US20040267348A1 - Medical device delivery systems - Google Patents

Abstract

Medical device delivery systems, and related methods and components, are disclosed.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application is a continuation-in-part of, and claims priority under 35 U.S.C. § 120 to, co-pending and commonly owned U.S. patent application Ser. No. 10/411,645, filed on Apr. 11, 2003, and entitled “Stent Delivery System With Securement and Deployment Accuracy Features”, the entire contents of which are herein incorporated by reference.[0001]
TECHNICAL FIELD
• This invention relates to medical device delivery systems, and related methods and components.[0002]
BACKGROUND
• Systems are known for delivering medical devices, such as stents, into a body lumen. Often, such systems include a proximal portion that remains outside the body during use and a distal portion that is disposed within the body during use. The proximal portion typically includes a handle that is held by an operator of the system (e.g., a physician) during use, and the distal portion can include a sheath surrounding a catheter with a stent positioned therebetween. Generally, the operator of the system positions the distal portion within the lumen at a desired location (e.g., so that the stent is adjacent an occlusion). The operator can then retract the sheath to allow the stent to engage the occlusion/lumen wall. Thereafter, the operator removes the distal portion of the system from the lumen. In many instances, a bumper can be included in the system to, for example, aid in deployment of the stent from the system.[0003]
SUMMARY
• The invention relates to medical device delivery systems, and related methods and components.[0004]
• In one aspect, the invention features an implantable medical endoprosthesis bumper with a retainer that is configured to interdigitate with a cell of an implantable medical endoprosthesis to unidirectionally position the implantable medical endoprosthesis with respect to the bumper.[0005]
• In an additional aspect, the invention features a catheter that has an implantable medical endoprosthesis bumper. The bumper includes a retainer that can interdigitate with a cell of an implantable medical endoprosthesis to unidirectionally position the implantable medical endoprosthesis with respect to the bumper.[0006]
• In a further aspect, the invention features an implantable medical endoprosthesis delivery system that includes a catheter and a sheath at least partially surrounding the catheter. The catheter has an implantable medical endoprosthesis bumper that includes a retainer configured to interdigitate with a cell of an implantable medical endoprosthesis to unidirectionally position the implantable medical endoprosthesis with respect to the bumper. The catheter and the sheath are configured so that the implantable medical endoprosthesis can be disposed between them.[0007]
• In another aspect, the invention features a method of positioning an implantable medical endoprosthesis on a catheter, the method including unidirectionally positioning the implantable medical endoprosthesis with respect to the catheter without reducing the diameter of the implantable medical endoprosthesis.[0008]
• In an additional aspect, the invention features a method of positioning an implantable medical endoprosthesis on a catheter, the method including interdigitating a cell of the implantable medical endoprosthesis with a retainer of the catheter without reducing the diameter of the implantable medical endoprosthesis.[0009]
• In a further aspect, the invention features a method of positioning an implantable medical endoprosthesis on a catheter. The method includes moving the implantable medical endoprosthesis in a longitudinal direction of the catheter to interdigitate a cell of implantable medical endoprosthesis with the catheter without reducing the diameter of the implantable medical endoprosthesis.[0010]
• In another aspect, the invention features a method of positioning an implantable medical endoprosthesis on a catheter, the method including interdigitating a partially open cell of the implantable medical endoprosthesis with a retainer of the catheter.[0011]
• In an additional aspect, the invention features a method of positioning an implantable medical endoprosthesis on a catheter, the method including expanding a retainer of the catheter to interdigitate the implantable medical endoprosthesis with the catheter.[0012]
• In a further aspect, the invention features a catheter with a catheter body that includes a retainer. The retainer is configured to interdigitate with a cell of an implantable medical endoprosthesis to unidirectionally position the implantable medical endoprosthesis with respect to the catheter body.[0013]
