary sheath, bunching of the endoprosthesis during retraction of the primary sheath is avoided. By avoiding bunching, of the endoprosthesis on the primary sheath during retraction is minimized thus facilitating smooth and easy retraction of the primary sheath. 
         [0019]    Once the endoprosthesis is properly positioned, the tapered tip is advanced to deploy the proximal anchor stent ring thus anchoring the endoprosthesis in position within the vessel. The anchor pins of the proximal anchor stent ring protrude radially outward and penetrate into the vessel wall, e.g., into healthy strong tissue. 
         [0020]    In accordance with one example, the proximal anchor stent ring of the endoprosthesis includes proximal apexes, distal apexes, and struts extending between the proximal apexes and the distal apexes. The struts, the proximal apexes, and the distal apexes define a cylindrical surface. A pair of the anchor pins is located on the struts adjacent each of the proximal apexes, the anchor pins extending inwards (relative to the curve of the proximal apexes) from inside surfaces of the struts and protruding from the struts radially outward from the cylindrical (outer circumferential) surface. 
         [0021]    By locating the anchor pins inwards, the delivery profile, sometimes called crimped profile, of the proximal anchor stent ring is minimized. 
         [0022]    In accordance with another embodiment, a method of deploying an endoprosthesis includes radially constraining a proximal anchor stent ring of the endoprosthesis in an annular space between a sleeve of a tip and a spindle, the spindle having distal spindle pins extending into proximal spindle pin catches of the proximal anchor stent ring. A distal anchor stent ring of the endoprosthesis is radially constrained in an annular space between a middle member sleeve and the spindle, the spindle comprising proximal spindle pins extending into distal spindle pin catches of the distal anchor stent ring. Further, a graft material of the endoprosthesis is radially constrained in a primary sheath, the graft material being attached to the proximal anchor stent ring and the distal anchor stent ring. 
         [0023]    The primary sheath is retracted to deploy at least a portion of the endoprosthesis. The tip is advanced to deploy the proximal anchor stent ring. Further, the middle member sleeve is retracted to deploy the distal anchor stent ring. 
         [0024]    By providing a proximal capture and release mechanism for controlled deployment of proximal anchor stent ring and a distal capture and release mechanism for controlled deployment of distal anchor stent ring, deployment of the endoprosthesis occurs in three distinct and interchangeable operations. This provides maximum control in the deployment of the endoprosthesis. 
         [0025]    These and other features according to the present invention will be more readily apparent from the detailed description set forth below taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]      FIG. 1  is a partial cross-sectional view of a stent-graft delivery system without a stent-graft and outer sheath in accordance with one embodiment; 
           [0027]      FIG. 2  is a partial cross-sectional view of the stent-graft delivery system of  FIG. 1  including a stent-graft located within a retractable primary sheath in a pre-deployment un-retracted position; 
           [0028]      FIG. 3  is a partial cross-sectional view of the stent-graft delivery system of  FIG. 2  with the retractable primary sheath partially retracted; 
           [0029]      FIG. 4  is a partial cross-sectional view of the stent-graft delivery system of  FIG. 3  after deployment of a proximal anchor stent ring of the stent-graft; 
           [0030]      FIG. 5  is a perspective view of an expanded stent-graft similar to the stent-graft of  FIGS. 2 ,  3  and  4 ; 
           [0031]      FIG. 6  is perspective view of an expanded proximal anchor stent ring similar to a proximal anchor stent ring of the stent-graft of  FIG. 5 ; 
           [0032]      FIG. 7  is a top view of the proximal anchor stent ring of  FIG. 6 ; 
           [0033]      FIG. 8  is a cross-sectional view of the proximal anchor stent ring along the line VIII-VIII of  FIG. 7 ; 
           [0034]      FIG. 9  is an enlarged view of a region IX of the proximal anchor stent ring of  FIG. 8 ; 
           [0035]      FIG. 10  is a side view of the region of the proximal anchor stent ring of  FIG. 9 ; 
           [0036]      FIG. 11  is a cross-sectional view of the proximal anchor stent ring along the line XI-XI of  FIG. 7 ; 
           [0037]      FIG. 12  is an a flattened pattern of the as cut proximal anchor stent ring of  FIGS. 6-11 ; 
           [0038]      FIG. 13  is a partial cross-sectional view of a proximal anchor stent ring anchored in a vessel wall in accordance with one embodiment; 
           [0039]      FIG. 14  is an enlarged partially cutaway view of a stent-graft delivery system in accordance with another embodiment; 
           [0040]      FIG. 15  is a cross-sectional view of a stent-graft delivery system in accordance with another embodiment; 
           [0041]      FIG. 16  is a cross-sectional view of the stent-graft delivery system of  FIG. 15  at a further stage during deployment of a stent-graft; 
           [0042]      FIG. 17  is a cross-sectional view of the stent-graft delivery system of  FIG. 16  at a final stage during deployment of the stent-graft; 
           [0043]      FIG. 18  is a handle of a stent-graft delivery system in accordance with one embodiment; 
           [0044]      FIG. 19  is a partial cross-sectional view of a stent-graft delivery system in accordance with another embodiment; 
           [0045]      FIG. 20  is an enlarged side view of the region XX of the stent-graft delivery system of  FIG. 19 ; 
           [0046]      FIG. 21  is a handle of a stent-graft delivery system in accordance with one embodiment; 
           [0047]      FIG. 22  is the stent-graft delivery system of  FIGS. 19 ,  20  including a handle; 
           [0048]      FIG. 23  is a partial cross-sectional view of the stent-graft delivery system of  FIG. 22 ; 
           [0049]      FIG. 24  is a side view of a middle member of the stent-graft delivery system of  FIGS. 22 and 23 ; 
           [0050]      FIG. 25  is a side view of a portion of a housing of the stent-graft delivery system of  FIGS. 22 and 23 ; 
           [0051]      FIGS. 26 ,  27 ,  28  are side views of the stent-graft delivery system of  FIGS. 22 and 23  at various stages during deployment of a stent-graft; and 
           [0052]      FIG. 29  is an enlarged side view of a region of a stent-graft delivery system in accordance with one embodiment. 
       
    
    
       [0053]    In the following description, the same or similar elements are labeled with the same or similar reference numbers. 
