Patent Publication Number: US-2020281751-A1

Title: Catheter system and methods of using same

Description:
PRIORITY CLAIM 
     The present application is a continuation of U.S. patent application Ser. No. 15/379,268, filed Dec. 14, 2016, which is a continuation of U.S. patent application Ser. No. 14/462,485, filed Aug. 18, 2014, now U.S. Pat. No. 9,549,835, which is a divisional of U.S. patent application Ser. No. 13/408,952, filed Feb. 29, 2012, now U.S. Pat. No. 8,808,350, issued Aug. 19, 2014, which claims priority from U.S. Patent Application No. 61/448,154, filed Mar. 1, 2011, the content of both of which is incorporated by reference herein in its entirety. The benefit of priority is claimed under the appropriate legal basis including, without limitation, under 35 U.S.C. § 119(e). 
    
    
     INCORPORATION BY REFERENCE 
     U.S. application Ser. No. 11/623,022, filed Jan. 12, 2007, entitled “DUAL CONCENTRIC GUIDEWIRE AND METHODS OF BIFURCATED GRAFT DEPLOYMENT.” U.S. application Ser. No. 12/101,863, filed Apr. 11, 2008, entitled “BIFURCATED GRAFT DEPLOYMENT SYSTEMS AND METHODS,” U.S. application Ser. No. 12/496,446, filed Jul. 1, 2009, entitled “CATHETER SYSTEM AND METHODS OF USING SAME,” U.S. application Ser. No. 12/769,506, filed Apr. 28, 2010, entitled “APPARATUS AND METHOD OF PLACEMENT OF A GRAFT OR GRAFT SYSTEM.” and U.S. Pat. No. 6,077,296, entitled “ENDOLUMINAL VASCULAR PROSTHESIS,” are hereby incorporated by reference as if fully set forth herein. 
     TECHNICAL FIELD 
     The present disclosure relates to catheter systems, in particular, catheter systems for delivering a medical prosthesis. 
     BACKGROUND 
     Introducer catheters or introducer sheaths can be used for minimal invasive placement of catheters into blood vessels. Introducer catheter sheaths typically comprise tubing that is inserted into the blood vessel and a seal or valve at the proximal end of the tubing which is positioned outside of the body. The seal can provide a hemostatic seal against blood loss. Stents or other medical prostheses are typically passed through the introducer sheath into the blood vessel or body passageway. The introducer sheath thus provides continuous access for the delivery of stents or other medical prostheses, protects the inner wall of the blood vessel or body passageway against damage when the stent or other prostheses is advanced through the body passageway, and provides a hemostasis seal against blood loss. 
     There are situations in which the catheters require substantial maneuvering within the blood vessel. For example, placement of a stent or stent graft may require the delivery catheter to be positioned precisely axially as well as rotationally at a specific location within the blood vessel. In addition deployment of the stent may require precise operation of the delivery system within the introducer. In these situations, the operator has to carefully control both the position of the introducer and the delivery system. A need exists for a delivery system that permits a user or medical practitioner to precisely control the axial position of the stent or prosthesis during deployment. 
     SUMMARY 
     Embodiments disclosed herein pertain to a catheter system for the insertion and positioning of diagnostic or therapeutic devices into blood vessels. The system comprises an introducer or an introducer sheath (also referred to herein as an outer sheath) and at least one delivery catheter. The introducer catheter can be introduced through a percutaneous puncture site into the blood stream. A docking mechanism can engage the proximal end of the introducer catheter assembly with a distal end portion of a delivery catheter and can prevent axial movement between the introducer catheter assembly and the delivery catheter assembly. 
     The catheter system can include an introducer catheter and a delivery catheter, where the introducer catheter includes an outer sheath and a seal that has an adjustable hemostasis valve connected to the proximal portion of the outer sheath. The introducer catheter and the delivery catheter can be configured such that the delivery catheter can removably engage with the introducer catheter such that, when the delivery catheter is engaged with the introducer catheter, the delivery catheter can be axially fixed to the introducer catheter so as to prevent substantial axial movement between the introducer catheter and the delivery catheter and to enable the catheters to be manipulated in an axial direction as a single unit. 
     Alternatively, the delivery catheter and introducer catheter can be configured such that, when the delivery catheter is engaged with the introducer catheter, an inner core of the delivery catheter can be rotated relative to the introducer catheter and the introducer sheath (also referred to herein as an outer sheath). Alternatively, the delivery catheter can be configured such that the inner core thereof can be locked or substantially prevented from rotational movement relative to the outer sheath of the introducer catheter and/or relative to the introducer catheter. Also disclosed is a method of placement of a stent or medical prosthesis into a blood vessel, wherein the stent or medical prosthesis is passed through an introducer sheath and the proximal end of the introducer catheter physically engages with or is removably docked with a distal end portion of the delivery catheter to prevent substantial axial motion between the introducer sheath and the delivery catheter. 
     Some endoprostheses, including stents, grafts, stent grafts, and dissection treatment devices, (all such endoprostheses are collectively referred to herein as a stent or stents) may require precise placement in both axial and rotational direction. For example, stents or stent grafts with fenestrations require accurate placement of those fenestrations relative to the branch vessels. The catheter systems disclosed herein can be configured to allow for the rotation of the delivery catheter and, hence, the stent, relative to the introducer sheath, in some embodiments, the friction that can otherwise impede the rotational freedom of the delivery catheter can be further reduced by lining the inner surface of the introducer sheath and/or the tubular sheath of the deployment catheter with a low-friction coating such as polytetrafluoroethylene, silicone, hydrophobic silicone, or other lubricating substance, or by applying a hydrophilic coating to the outer surface of the inner core or restraining sheaths of the delivery catheter. The lubrication can be swabbed onto the target surface. 
     Thus, the introducer sheath can remain rotationally static or fixed while the delivery catheter is rotated within the introducer sheath. This can protect the delivery catheter and stent from being damaged, torqued, or stressed during the rotational manipulation of the delivery catheter and stent, and also prevent any damage or stress on the vessel wall from the rotation of the delivery catheter or stent. 
     Additionally, the delivery catheter can be configured to permit a user or medical practitioner to selectively control or prevent, the rotational movement of the delivery catheter and stent relative to the introducer catheter, or the inner core of the delivery catheter and stent relative to the outer sheath of the delivery catheter. For example, the delivery catheter can comprise a threaded hub supported at the proximal end portion of the delivery catheter configured to selectively constrict or tighten against an outer wall of the inner core of the delivery catheter. By constricting the hub against the inner core, the inner core can be prevented or inhibited from rotating relative to the introducer catheter. By loosening the hub relative to the inner core, the rotational freedom of the inner core or delivery catheter relative to the introducer sheath can be restored. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features, aspects and advantages will now be described in connection with certain embodiments, in reference to the accompanying drawings. The illustrated embodiments, however, are merely examples and are not intended to be limiting. The following are brief descriptions of the drawings. 
         FIG. 1A  is a schematic representation of a catheter system comprising a docking arrangement to physically engage a catheter with an introducer sheath. 
         FIG. 1B  is a schematic representation of the catheter system shown in  FIG. 1A , showing the catheter engaged with the introducer sheath. 
         FIG. 2A  is a schematic representation of another catheter system comprising a docking arrangement to physically engage a catheter with an introducer sheath. 
         FIG. 2B  is a schematic representation of the catheter system shown in  FIG. 2A , showing the catheter engaged with the introducer sheath. 
         FIG. 2C  is a schematic representation of the catheter system shown in  FIG. 2A , showing a mechanism for disengaging the catheter from the introducer sheath. 
         FIG. 3A  is a schematic representation of another catheter system comprising a docking arrangement to physically engage a catheter with an introducer sheath, the catheter system being configured to deliver a stent or stent graft into a blood vessel. 
         FIG. 3B  is a schematic representation of the catheter system shown in  FIG. 3A , showing the catheter engaged with the introducer sheath. 
         FIG. 3C  is a schematic representation of the catheter system shown in  FIG. 3A , illustrating the axial insertion of a stent into the tubular sheath of the introducer sheath shown in  FIG. 3A . 
         FIG. 3D  is a schematic representation of the catheter system shown in  FIG. 3A , illustrating the stent being deployed after the tubular sheath of the introducer sheath shown in  FIG. 3A  has been retracted from the stent. 
         FIG. 4  is an oblique view of a catheter system comprising an introducer and a delivery catheter. 
         FIG. 5  is an oblique view of the introducer shown in  FIG. 4 . 
         FIG. 6A  is a first exploded assembly view of the introducer shown in  FIG. 5 . 
         FIG. 6B  is a second exploded assembly view of the introducer shown in  FIG. 5 . 
         FIG. 7  is an oblique view of the delivery catheter shown in  FIG. 4 . 
         FIG. 8A  is a first exploded assembly view of the delivery catheter shown in  FIG. 7 , 
         FIG. 8B  is a second exploded assembly view of the delivery catheter shown in  FIG. 7 . 
         FIG. 9  is an oblique view of the catheter system shown in  FIG. 4 , showing the delivery catheter before the docking mechanism of the delivery catheter has been engaged with the docking mechanism of the introducer. 
         FIG. 10  is an oblique view of the catheter system shown in  FIG. 4 , showing the delivery catheter after the docking mechanism of the delivery catheter has been engaged with the docking mechanism of the introducer. 
         FIG. 11  is an end view of the catheter system shown in  FIG. 4 . 
         FIG. 12  is a cross-sectional view of the catheter system shown in  FIG. 4 , taken at line  12 - 12  of  FIG. 11 . 
         FIG. 13  is an enlarged cross-sectional view of the catheter system shown in  FIG. 4 , showing a close up of  13 - 13  of  FIG. 12 . 
         FIG. 14  is an enlarged section view of the catheter system shown in  FIG. 4 , showing a close up of  14 - 14  of  FIG. 13 . 
         FIG. 15  is a cross-sectional view of the catheter system shown in  FIG. 4 , taken at line  15 - 15  of  FIG. 11 . 
         FIG. 16  is an oblique view of a catheter system, having a delivery catheter assembly docked to an introducer catheter assembly. 
         FIG. 17  is an oblique view of the delivery catheter assembly of  FIG. 16 . 