• In another aspect, the invention features an implantable medical endoprosthesis delivery system that includes a catheter and a sheath at least partially surrounding the catheter. The catheter has a catheter body that includes a retainer configured to interdigitate with a cell of an implantable medical endoprosthesis to unidirectionally position the implantable medical endoprosthesis with respect to the catheter body. The catheter and the sheath are configured so that the implantable medical endoprosthesis can be disposed between them.[0014]
• In an additional aspect, the invention features an implantable medical endoprosthesis with first and second ends along a longitudinal direction, and a plurality of cells. The cells include a partially open cell that is located at the first end of the implantable medical endoprosthesis. The partially open cell can flex in a plane that is parallel to the longitudinal direction.[0015]
• Embodiments can include one or more of the following advantages.[0016]
• In some embodiments, the implantable medical endoprosthesis delivery system can exhibit relatively high accuracy in positioning an implantable medical endoprosthesis, and/or increased control over the deployment of an implantable medical endoprosthesis.[0017]
• In certain embodiments, an implantable medical endoprosthesis can be positioned within an implantable medical endoprostlhesis delivery system without reducing the diameter of the implantable medical endoprosthesis. This can increase the efficiency and/or accuracy of positioning the implantable medical endoprosthesis within the implantable medical endoprosthesis delivery system.[0018]
• In some embodiments, a retainer can provide an operator of an implantable medical endoprosthesis delivery system with information about the location of an implantable medical endoprosthesis within the system. If the retainer is interdigitated with a cell of the implantable medical endoprosthesis, then the location of the implantable medical endoprosthesis should be near the location of the retainer.[0019]
• Features and advantages of the invention are in the description, drawings, and claims.[0020]
DESCRIPTION OF DRAWINGS
• FIGS. 1A-1C illustrate a process for attaching an embodiment of a stent to an embodiment of a stent bumper.[0021]
• FIGS. 1D-1F illustrate the deployment of the stent of FIGS. 1A-1C.[0022]
• FIG. 1G is a perspective view of the stent bumper of FIGS. 1A-1F.[0023]
• FIG. 2 is a perspective view of an embodiment of a stent bumper.[0024]
• FIG. 3 is a perspective view of an embodiment of a stent bumper.[0025]
• FIGS. 4A and 4B illustrate a process for attaching an embodiment of a stent to an embodiment of a stent bumper.[0026]
• FIG. 5 is a perspective view of an embodiment of a stent bumper.[0027]
• FIG. 6 is a perspective view of an embodiment of a stent bumper.[0028]
• FIGS. 7A-7C illustrate a process for attaching an embodiment of a stent to the stent bumper of FIG. 6.[0029]
• FIGS. 8A-8G illustrate a process for attaching an embodiment of a stent to an embodiment of a stent bumper.[0030]
• FIG. 9 is a perspective view of an embodiment of a stent bumper.[0031]
• FIG. 10 is a perspective view of an embodiment of a stent bumper.[0032]
• FIG. 11 is a perspective view of an embodiment of a stent bumper.[0033]
• FIG. 12 is a perspective view of an embodiment of a stent bumper.[0034]
• FIGS. 13A-13C illustrate a process for attaching an embodiment of a stent to the stent bumper of FIG. 12.[0035]
• FIG. 14 is a perspective view of an embodiment of a stent bumper.[0036]
• FIG. 15 is a side view of an embodiment of a stent bumper.[0037]
• FIG. 16 is a side view of an embodiment of a stent bumper.[0038]
• FIG. 17 is a side view of an embodiment of a stent bumper.[0039]
• FIG. 18 is a side view of an embodiment of a stent bumper.[0040]
• FIG. 19 is a side view of an embodiment of a stent bumper.[0041]
• FIGS. 20A and 20B illustrate a process for attaching an embodiment of a stent to an embodiment of a stent bumper.[0042]
• FIG. 21 is a front view of an embodiment of a stent bumper.[0043]
• FIGS. 22A and 22B illustrate a process for attaching a stent to the stent bumper of FIG. 21.[0044]
DETAILED DESCRIPTION
• In general, the delivery systems are designed to temporarily retain an implantable medical endoprosthesis during delivery to a target site by interdigitating a retainer with a cell of the endoprosthesis so that the endoprosthesis does not prematurely deploy from the delivery device. It is believed that such systems can increase the accuracy of positioning the implantable medical endoprosthesis within a subject. Certain embodiments of the systems are disclosed below.[0045]