       DETAILED DESCRIPTION 
       [0054]      FIG. 1  is a partial cross-sectional view of a stent-graft delivery system  100  without a stent-graft and outer sheath in accordance with one embodiment. Stent-graft delivery system  100  includes a tapered tip  102  that is flexible and able to provide trackability in tight and tortuous vessels. Tapered tip  102  includes a guidewire lumen  104  therein for connecting to adjacent members and allowing passage of a guidewire through tapered tip  102 . Other tip shapes such as bullet-shaped tips could also be used. 
         [0055]    An inner tube  106  defines a lumen, e.g., a guide wire lumen, therein. A distal end  107  of inner tube  106  is located within and secured to tapered tip  102 , i.e., tapered tip  102  is mounted on inner tube  106 . As shown in  FIG. 1 , the lumen of inner tube  106  is in fluid communication with guidewire lumen  104  of tapered tip  102  such that a guide wire can be passed through inner tube  106  and out distal end  107 , through guidewire lumen  104  of tapered tip  102 , and out a distal end  103  of tapered tip  102 . 
         [0056]    Tapered tip  102  includes a tapered outer surface  108  that gradually increases in diameter. More particularly, tapered outer surface  108  has a minimum diameter at distal end  103  and gradually increases in diameter proximally, i.e., in the direction of the operator (or handle of stent-graft delivery system  100 ), from distal end  103 . 
         [0057]    Tapered outer surface  108  extends proximally to a primary sheath abutment surface (shoulder)  110  of tapered tip  102 . Primary sheath abutment surface  110  is an annular ring perpendicular to a longitudinal axis L of stent-graft delivery system  100 . 
         [0058]    Tapered tip  102  further includes a (tip) sleeve  112  extending proximally from primary sheath abutment surface  110 . Generally, sleeve  112  is at a proximal end  105  of tapered tip  102 . Sleeve  112  is a hollow cylindrical tube extending proximally and longitudinally from primary sheath abutment surface  110 . Sleeve  112  includes an outer cylindrical surface  114  and an inner cylindrical surface  116 . 
         [0059]    Stent-graft delivery system  100  further includes an outer tube  118  having a spindle  120  located at and fixed to a distal end  119  of outer tube  118 . Spindle  120  includes a spindle body  122  having a cylindrical outer surface, a plurality of spindle pins  124  protruding radially outward from spindle body  122 , and a plurality of primary sheath guides  126  protruding radially outward from spindle body  122 . Primary sheath guides  126  guide the primary sheath into position over (tip) sleeve  112  (see  FIG. 2  for example). 
         [0060]    As illustrated in  FIG. 1 , spindle  120  is configured to slip inside of sleeve  112  such that spindle pins  124  are directly adjacent to, or contact, inner cylindrical surface  116  of sleeve  112 . Spindle pins  124  extend from spindle body  122  towards and to sleeve  112 . Generally, the diameter to which spindle pins  124  extend from spindle body  112  is approximately equal to, or slightly less than, the diameter of inner cylindrical surface  116  of sleeve  112  allowing spindle pins  124  to snugly fit inside of sleeve  112 . An annular space  128  exists between inner cylindrical surface  116  and spindle body  122 . 
         [0061]    Inner tube  106  is within and extends through outer tube  118  and spindle  120 . Inner tube  106  and thus tapered tip  102  is moved along longitudinal axis L (longitudinally moved) relative to outer tube  118  and thus spindle  120  to release the proximal end of a stent-graft as discussed further below. The term “stent-graft” used herein should be understood to include stent-grafts and other forms of endoprosthesis. 
         [0062]      FIG. 2  is a partial cross-sectional view of the stent-graft delivery system  100  of  FIG. 1  including a stent-graft  202  located within a retractable primary sheath  204  in a pre-deployment un-retracted position. 
         [0063]    Primary sheath  204  is a hollow tube and defines a lumen  206  therein through which outer tube  118  and inner tube  106  extend. Primary sheath  204  is in a pre-deployment un-retracted position in  FIG. 2 . Primary sheath  204  is moved proximally along longitudinal axis L, sometimes called retracted, relative to outer tube  118 /spindle  120  and thus stent-graft  202  to deploy a portion of stent-graft  202  as discussed further below. In one embodiment, stent-graft  202  is a self-expanding stent-graft such that stent-graft  202  self-expands upon being released from its radially constrained position. In accordance with this example, stent-graft  202  includes a graft material and support structures attached to the graft material as discussed in greater detail below with reference to  FIG. 5 . Stent-graft  202  includes a proximal end  203  and a distal end  205 . 
         [0064]    As shown in  FIG. 2 , stent-graft  202  is in a radially constrained configuration over outer tube  118  and spindle  120 . Stent-graft  202  is located within and radially compressed by primary sheath  204 . Further, a proximal anchor stent ring  208 , sometimes called the proximal tip, of stent-graft  202  is radially constrained and held in position in annular space  128  between spindle body  122  and inner cylindrical surface  116  of sleeve  112 . Proximal anchor stent ring  208  is at proximal end  203  of stent-graft  202 . 
         [0065]    Generally, the graft material of stent-graft  202  is radially constrained by primary sheath  204  and the proximal portion of proximal anchor stent ring  208  is radially constrained by sleeve  112  allowing sequential and independent deployment of the graft material and proximal anchor stent ring  208  of stent-graft  202 . 
         [0066]    Primary sheath  204  includes a distal end  204 D adjacent to or in abutting contact with primary sheath abutment surface  110  of tapered tip  102 . Distal end  204 D fits snugly around sleeve  112  and in one example lightly presses radially inward on outer cylindrical surface  114  of sleeve  112 . 
         [0067]      FIG. 3  is a partial cross-sectional view of the stent-graft delivery system  100  of  FIG. 2  with retractable primary sheath  204  partially retracted. Referring now to  FIG. 3 , primary sheath  204  is partially retracted such that distal end  204 D is spaced apart from tapered tip  102 . Further, due to the retraction of primary sheath  204 , a proximal portion  302  of stent-graft  202  is exposed and partially deployed. Proximal portion  302  is a portion of stent-graft  202  distal to proximal anchor stent ring  208  but proximal to the remaining portion of stent-graft  202 . 