         FIG. 18  is a top view of the delivery catheter assembly of  FIG. 16 . 
         FIG. 19  is a side view of the delivery catheter assembly of  FIG. 16 . 
         FIG. 20  is an oblique view of the delivery catheter assembly of  FIG. 16 , illustrating the sheath in a fully retracted position relative to the inner core member. 
         FIG. 21  is a side view of the delivery catheter of  FIG. 16 , showing the handle member and the inner core in a pre-deployment first position relative to the housing shaft of the delivery catheter. 
         FIG. 22  is a side view of the delivery catheter of  FIG. 16 , showing the handle member and the inner core in a second, partial deployment position relative to the housing shaft of the delivery catheter. 
         FIG. 23  is a side view of the delivery catheter of  FIG. 16 , showing the handle member and the inner core in a third, fully advanced position on the housing shaft of the delivery catheter. 
         FIG. 24  is an oblique view of the inner core engagement assembly and the inner core, showing the inner core in a first, disengaged position relative to the inner core engagement assembly, other components of the delivery catheter being removed from this view for clarity. 
         FIG. 25  is a cross-sectional view of a portion of the delivery catheter through the axial centerline of the delivery catheter, showing the inner core in the first, disengaged position relative to the inner core engagement assembly. 
         FIG. 26  is an oblique view of the inner core engagement assembly and the inner core as in  FIG. 24 , showing the inner core in a second, partially engaged position relative to the inner core engagement assembly. 
         FIG. 27  is a side view of the inner core engagement assembly and the inner core as in  FIG. 26 , showing the inner core in the second, partially engaged position relative to the inner core engagement assembly. 
         FIG. 27A  is a cross-sectional view of a portion of the delivery catheter taken through the line  27 A- 27 A of  FIG. 29 , showing one or more components of the delivery catheter in a first position. 
         FIG. 27B  is a cross-sectional view of a portion of the delivery catheter taken through the line  27 A- 27 A of  FIG. 29 , showing one or more components of the delivery catheter in a second position, 
         FIG. 28  is a top view of the inner core engagement assembly and the inner core as in  FIG. 26 , showing the inner core in the second, partially engaged position relative to the inner core engagement assembly. 
         FIG. 29  is a cross-sectional view of a portion of the delivery catheter through the axial centerline of the delivery catheter, showing the inner core in a second, partially engaged position relative to the inner core engagement assembly. 
         FIG. 30  is an oblique view of the inner core engagement assembly and the inner core as in  FIG. 24 , showing the inner core in a third, engaged position relative to the inner core engagement assembly. 
         FIG. 31  is a side view of the inner core engagement assembly and the inner core as in  FIG. 30 , showing the inner core in the third, engaged position relative to the inner core engagement assembly. 
         FIG. 32  is a top view of the inner core engagement assembly and the inner core as in  FIG. 30 , showing the inner core in the third, engaged position relative to the inner core engagement assembly. 
         FIG. 33  is a cross-sectional view of a portion of the delivery catheter through the axial centerline of the delivery catheter, showing the inner core in the third, engaged position relative to the inner core engagement assembly. 
         FIG. 34  is a cross-sectional view of a portion of the delivery catheter through the axial centerline of the delivery catheter, showing the inner core in the disengaged position relative to the inner core engagement assembly. 
         FIG. 35  is a cross-sectional view of a portion of the delivery catheter through the axial centerline of the delivery catheter, showing the inner core in the engaged position relative to the inner core engagement assembly. 
         FIG. 36  is an illustration of a prosthesis partially deployed by the delivery catheter. 
         FIG. 37  is a side view of an exemplifying stent that can be deployed with the delivery catheter illustrated in  FIG. 36 . 
         FIG. 38  is a schematic side view of a catheter system having an introducer catheter assembly showing a stent being loaded into an outer sheath of the introducer catheter. 
         FIG. 39  is a schematic side view of a catheter system having a deployment catheter assembly showing a stent supported therein, and a branch vessel wire assembly loaded in the delivery catheter. 
         FIG. 40  is a cross-sectional view of the branch vessel wire assembly taken at line  40 - 40  of  FIG. 39 . 
         FIG. 41  is an enlarged schematic view of a portion  41  . . .  41  of the branch vessel wire assembly of  FIG. 39 . 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description is now directed to certain specific embodiments. In this description, reference is made to the figures wherein like parts are designated with like numerals throughout the description and the drawings. Described below are various embodiments of a catheter system that can comprise an introducer sheath and a docking arrangement. The catheter systems disclosed herein can be used in diagnostic or therapeutic procedures such as, but not limited to, endoluminal vascular prosthesis deployment procedures. 
       FIG. 1A  is a schematic representation of a catheter system  10  comprising a docking arrangement configured to physically engage a catheter  20  with an introducer  12 .  FIG. 1B  is a schematic representation of the catheter system.  10  shown in  FIG. 1A , showing the catheter  20  engaged with the introducer  12 . The catheter  20  or any catheter disclosed herein can be a diagnostic or therapeutic catheter, or any other suitable catheter. The introducer  12  can comprise a tubular sheath  14 , a seal  16 , and a female docking mechanism  18 . The first seal  16  can be a rubber seal, an interference or close tolerance fit between adjacent components, an adjustable hemostasis valve, or any other suitable sealing component or feature. 
     The catheter  20  catheter has a shaft  24  and a male docking mechanism  22 . As illustrated in  FIG. 1B , the catheter  20  is inserted into the introducer  12  and the female docking mechanism  18  is engaged with the male docking mechanism  22 . The docking mechanism prevents the introducer  12  and the catheter  20  from moving axially with respect to each other when the docking mechanism is engaged. Additionally, the catheter system  10  is configured so that the catheter  20  can rotate within the introducer  12 , even when the catheter  20  is docked with the introducer  12 . 
     The introducer  12  comprises a tubular introducer sheath  14  and a seal  16  (which, again, can be a rubber seal, an interference or close tolerance fit, an adjustable hemostasis valve, or any other suitable scaling component or feature) connected to the proximal end of the introducer sheath  14 . The overall design of the sheath  14  and seal  16  may be similar to the design of commercially available introducers, or any other introducers presently known or later developed. The catheter  20  has an outside dimensional profile (crossing profile) that is sized and/or configured to pass through the introducer sheath  14 . The proximal end of the catheter  20  and the proximal end of the introducer sheath  14  are configured to permanently or removably engage with each other, and to allow for the rotation of the catheter  20  within the introducer sheath  14  while substantially limiting the axial movement of the catheter  20  with respect to the introducer sheath  14 . 
     With respect to the sizing of the introducer lumen versus the size of the outer sheath (containing the stent graft), in one configuration they are the same size and the introducer acts as a sheath, as the stent graft is pushed from its initial position within the outer sheath through to the lumen of the introducer. In a second configuration, the introducer lumen is larger than the outside diameter of the outer sheath and the two easily rotate relative to one another as needed for rotational alignment. Further, the introducer material can be softer or more flexible material than the outer sheath, so while the stent graft could be initially loaded into a strong high-strength sheath material, it could be extruded through to the lower strength more highly flexible introducer material for the short time needed to deliver the stent grafts to its treatment site, the materials that might be used to provide this feature, include any kind of soft polymer extrusion including Nylon. PEBAX, and PE. 
     After engagement of the catheter and introducer, the combined system is operable by a single operator. The catheter system  10  is configured so that the catheter  20  can substantially freely rotate within the introducer sheath  14 , which can allow for precise rotational positioning of the catheter within the introducer. After completion of the procedure, the catheter  20  is disengaged from the introducer  12  so that the catheter  20  can be removed from the patient&#39;s body. Additionally, the introducer  12  can be repositioned for a second intervention and a second catheter can be inserted and engaged with the introducer  12  for additional procedures. 
       FIG. 2A  is a schematic representation of a catheter system  40  comprising a docking arrangement to physically engage a catheter  50  with an introducer  42 .  FIG. 2B  is a schematic representation of the catheter system  40 , showing the catheter  50  engaged with the introducer  42 .  FIG. 2C  is a schematic representation of the catheter system  40  shown in  FIG. 2A , showing a mechanism for disengaging the catheter  50  from the introducer  42 . 
     In particular.  FIG. 2C  schematically illustrate that the catheter  50  can be disengaged from the male docking mechanism  52  and the introducer  42  by compressing the levers or tabs  56 . Accordingly, as illustrated the male docking mechanism  52  can be elongated and can comprise levers  56 . 
       FIG. 3A  is a schematic representation of a catheter system  60  comprising a docking arrangement to physically engage a catheter  70  with an introducer  62 , the catheter system  60  being configured to deliver a stent or stent graft  80  into a blood vessel. 
       FIG. 3B  is a schematic representation of the catheter system  60  shown in  FIG. 3A , showing the catheter  70  engaged with the introducer  62 .  FIG. 3C  is a schematic representation of the catheter system  60  shown in  FIG. 3A , illustrating the axial insertion of a stent or stent graft  80  into the tubular sheath  64  of the introducer  62  shown in  FIG. 3A .  FIG. 3D  is a schematic representation of the catheter system  60  shown in  FIG. 3A , illustrating the stent  80  being deployed after the tubular sheath  64  of the introducer  62  shown in  FIG. 3A  has been retracted from the stent  80 . 
     Self-expanding stent or stents grafts are typically retained in a deployment sheath within the delivery catheter. The deployment sheath can protect the stent or stent graft and the vessel wall from damage during insertion and can retain the stent or stent graft in a collapsed low-profile configuration during delivery. The stent or stent graft can be deployed in the desired position of the blood vessel by removing the deployment sheath and allowing the stent or stent graft to radially expand against the wall of the blood vessel. To pass such a delivery catheter into the desired blood vessel, the catheter system can be configured so that the inner diameter of the introducer sheath is larger than the outer diameter of the deployment sheath. Clinicians prefer a low profile of the introducer sheath to minimize damage to the blood vessel and allowing for access into small blood vessels. 