• For example, FIGS. 1A-1C show the interdigitation of a partially[0046]open cell22 of a self-expandingstent10 with abumper retainer12 of abumper14.Stent10 has an end18 that includes partiallyopen cell22, which has twopaddles20, each withrespective heads26 andlegs28. With this arrangement, partiallyopen cell22 can interdigitate withstent retainer12 so thatstent10 is unidirectionally positioned with respect to bumper14 (see discussion below).Paddles20, which are formed of a flexible material, can be used, for example, to incorporate radiopaque material (e.g., radiopaque markers) that rendersstent10 radiopaque. Partiallyopen cell22 has an opening24 that is smaller thanbumper retainer12. When paddles20 are pushed againstbumper retainer12 in the direction of arrow A, as shown in FIG. 1B, paddles20 flex to extend aroundbumper retainer12. Aspaddles20 flex, the size of opening24 temporarily increases, such thatbumper retainer12 is accommodated by opening24. As FIG. 1C shows, once heads26 ofpaddles20 have passedbumper retainer12, paddles20 return to their original position. In doing so, paddles20lock bumper retainer12 betweenlegs28, thereby interdigitating partiallyopen cell22 withbumper retainer12. The flexing ofpaddles20 aroundbumper retainer12 allows for interdigitation between partiallyopen cell22 andretainer12 without a reduction in the diameter ofstent10.
• The interdigitation of partially[0047]open cell22 ofstent10 withbumper retainer12 precludesstent10 from moving distally relative tobumper14 as the sheath of a stent delivery system is withdrawn overstent10 during delivery ofstent10 to a target site (i.e.,stent retainer12unidirectionally positions stent10 relative to bumper14).
• FIGS. 1D-1F illustrate the delivery of[0048]stent10 to a target site using a delivery device40. Delivery device40 includes aninner catheter42 and asheath44.Bumper14 is loaded ontoinner catheter42, and is located betweeninner catheter42 andsheath44.Stent10 is positioned oninner catheter42, and is disposed betweeninner catheter42 andsheath44.Bumper retainer12 preventsstent10 from deploying prematurely (e.g., beforesheath44 is substantially retracted) by interdigitating with partiallyopen cell22.
• FIGS. 1E and 1F show the deployment of[0049]stent10. Assheath44 is retracted,stent10 begins to expand, lifting paddles26 away frombumper retainer12. Oncesheath44 has been retractedpast paddles26,bumper retainer12 no longer interdigitates with partiallyopen cell22.Inner catheter42 can then be proximally withdrawn while leavingstent10 at the target site.
• FIG. 1G shows[0050]bumper14 in enlarged detail.Bumper14 includes abody portion30 and ahead portion32 that is integral withbody portion30.Bumper retainer12, which is diamond-shaped, protrudes radially from the surface ofbody portion30.Bumper retainer12 can be integrally formed (e.g., molded) withbody portion30, or can be formed separately frombody portion30 and then attached (e.g., adhesive-bonded) tobody portion30.
• [0051]Bumper retainer12 can be formed of, for example, a polymer, a metal, an alloy or a combination of these materials. Examples of polymers include polyether-block co-polyamide polymers (e.g., PEBAX®), copolyester elastomers (e.g., Arnitel® copolyester elastomers), thermoplastic polyester elastomers (e.g., Hytrel®), thermoplastic polyurethane elastomers (e.g., Pellethane™), polyeolefins (e.g., Marlex® polyethylene, Marlex® polypropylene), high-density polyethylene (HDPE), low-density polyethylene (LDPE), polyamides (e.g., Vestamid®), and combinations of these materials. Examples of metals and alloys include stainless steel, platinum, gold, tantalum, and MP35N (a nickel-cobalt-chromium-molybdenum alloy). In some embodiments,bumper retainer12 andbody portion30 and/orhead portion32 can be formed of the same materials. In certain embodiments,bumper retainer12 andbody portion30 and/orhead portion32 can be formed of different materials.
• While a diamond-shaped bumper retainer is shown in FIGS. 1A-1G, bumper retainers can have other shapes. In general, bumper retainers can be shaped to unidirectionally position an implantable medical endoprosthesis with respect to a bumper. For example, FIG. 2 shows a[0052]bumper50 with a triangular bumper retainer52, and FIG. 3 shows a bumper60 with a hemispherical bumper retainer62.
