Delivery system with device deployment features, and associated methods

Abstract

To provide a favorable delivery catheter and the like.SOLUTION: Delivery systems (100) are described that include: endoprostheses (102) configured to transition from compact delivery configurations to enlarged deployed configurations; delivery catheters including body portions (108) and tip portions (112), where the endoprostheses are received on the body portions in the compact delivery configurations, and where the tip portions including lips (114) are configured to define pockets (114A) that releasably receive the endoprostheses in the compact delivery configuration; and constraints releasably maintaining the endoprostheses in the compact delivery configuration. Additional and alternative delivery system features and associated methods are provided.SELECTED DRAWING: Figure 2A

Description

[Technical field]

[0001] Field The present disclosure relates generally to medical device delivery systems, and more specifically to device deployment functions of such systems. [Background technology]

[0002] background A variety of implantable devices are positioned and deployed at treatment sites within a patient's body through intraluminal means using a transcatheter approach. Such devices may be transitionable from a smaller profile delivery configuration to an enlarged profile deployed configuration. In some instances, the delivery systems used to deliver and deploy such devices include removable and / or retractable sheaths or sleeves that are detached from the device to facilitate transition to the deployed configuration. Summary of the Invention

[0003] Abstract A delivery system is described that includes an endoprosthesis configured to transition from a compact delivery configuration to an expanded deployed configuration, a delivery catheter including a body portion and a tip portion, where such endoprosthesis is received in the body portion in the compact delivery configuration, the tip portion including a lip configured to define a pocket that releasably receives the endoprosthesis in the compact delivery configuration, and a restraint that releasably maintains the endoprosthesis in the compact delivery configuration. Additional and alternative delivery system features and related methods are provided.

[0004] According to a first example ("Example 1"), a delivery system includes an endoprosthesis having a first end and a second end, where the endoprosthesis is configured to transition from a compact delivery configuration to an expanded, deployed configuration; a delivery catheter including a body portion and a tip portion, where the endoprosthesis is received in the body portion of the delivery catheter in the compact delivery configuration, the tip portion including a lip configured to define a pocket that releasably receives the first end of the endoprosthesis in the compact delivery configuration; and a constraint that releasably maintains the endoprosthesis in the compact delivery configuration, where the constraint has a first end and a second end, and where the constraint extends over at least a portion of the endoprosthesis and the lip of the tip portion.

[0005] According to another example ("Example 2") in addition to Example 1, the restraint includes a tubular knitted sleeve.

[0006] According to another example ("Example 3") in addition to Examples 1 or 2, the constraint is configured to unravel and disintegrate to release the endoprosthesis.

[0007] According to another example ("Example 4") in addition to any of the preceding examples, the lip of the tip portion is interposed between the first end of the endoprosthesis and the constraint.

[0008] According to another example ("Example 5") in addition to any of the preceding examples, the endoprosthesis includes a support portion formed from one or more rows defined by stent elements defining a wave pattern, and further, the first end of the endoprosthesis releasably received in the pocket includes at least one of the one or more rows defined by the stent elements.

[0009] According to another example ("Example 6") in addition to any of the previous examples, the first end of the endoprosthesis is configured to be released from the pocket when the endoprosthesis transitions from a compact delivery configuration to an expanded deployed configuration.

[0010] According to another example ("Example 7") in addition to any of the previous examples, the lip of the tip portion is elastically deformable.

[0011] According to another example ("Example 8") in addition to any of the preceding examples, the lip of the tip portion is configured to transition from a first configuration to a second configuration following release of the endoprosthesis from the pocket defined by the lip, and the second configuration of the lip has a lower profile than the first configuration of the lip.

[0012] According to another example ("Example 9") in addition to any of the previous examples, the tip portion includes a serrated portion configured to mechanically engage the first end of the constraint.

[0013] According to another example ("Example 10"), a delivery catheter includes a body portion configured to receive the endoprosthesis in a compact delivery configuration and a tip portion including a lip configured to releasably receive a first end of the endoprosthesis in the compact delivery configuration.

[0014] According to another example ("Example 11") in addition to Example 10, the lip of the tip portion is elastically deformable.