     Cartridge systems have been developed, in which the stent or stent graft can be transferred from delivery sheath into the introducer sheath and the stent or stent graft can be passed through the introducer sheath to the target location. In such cartridge systems, the introducer sheath effectively acts as a deployment sheath. The transfer eliminates the need for a second sheath and minimizes the profile of the system in the blood vessel. The docking arrangement provides a secure engagement of the delivery catheter and the introducer sheath prior to transfer of the stent or stent graft into the introducer sheath. This prevents potential user errors in the transfer and further converts the delivery catheter and introducer sheath into a single-user system. 
     As illustrated in  FIGS. 3A-3D , the catheter system  60  is used to transfer and deploy a stent or stent graft  80  into a blood vessel (blood vessel not shown). As illustrated therein, the introducer  62  comprises a tubular sheath  64  that is inserted into the body of the patient. The proximal end  62   a  of the introducer  62  can be sized and/or configured to accommodate the deployment sheath  74  of the catheter  70 . The introducer sheath can also have a seal  66  (referred to herein as a first seal) and a female docking mechanism  68 , similar to any of the embodiments of the seal, hemostasis valve, and/or docking mechanisms described above. The seal  66  can be an annular rubber seal (as illustrated), an interference or close tolerance fit between adjacent components, an adjustable hemostasis valve, or any other suitable sealing component or feature. The stent delivery catheter  70  can comprise an inner core  78 , a pocket  82  that can house the collapsed stent  80 , a deployment sheath  74  that can retain the collapsed stent  80 , and a catheter tip  76 . 
     As illustrated in  FIG. 38 , the catheter  70  can be inserted into the introducer  62  when the docking mechanisms  68  and  72  are engaged. In some embodiments (not illustrated), the deployment sheath  74  of the delivery catheter  70  can be sized and con-figured to be received within the larger diameter proximal end  62   a  of the introducer sheath and to extend into the distal tubular sheath  64  of the introducer  62 . Alternatively, the deployment sheath  74  of the delivery catheter  70  can be sized and configured to be received within the larger diameter proximal end  62   a  of the introducer sheath but not the distal tubular sheath  64  of the introducer  62 . In some embodiments, as illustrated in  FIGS. 3C and 3D , the deployment sheath  74  and the tubular sheath  64  can be sized and configured such that, when the deployment sheath  74  has advanced through the proximal end  62   a  of the introducer sheath, the similar size or shape of the distal tubular sheath  64  can prevent the deployment sheath  74  from advancing through the distal tubular sheath  64 . The inner and/or outer diameters of the deployment sheath  74  and the tubular sheath  64  can be substantially the same. 
     As illustrated in  FIG. 3C . The inner core  78  of the catheter  70  can be pushed distally, thereby transferring the stent  80  from the deployment sheath  74  into the tubular sheath  64  of the introducer  62 . The stent  80  can be advanced until the catheter tip  76  reaches the distal end of the tubular sheath  64 . In this configuration, the catheter/introducer system effectively becomes a single-unit deployment catheter. Thus, the tubular sheath  64  can function as a deployment sheath. The stent  80  can be advanced in a collapsed configuration within the protective introducer  62  to the target location in the blood vessel without increasing the profile of the delivery system. If the delivery catheter were passed through a traditional introducer sheath, the sheath of the introducer would have to be of a larger diameter than the deployment sheath of the delivery catheter to accommodate the stent and the deployment sheath. 2) other advantages which were mentioned: 
     in the configuration described the device can be rotated after it has been introduced to the introducer, but before it is deployed, further the device can be accurately position as a result of the low friction between the introducer and the outer sheath. When devices having an expanded diameter of 25 and 28 mm diameter devices are to be used, the same (one size) introducer sheath can be used for either and both devices delivery. Only when a larger 34 mm diameter device, having a larger compressed crossing profile, is to be delivered, is it necessary to use a larger introducer. The fact that the introducer and delivery catheter mechanically engage and create a single unitary structure which can be held by one hand, allows a single user to manipulate the whole system with two hands) one hand holding the core stationary and the second hand manipulating the sheath retraction mechanism. 
     As is known in the art, delivery catheters with loaded stent grafts typically have less trackability and pushability than an introducer sheath supported by a dilator. This is due to the fact that the stent grafts alter the local stiffness of the catheters. This can lead to kinking of the delivery catheter during insertion. By placing the introducer sheath with a dilator first, a conduit for placing the stent graft is established. Kinking of the delivery system pacing through the sheath is very unlikely. 
       FIG. 4  is an oblique view of another catheter system  100  comprising an introducer catheter  102  (also referred to as an introducer) and a delivery catheter  104 . The delivery catheter  104  can be configured for the delivery of an endoluminal prosthesis, or for any other suitable use. Therefore, the embodiments of the catheters and introducers disclosed herein can be configured for any suitable purpose, and the embodiments of the introducers disclosed herein can be configured to receive any suitable catheter design. 
       FIG. 5  is an oblique view of the introducer  102  of the catheter system  100  shown in  FIG. 4 .  FIGS. 6A and 6B  are a first and a second exploded assembly view of the introducer  102  shown in  FIG. 5 . With reference to  FIGS. 4-6 , the introducer  102  can have a main body  106 , a threadably engageable hub portion  108 , an introducer sheath  110 , and a threaded cap  111  configured to threadably engage with a threaded end portion of the main body  106 . 
     In some embodiments, a first tube  107  can be supported by the main body  106  so as to provide an orifice or access port into the main body  106 . The first tube  107  can be used to flush the introducer  102  with saline or other suitable substances at any stage, such as but not limited to prior to the advancement of an endoluminal prosthesis through the introducer  102 , or prior to other procedures for which an introducer may be used. The first tube  107  can support any suitable medical connector and/or valve on the distal end thereof. 
     The introducer sheath  110  can have an elongate portion  110   a  extending to any predetermined or desired length. As will be discussed in greater detail below, similar to the introducer  12  of the catheter system  10  described above, the introducer sheath  110  can be configured such that an endoluminal prosthesis that is advanced into the introducer sheath  110  can be constrained or restrained by the introducer sheath  110 . In this arrangement, the inside and/or outside diameter of the introducer sheath  110  can be approximately the same as or similar to the inside and/or outside diameter of the outer sheath of a delivery catheter that is engaged with the introducer  102 . The elongate portion  110   a  can be circular in cross-section (as illustrated), or can define any suitable cross-sectional shape such as without limitation triangular, square, hexagonal, octagonal, or polygonal. 
     Further, as shown most clearly in  FIG. 6A , the introducer sheath  110  can have a flared end portion  110   b  that can be configured to abut against a fore surface  106   a  of the main body  106 . With reference to  FIG. 6A , the elongate portion  110   a  of the introducer sheath  110  can pass through an opening formed in the cap  111  so that the flared portion  110   b  of the introducer sheath  110  can be engaged with and/or overlap an inside surface of the cap  111 . In this configuration, the cap  11  supporting the introducer sheath  110  can be threadedly engaged with the main body  106  so that the introducer sheath  110  can be supported by the main body  106 . 
     Additionally, with reference to  FIGS. 6A and 6B , a tubular support or spacer  109  can be inserted over the elongate portion  110   a  of the introducer sheath  110  and positioned approximately adjacent to the flared portion  110   b . The tubular spacer  109  can improve the fit and, hence, the seal between the outside surface of the introducer sheath  110  and the cap  111 . The tubular spacer  109  can also provide additional support to the introducer sheath  110 . 
       FIG. 7  is an oblique view of the delivery catheter  104  of the embodiment of the catheter system  100  shown in  FIG. 4 . 
       FIGS. 8A and 8B  are a first and second exploded assembly view of the delivery catheter  104  shown in  FIG. 7 . 
       FIG. 9  is an oblique view of the catheter system  100  shown in  FIG. 4 , showing the delivery catheter  104  before the docking mechanism of the delivery catheter  104  has been engaged with the docking mechanism of introducer  102 . 
       FIG. 10  is an oblique view of the catheter system  100  shown in  FIG. 4 , showing the delivery catheter  104  after the docking mechanism of the delivery catheter  104  has been engaged with the docking mechanism of the introducer  102 . 
       FIG. 11  is an end view of the catheter system shown in  FIG. 4 , with the delivery catheter  104  engaged with the introducer  102 .  FIG. 12  is a section view of the embodiment of the catheter system  100  shown in  FIG. 4 , taken at line  12 - 12  of  FIG. 11 .  FIG. 13  is an enlarged section view of the catheter system  100  shown in  FIG. 4 , defined by curve  13 - 13  of  FIG. 12 .  FIG. 14  is an enlarged section view of the embodiment of the catheter system shown in  FIG. 4 , defined by curve  14 - 14  of  FIG. 13 . Finally,  FIG. 15  is a section view of the catheter system shown in  FIG. 4 , taken at line  15 - 15  of  FIG. 11 . 
     As shown most clearly in  FIGS. 12 and 15 , the hub portion  108  of the introducer  102  can have a docking mechanism or flange  112  or can be configured to removably receive or engage with the delivery catheter  104 . In some embodiments, as in the illustrated embodiment, the docking mechanism  112  of the introducer  102  can be configured to be a female receiver, con-figured to receive a male docking member of the catheter  104 , as will be described below. The hub portion  108  can comprise one or more tabs  114  configured to improve a user&#39;s grip on the hub portion  108 , and ability to rotate the hub portion  108  relative to the main body  106 . 
     With reference to  FIGS. 12, 13, and 15 , some embodiments of the seal portion of the introducer  102  will be described. As mentioned above, the hub portion  108  can be configured to be threadably engageable with the main body  106 . The main body  108  can define an inner annular surface  116  that can be angled (so as to not be perpendicular to the axial centerline of the catheter system  100 ). The surface  116  can be angled approximately 75 degrees relative to the axial centerline of the catheter system  100 , or from approximately 65 degrees or less to approximately 80 degrees or more relative to the axial centerline of the catheter system  100 . The surface  116  can be approximately perpendicular to the axial centerline of the catheter system  100 . 