• In some embodiments, a bumper can include a nodular bumper retainer. In such embodiments, a stent that interdigitates with the bumper retainer can have a partially open cell that is designed to have a reduced likelihood of becoming prematurely disengaged from the bumper retainer. For example, FIG. 4A shows a[0053]stent600 with a partiallyopen cell601 having twopaddles602, each of which has atriangular head604 and aleg606. As shown in FIG. 4B, afterpaddles602 have flexed around a nodular bumper retainer608 of abumper610, heads604 ofpaddles602 temporarily lock around bumper retainer608. The shape oftriangular heads604 helps to limit the likelihood that partiallyopen cell601 will prematurely disengage from bumper retainer608.
• In some embodiments, a bumper can include more than one bumper retainer. For example, FIG. 5 shows a[0054]bumper70 with ahead portion74, a body portion76, and two oppositely disposednodular bumper retainers72, which protrude radially from body portion76. While two bumper retainers are shown in FIG. 5, in some embodiments, a bumper can include more than two (e.g., three, four, five, six, seven, eight, nine, ten) bumper retainers. As the number of bumper retainers on a bumper increases, the retention of an endoprosthesis can be enhanced, and the accuracy of endoprosthesis positioning can increase. In certain embodiments, the number of bumper retainers on a bumper can correspond to the number of partially open cells in a stent with which the bumper is interdigitating. The bumper retainers can be disposed equidistantly from each other on the bumper, or can be disposed at varying distances from each other. The bumper retainers can have the same shapes or different shapes.
• While certain shapes of bumper retainers have been shown, other shapes may also be used. For example, a bumper retainer can be a flap, a hook, or a barb or spike. As an example, FIG. 6 shows a[0055]bumper100 with ahead portion102 and abody portion104. Abumper retainer106 in the form of a rectangular-shaped flap projects radially frombody portion104.
• FIGS. 7A-7C show the interdigitation of[0056]bumper retainer106 with a partially open cell148 of astent150. As shown in FIG. 7A,stent150 has anend154 that includes partially open cell148, which has twoflexible paddles152, each withrespective heads156 andlegs158. As FIG. 7B shows, whenstent150 is pushed towardbumper retainer106, paddles152 flex outwardly to fit aroundbumper retainer106. Afterheads156 ofpaddles152 have flexed aroundbumper retainer106,stent150 is pulled back in the direction of arrow Al, such that heads156 contact theproximal end157 ofbumper retainer106, thereby interdigitatingbumper retainer106 with partially open cell148. Asstent150 is delivered to a target site and expanded, paddles152 lift away frombumper retainer106, thereby disengaging from partially open cell148.
• While interdigitation by paddle flexing has been shown, in some embodiments, a flap-shaped bumper retainer can interdigitate with a partially open cell by flexing through the partially open cell, while the components of the partially open cell do not flex substantially. For example, FIG. 8A shows a[0057]bumper650 with abumper retainer652 in the form of a rectangular flap. As FIGS. 8B and 8C show,bumper retainer652 can flex upward (in the direction of arrow A2). However, and referring also now to FIGS. 8D and 8E, as astent656 with a partiallyopen cell654 includingpaddles672 approaches andcontacts bumper retainer652, paddles672 push down onbumper retainer652. As shown in FIGS. 8F and 8G, once paddles672 have passed overbumper retainer652,bumper retainer652 flexes back upward in the direction of arrow A2, through partiallyopen cell654. Thus,bumper retainer652 interdigitates with partiallyopen cell654.
• While[0058]bumper retainer652 of FIGS. 8A-8G is a rectangular-shaped flap, flaps with other shapes can be used as bumper retainers. As an example, FIG. 9 shows abumper680 with ahead portion682 integrally connected to abody portion684 that includes abumper retainer686.Bumper retainer686 is in the form of a diamond-shaped flap that protrudes frombody portion684. As another example, FIG. 10 shows a bumper200 with ahead portion210 integrally connected to abody portion220 that includes abumper retainer230.Bumper retainer230 is in the form of a triangular flap that protrudes frombody portion220. As a further example, FIG. 11 shows abumper250 with ahead portion260 integrally connected to abody portion270 that includes abumper retainer280.Bumper retainer280 is in the form of a hemispherical flap that protrudes frombody portion270. Another example of a suitable shape for a flap-style bumper retainer is a J-hook.