[0015] According to another example ("Example 12") in addition to Examples 10 or 11, the lip of the tip portion is configured to elastically transition from a first configuration to a second configuration, and the second configuration of the lip has a lower profile than the first configuration of the lip.

[0016] According to any one of Examples 10-12 plus another Example ("Example 13"), the tip portion includes a serrated portion configured to mechanically engage a constraint for the endoprosthesis.

[0017] According to another example ("Example 14"), a delivery system includes an endoprosthesis having a first end and a second end, where the endoprosthesis is configured to transition from a compact delivery configuration to an expanded deployed configuration, and a delivery catheter including a body portion and a tip portion, where the endoprosthesis is received in the body portion of the delivery catheter in the compact delivery configuration, the tip portion including a lip configured to define a pocket that releasably receives the first end of the endoprosthesis in the compact delivery configuration, the lip configured to resiliently transition from the first configuration to a second configuration upon removal of the first end of the endoprosthesis from the pocket, where the second configuration has a lower profile than the first configuration.

[0018] According to another example ("Example 15") in addition to Example 14, the delivery system further includes a constraint that maintains the prosthetic device in a compact delivery configuration.

[0019] According to another example ("Example 16") in addition to Example 15, the constraint is configured to unravel and degrade to release the endoprosthesis.

[0020] According to another example ("Example 17") in addition to Example 15 or 16, the lip of the tip portion is interposed between the first end of the endoprosthesis and the constraint.

[0021] According to another example ("Example 18") in addition to any of Examples 14-17, the endoprosthesis includes a support portion formed from one or more rows defined by stent elements defining a wave pattern, and further, the first end of the endoprosthesis releasably received in the pocket includes at least one of the one or more rows defined by the stent elements.

[0022] According to another example ("Example 19") in addition to any of Examples 14-18, the first end of the endoprosthesis is configured such that when transitioning from a compact delivery configuration to an expanded, deployed delivery configuration, the first end of the endoprosthesis is released from the pocket.

[0023] The foregoing examples are merely illustrative and should not be read to limit or otherwise narrow the scope of any of the inventive concepts otherwise provided by this disclosure. While multiple examples have been disclosed, still other embodiments will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative examples. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive. [Brief description of the drawings]

[0024] BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings are included to provide a further understanding of the disclosure, are incorporated in and constitute a part of this specification, illustrate embodiments, and together with the description, serve to explain the principles of the disclosure.

[0025] [Figure 1A] FIG. 1A illustrates a delivery system according to some embodiments.

[0026] [Figure 1B] FIG. 1B shows a selected portion of a delivery system corresponding to the area designated as BB in FIG. 1A, according to some embodiments.

[0027] [Figure 2A]FIG. 2A shows a tip portion of a delivery system including an implantable device received by the tip portion, according to some embodiments.

[0028] [Figure 2B] FIG. 2B shows a distal portion of a delivery system, according to some embodiments.

[0029] [Figure 3A] FIG. 3A shows another tip portion of a delivery system including an implantable device received by the tip portion, according to some embodiments.

[0030] [Figure 3B] FIG. 3B shows another distal portion of a delivery system, according to some embodiments.

[0031] [Figure 4] 4A-4C are diagrams illustrating a deployment sequence according to some embodiments.

[0032] Those skilled in the art will readily appreciate that the various aspects of the present disclosure may be implemented by any number of methods and devices configured to perform the intended functions. It should also be noted that the accompanying drawings referenced herein are not necessarily drawn to scale and may be exaggerated to illustrate various aspects of the present disclosure, and in that regard, the drawings should not be construed as limiting. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Detailed Description Definitions and Terminology This disclosure is not intended to be read in a restrictive manner, for example, the terms used in this application should be read broadly with respect to the meaning that terms of the art are ascribed to such terms.

[0034] Those skilled in the art will readily appreciate that the various aspects of the present disclosure can be implemented by any number of methods and devices configured to perform the intended functions. In other words, other methods and devices can be incorporated herein to perform the intended functions. It should also be noted that all of the accompanying drawings referenced herein are not drawn to scale and may be exaggerated to illustrate various aspects of the present disclosure, and in that respect, the drawings should not be construed as limiting. Finally, the present disclosure may be described in conjunction with various principles and beliefs, but the present disclosure should not be bound by theory.