     Similarly, the hub portion  108  can define an inner annular surface  118  that can be angled so as to not be perpendicular to the axial centerline of the catheter system  100 . The surface  118  of the hub portion  108  can be angled approximately 75 degrees relative to the axial centerline of the catheter system  100 , or from approximately 65 degrees or less to approximately 80 degrees or more and relative to the axial centerline of the catheter system  100  in a direction that is opposite to the direction of the angle defined by the surface  116  of the main body  106 . In some embodiments, as in the illustrated embodiment, the shape and angular orientation of the surface  118  of the hub portion  108  can approximately mirror the shape and angular orientation of the surface  116  of the main body  106 . The surface  118  can be approximately perpendicular to the axial centerline of the catheter system  100 . 
     An annular seal member  120  can be supported by the introducer  102  and positioned between the surface  116  of the main body  106  and the surface  118  of the hub portion  108 . The seal member  120  can be formed from a resilient material, such as silicone, rubber or any other suitable material. The seal member  120  can be configured such that, when the hub portion  108  is threaded onto the main body  106 , the surface  118  of the hub portion  108  can be moved axially toward the surface  116  of the main body  106 , thereby compressing or squeezing the seal member  120 . The relative angles of the surface  116  of the main body  106  and the surface  118  of the hub portion  108  can cause the seal member  120  to be forced against an outer sheath  122  of the delivery catheter  104  or other component of the delivery catheter  104  that is engaged with the introducer  102 , thereby creating an adjustable seal between the outer sheath  122  of the delivery catheter  104 , which can project distally from an end portion of the delivery catheter  104 , and the introducer  102 . The level of seal can be adjusted by tightening or loosening the hub portion  108  of the introducer  102  relative to the main body  106  of the introducer  102 . The introducer  102  can be configured to provide a seal against devices with a profile ranging from 1 Fr to 20 Fr. 
     Alternatively, in some embodiments, any of the seals or seal portions described herein can be an interference or close tolerance fit between adjacent components such as, the outer sheath  122  and one or more inside surfaces of the main body  106  or the hub portion  108  of the introducer  102 . In some embodiments, any of the seals or seal portions described herein can be an interference or close tolerance fit between the inner core  154  and one or more inside surfaces of the main body  140  or the hub portion  142  of the catheter  104 . 
     As shown in  FIGS. 7, 8A, and 88 , some embodiments of the delivery catheter  104  can comprise a main body  140  and a hub portion  142  threadably engageable with the main body  140 . Some embodiments of the delivery catheter  104  can also have an outer sheath  122  supported by the main body  140 . In particular, the outer sheath  122  can be removably sup-ported by the main body  140  using a cap  123  threadably supported by the main body  140 . Further, the outer sheath  122  can have an elongate portion  122   a  extending to any predetermined or desired length. 
     As mentioned above, the inside and/or outside diameter of the outer sheath  122  of a delivery catheter  104  can be approximately the same as or similar to the inside and/or outside diameter of the introducer sheath  110 . The elongate portion  122   a  can be circular in cross-section (as illustrated), or can define any suitable cross-sectional shape such as without limitation triangular, square, hexagonal, octagonal, or polygonal. 
     The outer sheath  122  can have a flared end portion  122   b  that can be configured to abut against a fore surface  140   a  of the main body  140 . With reference to  FIG. 8A , the elongate portion  122   a  of the outer sheath  122  can pass through an opening formed in the cap  123  so that the flared portion  122   b  of the outer sheath  122  can be engaged with and/or overlap an inside surface of the cap  123 . In this configuration, the cap  123  supporting the outer sheath  122  can be threadedly engaged with the main body  140  as mentioned above so that the outer sheath  122  is supported by the main body  140 . 
     Additionally, with reference to  FIGS. 8A and 8B , a tubular support or spacer  125  can be inserted over the elongate portion  122   a  of the outer sheath  122  and positioned approximately adjacent to the flared portion  122   b  of the outer sheath  122 . The tubular spacer  125  can improve the fit and, hence, the seal between the outside surface of the outer sheath  122  and the cap  123 . The tubular spacer  125  can also provide additional support to the outer sheath  122 . 
     Similar to the hub portion  108  of the introducer  102 , the hub portion  142  of the delivery catheter  104  can be configured to be threadably engageable with the main body  140  of the delivery catheter  104 . The main body  140  can define an inner annular surface  146  that can be angled so as to not be perpendicular to the axial centerline of the catheter system  100 . The surface  146  can be angled approximately 75 degrees relative to the axial centerline of the catheter system  100 , or from approximately 80 degrees or more to approximately 65 degrees or less relative to the axial centerline of the catheter system  100 . The surface  146  can be approximately perpendicular to the axial centerline of the catheter system  100 . 
     In some embodiments, a second tube  141  can be supported by the main body  140  so as to provide an orifice or access port into the main body  140 . The second tube  141  can be used to flush the delivery catheter  104  with saline or other suitable substances at any stage, such as but not limited to prior to the advancement of an endoluminal prosthesis through the delivery catheter  104  and/or introducer  102 , or prior to other procedures for which an delivery catheter may be used. The second tube  141  can support any suitable medical connector and/or valve on the distal end thereof. 
     Similarly, the hub portion  142  can define an inner annular surface  148  that can be angled so as to not be perpendicular to the axial centerline of the catheter system  100 . The surface  148  of the hub portion  142  can be angled approximately 75 degrees relative to the axial centerline of the catheter system  100 , or from approximately 65 degrees or less to approximately 80 degrees or more relative to the axial centerline of the catheter system  100  in a direction that is opposite to the direction of the angle defined by the surface  146  of the main body  140 . The surface  148  can be approximately perpendicular to the axial centerline of the catheter system  100 . 
     Similar to that of the introducer, in some embodiments, a seal or seal portion comprising an annular seal member  150  can be supported by the delivery catheter  104  and positioned between the surface  146  of the main body  140  and the surface  148  of the hub portion  142 . The seal member  150  can be formed from a resilient material, such as silicone, rubber or any other suitable material. The seal member  150  can be configured such that, when the hub portion  142  is threaded onto the main body  140 , the surface  148  of the hub portion  142  can be moved axially toward the surface  146  of the main body  140 , thereby compressing or squeezing the seal member  150 . The relative angles of the surface  146  of the main body  140  and the surface  148  of the hub portion  142  can cause the seal member  150  to be forced against the inner core  154  of the delivery catheter  104 , thereby creating an adjustable seal between the inner core  154  the outer sheath  122  of the delivery catheter  104 . 
     The level of seal can be adjusted by tightening or loosening the hub portion  142  of the delivery catheter  104  relative to the main body  140  of the delivery catheter  104 . Additionally, The rotational freedom of inner core  154  of the delivery catheter  104  can be inhibited or prevented by tightening the seal member  150  as described above. Thus, the force exerted by the seal member  150  on the inner core  154  can be adjusted to permit the inner core  154  and/or other components to rotate relative to the main body  140  and hub portion  142  of the delivery catheter  104 . As illustrated in  FIG. 4 , an end portion or cap  158  can be supported at the proximal end of the inner core  154  to facilitate a user&#39;s ability to axially slide and/or rotate that inner core  154  relative to the main body  140  and hub portion  142  of the delivery catheter  104 . The cap  158  can have wings or tabs formed thereon to increase the torque or rotational force that can be exerted on the inner core  154 . Alternatively, The seal or seal portion within the catheter  104  can be formed from an interference or close tolerance fit between adjacent components such as, without limitation, the inner core  154  and one or more inside surfaces of the main body  140  or the hub portion  142  of the catheter  104 . 
     The inner core  154  can have a band or other marking  155  near a distal end thereof. The marking  155  can be sized, positioned, and configured to provide a visual indication to the medical practitioner as to the location of the end portion  154   a  of the inner core  154  and/or the location of a catheter tip  162  as the inner core  154  is being advanced into or withdrawn from the introducer  102 . 
     In some embodiments, as illustrated most clearly in  FIGS. 12 and 13 , an additional seal member  160  can be supported by the main body  106  of the introducer  102  to provide an additional seal between the outer sheath  122  of the delivery catheter  104  and the introducer  102 . The seal  160  can be a flap type seal formed from a conically shaped piece of resilient material such as, but not limited to, rubber having one or more slits therein to allow the distal tip  162  and the outer sheath  122  to pass therethrough. In some embodiments, a supported flange  161  can be supported within the main body  106  and positioned behind the seal  160  to support the seal  160  and maintain the position of the seal  160  so that the seal  160  does not become inverted when the delivery catheter  104  is removed from the introducer  102 . The distal tip  162  can be formed from a soft material such as rubber and can be configured to be atraumatic so as to prevent any damage to a patient&#39;s vasculature as the catheter  104  is being advanced through the patient&#39;s vasculature. 
     As mentioned above, in some embodiments, as in the illustrated embodiment, the docking mechanism  112  of the introducer  102  can be configured to receive a male docking member or portion of the catheter  104 . In particular, with reference to  FIGS. 7, 8A and 8B , one or more deflectable tabs  170  can be supported by the main body  140  of the catheter  104 . The tabs  170  can be deflected by pressing or exerting a radial inward force against pads  172 , causing the ends of the tabs  170  to move radially inward toward the axial centerline of the main body  104 . By deflecting the tabs  170  inwardly, the main body  140  of the catheter  104  can be moved axially into engagement with the hub portion  108  of the introducer  102 . The tabs  170  can be automatically deflected inwardly when the main body  140  of the catheter  104  is moved axially into engagement with the hub portion  108  of the introducer  102 . Once the main body  140  of the catheter  104  is moved axially into engagement with the hub portion  108  of the introducer  102  so as to abut against the hub portion  108  of the introducer, the tabs  170  can be released, thereby removably locking the main body  140  of the catheter  104  to the hub portion  108  of the introducer  102 . 
     In this configuration, the catheter  104  can be axially engaged with or locked to the introducer  102  so that a user can axially manipulate the introducer  102  and the catheter  104  simultaneously. Additionally, in some embodiments, in this configuration, as discussed above, the catheter system  100  can be configured such that at least the inner core  154  of the catheter  104  can be rotated relative to the main body  140  of the catheter  104  and the introducer  102 . 