         [0068]    As proximal portion  302  is only partially deployed and a portion of proximal anchor stent ring  208  is radially constrained and un-deployed, stent-graft  202  can be repositioned in the event that the initial positioning of stent-graft  202  is less than desirable. More particularly, to reposition stent-graft  202 , the retraction of primary sheath  204  is halted. Stent-graft delivery system  100  is then moved to reposition stent-graft  202 , for example, stent-graft  202  is rotated or moved proximally or distally without a substantial risk of damaging the wall of the vessel in which stent-graft  202  is being deployed. 
         [0069]    Further, as proximal end  203  of stent-graft  202  is secured fixing proximal end  203  of stent-graft  202  and keeping it in tension as primary sheath  204  is retracted and, in one example, distal end  205  is free to move within primary sheath  204 , bunching of stent-graft  202  during retraction of primary sheath  204  is avoided. By avoiding bunching, frictional drag of stent-graft  202  on primary sheath  204  during retraction is minimized thus facilitating smooth and easy retraction of primary sheath  204 . 
         [0070]    Once stent-graft  202  is properly positioned, proximal anchor stent ring  208  is released and deployed securing stent-graft  202  in position within the vessel as discussed in greater detail below. 
         [0071]      FIG. 4  is a partial cross-sectional view of the stent-graft delivery system  100  of  FIG. 3  after deployment of proximal anchor stent ring  208  of stent-graft  202 . Referring now to  FIG. 4 , tapered tip  102  is advanced relative to spindle  120  to expose the proximal end of proximal anchor stent ring  208 . Upon being released from sleeve  112  of tapered tip  102 , the proximal end of proximal anchor stent ring  208  self-expands into the wall of the vessel in which stent-graft  202  is being deployed. 
         [0072]    As set forth below, proximal anchor stent ring  208  includes anchor pins which penetrate into the surrounding vessel wall thus anchoring proximal anchor stent ring  208  to the wall of the vessel. Accordingly, after deployment and anchoring of proximal anchor stent ring  208  to the vessel wall, primary sheath  204  is fully retracted to fully deploy stent-graft  202  without migration. 
         [0073]    However, in another example, primary sheath  204  is fully retracted prior to release of proximal anchor stent ring  208 . To illustrate, instead of being partially retracted at the stage of deployment illustrated in  FIG. 3 , primary sheath  204  is fully retracted while the proximal end of proximal anchor stent ring  208  is still radially constrained. 
         [0074]    Further, stent-graft  202  is set forth above as being a self-expanding stent. In accordance with another embodiment, instead of being a self-expanding stent-graft, stent-graft delivery system  100  includes an expansion member, e.g., a balloon, which is expanded to expand and deploy the stent-graft. 
         [0075]      FIG. 5  is a perspective view of an expanded stent-graft  202 A similar to stent-graft  202  of  FIGS. 2 ,  3  and  4 . Referring now to  FIG. 5 , stent-graft  202 A includes a graft material  502 , e.g., formed of polyester or Dacron material, and a plurality of resilient self-expanding support structures  504 , e.g., formed of super elastic self-expanding memory material such as Nitinol, including a proximal anchor stent ring  208 A at a proximal end  203 A, a distal stent ring  506  at a distal end  205 A, and stent rings  508  between proximal anchor stent ring  208 A and distal stent ring  506 . Support structures  504  are attached to graft material  502 , e.g., by sutures, adhesive, or other means. 
         [0076]    Typically, stent-graft  202 A is deployed such that graft material  502  spans, sometimes called excludes, a diseased portion of the vessel, e.g., an aneurysm. Further, proximal anchor stent ring  208 A, e.g., a suprarenal stent structure, is typically engaged with a healthy portion of the vessel adjacent the diseased portion, the healthy portion having stronger tissue than the diseased portion. By forming proximal anchor stent ring  208 A with anchor pins as discussed below, the anchor pins penetrate (land) into the vessel wall of the healthy tissue thus anchoring proximal anchor stent ring  208  to strong tissue. 
         [0077]      FIG. 6  is perspective view of an expanded proximal anchor stent ring  208 B similar to proximal anchor stent ring  208 A of stent-graft  202 A of  FIG. 5 .  FIG. 7  is a top view of proximal anchor stent ring  208 B of  FIG. 6 .  FIG. 8  is a cross-sectional view of proximal anchor stent ring  208 B along the line VIII-VIII of  FIG. 7 .  FIG. 9  is an enlarged view of a region IX of proximal anchor stent ring  208 B of  FIG. 8 .  FIG. 10  is a side view of the region of proximal anchor stent ring  208 B of  FIG. 9 .  FIG. 11  is a cross-sectional view of proximal anchor stent ring  208 B along the line XI-XI of  FIG. 7 . 
         [0078]    Referring now to  FIGS. 6 ,  7 ,  8 ,  9 ,  10 , and  11  together, proximal anchor stent ring  208 B includes a zigzag pattern of struts  602  alternating between proximal apexes  604  and distal apexes  606 . Illustratively, proximal anchor stent ring  208 B is laser cut from a one-piece material such as a tube. After being cut, proximal anchor stent ring  208 B is sequentially expanded, e.g., using a mandrel, and heat set, into its final expanded configuration as those of skill in the art will understand in light of this disclosure. In one example, the mandrel includes protruding features which facilitate heat setting of the anchor pins in position. 
         [0079]    Distal apexes  606  are attached to the graft material of the stent-graft, e.g., see graft material  502  of  FIG. 5 . Proximal anchor stent ring  208 B further includes anchor pins  608 . 
         [0080]    More particularly, a pair of anchor pins  608  is located on struts  602  adjacent each proximal apex  604 . By locating anchor pins  608  adjacent proximal apexes  604 , the effect on the flexibility of proximal anchor stent ring  208 B by anchor pins  608  is minimal. Further, as proximal anchor stent ring  208 B is integral in one example, i.e., is a single piece laser cut from a tube and not a plurality of separate pieces attached together, anchor pins  608  are durable, e.g., are not likely to break off or otherwise fail. 
         [0081]    Referring now to  FIG. 9 , a first proximal apex  604 A of the plurality of proximal apexes  604  is illustrated. First and second struts  602 A,  602 B of the plurality of struts  602  extends distally from proximal apex  604 A. A first anchor pin  608 A of the plurality of anchor pins  608  extends from strut  602 A adjacent proximal apex  604 A. Similarly, a second anchor pin  608 B of the plurality of anchor pins  608  extends from strut  602 B adjacent proximal apex  604 A. 