• In some embodiments, a bumper retainer can be in the form of a flexible, bent flap which can, for example, interdigitate with a stent having a partially open cell or a stent without a partially open cell. For example, FIG. 12 shows a[0059]bumper700 that includes ahead portion702 and a body portion704, from which a rectangular flap-shapedbumper retainer706 protrudes.Bumper retainer706 is bent so that its end708 contacts the surface709 of body portion704. As shown in FIGS. 13A-13C, asbumper retainer706 comes into contact with astent710,bumper retainer706 flexes in a downward direction to accommodatestent710. However, when acell712 ofstent710 is disposed overbumper retainer706,bumper retainer706 flexes up into the cell, thereby interdigitating with the cell.
• While FIGS. 12-13C show a bent rectangular flap-shaped bumper retainer, bumper retainers with other shapes can also be bent. For example, FIG. 14 shows a[0060]bumper750 with ahead portion752 and abody portion754 from which aflexible bumper retainer756 in a diamond-shaped flap style protrudes.Bumper retainer756 is bent so thatend758 ofbumper retainer756 contacts the surface757 ofbody portion754.
• As noted above, in some embodiments, a bumper retainer can be in the form of a barb or a spike. For example, FIG. 15 shows a[0061]bumper300 with a head portion310 and a body portion320, and a bumper retainer330 protruding radially from body portion320. Bumper retainer330 protrudes radially from body portion320 at an angle a selected to accommodate a partially open cell of a stent. In some embodiments, angle a can be up to about 90° (e.g., from about 30° to about 90°, up to about 10°, up to about 15°, up to about 20°).
• In certain embodiments, a bumper can include multiple spike-shaped bumper retainers. For example, FIG. 16 shows a bumper[0062]350 with ahead portion360 and a body portion370, and multiple spike-shapedbumper retainers380 protruding radially from body portion370.
• In some embodiments, a portion of a bumper can be molded to include one or more components that can interdigitate with a cell of a stent. For example, FIG. 17 shows a[0063]bumper400 with ahead portion410, abody portion420, and a collar430 molded aroundbody portion420. Collar430 functions as a bumper retainer, and is shaped to interdigitate with a cell of a stent to unidirectionally position the stent with respect tobumper400. Similarly, FIG. 18 shows a bumper450 with ahead portion460, a body portion470, and a bumper retainer480 molded to an end490 of body portion470. As another example, FIG. 19 shows abumper600 with ahead portion610 and abody portion620 that includes abumper retainer630 withmultiple peaks640. In some embodiments, bumper retainers such as those described above can have relatively smooth surfaces to, for example, limit damage to an endoprosthesis upon interdigitation of a cell of the endoprosthesis with the bumper retainer. In certain embodiments, bumper retainers such as those shown in FIGS. 17-19 can be formed of a relatively soft polymer, such as a low durometer polyether-block co-polyamide polymers (e.g., low durometer Pebax®), a thermoplastic resin (e.g., C-Flex®, a thermoplastic polyurethane (e.g., an aromatic polyether-based thermoplastic polyurethane such as Tecothane®)), an elastomer, or silicone. In embodiments in which a bumper retainer is formed of a relatively soft polymer, the bumper retainer can, for example, adjust to accommodate a stent as the stent is being disposed over the bumper retainer.
• In certain embodiments, an endoprosthesis can be temporarily retained by disposing the endoprosthesis over a retainer and expanding the retainer such that it interdigitates with a cell of the endoprosthesis.[0064]
• For example, FIGS. 20A and 20B show a stent delivery system[0065]500 that includes asheath510, aninner catheter520 concentrically disposed withinsheath510, and abumper530 attached toinner catheter520 and restrained withinsheath510.Bumper530 includes ahead portion532, a body portion534, and abumper retainer536 on body portion534.Bumper retainer536 is formed of a shape-memory material. Astent540 abutshead portion532 ofbumper530 and is constrained betweensheath510 andinner catheter520. FIG. 20A shows stent delivery system500 when there is no interdigitation between any of the cells ofstent540 andbumper retainer536. However, as FIG. 20B shows, whenbumper retainer536 is exposed to a change in temperature (e.g., when stent delivery system500 is delivered into the body of a subject),bumper retainer536 expands to interdigitate withcells542 and544 ofstent540.