[0035] The term "distal" refers to a relative location away from the location within the body where the medical device is introduced. Similarly, the term "distally" refers to a direction away from the location within the body where the medical device is introduced.

[0036] The term "proximal" refers to a relative location closer to the location within the body where the medical device is introduced. Similarly, the term "proximally" refers to a direction toward the location within the body where the medical device is introduced.

[0037] Description of Various Embodiments 1A shows a delivery system 100 including an endoprosthesis 102, a body portion 108, a delivery catheter 101 including a tip portion 112 coupled to the body portion 108 and a handle portion 113 coupled to the body portion 108, a restraint 116 including a first end 121 and a second end 122 (see FIG. 1B) extending along at least a portion of the body portion 108, the endoprosthesis 102 and the tip portion 112, and an outer sheath 117 configured to facilitate intraluminal passage of the delivery system 100 (e.g., having a relatively smooth outer profile), and in particular to facilitate insertion of the endoprosthesis 102 into a treatment site within the body. In general, the delivery system 100 is configured to position the endoprosthesis 102 at a desired treatment site within a patient's body and to control the deployment of the endoprosthesis 102 from a compact delivery configuration to an expanded deployed configuration.

[0038] In various examples, endoprosthesis 102 is a device configured to replace or repair a body part, and endoprosthesis 102 is implantable (permanently or temporarily) within a patient's body. In various examples, endoprosthesis 102 includes a support portion 118 (e.g., a stent) and can optionally include a covering 119 (e.g., a graft material). Examples of endoprostheses 102 include stents, stent-grafts, grafts, filters, occluders, balloons, leads, artificial valves, and the like. As shown, endoprosthesis 102 has a first end 104 and a second end 106. As will be described later, when endoprosthesis 102 is in a compact delivery configuration, first end 104 of endoprosthesis 102 is releasably held and / or covered by tip portion 112.

[0039] The support portion 118 of the endoprosthesis 102 can include one or more stent elements extending in a wave-like pattern defining one or more rows 118A. The rows 118A can be defined by one or more turns of the stent elements (e.g., extending in a spiral such that the wave-like pattern defines a tubular shape). Alternatively, the rows 118A can be configured as one or more separate rings that collectively define the tubular shape. The support portion 118 can be formed, for example, by a wrapping technique (e.g., wire wrapping or braiding) or by a molding technique (e.g., cutting, depositing, or otherwise forming a pattern into a tubular structure or a sheet that is subsequently processed into a tubular structure). The support portion 118 can be formed from a metallic material, a polymeric material, a natural material, or a combination thereof, as desired. The support portion 118 can include conventional medical grade materials such as nylon, polyacrylamide, polycarbonate, polyethylene, polyformaldehyde, polymethylmethacrylate, polypropylene, polytetrafluoroethylene, polytrifluorochloroethylene, polyvinyl chloride, polyurethane, elastomeric organosilicon polymers, metals such as stainless steel, cobalt chromium alloys and nitinol, and bio-derived materials such as bovine arteries / veins, pericardium and collagen. The support portion 118 can also include bioresorbable materials such as poly(amino acids), poly(anhydrides), poly(caprolactone), poly(lactic / glycolic acid) polymers, poly(hydroxybutyrates) and poly(orthoesters).

[0040] The cover 119 of the endoprosthesis 102 can be configured as, for example, a graft. Potential materials for the cover 119 include, for example, fluoropolymers such as expanded polytetrafluoroethylene (ePTFE), polyesters, polyurethanes, perfluoroelastomers, polytetrafluoroethylene, silicones, urethanes, ultra-high molecular weight polyethylene, aramid fibers, and combinations thereof. Other embodiments of the graft member material can include high strength polymer fibers such as ultra-high molecular weight polyethylene fibers or aramid fibers. Additionally, grafts can include polyesters such as polyethylene terephthalate and polyaramids, polyfluorocarbons such as polytetrafluoroethylene (PTFE) with or without copolymerized hexafluoropropylene, and classes of porous or non-porous polyurethanes.