         [0082]    In one embodiment, the angle of anchor pins  608  from the vertical (horizontal in the view of  FIG. 9 ) is in the range of 0° to 50°, e.g., feature A 9  is in the range of 0° to 50° and in one example is 45°. By forming anchor pins  608  at an angle in the range of 0° to 50° from the vertical, anchor pins  608  are in line with any force for migration, e.g., force in the distal direction (force in the left direction in the view of  FIG. 9 ). In one embodiment, the vertical is parallel to the longitudinal axis L of proximal anchor stent ring  208 B. 
         [0083]    Anchor pins  608 A,  608 B extend from the inside surfaces  902 A,  902 B of struts  602 A,  602 B, respectively. As used herein, the inside and outside surfaces of struts  602  are defined relative to proximal apexes  604 . More particularly, the inside surface of a strut  602  is the surface that correlates and extends smoothly from the inside radial surface of the curved apex, i.e., the curvature of proximal apexes  604 . Conversely, the outside surface of a strut  602  correlates to the outside radial surface of proximal apexes  604 . Generally, the outside surfaces of struts  602  are proximal to the inside surfaces of struts  602 . 
         [0084]    To illustrate, proximal apex  604 A includes an intrados (the interior curve of an arch) surface  904  and an extrados (the exterior curve of an arch) surface  906 , extrados surface  906  having a greater radius then intrados surface  904 . Extrados surface  906  is continuous with outside surfaces  908 A,  908 B of struts  602 A,  602 B, respectively. Similarly, intrados surface  904  is continuous with inside surfaces  902 A,  902 B of struts  602 A,  602 B, respectively. Stated another way, anchor pins  608 A,  608 B extend inwards from struts  602 A,  602 B, respectively. 
         [0085]    Generally, anchor pins  608  are located inwards of struts  602 . By locating anchor pins  608  inwards, the delivery profile, sometimes called crimped profile, of proximal anchor stent ring  208 B is minimized in contrast to a configuration where anchor pins are located outward and space must be allocated to accommodate the anchor pins. 
         [0086]    In accordance with this example, anchor pins  608  include distal tips, e.g., sharp points, which facilitate penetration of anchor pins  608  into the wall of the vessel in which the stent-graft is deployed. To illustrate, paying particular attention to  FIG. 9 , anchor pins  608 A,  608 B include distal tips  910 A,  910 B, respectively. 
         [0087]    Further, anchor pins  608 A,  608 B protrude radially outward from the cylindrical surface (plane) defined by the zigzag pattern of struts  602  alternating between proximal apexes  604  and distal apexes  606 . Generally, anchor pins  608 A,  608 B protrude radially outward from proximal anchor stent ring  208 B. 
         [0088]    Paying particular attention now to  FIGS. 7 and 10 , struts  602 , proximal apexes  604 , and distal apexes  606  define a cylindrical surface  702 . Anchor pins  608  protrude from struts  602  radially outward from (imaginary) cylindrical surface  702 . As discussed in greater detail below with reference to  FIG. 13 , by protruding radially outwards from proximal anchor stent ring  208 B, anchor pins  608  penetrate into the vessel wall thus anchoring proximal anchor stent ring  208 B and the corresponding stent-graft to the vessel wall. 
         [0089]    Illustratively, anchor pins  608  protrude radially outward (the radial distance from the imaginary cylindrical surface  702  in contrast to the length of anchor pins  608 ) from struts  602  a distance in the range of one millimeter to three millimeters, i.e., feature B 10  of  FIG. 10  is 3 mm, in the range of 1 mm to 3 mm in one example, and in the range of 2 mm to 3 mm in another example. Further, feature A 10 , i.e., the angle of intersection between anchor pins  608  and struts  602  is 45° or in the range of 30° to 75° in one example. By forming the angle of intersection in the range of 30° to 75°, any force in the distal direction on proximal anchor stent ring  208 B (left in the view of  FIG. 10 ) causes anchor pins  608  to penetrate (dig) deeper into the vessel wall thus pulling struts  602  and proximal apexes  604  tighter to the vessel wall effectively locking proximal anchor stent ring  208 B to the vessel wall. 
         [0090]      FIG. 12  is an as cut flat pattern of proximal anchor stent ring  208 B of  FIGS. 6-11 . Referring now to  FIG. 12 , proximal anchor stent ring  208 B is illustrated in its unexpanded configuration, sometimes called delivery profile. In its unexpanded configuration, proximal apexes  604  and anchor pins  608  define spindle pin catches  1202 . 
         [0091]    Spindle pin catches  1202  are pockets, sometimes called openings or holes, in which the spindle pins of the stent-graft delivery system are located to radially constrain proximal anchor stent ring  208 B in its unexpanded configuration (crimped profile) prior to deployment as discussed in greater detail below. Generally, anchor pins  608  are positioned slightly distal from proximal apexes  604  to leave room for the spindle pins. 
         [0092]    Although proximal anchor stent ring  208 B is illustrated as having five proximal apexes  604  and five distal apexes  606 , sometimes called a five apex proximal anchor stent ring, in other examples, a proximal anchor stent ring has more or less than five proximal apexes and five distal apexes, e.g., four or six of each, sometimes called a four or six apex proximal anchor stent ring. 
         [0093]      FIG. 13  is a partial cross-sectional view of a proximal anchor stent ring  208 C of a stent-graft  202 C anchored in a vessel wall  1302  in accordance with one embodiment. Referring now to  FIG. 13 , an anchor pin  608 C is extending radially outward from a strut  602 C and penetrating into vessel wall  1302 . Distal tip  910 C of anchor pin  608 C facilitates penetration of anchor pin  608 C into vessel wall  1302 , e.g., healthy tissue. Accordingly, proximal anchor stent ring  208 C is anchored to vessel wall  1302  preventing migration of stent-graft  202 C in the distal direction, i.e., prevents motion of stent-graft  202 C towards the left in the view of  FIG. 13 . 