     In some embodiments, as shown in  FIGS. 7, 8A, and 8B , the inner core  154  has a central tube or wire  176  configured to support a stent, such as stent  157  illustrated in  FIGS. 7 and 12-1.4 . Additionally, one or more beads or tabs  174  can be formed on or supported by the central tube or wire  176 . The tabs  174  can be configured to increase the axial support or connection between the inner core  154  and an endoluminal prosthesis supported by the central tube  176  when the prosthesis is supported in a collapsed configuration by the central tube  176 . The catheter  104  can be configured such that an opening passes through the distal tip  162 , the central tube  176 , and the inner core  154 . The opening can be configured so that at least the distal tip  162 , the central tube  176 , and the inner core  154  can be advanced over a guidewire positioned within a patient&#39;s vasculature, such as is described in U.S. patent application Ser. No. 12/101,863 filed on Apr. 11, 2008 (titled: BIFURCATED GRAFT DEPLOYMENT SYSTEMS AND METHODS), which application is hereby incorporated by reference in its entirety as if fully set forth herein. 
     Additionally, in some embodiments (not illustrated), the tabs  174  can be sized, spaced, and otherwise configured to provide axially support to multiple individual stent segments. For example, without limitation, multiple independent or tethered stent segments can be positioned within a tubular or bifurcated graft, and the stent graft can be positioned relative to the tabs  174  such that the tabs  174  are positioned between the stent segments. This arrangement can reduce the overall diameter of the outer sheath  122 , the introducer sheath  110 , and other components comprising the catheter system, can enhance the axial support provided by the tabs  174  to the endoluminal prosthesis, and can allow for a more uniform distribution of support forces between the tabs  174  and the endoluminal prosthesis. The tabs  174  can be sized, spaced, and otherwise configured so as to be positioned adjacent to the links, bends, loops, and/or other connectors formed in a tubular or bifurcated stent, such as the links, bends, loops, and/or other connectors comprising the embodiments of the stents disclosed in U.S. Pat. No. 6,077,296 titled ENDOLUMINAL VASCULAR PROSTHESIS, which patent is hereby incorporated by reference as if fully set forth herein. 
     With reference to  FIGS. 13-15 , the outer sheath  122  of the deployment catheter  104  can be advanced into an axial opening within the introducer  102  when the deployment catheter  104  is engaged with the introducer  102 . The outer sheath  122  can be sized and configured such that the distal end portion  122   c  of the outer sheath  122  can terminate within the introducer  102  prior or proximal to the proximal end or flared portion  110   b  of the introducer sheath  110 . Although not required, the introducer  102  can have a constricted portion  113  formed in the main body  106  of the introducer. In some embodiments, as shown most clearly in  FIG. 14 , the catheter system  100  can be configured such that the distal end  122   c  of the outer sheath  122  terminates prior to or approximately adjacent to a constricted portion  113  of the main body  106  of the introducer  102 . 
     In some embodiments (not illustrated), the distal end portion  122   c  of the outer sheath  122  can be positioned near to or approximately adjacent to the proximal end portion or the flared portion  110   b  of the introducer sheath  110 , regardless of whether the catheter  104  has a constricted portion  113 . The inner diameter of the constricted portion  113  can be approximately the same as the inner diameter of the outer sheath  122  and/or the inner diameter of the introducer sheath  110 . 
     Therefore, The outer sheath  122  of the catheter  104  and the introducer sheath  110  can be configured to provide a lumen having a generally uniform cross-sectional size through the catheter system through which the endoluminal prosthesis can be advanced. The lumen through the catheter system  100  through which the endoluminal prosthesis can be advanced can be substantially continuous, so that the endoluminal prosthesis can be advanced through the catheter system  100  without the pros-thesis being obstructed by or snagging on any components or features of the catheter system  100  as it is being advanced. The lumen can be substantially continuous but have short gaps on the order of approximately 1 mm to approximately 3 mm in the lumen such as, without limitation, adjacent to the distal end of the outer sheath  122  of the catheter  104  and/or adjacent to the proximal or flared end  110   b  of the introducer sheath  110 . For example, in some embodiments, short gaps can be formed adjacent to the distal end of the outer sheath  122  of the catheter  104  and/or adjacent to the proximal or flared end  110   b  of the introducer sheath  110  as some components comprising the catheter system  100  are threadedly engaged with other components comprising the catheter system  100 . Further, in some embodiments, one or more surfaces of other components comprising the catheter  104  or the introducer  102  in addition to the outer sheath  122  and the introducer sheath  110 , such as without limitation the constricted portion  113  of the main body  106  of the introducer  102  as discussed above, can form portions of the lumen through the catheter system  100 . 
     The outer sheath  122  can constrain or restrain an endoluminal prosthesis supported by the central tube  176  as described above. In this configuration, as the catheter tip  162 , central core  154 , and an endoluminal prosthesis (such as, but not limited to, stent  157  illustrated in  FIGS. 7 and 12-14 ) are advanced through the outer sheath  122 , the outer sheath  122  can restrain the endoluminal prosthesis and prevent the endoluminal pros-thesis from expanding before reaching the target position within the patient&#39;s vasculature. Additionally, the catheter system  100  can be configured such that, as the catheter tip  162 , central core  154 , and endoluminal prosthesis are advanced past the distal end  122   c  of the outer sheath  122 , the constricted portion  113  and, subsequently, the introducer sheath  110  can radially restrain the endoluminal prosthesis as the endoluminal prosthesis is advanced through the introducer sheath  110 . 
     The endoluminal prosthesis or the stent  157  can be a tubular stent, a bifurcated stent, or any other desirable stent, graft, stent graft, or endoluminal prosthesis (collectively referred to herein as stent or stents), including without limitation any of the stents or grafts disclosed in U.S. patent application Ser. No. 12/101,863 referenced above and incorporated herein by reference as if fully set forth herein. Accordingly, the catheter system  100  or catheter  104  can be configured to deploy any suitable or desirable stent or stents. 
     Thus, in this configuration, the endoluminal prosthesis can be transferred from the outer sheath  122  to the introducer sheath  110 . In this arrangement, using the introducer sheath  110  as the restraint can allow the outside diameter of the introducer sheath  110  to be reduced, which can minimize trauma to the patient&#39;s vasculature and assist in the deployment of the endoluminal prosthesis. 
     Many embodiments of the docking mechanism and catheter system have been described in connection with  FIGS. 1-15 . It will apparent to one of ordinary skill in the art that there are many potential embodiments of a permanent or removable docking mechanism that may be suitable for medical use and which are contemplated herein. For example, in some embodiments, a nut-screw combination could be used to connect the introducer sheath and the catheter. As another example, a bayonet style locking mechanism, such as is used for camera lenses, can also be used. In some embodiments, any of the components or features of some embodiments of the catheters disclosed herein or other catheters available in the field can be combined to form additional embodiments, all of which are contemplated herein. 
     The catheter system disclosed in  FIG. 16  has an introducer catheter assembly, also referred to herein as an introducer catheter, and a delivery catheter assembly, also referred to herein as a delivery catheter. 
     The catheter systems disclosed herein can be used for diagnostic or therapeutic procedures such as, but not limited to, endoluminal vascular prosthesis deployment procedures. It should be apparent to one skilled in the art that the catheter system embodiments disclosed herein can be used for delivering prostheses for supporting body tissue in general as well as various blood vessels and aneurysms. Examples of such blood vessels that can be treated with the catheter system embodiments disclosed herein include the aorta, aortic aneurysms such as abdominal aortic aneurysms, saphenous vein grafts, the vena cava, the renal arteries, the iliac arteries, the femoral arteries, the popliteal artery, the carotid artery, the cranial arteries, pulmonary arteries, etc. Other organs or body tissue that can be treated with some catheter system embodiments disclosed herein include the prostate, the biliary tract, the esophagus, the trachea, the fallopian tubes, the vas deferens, the ureters, the tear ducts, the salivary ducts. 
     The catheter systems disclosed herein can be configured for deployment of a wide range of endoluminal prostheses, including mechanically expandable stents, self-expanding stents, drug eluting stents, grafts, bifurcated and non-bifurcated stent grafts, fenestrated stent grafts, suprarenal stent extensions, stent segments, dissection treatment devices, medical prostheses deployable in any suitable region of the body, and any of the stents or prostheses disclosed in U.S. application Ser. No. 12/101,863, filed Apr. 11, 2008. U.S. application Ser. No. 12/496,446, filed Jul. 1, 2009, U.S. application Ser. No. 12/769,506, filed Apr. 28, 2010, and U.S. Pat. No. 6,077,296, which are hereby incorporated by reference as if fully set forth herein. 
     The stent can have an oversized graft have a mid portion that is not sutured or otherwise attached to the stent frame. In this configuration, the mid portion can be permitted to expand against an inside wall of the vessel or passageway to further improve the seal between the graft and the vessel wall. Additionally, the stent can have an oversized graft of highly collapsible, flexible material (e.g., expanded polytetrafluoroethylene) such that, when the stent is expanded, the graft can form tight folds in the seal zone to reduce cross-sectional area of leak zones between the stent and the vessel wall. 
     For simplicity, all such foregoing stents or prostheses are collectively referred to herein as a stent or stents unless otherwise defined. Therefore, while illustrations and the disclosure that follows may describe stents and may show deployment in a particular passageway or in a region of the body, it is contemplated that any of the embodiments disclosed herein can be used, with or without modifications within the capabilities of one of ordinary skill in the art, for deployment of any desired prosthesis in any suitable portion of the body. 
       FIG. 16  is an oblique view of a catheter system  100 , having a delivery catheter assembly  104  docked to an introducer catheter assembly  102 .  FIGS. 17-19  are oblique, top, and side views, respectively, of the delivery catheter assembly  104  of  FIG. 1 . With reference to  FIGS. 16-17 , the catheter system  100  has a docking arrangement wherein a proximal end portion of an introducer catheter assembly  102  can receive and dock with a distal end portion  121   a  of the main body  121  (also referred to herein as housing member or housing shaft) of a delivery catheter assembly  104 . The introducer catheter  102  can have an outer sheath  110  (also referred to herein as an introducer sheath) supported by and extending from a distal end portion of the introducer catheter  102 . Similarly, the delivery catheter assembly  104  has a tubular sheath  127  (also referred to herein as a delivery catheter sheath) extending from a distal end portion  121   a  of the housing shaft  121 . The sheath  127  can be made from polyether ether ketone (PEEK), or any other suitable material. 