[0041] Delivery catheter 101 can take a variety of configurations, but is generally suitable for placing an endoprosthesis within a patient (not shown) via an endoluminal approach. Body portion 108 of delivery catheter 101 can be tubular and elongated in shape, providing a means for maintaining and supporting the endoprosthesis as it traverses the body to a desired treatment site. Handle portion 113 of delivery catheter 101 is configured to aid in manipulation of delivery catheter 101 to facilitate passing endoprosthesis 102 to the treatment site, and can include deployment features (e.g., actuators for expanding endoprosthesis 102), steering features (e.g., actuators for steering delivery catheter 101 through the body), and the like.

[0042] As shown, a tip portion 112 of the delivery catheter 101 extends from a distal end 110 of the body portion 108. In some examples, the tip portion 112 has a lip 114 interposed between the first end 104 of the endoprosthesis 102 and a restraint 116 configured to define a pocket 114A (see FIG. 2A ) (e.g., in combination with the body portion 108) that releasably receives the first end 104 of the endoprosthesis 102 when the endoprosthesis 102 is in a compact delivery configuration. The first end 104 of the endoprosthesis 102 can include at least one of the rows 118A defined by the stent elements of the support portion 118. In some examples, the lip 114 is formed from an elastomeric material or is otherwise configured to be elastically deformable. The first end 104 is released from the pocket 114A when the endoprosthesis 102 transitions from the compact delivery configuration to the expanded deployed configuration. In some instances, the lip 114 is configured to deflect outwardly to form a pocket 114A to receive the first end 104 of the endoprosthesis 102, or to retract or collapse to a smaller profile when the first end 104 is removed from the pocket 114A. By elastically recovering toward the smaller profile, the lip 114 can help retain the first end 104 of the endoprosthesis 102 and / or reduce the profile of the tip portion 112 following release of the endoprosthesis to facilitate withdrawal of the delivery catheter 101 from the patient's body. In some embodiments, the lip 114 can provide a radial compressive force to at least partially retain the first end 104 of the endoprosthesis 102 in a compact delivery configuration. Additionally, the lip 114 and the first end 104 of the endoprosthesis 102 can be engaged such that a frictional force between the lip 114 and the endoprosthesis 102 resists longitudinal movement of the endoprosthesis 102 relative to the tip portion 112 when engaged. The constraint 116 can further increase the frictional force between the endoprosthesis 102 and the lip 114 when the constraint 116 maintains the endoprosthesis in a compact delivery configuration.The distal portion 112 can be formed of a deformable material, such as a low durometer polymeric material, for example a biocompatible elastomer, hi some examples, the distal portion 112 is formed of a low durometer polymeric material having a durometer hardness of 15 to 70 Shore on the Type A scale.

[0043] In some embodiments, the tip portion 112 includes a serrated portion 120 that includes one or more (e.g., 2, 3, 4, 5, 6, or more) serrations. The serrated portion 120 can be configured to mechanically engage the constraint 116 to help prevent the constraint 116 from slipping or translating (e.g., during passage through a patient's body and / or during release of the constraint 116). For example, in embodiments in which the constraint 116 is pulled longitudinally proximally to release the constraint 116 from the endoprosthesis 102, having a feature that helps maintain the position of the constraint 116 can help avoid inadvertent slippage or other translation.

[0044] In some embodiments, the serrated portion 120 is a portion formed on the outer surface of the tip portion 112. For example, the outer surface of the tip portion can include a generally smooth outer profile, except for the serrated portion 120. For example, the outer surface of the tip portion 112 can include a transition with an outer profile that is rounded or curved, or forms an obtuse angle, except for the serrated portion 120, which can include a portion of the outer surface that forms an acute angle. With reference to FIG. 2A, for example, the serrated portion 120 includes an outer profile that forms an acute angle along the profile of the body, and the tip of the serrated portion 120 is operable to contact and maintain contact with the restraint 116 at a predetermined longitudinal position. The serrated portion 120 can also extend circumferentially around the tip portion 112 at a predetermined longitudinal position along the length of the tip portion 112. In some embodiments, the serrated portion 120 can be described as having a plurality of frusto-conical portions disposed adjacent to one another.