• As noted,[0066]bumper retainer536 is formed of a shape-memory material. Examples of shape memory materials include metal alloys, such as nitinol (e.g., 55% nickel, 45% titanium), silver-cadmium (Ag—Cd), gold-cadmium (Au—Cd), gold-copper-zinc (Au—Cu—Zn), copper-aluminum-nickel (Cu—Al—Ni), copper-gold-zinc (Cu—Au—Zn), copper- zinc/(Cu—Zn), copper-zinc-aluminum (Cu—Zn—Al), copper-zinc-tin (Cu—Zn—Sn), copper-zinc-xenon (Cu—Zn—Xe), iron beryllium (Fe₃Be), iron platinum (Fe₃Pt), indium-thallium (In—Tl), iron-manganese (Fe—Mn), nickel-titanium-vanadium (Ni—Ti—V), iron-nickel-titanium-cobalt (Fe—Ni—Ti—Co) and copper-tin (Cu—Sn). See, e.g., Schetsky, L. McDonald, “Shape Memory Alloys”,Encyclopedia of Chemical Technology(3rd ed.), John Wiley & Sons, 1982, vol. 20. pp. 726-736.
• While certain embodiments have been described, other embodiments are possible.[0067]
• As an example, while certain embodiments of a partially open cell have been described, other embodiments are also possible. In general, a partially open cell of an implantable medical endoprosthesis can have a configuration capable of interdigitating with a retainer (e.g., a bumper retainer) of an implantable medical endoprosthesis delivery system.[0068]
• As another example, in some embodiments, a bumper retainer can be formed of a moldable material, such as a wax. One or more cells of an endoprosthesis can be interdigitated with the bumper retainer by molding the wax so that it extends into the cell(s). The cell(s) of the endoprosthesis can be subsequently disengaged from the bumper retainer when the endoprosthesis expands. Examples of waxes include medical-grade viscoelastic wax, such as dental wax (e.g., utility dental wax, dental modeling wax).[0069]
• As an additional example, in certain embodiments, a bumper retainer can be formed of a swellable material, such as a hydrogel (e.g., the Tecophilic® family of hydrogels, such as Tecogel®) or a polyamide. For example, the bumper retainer can be formed of a heat-activated swellable material that expands upon exposure to an increase in temperature. In some embodiments, the bumper retainer can be formed of a material used in certain types of gaskets, such as O-rings. Examples of heat-activated swellable materials include virgin Teflon®, filled Teflon® (e.g., Teflon® including a strength-enhancing filler), expanded Teflon®, Viton®, Kalrez®, Simriz®, Chemraz®, Aflas™, fluorosilicone, urethane, hydrogenated nitrile elastomer (HNBR), polyacrylate, neoprene, and chlorosulfonated polyethylene (e.g., Hypalon®). The bumper retainer can interdigitate with a cell of an endoprosthesis by disposing the cell over the bumper retainer and allowing the bumper retainer to swell (e.g., upon exposure to a change in temperature, pH, or ion concentration) and protrude into the cell.[0070]
• As a further example, while bumper retainers have been described, in some embodiments, an endoprosthesis delivery system can alternatively or additionally include one or more retainers in a different location. For example, a retainer can protrude radially from the inner catheter of an endoprosthesis delivery system. In certain embodiments, a retainer can be formed on a tubular band (e.g., a metallic band) that can, for example, be loaded onto an inner catheter and disposed between the inner catheter and an endoprosthesis.[0071]
• As another example, while interdigitation with a partially open cell has been shown, in some embodiments, a retainer can interdigitate with a closed cell of an implantable medical endoprosthesis (a cell that is defined by a boundary that has no openings). For example, a bumper retainer can be flexed to extend through a closed cell of a stent.[0072]
• As an additional example, while interdigitation of a stent with a bumper retainer by moving the stent in a longitudinal direction has been shown, in some embodiments, a bumper retainer can be rotated to interdigitate with a stent. For example, FIG. 21 shows a front view of a[0073]bumper800 with several flexible flap-style bumper retainers810 protruding from itssurface820. As shown in FIGS. 22A and 22B, when astent850 is disposed overbumper800, andbumper800 is rotated in a counterclockwise direction,bumper retainers810 push againststent850, which causesbumper retainers810 to protrude more fromsurface820. As a result,bumper retainers810 interdigitate with thecells860 ofstent850.
• As an additional example, while the retention of self-expanding stents has been described, other types of implantable medical endoprostheses are capable of being retained by the above-described retainers. For example, a retainer can be used to retain a balloon-expandable stent. In some embodiments, a retainer can retain a stent-graft or a vena cava filter.[0074]
• Other embodiments are in the claims.[0075]