     Additional details regarding the features and components of such a docking arrangement and other details regarding the catheter system are disclosed in U.S. application Ser. No. 12/101,863, filed Apr. 11, 2008, entitled “BIFURCATED GRAFT DEPLOYMENT SYSTEMS AND METHODS” and U.S. application Ser. No. 12/496,446, filed Jul. 1, 2009, entitled “CATHETER SYSTEM AND METHODS OF USING SAME.” both incorporated by reference as if fully set forth herein. Any of the embodiments of the catheter systems, the delivery catheters, and the introducer catheters disclosed herein can have any of the components, features, materials, or other details of any of the embodiments of the catheters disclosed in the foregoing applications, which combinations are made part of this disclosure. 
     One or more stents can be loaded in, supported by, and delivered by the catheter system  100  embodiments disclosed herein. A stent or stents can be loaded into the delivery catheter assembly  104  during assembly of the delivery catheter assembly  104  or just before the surgical procedure by compressing the stent around an outer surface of an inner core member  115  of the delivery catheter assembly  104 . 
     A removable restraint and/or an outer sheath of the introducer catheter and/or delivery catheter can hold the stent in a compressed state. In the compressed state, the stent can be held in a generally fixed axial position relative to the inner core such that axial or rotational movement of the inner core will result in axial and rotationally movement of the stent. As will be discussed, the inner core can have features, such as fins, beads, tabs, or other projections, to improve the traction or grip between the compressed stent and the inner core or inner core wire, the inner core with the stent compressed around the outer surface thereof will be advanced through a constriction element in or adjacent to the introducer catheter to compress the stent to the approximate inner diameter of the outer sheath projecting from the introducer catheter. 
     The inner core member  115  can have a core wire  117  forming a portion of the inner core member  115 . An atraumatic distal tip  119  can be supported at a distal end portion of the core wire  117 . The inner core member  115 , core wire  117 , and the distal tip  119  can comprise a continuous lumen therethrough, being configured to receive a guide wire therein such that the inner core member  115 , the core wire  117 , and the distal tip  119  can be advanced over the guide wire, the stent can be collapsed or compressed about at least a portion of the inner core wire  117  in the stent loaded condition. 
     As mentioned, the catheter system can be configured such that the inner core member  115  is axially slidable relative to the outer sheath  110 . In this configuration, the stent can be deployed in the target region of the patient&#39;s vasculature by retracting the outer sheath  110  relative to the inner core member  115 , thereby exposing the stent. In some embodiments where the outer sheath  110  provides radial constraint to the stent, exposing the stent will permit a self-expanding stent to self-expand against the vessel wall as the outer sheath  110  is being retracted. 
     As will be described in greater detail, some embodiments of the catheter system  100  disclosed herein are configured such that, when a user or surgeon manipulates the delivery catheter assembly  104  slowly and with mechanical advantage in a first manner, the delivery catheter can be used to slowly and controllably deploy a stent or a portion of a stent from the delivery catheter assembly  104 . Some embodiments of the catheter system disclosed herein are further configured such that, when a user or surgeon manipulates the delivery catheter assembly  104  quickly by directly pulling the adjustment member in a second manner, the delivery catheter assembly  104  is used to more rapidly deploy the stent or a portion of the stent from the delivery catheter assembly  104 . 
     The catheter systems disclosed herein can be configured to accommodate any combination of the manners of deployment described above. For example, the user or surgeon can initially manipulate the delivery catheter in the first manner to slowly deploy the stent from the delivery catheter assembly  104  and then, once the proper positioning of the partially deployed stent is confirmed, the surgeon can then manipulate the delivery catheter assembly  104  in the second manner to rapidly deploy the remainder of the stent. 
     With reference to  FIG. 16 , a distal end portion  121   a  of the housing shaft  121  of the delivery catheter assembly  104  is removably and axially supported by a female receiving portion  105  supported at a proximal end portion of the introducer catheter  102 . The introducer catheter  102  supports an outer sheath  110  at a distal end thereof, the outer sheath  110  defining a lumen therethrough that is configured to slidably receive an inner core member  115  therein. The inner core member  115  can be slidably advanced through an opening or lumen in the delivery catheter assembly  104 , through an opening or lumen in the introducer catheter  102 , and through a lumen in the outer sheath  110 . 
     The delivery catheter assembly  104  has a main body or housing shaft  121  having a distal end portion  121   a  and a proximal end portion  121   b . The housing shaft  121  pounds a generally tubular cross-sectional shape, and has external threads  126  along a portion of the housing shaft  121  (referred to as the threaded portion  126 ). 
     The housing shaft  121  supports a slidable handle member  128  that can be configured to slide axially along the housing shaft  121  between the distal end portion  121   a  of the housing shaft  121  and an rotatable adjustment member  130  supported by the housing shaft  121 . As will be described, the delivery catheter assembly  104  is configured such that the handle member  128  is selectively engageable with the inner core member  115 . When in the engaged configuration, movement of the handle member  128  results in simultaneous and equal movement of the inner core member  115 , the delivery catheter assembly  104  can be configured such that the handle member  128  is prevented from rotating relative to the housing shaft  121  and, consequently, the introducer catheter  102  and outer sheath  110 , to prevent any inadvertent rotation of the inner core member  115  when the handle member  128  is engaged with the inner core member  115 . 
     The threaded portion  126  extends along approximately 60% of the length of the housing shaft  121 . The threaded portion  126  can extend along approximately 40% to approximately 70% of the length of the housing shaft  121 . The threaded portion  126  can be positioned adjacent to the proximal end portion  121   b  of the housing shaft  121 . The length of the threaded portion  126  can be from approximately 20% to approximately 200% of the length of the stent to be deployed by the catheter. For example, if only the proximal end portion of the stent is to be deployed by rotation of the adjustment member  130 , the length of the threaded portion can be approximately from 20% to approximately 50% of the length of the stent. As used throughout this disclosure, the term approximately can mean plus or minus 15% of the stated value. 
     Preventing the rotational movement of the handle member  128  can be achieved in any number of ways. For example, the handle member  128  has a tab, protrusion, or similar feature or features that can project into one or more channels or slots formed in the housing shaft  121 . As illustrated in  FIG. 16 , the housing shaft  121  can have a single slot  134  extending in a linear fashion along a portion of the length of the housing shaft  121 , the slot  134  configured to slidingly receive therein a tab, protrusion, or other similar feature supported by the handle member  128 . 
     The handle member  128  pounds an inner core engagement assembly  139  supported by the handle member  128 . As mentioned, the delivery catheter assembly  104  is configured such that, when the inner core member  115  is axially engaged with the handle member  128 , any axial movement of the handle member  128  will result in simultaneous axial movement of the inner core member  115  relative to the introducer catheter  102  and the outer sheath  110 . Depressing the inner core engagement assembly  139  can release the inner core member  115  from the handle member  128  so that the inner core member  115  can be axially moved relative to the handle member  128 . In some configurations, the inner core member  115  can be rotated relative to the handle member  128  even when the inner core member  115  is axially engaged with the handle member  128 . 
     As mentioned, the rotatable adjustment member  130  is supported by the housing shaft  121 . The rotatable adjustment member  130  is threadedly engaged with the outer threads on the threaded portion  126  of the handle member  128 . In this configuration, rotating or turning the rotatable adjustment member  130  in one direction causes the rotatable adjustment member  130  to advance along the threads and move in an axial direction toward the distal end portion  121   a  of the housing shaft  121 . Rotating or turning the rotatable adjustment member  130  in a second, opposite direction causes the rotatable adjustment member  130  to move in an axial direction away from the distal end portion  121   a  of the housing shaft  121  of the delivery catheter assembly  104 . As a result of the threaded engagement between the rotatable adjustment member  130  and the housing shaft  121 , the rotatable adjustment member  130  can be prevented from axially sliding relative to the housing shaft  121 . Accordingly, the handle member  128  can axially slide but be prevented from rotating relative to the housing shaft  121 , and the rotatable adjustment member  130  can rotate but be prevented from axially sliding relative to the housing shaft  121 . 
     In use, a surgeon may grasp the handle member  128  with one hand (for example, the left hand) and the rotatable adjustment member  130  (which is initially axially positioned adjacent the proximal  130   a  of the housing shaft) with the other hand. The surgeon moves the inner core member  115  to engage with the handle member  128 . To retract the outer sheath  110  of the introducer catheter  102  relative to the inner core member  115 , the surgeon holds the handle member  128  in a fixed position while axially withdrawing the housing shaft  121  of the delivery catheter assembly  104 , which is axially fixed to the introducer catheter  102  and to outer sheath  110 . Holding the handle member  128  in a fixed position, with the inner core engagement (and release) assembly  139  engaged with the inner core member  115 , holds the inner core member  115  fixed as the outer sheath  110  is axially retracted relatively inner core member  115  fixed to the housing shaft  121 . Retracting the housing shaft  121  portion of the delivery catheter assembly  104  can be done by grasping and rotating the rotatable adjustment member  130  or directly by applying a pull force to retracting the rotatable adjustment member  130  relative to the handle member  128 . This step causes withdrawal of the outer sheath  110  relative to the inner core member  115  is desired. 
     The slower incremental withdrawal of the outer sheath  110  relative to the inner core member  115  is accomplished as the rotatable adjustment member  130  axially abuts a proximal end  128   a  of the handle member  128 . Rotating the rotatable adjustment member  130  in a first direction while holding the handle member  128  in a fixed axial position will slowly and incrementally and controllably retract or withdraw the housing shaft  121  of the delivery catheter assembly  104  and, consequently, the outer sheath  110 . This controlled withdrawal of the outer sheath  110  is usually performed during the initial deployment phase of exposing and deploying a stent, to allow the surgeon greater control and accuracy in positioning the stent in the target location. 