[0045] In some instances, the constraint 116 extends along the endoprosthesis 102, over the lip 114 of the tip portion 112, and also partially along the body portion 108 and partially along the tip portion 112. Generally, the constraint 116 surrounds at least a portion of the endoprosthesis 102 when the endoprosthesis 102 is in a compact delivery configuration. If the endoprosthesis 102 is self-expanding, the constraint 116 can help keep the endoprosthesis 102 in the compact delivery configuration. In instances where the endoprosthesis is expandable (e.g., balloon expandable), the constraint can passively restrain the endoprosthesis 102 (e.g., not necessarily preventing expansion, but actually surrounding and covering the endoprosthesis 102), e.g., act primarily to cover or protect the endoprosthesis rather than actively restraining it.

[0046] In various examples, the constraint 116 is configured as a tubular knit sleeve of material that is releasable by unraveling and / or disintegrating when a portion of the sleeve (e.g., a pull line) is tensioned. Such a tubular knit sleeve can include one or more knitted fibers, which can include, for example, woven warp knit or braided. Suitable examples of knit sleeves and related deployment features and techniques can be found in U.S. Patent No. 6,315,792, issued Nov. 13, 2001 to Armstrong et al., entitled "Remotely Removable Covers and Supports." In various examples, one layer of the constraint 116 is configured to unravel in a first direction (e.g., proximal to distal) first, and then a second layer (e.g., lower layer) is configured to unravel in a second direction (e.g., distal to proximal). In this manner, the constraint can be configured to deploy the "tip first" of the endoprosthesis if a first end (e.g., distal end) of the endoprosthesis is released from the constraint first, and then the remainder of the endoprosthesis is released in a proximal direction. In other instances, the restraint is configured as a tubular sheath of material having edges secured together with coupling elements (e.g., filaments) that can then be released by tensioning the coupling elements to open the tubular sheath. In yet other instances, the restraint 116 is a tubular member that is retractable to release the endoprosthesis.

[0047] As shown, endoprosthesis 102 is received on body portion 108 in a compact delivery configuration such that endoprosthesis 102 is disposed proximally toward a distal end 110 of body portion 108. In operation, endoprosthesis 102 is generally expandable to an expanded, deployed configuration, and in various instances, following expansion of endoprosthesis 102, endoprosthesis 102 separates from tip portion 112. As shown, first end 104 of endoprosthesis 102 is received in pocket 114A and is exposed and retracts from beneath lip 114 as endoprosthesis 102 expands toward the expanded, deployed configuration, either when or after restraint 116 is removed.

[0048] In some examples, one or more rows 118A of the support portion 118 form the portion of the first end 104 of the endoprosthesis 102 that is received in a pocket 114A formed by the lip 114 of the tip portion 112. For example, a distal-most of the rows 118A can form the portion of the first end 104 of the endoprosthesis 102 that is received in the pocket 114A. In some embodiments, the one or more rows 118A define a plurality of apexes 200 that are received in the pocket 114A of the lip 114.

[0049] In various examples, the tip portion 112 defines a lumen 204 that passes longitudinally therethrough (e.g., in various examples, helps secure the body portion 108 to the tip portion 112). In examples where the tip portion 112 is elastic, the lumen 204 is expandable, or inflatable, by deflecting the lip 114 such that the lumen 204 can transition between configurations corresponding to an expanded lumen 204A and a contracted lumen 204B. The expanded lumen 204 configuration corresponds to a state when the lip 114 receives the first end 104 of the endoprosthesis 102 and is inserted between the constraint 116 and the first end 104 of the endoprosthesis 102. 2B shows delivery system 100 with endoprosthesis 102 (FIG. 2A) removed from tip portion 112, such that first end 104 is no longer in contact with lip 114 and tip portion 112 defines a contracted lumen 204B configuration. In the contracted lumen 204B configuration or state, tip portion 112 returns to a smaller profile.

[0050] 3A and 3B show various examples of a delivery system 100. In the illustrations of FIG. 3A and 3B, the body portion 108 is not shown to facilitate visualization of other components of the system 100. As shown, the tip portion 112 is optionally configured as a multi-component assembly with a first component 112A coupled to a second component 112B. As shown, the first component 112A includes an insertable portion 302 having one or more retention features 304, and the second component 112B includes a serrated portion 120 and a bore 306 configured to receive the insertable portion 302. The insertable portion 302 is inserted into the bore 306, with the lip 114 and the insertable portion 302 defining a pocket 114A for receiving the first end 104 of the endoprosthesis 102.