         [0094]      FIG. 14  is an enlarged partially cutaway view of a stent-graft delivery system  100 D in accordance with another embodiment. Referring now to  FIG. 14 , a proximal portion of proximal anchor stent ring  208 D is restrained within a sleeve  112 D of a tapered tip  102 D. Sleeve  112 D is illustrated as a transparent sleeve in  FIG. 14  to illustrate features within sleeve  112 D. However, in other examples, sleeve  112 D is opaque. Illustratively, sleeve  112 D is stainless steel, Nitinol, MP35N alloy, or a polymer. 
         [0095]    Spindle pins  124 D of a spindle  120 D extend into and are located within spindle pin catches  1202 D of proximal anchor stent ring  208 D. Accordingly, the proximal end of proximal anchor stent ring  208 D is locked around spindle pins  124 D and between sleeve  112 D and a spindle body  122 D. Illustratively, spindle  120 D is stainless steel, Nitinol, MP35N alloy, or a polymer. 
         [0096]    Further, sleeve  112 D holds anchor pins  608 D down (radially inward) thus providing a minimal delivery profile for proximal anchor stent ring  208 D. Generally, sleeve  112 D holds anchor pins  608 D bent in a lower profile. 
         [0097]    Sleeve  112 D does not cover (exposes) distal tips  910 D of anchor pins  608 D. Stated another way, sleeve  112 D extends distally only partially over anchor pins  608 D. This prevents distal tips  910 D, e.g., sharp tips, from engaging (digging into, scratching, gouging) sleeve  112 D. This minimizes the deployment force necessary to advance sleeve  112 D relative to proximal anchor stent ring  208 D. 
         [0098]    Tapered outer surface  108 D, primary sheath abutment surface  110 D, primary sheath guides  126 D, struts  602 D, proximal apexes  604 D are similar to tapered outer surface  108 , primary sheath abutment surface  110 , primary sheath guides  126 , struts  602 , proximal apexes  604  as discussed above, respectively, and so the description thereof is not repeated here. 
         [0099]      FIG. 15  is a cross-sectional view of a stent-graft delivery system  100 E in accordance with another embodiment.  FIG. 15  corresponds to the stage similar to that illustrated in  FIG. 3  of deployment of a stent-graft  202 E, i.e., after at least partial retraction of the primary sheath. 
         [0100]    Referring now to  FIG. 15 , stent-graft delivery system  100 E includes a tapered tip  102 E, an inner tube  106 E, a tapered outer surface  108 E, a primary sheath abutment surface  110 E, a sleeve  112 E, an outer cylindrical surface  114 E, an inner cylindrical surface  116 E, an outer tube  118 E, a spindle  120 E, a spindle body  122 E, spindle pins  124 E, primary sheath guides  126 E, an annular space  128 E similar to tapered tip  102 , inner tube  106 , tapered outer surface  108 , primary sheath abutment surface  110 , sleeve  112 , outer cylindrical surface  114 , inner cylindrical surface  116 , outer tube  118 , spindle  120 , spindle body  122 , spindle pins  124 , primary sheath guides  126 , annular space  128  of stent-graft delivery system  100  of  FIGS. 1-4 , respectively. 
         [0101]    Further, stent-graft  202 E includes a proximal anchor stent ring  208 E including struts  602 E, proximal apexes  604 E, anchor pins  608 E, distal tips  910 E, and spindle pin catches  1202 E similar to proximal anchor stent ring  208 B including struts  602 , proximal apexes  604 , anchor pins  608 , distal tips  910 , and spindle pin catches  1202  of proximal anchor stent ring  208 B of  FIGS. 6-12 , respectively. 
         [0102]    As shown in  FIG. 15 , the proximal end of proximal anchor stent ring  208 E is restrained within sleeve  112 E of tapered tip  102 E. Spindle pins  124 E of spindle  120 E are located within spindle pin catches  1202 E of proximal anchor stent ring  208 E. Accordingly, proximal anchor stent ring  208 E is locked around spindle pins  124 E and between sleeve  112 E and a spindle body  122 E. 
         [0103]      FIG. 16  is a cross-sectional view of stent-graft delivery system  100 E of  FIG. 15  at a further stage during deployment of stent-graft  202 E. Referring now to  FIG. 16 , tapered tip  102 E and thus sleeve  112 E are advanced relative to spindle  120 E. However, as spindle pins  124 E are still located within sleeve  112 E, the proximal end of proximal anchor stent ring  208 E continues to be locked around spindle pins  124 E and between sleeve  112 E and spindle body  122 E. 
         [0104]      FIG. 17  is a cross-sectional view of stent-graft delivery system  100 E of  FIG. 16  at a final stage during deployment of stent-graft  202 E.  FIG. 17  corresponds to the stage of deployment of stent-graft  202 E similar to that illustrated in  FIG. 4 , i.e., after the proximal end of the proximal anchor stent ring has been deployed. 
         [0105]    Referring now to  FIG. 17 , tapered tip  102 E and thus sleeve  112 E are advanced relative to spindle  120 E such that sleeve  112 E uncovers and exposes spindle pins  124 E and proximal apexes  604 E of proximal anchor stent ring  208 E. Upon being released, proximal anchor stent ring  208 E self-expands and anchors into the vessel wall, e.g., in a manner similar to that discussed above regarding  FIG. 13 . 
         [0106]      FIG. 18  is a handle  1800  of a stent-graft delivery system  100 F in accordance with one embodiment. Handle  1800  includes a housing  1802  having a primary sheath retraction slot  1804  and an inner tube advancement slot  1806 . A primary sheath actuation member  1808 , sometimes called a thumb slider, extends from a primary sheath  204 F and through primary sheath retraction slot  1804 . Similarly, an inner tube actuation member  1810 , sometimes called a thumb slider, extends from an inner tube  106 F and through inner tube advancement slot  1806 . Further, an outer tube  118 F is mounted to housing  1802  by an outer tube support  1812 . 
         [0107]    To retract primary sheath  204 F relative to outer tube  118 F, primary sheath actuation member  1808  is moved (retracted), e.g., by the physician, in the direction of arrow  1814 . To advance inner tube  106 F relative to outer tube  118 F, inner tube actuation member  1810  is moved (advanced), e.g., by the physician, in the direction of arrow  1816 . Illustratively, inner tube  106 F and outer tube  118 F are stainless steel, Nitinol, MP35N alloy, or a braided polymer. 