     In sum, in this configuration, with the handle member  128  initially positioned on a proximal portion of the housing shaft  121 , a surgeon can controllably retract the outer sheath  110  to expose the stent by holding the handle member  128  in a fixed position relative to the patient in one hand, while using his or her other hand to turn the rotatable adjustment member  130  in a first direction to retract the housing shaft  121  and outer sheath  110  relative to the handle member  128  and inner core member  115 . Once the surgeon is confident that the stent is in the desired position, the surgeon can then more rapidly retract the outer sheath  110  relative to the inner core member  115  by grabbing and axially retracting the housing shaft  121  relative to the handle member  128 . 
     As illustrated in  FIGS. 17-19 , the delivery catheter assembly  104  can have a selectively engageable locking feature positioned on the inner core member  115 , such as the lock engagement ring  147 . As will be described in greater detail below, the engagement ring  147  can be configured to removably engage with the inner core engagement assembly  139 . As discussed above, when the inner core member  115  is engaged with the engagement assembly  139 , the inner core member  115  is axially locked to the engagement assembly  139  such that axial movement of the handle member  128  results in simultaneous axial movement of the inner core member  115 , the inner core member  115  can be free to rotate relative to the engagement assembly  139  and the handle member  128  even when in the locked or engaged position. The engagement ring  147  can be adhered to, integrally formed with, or otherwise permanently fixed to an outer surface of the inner core member  115 . 
     With reference to  FIGS. 17-19 , some embodiments of the engagement ring  147  can have a tapered surface  149  and an annular channel  152 . The tapered surface  149  can improve the ease with which the engagement ring  147  can be advanced into the engagement assembly  139 . Additional details regarding these components will be described below. 
       FIG. 20  is an oblique view of the delivery catheter assembly  104  of  FIG. 16 , illustrating the inner core member  115  in a fully or approximately fully advanced position relative to the delivery catheter assembly  104 . In this position, the inner core member  115 , the inner core wire  117 , and the distal tip  119  are all advanced past the end of the sheath  127  of the delivery catheter assembly  104 . When the delivery catheter assembly  104  is engaged with the introducer catheter  102 , the inner core member  115 , the inner core wire  117 , and the distal tip  119  are also be advanced relative to the end of the outer sheath  110  such that a stent supported by the inner core member  115  would be at least partially, and in some cases fully, exposed. 
       FIGS. 21-23  are side views of the delivery catheter of  FIG. 16 , showing the sheath in a first, pre-deployment position, a second, partial deployment position, and a third, fully retracted position, respectively, and the positions of the housing shaft  121 , handle member  128 , and the inner core member  115  of the delivery catheter assembly  104 . The delivery catheter assembly  104  is configured such that the handle member  128  slides along the housing shaft  121  between the first position, as illustrated in  FIG. 21 , and at least a third position, as illustrated in  FIG. 23 . Therefore, in this configuration, the handle member  128  is held stationary while the user or surgeon can retract the housing shaft  121  by sliding it relative to the handle member  128 . Accordingly, when the handle member  128  is engaged with the inner core member  115 , a surgeon can very rapidly advance the inner core member  115  relative to the distal end portion  121   a  of the housing shaft  121  of the delivery catheter assembly  104  by sliding the handle member  128  toward the distal end portion  121   a  of the housing shaft  121 . Similarly, if the surgeon desires to hold the inner core member  115  and prosthesis in a fixed position within the patient&#39;s vasculature, the surgeon or user can hold the handle member  128  in a fixed position and axially slide or retract the delivery catheter assembly  104  away from the patient&#39;s body so as to retract the outer sheath  110  of the introducer catheter  102  relative to the inner core member  115  and prosthesis, thereby exposing the prosthesis. 
     The rotatable adjustment member  130  is separable from the handle member  128  so that the adjustment member  130  and housing shaft  121  can move independently of the handle member  128 . The adjustment member  130  includes inside threads that engage with the external threads on the threaded portion  126  of the housing shaft  121 . Rotating the adjustment member  130  in a first direction axially retracts the housing shaft  121  and sheath as the adjustment member  130  maintains contact with the handle member  128  as the adjustment member rotates. Rotation of the adjustment member  130  is used to control the speed of slow retraction of the housing shaft  121  or an axial force applied to the adjustment member provides the option of a quick retraction. 
     The handle member  128  is selectively engageable with the inner core member  115 .  FIG. 24  is an oblique view of the inner core engagement assembly  139  and the inner core member  115 , showing the inner core member  115  in a first, disengaged position relative to the inner core engagement assembly  139 , other components of the delivery catheter being removed from this view for clarity.  FIG. 25  is a cross-sectional view of a portion of the delivery catheter assembly  104  through the axial centerline of the delivery catheter assembly  104 , showing the inner core member  115  in a first, disengaged position relative to the inner core engagement assembly  139 .  FIG. 26  is an oblique view of the inner core engagement assembly  139  and the inner core member  115  as in  FIG. 24 , showing the inner core in a second, partially engaged position relative to the inner core engagement assembly. 
     With reference to  FIGS. 24-26 , in some embodiments of the delivery catheter assembly  104 , an engagement ring  147  is supported by the inner core member  115 . The engagement ring  147  has a tapered fore surface  149  and a channel or depression  152  formed around an outside surface of the engagement ring  147 . The fore surface  149  can have a generally frustoconical shape, and the channel  152  can be formed all around the engagement ring  147  forming a ring groove. The engagement ring  147  is adhered to, formed integrally with, or otherwise fastened to or supported by the inner core member  115  at any desired position along the length of the inner core member  115 . 
     With reference to  FIGS. 24-26 , a body member  155  of the engagement assembly  139  supports one or more tabs or arms  159  configured to engage with the engagement ring  147 . The one or more arms  159  can have inward facing tabs or projections  166  supported at the proximal end  159   b  of the one or more arms  159 . The arms  159  are supported by the body member  155  in a cantilevered configuration so that the base portion  159   a  of the one or more arms  159  is fixed to the body member  155  and such that the proximal end portion  159   b  of the one or more arms  159  is unsupported. The arms  159  are supported by the body member  155 . 
     The engagement ring  147  is configured to be received by the inner core engagement assembly  139  by sliding the inner core member  115  in a first (distal) direction (represented by arrow A 1  in  FIG. 24 ) until the engagement ring  147  is engaged with the engagement assembly  139 . As illustrated in  FIG. 26 , as the inner core member  115  and engagement ring  147  are moved toward the engagement assembly  139 , a tapered fore surface  149  of the engagement ring  147  causes the tabs or arms  163  spread apart as the engagement ring  147  is advanced into the engagement assembly  139 , as illustrated in  FIGS. 26-28 . With further advancement of the inner core member  115  relative to the handle member  128 , when the protruding portions  166  of the arms  159  are in axial alignment with the channel  152 , the protruding portions  166  of the arms  159  can compress and shrink (spring) toward each other and into the channel  152  due to the bias of the one or more arms  159 . As illustrated in  FIGS. 30-32 , the inner core member  115  is axially engaged with the handle member  128  until the user disengages the engagement assembly  139  from the engagement ring  147 , the inner core member  115  can be freely rotated relative to the handle member  128  even when axially engaged with the handle member  128 . 
     The engagement assembly  139  is further configured so that moving the one or more arms  159  in a radial direction (spreading them, as shown in  FIG. 27B ) will cause the protruding portions  166  of the arms  159  to be lifted away from the channel  152  of the engagement ring  147 . The one or more spread tabs  173  supported by a body portion  175  or configured to exert the necessary radial force (spreading) on the arms  159  to lift the protruding portions  166  away from the engagement ring  147 . The spread tabs  173  can have a tapering shape such that, moving the spread tabs  173  in a downward direction relative to the one or more arms  159  deflects the arms  159  outward. Depressing button  180  forces the spread tabs  173  downward, thereby deflecting the arms  159  outward so that the engagement ring  147  is axially released and axially moved away from the engagement assembly  139 . 
       FIG. 34  is a cross-sectional view of a portion of the delivery catheter through the axial centerline of the delivery catheter, showing the inner core member  115  in a disengaged position relative to the inner core engagement assembly  139 . 
       FIG. 35  is a cross-sectional view of a portion of the delivery catheter assembly  104  through the axial centerline of the delivery catheter assembly  104 , showing the inner core member  115  in an engaged position relative to the inner core engagement assembly  139 . As illustrated therein, a biasing mechanism or spring member  184  is supported by the handle member  128  and is configured to bias the button  180  and, consequently, the spread tabs  175 , in a first direction away from the inner core member  115 . 
     Further, with reference to  FIGS. 34-35 , the handle member  128  has a stop member  198  configured to limit the range of motion of the engagement ring  147  and inner core member  115  relative to the handle member  128 . For example, the first end portion  198   a  of the stop member  198  is configured to abut against a fore surface  149  of the engagement ring  147  when the engagement ring  147  is advanced into the handle member  128 . 
     The stent can be preloaded in the introducer catheter assembly or introducer sheath such that the stent need not be transferred into the catheter assembly or introducer sheath during the surgical operation. The delivery catheter system can have an introducer sheath, inner core, and some or all of the other features of the delivery catheter disclosed herein in one apparatus. In of this inclusive apparatus, the inner core can be permanently joined to the handle member  128  such that there would be no need to configure the delivery catheter to be selectively engageable with the inner core, thereby simplifying the assembly and potentially simplifying the surgical procedures. Therefore, some embodiments of this inclusive delivery catheter assembly, the delivery catheter assembly can have all of the components, features, details, or configurations of the embodiments of the catheter system  100  described above, wherein the inner core engagement assembly  139  and the lock engagement ring  147  of the inner core member  115  can be replaced with a non-selectable coupling or other connection between the inner core member  115  and the handle member  128 . 
       FIG. 36  is an illustration of a prosthesis partially deployed by the delivery catheter assembly  104 .  FIG. 37  is a partial side view exemplifying a stent that can be deployed with the delivery catheter assembly  104 . The deployment catheter illustrated in  FIG. 36  can be adapted for deployment of any suitable prosthesis and is not limited to deployment of the stent illustrated in  FIG. 37 . With reference to  FIGS. 20, 36, and 37 , one or more beads or tabs  174  can be formed on or supported by the core wire  117 . The tabs  174  can be configured to increase the axial support or connection between the inner core wire  117  and a stent  214  supported by the core wire  117  when the stent is supported in a compressed on the core wire  117 . Additionally, the tabs  174  can be sized, spaced, and otherwise configured to provide axial support to multiple individual stent segments (not illustrated). For example, multiple independent or tethered stent segments can be positioned within a tubular or bifurcated graft or otherwise, and the stent can be positioned relative to the tabs  174  such that the tabs  174  are positioned between the stent segments  216  or between the apices, knuckles, or connection points  218  interconnecting the struts. 