[0051] 4A, 4B, and 4C illustrate some example deployment processes and show how the first end 104 of the endoprosthesis 102 separates from the tip portion 112, according to some embodiments. For simplicity, the body portion 108 is not shown in these figures. In FIG. 4A, the endoprosthesis 102 is restrained by both the lip 114 and the restraint 116 of the tip portion 112, with the lip 114 inserted between the first end 104 of the endoprosthesis 102 and the restraint 116 in a compact delivery configuration. According to various examples, upon receiving the first end 104 of the endoprosthesis 102, the lumen 204 within the tip portion 112 is biased or expanded outward to receive the first end 104.

[0052] In FIG. 4B, the restraint 116 has been partially withdrawn from the endoprosthesis 102. The lip 114 protects the first end 104 of the endoprosthesis 102 and separates it from the restraint 116, which helps avoid chipping of the restraint 116 on the first end 104 and / or otherwise facilitates smooth release of the restraint 116 on the first end 104. As shown, the restraint 116 has been detached from the tip portion 112 and the portion of the endoprosthesis proximal to the first end 104, but still restrains the portion of the endoprosthesis 102 proximal to the first end 104. The endoprosthesis 102 is shown partially restrained by the lip 114 of the tip portion 112. The unconstrained portion 400 of the endoprosthesis 102 expands outward (radially) toward the expanded deployed configuration, while the first end 104 (restrained by the lip 114) is at least partially retained in the compact delivery configuration. As shown, first end 104 begins to angle and / or retract from pocket 114A as the portion of endoprosthesis 102 adjacent tip portion 112 expands.

[0053] 4C, the restraint 116 is further withdrawn from the endoprosthesis 102, causing the outward expansion force of the endoprosthesis 102 to overcome its engagement with the lip 114 and cause the first end 104 to release from the pocket 114A and expand outwardly and / or radially toward the expanded, deployed configuration. In some instances, a portion of the endoprosthesis 102 (e.g., a proximal portion) remains restrained by the restraint 116, while the first end 104 is freed from the lip 114. As shown, the lumen 204 optionally retracts to a low-profile configuration following release of the first end 104 of the endoprosthesis 102. The restraint 116 is removed / released from the endoprosthesis as desired, and the endoprosthesis is transitioned to the expanded, deployed configuration.

[0054] A method of assembling a delivery system 100 for an endoprosthesis 102 is provided. The method includes placing an endoprosthesis 102 having a first end 104 on an elongate element or body portion 108 in a compact delivery configuration, elastically deforming a lip 120 of a tip portion 120 to receive the first end 104 of the endoprosthesis 102, and placing a tip portion 112 on the elongate element adjacent the first end 104 of the endoprosthesis 102, the first end 104 of the endoprosthesis 102 being releasably received within the lip 114 of the tip portion 112. The lip 120 can be elastically deformed such that the lip 120 expands radially outwardly to form a pocket 114a or the pocket 114a is sufficiently enlarged to receive the first end 104 of the endoprosthesis 102. The method can also include placing a restraint 116 radially outwardly or around the endoprosthesis 102. The restraint 116 can be disposed radially outward of the lip 114 of the tip portion 112. In some embodiments, the restraint 116 can also be disposed on a serrated portion 120 that is operable to contact and maintain the restraint 116 and resist longitudinal movement of the restraint 116 relative to the tip portion 112, the endoprosthesis 102, and the body portion 108.

[0055] The embodiments have been described above both generally and with reference to specific embodiments. It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments without departing from the scope of the present disclosure. Therefore, the embodiments are intended to cover the modifications and variations of the embodiments provided they come within the scope of the appended claims and their equivalents.