         [0108]    Although one example of a handle is set forth in  FIG. 18 , in light of this disclosure, those of skill in the art will understand that other handles can be used. Illustratively, handles having ratcheting mechanisms, threaded mechanisms, or other mechanisms to retract the primary sheath and advance the inner tube relative to the outer tube are used. 
         [0109]      FIG. 19  is a partial cross-sectional view of a stent-graft delivery system  1900  in accordance with another embodiment. Referring now to  FIG. 19 , stent-graft delivery system  1900  includes a tapered tip  102 G, an inner tube  106 G, a tapered outer surface  108 G, a primary sheath abutment surface  110 G, a sleeve  112 G, an outer tube  118 G, a spindle  120 G, a spindle body  122 G, spindle pins  124 G, sometimes called distal spindle pins, an annular space  128 G, and a primary sheath  204 G similar to tapered tip  102 , inner tube  106 , tapered outer surface  108 , primary sheath abutment surface  110 , sleeve  112 , outer tube  118 , spindle  120 , spindle body  122 , spindle pins  124 , annular space  128 , and primary sheath  204  of stent-graft delivery system  100  of  FIGS. 1-4 , respectively. 
         [0110]    Further, stent-graft delivery system  1900  includes a stent-graft  1902 , e.g., an abdominal or thoracic stent-graft. Stent-graft  1902  includes a proximal anchor stent ring  208 G including struts, proximal apexes, anchor pins, distal tips, and proximal spindle pin catches similar to proximal anchor stent ring  208 B including struts  602 , proximal apexes  604 , anchor pins  608 , distal tips  910 , and spindle pin catches  1202  of proximal anchor stent ring  208 B of  FIGS. 6-12 , respectively. Further, stent-graft  1902  includes a graft material  502 G similar to graft material  502  of stent-graft  202 A of  FIG. 5 . Generally, spindle  120 G and sleeve  112 G form a proximal capture and release mechanism for proximal anchor stent ring  208 G. 
         [0111]      FIG. 20  is a side perspective view of the region XX of stent-graft delivery system  1900  of  FIG. 19 . Referring now to  FIGS. 19 and 20  together, stent-graft  1902  further includes distal anchor stent ring  1908  including struts  2002 , distal apexes  2004 , anchor pins  2008 , proximal tips  2010 , and spindle pin catches  2012  similar to proximal anchor stent ring  208 B including struts  602 , proximal apexes  604 , anchor pins  608 , distal tips  910 , and spindle pin catches  1202  of proximal anchor stent ring  208 B of  FIGS. 6-12 , respectively. 
         [0112]    Generally, proximal anchor stent ring  208 G is located at the proximal end  202 P of stent-graft  202 G and distal anchor stent ring  1908  is located at the distal end  202 D of stent-graft  202 G. Proximal anchor stent ring  208 G and distal anchor stent ring  1908  are attached to graft material  502 G of stent-graft  1902 . Distal anchor stent ring  1908  is similar or identical to proximal anchor stent ring  208 G except that the orientation is reversed. More particularly, spindle pin catches  2012  are located at the distal end of distal anchor stent ring  1908  and anchor pins  2008  point proximally away from spindle pin catches  2012  towards proximal anchor stent ring  208 G. 
         [0113]    Stent-graft delivery system  1900  further includes a middle member  2020  having a middle member sleeve  2022  extending distally from a middle member tube  2024  of middle member  2020 . Generally, middle member sleeve  2022  is at a distal end  2020 D of middle member  2020 . Middle member sleeve  2022  is a hollow cylindrical tube extending distally and longitudinally from middle member tube  2024 . Middle member sleeve  2022  includes an outer cylindrical surface  2026  and an inner cylindrical surface  2028 . Middle member sleeve  2022  is sometimes called a stent stop or a distal stent cup/sleeve. 
         [0114]    Stent-graft delivery system  1900  further includes outer tube  118 G having spindle  120 G located at and fixed to the distal end of outer tube  118 G. Spindle  120 G includes spindle body  122 G having a cylindrical outer surface, distal spindle pins  124 G protruding radially outward from spindle body  122 G, and a plurality of proximal spindle pins  2030  protruding radially outward from spindle body  122 G. 
         [0115]    As illustrated in  FIGS. 19 and 20 , spindle  120 G is configured to slip inside of middle member sleeve  2022  such that proximal spindle pins  2030  are directly adjacent to, or contact, inner cylindrical surface  2028  of middle member sleeve  2022 . Proximal spindle pins  2030  extend from spindle body  122 G towards and to middle member sleeve  2022 . Generally, the diameter to which proximal spindle pins  2030  extend from spindle body  122 G is approximately equal to, or slightly less than, the diameter of inner cylindrical surface  2028  of middle member sleeve  2022  allowing proximal spindle pins  2030  to snugly fit inside of middle member sleeve  2022 . An annular space  2032  exists between inner cylindrical surface  2028  and spindle body  122 G. 
         [0116]    Middle member  2020  is a hollow tube and defines a lumen therein through which outer tube  118 G and inner tube  106 G extend. Middle member  2020  and thus middle member sleeve  2022  is moved along longitudinal axis L (longitudinally moved) relative to outer tube  118 G and thus spindle  120 G to release distal end  202 D (distal anchor stent ring  1908 ) of stent-graft  1902  as discussed further below. Primary sheath  204 G is a hollow tube and defines a lumen therein through which middle member  2020 , outer tube  118 G and inner tube  106 G extend. 
         [0117]    Distal anchor stent ring  1908  is illustrated in its unexpanded configuration, sometimes called delivery profile. In its unexpanded configuration, distal apexes  2004  and anchor pins  2008  define distal spindle pin catches  2012 . 
         [0118]    Spindle pin catches  2012  are pockets, sometimes called openings or holes, in which proximal spindle pins  2030  are located to radially constrain distal anchor stent ring  1908  in its unexpanded configuration (crimped profile) prior to deployment as discussed in greater detail below. Generally, anchor pins  2008  are positioned slightly proximal from distal apexes  2004  to leave room for proximal spindle pins  2030 . 
         [0119]    A distal portion of distal anchor stent ring  1908  is restrained within middle member sleeve  2022 . Middle member sleeve  2022  is illustrated as a transparent sleeve in  FIG. 20  to illustrate features within middle member sleeve  2022 . However, in other examples, middle member sleeve  2022  is opaque. Illustratively, middle member sleeve  2022  is stainless steel, Nitinol, MP35N alloy, or a polymer, or a combination thereof. 