Claims (39)

What is claimed is:

1. An implantable medical endoprosthesis bumper having a retainer configured to interdigitate with a cell of an implantable medical endoprosthesis to unidirectionally position the implantable medical endoprosthesis with respect to the bumper.

2. The implantable medical endoprosthesis bumper ofclaim 1, wherein the implantable medical endoprosthesis bumper includes a bumper body, and the retainer protrudes radially from the bumper body.

3. The implantable medical endoprosthesis bumper ofclaim 2, wherein the retainer comprises a flap that protrudes radially from the bumper body.

4. The implantable medical endoprosthesis ofclaim 2, wherein the retainer comprises a hook, a spike, or a barb.

5. The implantable medical endoprosthesis ofclaim 1, wherein the retainer comprises a wax.

6. The implantable medical endoprosthesis ofclaim 1, wherein the retainer is capable of flexing to interdigitate with the cell or to disengage from the cell.

7. A catheter having an implantable medical endoprosthesis bumper, the bumper including a retainer configured to interdigitate with a cell of an implantable medical endoprosthesis to unidirectionally position the implantable medical endoprosthesis with respect to the bumper.

8. An implantable medical endoprosthesis delivery system, comprising:

a catheter having an implantable medical endoprosthesis bumper, the bumper including a retainer configured to interdigitate with a cell of an implantable medical endoprosthesis to unidirectionally position the implantable medical endoprosthesis with respect to the bumper; and

a sheath at least partially surrounding the catheter,

wherein the catheter and the sheath are configured so that the implantable medical endoprosthesis can be disposed therebetween.

9. The endoprosthesis delivery system ofclaim 8, further comprising the implantable medical endoprosthesis between the catheter and the sheath.

10. A method of positioning an implantable medical endoprosthesis on a catheter, the method comprising:

unidirectionally positioning the implantable medical endoprosthesis with respect to the catheter without reducing a diameter of the implantable medical endoprosthesis.

11. The method ofclaim 10, wherein the catheter comprises a bumper including a retainer configured to interdigitate with a cell of the implantable medical endoprosthesis.

12. The method ofclaim 10, wherein the catheter comprises a catheter body including a retainer configured to interdigitate with a cell of the implantable medical endoprosthesis.

13. The method ofclaim 11, wherein the implantable medical endoprosthesis has a partially open cell, and unidirectionally positioning the implantable medical endoprosthesis with respect to the catheter comprises flexing the partially open cell to interdigitate the partially open cell with the retainer.