Claims

1. an endoprosthesis having a first end and a second end; a delivery catheter including a body portion and a tip portion; and a restraint that releasably maintains the endoprosthesis in a compact delivery configuration; A delivery system comprising: the endoprosthesis is configured to transition from a compact delivery configuration to an expanded deployed configuration; the endoprosthesis is received in the body portion of the delivery catheter in a compact delivery configuration, the tip portion including a lip configured to define a pocket that releasably receives the first end of the endoprosthesis in the compact delivery configuration; the constraint has a first end and a second end, the constraint extending across at least a portion of the endoprosthesis and the lip of the tip portion. Delivery system.

2. The delivery system of claim 1 , wherein the restraint comprises a tubular knitted sleeve.

3. 3. The delivery system of claim 1 or 2, wherein the constraint is configured to unravel and disintegrate to release the endoprosthesis.

4. The delivery system of any one of claims 1 to 3, wherein the lip of the tip portion is interposed between the first end of the endoprosthesis and the constraint.

5. 5. The delivery system of claim 1, wherein the endoprosthesis includes a support portion formed from one or more rows defined by stent elements defining a wave pattern, and further wherein the first end of the endoprosthesis releasably received in the pocket includes at least one of the one or more rows defined by the stent elements.

6. 6. The delivery system of claim 1, wherein the first end of the endoprosthesis is configured to be released from the pocket when the endoprosthesis transitions from a compact delivery configuration to an expanded deployed configuration.

7. A delivery system according to any preceding claim, wherein the lip of the tip portion is elastically deformable.

8. 8. The delivery system of claim 1, wherein the lip of the tip portion is configured to transition from a first configuration to a second configuration following release of the endoprosthesis from the pocket defined by the lip, and the second configuration of the lip has a lower profile than the first configuration of the lip.

9. The delivery system of any one of claims 1 to 8, wherein the tip portion includes a serrated portion configured to mechanically engage the first end of the constraint.

10. a body portion configured to receive the endoprosthesis in a compact delivery configuration; and a distal portion including a lip configured to releasably receive a first end of the endoprosthesis in a compact delivery configuration; A delivery catheter comprising:

11. The delivery catheter of claim 10 , wherein the lip of the tip section is resiliently deformable.

12. 12. The delivery catheter of claim 10 or 11, wherein the lip of the tip portion is configured to resiliently transition from a first configuration to a second configuration, the second configuration of the lip having a lower profile than the first configuration of the lip.

13. The delivery catheter of any one of claims 10 to 12, wherein the tip portion includes a serrated portion configured to mechanically engage a restraint for an endoprosthesis.

14. an endoprosthesis having a first end and a second end; and a delivery catheter including a body portion and a tip portion; A delivery system comprising: the endoprosthesis is configured to transition from a compact delivery configuration to an expanded deployed configuration; the endoprosthesis is configured to be received in the body portion of the delivery catheter in a compact delivery configuration, the tip portion including a lip configured to define a pocket to releasably receive the first end of the endoprosthesis in the compact delivery configuration, the lip configured to resiliently transition from a first configuration to a second configuration upon removal of the first end of the endoprosthesis from the pocket, the second configuration having a lower profile than the first configuration. Delivery system.

15. The delivery system of claim 14 , further comprising a constraint that maintains the endoprosthesis in a compact delivery configuration.

16. The delivery system of claim 15 , wherein the restraint is configured to unravel and disintegrate to release the endoprosthesis.

17. 17. The delivery system of claim 15 or 16, wherein the lip of the tip portion is interposed between the first end of the endoprosthesis and the constraint.

18. 18. The delivery system of claim 14, wherein the endoprosthesis includes a support portion formed from one or more rows defined by stent elements defining a wave pattern, and further wherein the first end of the endoprosthesis releasably received in the pocket includes at least one of the one or more rows defined by the stent elements.

19. 19. The delivery system of claim 14, wherein the first end of the endoprosthesis is configured to release from the pocket when the endoprosthesis transitions from a compact delivery configuration to an expanded deployed configuration.

20. 1. A method of assembling an endoprosthesis delivery device, comprising: placing an endoprosthesis having a first end onto the elongate element in a compact delivery configuration; elastically deforming a lip of a distal portion to receive the first end of the endoprosthesis; and placing the tip portion on an elongate element adjacent the first end of the endoprosthesis, where the first end of the endoprosthesis is releasably received within a lip of the tip portion; A method comprising:

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