         [0120]    Proximal spindle pins  2030  of spindle  120 G extend into and are located within spindle pin catches  2012  of distal anchor stent ring  1908 . Accordingly, the distal end of distal anchor stent ring  1908  is locked around proximal spindle pins  2030  and between middle member sleeve  2022  and spindle body  122 G. Generally, spindle  120 G and middle member sleeve  2022  form a distal capture and release mechanism for distal anchor stent ring  1908 . 
         [0121]    Further, middle member sleeve  2022  holds anchor pins  2008  down (radially inward) thus providing a minimal delivery profile for distal anchor stent ring  1908 . Generally, middle member sleeve  2022  holds anchor pins  2008  bent in a lower profile. 
         [0122]    Middle member sleeve  2022  does not cover (exposes) proximal tips  2010  of anchor pins  2008 . Stated another way, middle member sleeve  2022  extends proximally only partially over anchor pins  2008 . This prevents proximal tips  2010 , e.g., sharp tips, from engaging (digging into, scratching, gouging) middle member sleeve  2022 . This minimizes the deployment force necessary to retract middle member sleeve  2022  relative to distal anchor stent ring  1908 . However, in another example, a distal anchor stent ring similar to distal anchor stent ring  1908  without anchor pins  2008  is formed. 
         [0123]      FIG. 21  is a handle  2100  of a stent-graft delivery system  1900 A in accordance with one embodiment. Handle  2100  includes a housing  2102  having a primary sheath retraction slot  2104 , a middle member retraction slot  2105 , and an inner tube advancement slot  2106 . 
         [0124]    A primary sheath actuation member  2108 , sometimes called a thumb slider, extends from a primary sheath  204 H and through primary sheath retraction slot  2104 . Similarly, a middle member actuation member  2109 , sometimes called a thumb slider, extends from a middle member  2020 H and through middle member retraction slot  2105 . Further, an inner tube actuation member  2110 , sometimes called a thumb slider, extends from an inner tube  106 H and through inner tube advancement slot  2106 . Further, an outer tube  118 H is mounted to housing  2102  by an outer tube support  2112 . 
         [0125]    To retract primary sheath  204 H relative to outer tube  118 H, primary sheath actuation member  2108  is moved (retracted), e.g., by the physician, in the direction of arrow  2114 . To retract middle member  2020 H relative to outer tube  118 H, middle member actuation member  2109  is moved (retracted), e.g., by the physician, also in the direction of arrow  2114 . To advance inner tube  106 H relative to outer tube  118 H, inner tube actuation member  2110  is moved (advanced), e.g., by the physician, in the direction of arrow  2116 . 
         [0126]    Although one example of a handle is set forth in  FIG. 21 , in light of this disclosure, those of skill in the art will understand that other handles can be used. Illustratively, handles having ratcheting mechanisms, threaded mechanisms, or other mechanisms to retract the primary sheath/middle member and advance the inner tube relative to the outer tube are used such as the handle illustrate in  FIG. 22 . 
         [0127]      FIG. 22  is stent-graft delivery system  1900  of  FIGS. 19 ,  20  including a handle  2100 A. Handle  2100 A includes a housing  2102 A, a primary sheath actuation member  2108 A, sometimes called an external slider, a middle member actuation member  2109 A, sometimes called a moveable rear grip, and an inner tube actuation member  2110 A, sometimes called a rear wheel similar to housing  2102 , primary sheath actuation member  2108 , middle member actuation member  2109  and inner tube actuation member  2110  of handle  2100  of  FIG. 21 . Only the significant differences between handle  2100 A of  FIG. 22  and handle  2100  of  FIG. 21  are discussed below. 
         [0128]    Primary sheath actuation member  2108 A is coupled to primary sheath  204 G through housing  2102 A in such a manner that primary sheath actuation member  2108 A can be rotated without rotation of primary sheath  204 G yet longitudinal motion of primary sheath actuation member  2108 A causes an equal longitudinal motion of primary sheath  204 G. More particularly, primary sheath actuation member  2108 A is threadedly attached to screw gear  2218  of housing  2102 A. Rotation of primary sheath actuation member  2108 A on screw gear  2218  causes axial translation of primary sheath actuation member  2108 A and thus primary sheath  204 G. Further, a primary sheath actuation member release  2220  selectively disengages primary sheath actuation member  2108 A from screw gear  2218  allowing the physician to quickly retract primary sheath actuation member  2108 A and thus primary sheath  204 G with a single pull. 
         [0129]    Similarly, inner tube actuation member  2110 A is coupled to inner tube  106 G (shown in  FIG. 19 ) in such a manner that inner tube actuation member  2110 A can be rotated without rotation of inner tube  106 G yet longitudinal motion of inner tube actuation member  2110 A causes an equal longitudinal motion of inner tube  106 G. More particularly, inner tube actuation member  2110 A is threadedly attached to a second screw gear  2222  of housing  2102 A. Rotation of inner tube actuation member  2110 A on screw gear  2222  causes axial translation of inner tube actuation member  2110 A and thus inner tube  106 G and tapered tip  102 G. 
         [0130]    Further, spindle  120 G is mounted to housing  2102 A, e.g., by an outer tube and outer tube support similar to outer tube  118 H and outer tube  2112  of handle  2100  of  FIG. 21 . 
         [0131]      FIG. 23  is a partial cross-sectional view of stent-graft delivery system  1900  of  FIG. 22 .  FIG. 24  is a perspective view of middle member  2020  of stent-graft delivery system  1900  of  FIGS. 22 and 23 .  FIG. 25  is a perspective view of a portion of housing  2102 A of stent-graft delivery system  1900  of  FIGS. 22 and 23 . 
         [0132]    Referring now to  FIGS. 22 ,  23 ,  24  and  25  together, middle member actuation member  2109 A is coupled to middle member  2020  in such a manner that longitudinal motion of middle member actuation member  2109 A causes an equal longitudinal motion of middle member  2020 . To facilitate the coupling of middle member actuation member to middle member  2020 , middle member  2020  includes a middle member lock  2230  at a proximal end  2024 P of middle member tube  2024 . 