14. A method of positioning an implantable medical endoprosthesis on a catheter, the method comprising:

interdigitating a cell of the implantable medical endoprosthesis with a retainer of the catheter without reducing a diameter of the implantable medical endoprosthesis.

15. The method ofclaim 14, wherein the catheter comprises a bumper including the retainer.

16. The method ofclaim 15, wherein the bumper includes a bumper body, and the retainer protrudes radially from the bumper body.

17. The method ofclaim 14, wherein the catheter includes a catheter body comprising the retainer.

18. The method ofclaim 14, wherein interdigitating a cell of the implantable medical endoprosthesis with a retainer of the catheter comprises expanding the retainer from a first size to a second size.

19. The method ofclaim 14, wherein the retainer comprises a wax and interdigitating a cell of the implantable medical endoprosthesis with the retainer comprises molding the wax to extend into the cell.

20. A method of positioning an implantable medical endoprosthesis on a catheter, the method comprising:

moving the implantable medical endoprosthesis in a longitudinal direction of the catheter to interdigitate a cell of the implantable medical endoprosthesis with the catheter without reducing a diameter of the implantable medical endoprosthesis.

21. The method ofclaim 20, wherein the catheter comprises a bumper including the retainer configure to interdigitate the cell of the implantable medical endoprosthesis.

22. The method ofclaim 21, wherein the bumper includes a bumper body, and the retainer protrudes radially from the bumper body.

23. The method ofclaim 20, wherein the catheter comprises a catheter body including the retainer.

24. A method of positioning an implantable medical endoprosthesis on a catheter, the method comprising:

interdigitating a partially open cell of the implantable medical endoprosthesis with a retainer of the catheter.

25. The method ofclaim 24, wherein interdigitating a partially open cell of the implantable medical endoprosthesis with a retainer of the catheter comprises flexing the partially open cell.

26. The method ofclaim 24, wherein interdigitating a partially open cell of the implantable medical endoprosthesis with a retainer of the catheter comprises expanding the retainer.

27. The method ofclaim 24, wherein the retainer comprises a wax and interdigitating a cell of the implantable medical endoprosthesis with the retainer comprises molding the wax to extend into the cell.

28. A method of positioning an implantable medical endoprosthesis on catheter, the method comprising:

expanding a retainer of the catheter to interdigitate a cell of the implantable medical endoprosthesis with the catheter.

29. The method ofclaim 28, wherein the retainer comprises a shape memory material.

30. The method ofclaim 28, wherein the retainer comprises a swellable material.

31. The method ofclaim 28, further comprising disposing the implantable medical endoprosthesis over the retainer prior to expanding the retainer.

32. The method ofclaim 28, wherein the catheter comprises an implantable medical endoprosthesis bumper comprising the retainer.

33. The method ofclaim 28, wherein the catheter comprises a catheter body comprising the retainer.

34. A catheter having a catheter body, the catheter body including a retainer configured to interdigitate with a cell of an implantable medical endoprosthesis to unidirectionally position the implantable medical endoprosthesis with respect to the catheter body.

35. The catheter ofclaim 34, wherein the retainer protrudes radially from the catheter body.

36. The catheter ofclaim 34, wherein the retainer is capable of flexing to interdigitate with the cell or to disengage from the cell.

37. An implantable medical endoprosthesis delivery system, comprising:

a catheter having a catheter body, the catheter body including a retainer configured to interdigitate with a cell of an implantable medical endoprosthesis to unidirectionally position the implantable medical endoprosthesis with respect to the catheter body; and

a sheath at least partially surrounding the catheter,

wherein the catheter and the sheath are configured so that the implantable medical endoprosthesis can be disposed therebetween.

38. An implantable medical endoprosthesis having first and second ends along a longitudinal direction, and a plurality of cells including a partially open cell located at the first end, wherein the partially open cell is capable of flexing in a plane parallel to the longitudinal direction.

39. The implantable medical endoprosthesis ofclaim 38, wherein the partially open cell is capable of interdigitating with a retainer of a stent bumper.

Images