     In the configuration shown, the beads or tabs  174  supported by the core wire  117  can engage the struts  216  or connection points  218  of the stent  214  to help prevent the stent from axially slipping relative to the inner core wire  117  for portions of the stent  214  that remain compressed within the outer sheath  110 . This arrangement provides greater control over the stent  214  during the final stages of deployment of the stent  214 , for example, when only an end portion of the stent  214  remains compressed within the outer sheath  110 , as illustrated in  FIG. 36 . 
     Additionally, positioning the tabs  174  between the struts  216  or connection points  218  can reduce the compressed diameter or crossing profile of the compressed prosthesis, the outer sheath  110 , and other components comprising the catheter system. This arrangement can also allow for a more uniform distribution of support forces between the tabs  174 , the inner core wire  117 , and the stent  214 , the tabs  174  can be sized, spaced, and otherwise configured so as to be positioned adjacent to the links, bends, loops, and/or other connectors formed in a tubular or bifurcated stent, such as the links, bends, loops, and/or other connectors comprising the embodiments of the stents disclosed in U.S. Pat. No. 6,077,296, entitled ENDOLUMINAL VASCULAR PROSTHESIS, which patent is hereby incorporated by reference as if fully set forth herein. 
     In any of the catheter system embodiments disclosed herein, the catheter system can be configured as described herein such that the stent can be compressed from, a first diameter or size to a second diameter or size as the stent is being loaded into the introducer or introducer sheath. The first diameter or size can be the fully relaxed or expanded diameter of the stent, or the first diameter or size can be a partially compressed diameter. For example, for some of the embodiments disclosed herein, the stent can be compressed from a first diameter, as defined or controlled by the sheath of the delivery catheter or by an assembly apparatus surrounding the stent, to a second diameter, as defined or controlled by the introducer sheath. The reduction ratios of the stent when advanced into the introducer can be from approximately 50% to approximately 95%, meaning that the second diameter can be from approximately 50% to approximately 95% of the first diameter. 
       FIG. 38  is a side view of a catheter system  300  having an introducer catheter assembly  302 , showing a stent being loaded into an outer sheath of the introducer catheter assembly  302 . Only a portion of the delivery catheter  304  is illustrated and certain features of the introducer catheter assembly  302  have been omitted for clarity. The catheter system  300  and/or the introducer catheter assembly  302  can have any of the components, features, materials, or other details of any of the embodiments of the catheter systems or introducer catheter assemblies disclosed or incorporated by reference herein, including U.S. application Ser. No. 12/496,446, filed Jul. 1, 2009, entitled “CATHETER SYSTEM AND METHODS OF USING SAME.” Further, the embodiments of the introducer catheter assembly  302  can be configured to work with any of the delivery catheter assembly embodiments disclosed or incorporated by reference herein. 
     With reference to  FIG. 38 , the introducer catheter assembly  302  can have a main body portion  306  and an outer sheath  310  supported at a distal end  306   a  of the main body portion  306 . An inner aperture or opening  312  on the inside of the introducer catheter assembly  302  can be coaxial with the opening formed through the outer sheath  310 , the introducer catheter assembly  302  can have tapered or curved wall portions  314  that are configured to compress the stent  320  from a first diameter “a” to a second diameter “b” that is equal to an inside diameter of the (introducer) outer sheath  310  as the stent  320  is being advanced through the introducer catheter assembly  302 . 
     The introducer catheter assembly  302  and the delivery catheter can be configured such that the distal end  316   a  of the sheath  316  terminates prior to or approximately adjacent to the constricted portion of the main body portion  306 . In this configuration, the stent can be loaded into the delivery catheter in a relaxed or mostly relaxed (i.e., expanded) state having diameter “a”, and be compressed by the tapered wall portions  314  of the introducer catheter assembly  302  to a final, compressed diameter “b”, thereby reducing the stresses applied to the stent prior to loading the stent in the introducer catheter assembly  302 . 
     The sheaths supported by the delivery catheter, for example sheath  316  or the sheath  127  discussed above, can overlap or be advanceable into at least the proximal portion of the introducer or outer sheath  310 ,  110 , or so that the sheath  316  or the sheath  127  discussed above can be advanceable through the entire length of the introducer or outer sheath  310 ,  110 . A distal portion of the sheath supported by the delivery catheter can be tapered. In this configuration, the stent can be further compressed or compressed as it is being passed through the distal portion of the delivery catheter sheath into the introducer or introducer sheath. 
     The introducer catheter assembly  302  can be configured to receive and deploy any of a variety of prostheses, including non-bifurcated and bifurcated stents and stent grafts, stent segments, fenestrated stents, and other similar stents or stent grafts disclosed herein or otherwise, the introducer catheter assembly  302  or any other introducer catheter assembly embodiment disclosed herein can be configured to receive and removably couple with any of a variety of delivery catheters, including accessory stent catheters, suprarenal stents or stent extension catheters, or bifurcated stent delivery catheters. 
     The outer sheath  310  or any other outer sheath embodiment disclosed herein has an inner diameter of approximately 0.237 in, and an outer diameter of approximately 0.253 in. When used for the delivery of a bifurcated stent, the sheath  316  has an inner diameter of approximately 0.251 in, and an outer diameter of approximately 0.263 in. When used for the delivery of an accessory stent or non-bifurcated stent, the sheath  316  has an inner diameter of approximately 0.241 in. and an outer diameter of approximately 0.263 in. 
     When used for the delivery of a bifurcated stent, the inner core (not illustrated in  FIG. 38 ) the catheter system has an outer diameter of approximately 0.212 in. When used for the delivery of a non-bifurcated stent, the inner core of any catheter system has an outer diameter of approximately 0.213 in. 
       FIG. 39  is a schematic side view of a catheter system  400  having a deployment catheter assembly  404  comprising an inner core  408 , an outer sheath  410 , a plurality of tabs  412  supported by a core wire  414  axially attached to the inner core  408 , and a distal tip  415  axially attached to the core wire  414 . A stent  416  is supported by the delivery catheter  404  and is surrounded by the outer sheath  410 . The stent  416  is a self-expanding bifurcated stent, as herein illustrated, or can be any other stent or medical prosthesis disclosed or incorporated by reference herein or otherwise. The delivery catheter  404  can further comprise a branch vessel wire assembly  417  loaded in the delivery catheter  404 . 
       FIG. 40  is a cross-sectional view of the branch vessel wire assembly  417  taken at line  40 - 40  of  FIG. 39 , and  FIG. 41  is an enlarged schematic view of a portion of the branch vessel wire assembly  417  defined by curve  41 - 41 , of  FIG. 39 . The branch vessel wire assembly  417  includes an inner wire  418  positioned at least partially within a hollow tube or guidewire  420 . The branch vessel wire assembly  417 , the inner wire  418 , or the hollow tube  420  can have any of the sizes, features, materials, or other details of the dual concentric guidewire disclosed in U.S. application Ser. No. 11/623,022, filed Jan. 12, 2007, which is incorporated by reference as if fully set forth herein. 
     The hollow tube  420  can project through an inside lumen of the stent  416  such that a distal end  420   a  of the hollow tube  420  projects past an end portion  416   a  of the stent  416 . Additionally, the hollow tube  420  has a curved or kinked portion  420   b  proximal to the end of the stent  416 . The outer sheath  410  holds the curved portion  420   b  of the hollow tube  420  in the curved position or orientation (the first state) so as to mechanically link or lock the inner wire  418  axially to the hollow tube  420  until the curve or bend in the curved portion  420   b  is relaxed. As will be discussed, the curve or bend in the curved portion  420   b  can be relaxed by retracting or withdrawing the outer sheath  410  past the curved portion  420   b  of the hollow tube  420 , thereby allowing the hollow tube  420  and inner wire  418  to relax and straighten. Therefore, when the hollow tube  420  is in the first state, the inner wire  418  will be axially fixed to the hollow tube  420  such that the inner wire  418  is axially retracted without becoming disengaged from the hollow tube  420 . When the outer sheath  410  is retracted past the curved portion  420   b  of the hollow tube  420 , the hollow tube  420  relaxes so that the curved portion  420   b  is no longer be axially locked to the inner wire  418 . In this second, relaxed state, the inner wire  418  can be axially advanced or retracted into and out of the hollow tube  420 . 
     In this arrangement, the inner wire  418  can be advanced through a first puncture site in a first branch vessel or passageway (such as the ipsilateral iliac artery) and then withdrawn though a second branch vessel or passageway (such as the contralateral iliac artery), using any suitable cross-over techniques. For example, the inner wire can be advanced through the ipsilateral iliac artery in a slitted lumen formed in a dual lumen dilator. The dilator can be withdrawn and set aside, allowing the inner wire  418  to pass through the slit in the lumen of the dual lumen dilator, thereby leaving a proximal end of the inner wire  418  positioned within the abdominal aorta. In this position, the inner wire  418  can be snared and retracted through the contralateral iliac artery and through a second puncture site. 
     Many embodiments of the catheter system have been described in connection with the accompanying figures. It will apparent to one of ordinary skill in the art that there are many potential embodiments of the catheter system that may be suitable for medical use and which are contemplated herein. For example, any of the components or features of some embodiments of the catheters disclosed herein or other catheters available in the field can be combined to form additional embodiments, all of which are contemplated herein. 
     While the above description has shown, described, and pointed out features as applied to various embodiments, it will be understood that various omissions, substitutions, and changes in the form and details of the device or process illustrated may be made without departing from the spirit of the disclosure. Additionally, the various features and processes described above may be used independently of one another, or may be combined in various ways. All possible combinations and subcombinations are intended to fall within the scope of this disclosure. Further, as will be recognized, certain embodiments described herein may be embodied within a form that does not provide all of the features and benefits set forth herein, as some features may be used or practiced separately from others.