         [0133]    Middle member lock  2230  includes a pair of radially protruding posts  2232  opposite one another. Housing  2102 A includes a pair of lock slots  2234  through which posts  2232  of middle member lock  2230  pass to be connected to middle member actuation member  2109 A. 
         [0134]    Lock slots  2234  include circumferential slot portions  2236  extending along the outer cylindrical surface of housing  2102 A perpendicularly to a longitudinal axis L of handle  2100 A. Lock slots  2234  further include longitudinal slot portions  2238  extending along the outer cylindrical surface of housing  2102 A parallel to longitudinal axis L of handle  2100 A. 
         [0135]    By locating posts  2232  within circumferential slot portions  2236  of lock slots  2234 , longitudinal motion of posts  2232  is prevented effectively locking middle member  2020  to housing  2102 A. However, by rotating middle member actuation member  2109 A and thus middle member  2020  to position posts  2232  within longitudinal slot portions  2238  of lock slots  2234 , longitudinal motion of posts  2232  is enabled effectively unlocking middle member  2020  from housing  2102 A. 
         [0136]    As further illustrated in  FIG. 24 , middle member tube  2024  is formed with a flexible section  2460  having folds that provide flexibility to middle member tube  2024 . In one example, middle member  2020  is formed of a solid molded polymer. In another example, middle member tube  2024  is formed of a solid molded polymer and middle member sleeve  2022  is stainless steel, Nitinol, or MP35N alloy molded into middle member tube  2024 . 
         [0137]      FIGS. 26 ,  27 ,  28  are side views of stent-graft delivery system  1900  of  FIGS. 22 and 23  at various stages during deployment of stent-graft  1902 . Referring to  FIG. 26 , once stent-graft delivery system  1900  is tracked and positioned at the target anatomy, primary sheath actuation member  2108 A is moved (retracted), e.g., by the physician, in the direction of arrow  2640  as discussed above. This retracts primary sheath  204 G deploying the central section  1902 C of stent-graft  1902  between proximal anchor stent ring  208 G and distal anchor stent ring  1908 . However, proximal anchor stent ring  208 G and distal anchor stent ring  1908  of stent-graft  1902  remained captured within sleeve  112 G and middle member sleeve  2022 , respectively. In one example, stent-graft  1902  is repositioned after deployment of central section  1902 C. 
         [0138]    Referring now to  FIG. 27 , inner tube actuation member  2110 A is moved (advanced), e.g., by the physician as discussed above. This advances inner tube  106 G and thus sleeve  112 G deploying proximal anchor stent ring  208 G of stent-graft  1902 . In one example, deployment of proximal anchor stent ring  208 G sets the final position of stent-graft  1902 . 
         [0139]    Referring now to  FIG. 28 , middle member actuation member  2109 A is initially rotated in the direction of arrow  2844  to position posts  2232  within longitudinal slot portions  2238  of lock slots  2234  (see  FIGS. 23-25 ) to unlock middle member  2020  from housing  2102 A. Middle member actuation member  2109 A is then moved (retracted), e.g., by the physician, in the direction of arrow  2846 . This retracts middle member  2020  and thus middle member sleeve  2022  deploying distal anchor stent ring  1908  of stent-graft  1902 . In one example, middle member actuation member  2109 A is returned (advanced) back to its original longitudinal position, e.g., using a spring mechanism. 
         [0140]    Once stent-graft  1902  is completely deployed, the delivery system is withdrawn from the patient. 
         [0141]    Although  FIGS. 26 ,  27 ,  28  illustrate deployment of central section  1902 C, followed by deployment of proximal anchor stent ring  208 G, followed by deployment of distal anchor stent ring  1908 , it is to be understood that the three deployment phases are distinct and interchangeable and can be carried out in any desired order. 
         [0142]    By providing stent-graft delivery system  1900  with a proximal capture and release mechanism for controlled deployment of proximal anchor stent ring  208 G and a distal capture and release mechanism for controlled deployment of distal anchor stent ring  1908 , deployment of stent-graft  1902  occurs in three distinct operations as illustrated in  FIGS. 26 ,  27  and  28 . This provides maximum control in the deployment of stent-graft  1902 . 
         [0143]      FIG. 29  is an enlarged side view of a region of a stent-graft delivery system  2900  in accordance with one embodiment. Referring now to  FIG. 29 , a stent-graft  1902 A includes a distal anchor stent ring  1908 A including struts  2002 A and distal apexes  2004 A. In accordance with this example, distal anchor stent ring  1908 A has an absence of (does not include) anchor pins and spindle pin catches. 
         [0144]    Stent-graft delivery system  2900  further includes a middle member  2020 A having a middle member sleeve  2022 A extending distally from a middle member tube  2024 A of middle member  2020 A similar to middle member  2020  of  FIGS. 19 and 20 . 
         [0145]    Stent-graft delivery system  2900  further includes outer tube  1181  having a spindle (not shown) located at and fixed to the distal end of outer tube  1181  similar to spindle  120  of  FIG. 1 . An annular space exists between outer tube  1181  and middle member sleeve  2022 A. Stent-graft delivery system  2900  further includes a primary sheath  2041 . 
         [0146]    Distal anchor stent ring  1908 A is illustrated in its unexpanded configuration, sometimes called delivery profile. Generally, distal anchor stent ring  1908 A is restrained within middle member sleeve  2022 A. More particularly, distal anchor stent ring  1908 A is restrained within the annular space existing between outer tube  1181  and middle member sleeve  2022 A. 
         [0147]    In a manner similar to that discussed above in reference to  FIG. 28 , middle member  2020 A and thus middle member sleeve  2022 A are retracted to release distal anchor stent ring  1908 A of stent-graft  1902 A, which self-expands upon release. 
         [0148]    This application is related to Mitchell et al., commonly assigned U.S. patent application Ser. No. 11/559,754, entitled “DELIVERY SYSTEM FOR STENT-GRAFT WITH ANCHORING PINS”, filed on Nov. 14, 2006 and to Mitchell et al., commonly assigned U.S. patent application Ser. No. 11/559,765, entitled “STENT-GRAFT WITH ANCHORING PINS”, filed on Nov. 14, 2006, both of which are herein incorporated by reference in their entirety. 
         [0149]    The drawings and the forgoing description gave examples of embodiments according to the present invention. Numerous variations, whether explicitly given in the specification or not, such as differences in structure, dimension, and use of material, are possible.