US20140142688A1 - Medical Device Delivery System and Methods of Delivering a Medical Device - Google Patents

Abstract

A medical device delivery system can include a dilator including a tip having a taper in a distal direction, a coupler, and a flap that radially protrudes from the tip. The flap can be configured to bend against a body lumen to cover at least a portion of the delivery system when the dilator is tracked through the body lumen. A medical device delivery system can include a dilator including a tip having a lumen and a coupler having a lumen. The coupler can be configured to securely connect to the tip such that the lumen of the tip is aligned with the lumen of the coupler to allow a guide wire to pass therethrough. Methods for loading a medical device into a delivery catheter are also disclosed.

Description

BACKGROUND
• 1. Field
• Certain embodiments of the present invention are related to medical device delivery systems and methods of delivering a medical device.
• 2. Background Art
• Existing medical device delivery systems, such as those for use in percutaneous medical procedures, can allow a medical device to be delivered through a patient's vascular to a delivery site where it can be implanted within a patient. In some procedures a medical device in the form of a valve prosthesis can be compacted and loaded onto a delivery device for advancement through a patient's vasculature in a transfemoral, transapical, and/or transatrial procedure. There is a continuous need for improved delivery systems for use in percutaneous and other delivery techniques.
BRIEF SUMMARY
• In some embodiments, a medical device delivery system can include a dilator including a tip having a taper in a distal direction, a coupler, and a flap that radially protrudes from the tip. The flap can be configured to bend against a body lumen to cover at least a portion of the delivery system when the dilator is tracked through the body lumen.
• In some embodiments, a medical device delivery system can include a dilator including a tip having a lumen and a coupler having a lumen. The coupler can be configured to securely connect to the tip such that the lumen of the tip is aligned with the lumen of the coupler to allow a guide wire to pass therethrough. Methods for loading a medical device into a delivery catheter are also disclosed.
• In some embodiments, a method of loading a medical device into a delivery catheter can include securing a coupler to a delivery catheter shaft, the shaft having a lumen for receiving the medical device, crimping the medical device to a diameter permitting the medical device to be loaded into the shaft lumen, loading the medical device into the shaft lumen, and securing a dilator tip to the coupler after the medical device is loaded into the shaft lumen.
BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES
• The accompanying figures, which are incorporated herein, form part of the specification and illustrate embodiments of percutaneous medical procedure systems and related methods. Together with the description, the figures further serve to explain the principles of and to enable a person skilled in the relevant art(s) to make, use, and implant the valve prosthesis described herein.
• FIG. 1 illustrates a front view of a medical device that can be used in one or more of the systems described herein.
• FIG. 2 illustrates a delivery system in accordance with one embodiment.
• FIGS. 3a-cand4a-cillustrate the delivery system ofFIG. 2 in various states.
• FIG. 5 illustrates a cross-sectional view of a portion of the delivery system ofFIG. 2.
• FIG. 6 illustrates a cross-sectional view of a portion of the delivery system ofFIG. 2 in a body lumen.
• FIG. 7 illustrates a front perspective view of a dilator in accordance with one embodiment.
• FIG. 8 illustrates a side view of the dilator ofFIG. 7.
• FIG. 9 illustrates an exploded view of the dilator ofFIG. 7.
• FIG. 10 illustrates a cross-sectional view of a dilator in accordance with one embodiment in a first state.
• FIG. 11 illustrates a cross-sectional view of the dilator ofFIG. 10 in a second state.
DETAILED DESCRIPTION
• The following detailed description refers to the accompanying figures which illustrate several embodiments. Other embodiments are possible. Modifications can be made to the embodiments described herein without departing from the spirit and scope of the present invention. Therefore, the following detailed description is not meant to be limiting.
• FIG. 1 illustrates amedical device10 that can be used in one or more of the systems described herein. In some embodiments,medical device10 can be in the form of a prosthetic heart valve including aframe12 attached to avalve body14. In some embodiments,valve body14 can be formed, for example, from one or more of biocompatible synthetic materials, synthetic polymers, autograft tissue, homograft tissue, xenograft tissue, or one or more other suitable materials. In some embodiments,valve body14 can be formed, for example, from bovine, porcine, equine, ovine, and/or other suitable animal tissues. In some embodiments,valve body14 can be formed, for example, from heart valve tissue, pericardium, and/or other suitable tissue. In some embodiments,valve body14 can comprise one or more valve leaflets, such as for example, a tri-leaflet bovine pericardium valve, a bi-leaflet valve, or another suitable valve.
• A suitablemedical device10 is not limited to prosthetic heart valves. In some embodiments,medical device10 can be a device configured to be transported via a delivery catheter. In some embodiments,medical device10 can be an expandable device, such as, for example, a percutaneously delivered device configured to be compacted and loaded onto a delivery catheter for advancement through a natural or artificial body lumen, such as for example through a patient's vasculature. In some embodiments,medical device10 is not expandable. In some embodiments,medical device10 is not designed to be implanted within the patient's body. In some embodiments,medical device10 can be an embolic filter. In some embodiments,medical device10 can be a tool that can be used, for example, to retrieve an item from inside a patient.
• FIG. 2 illustrates adelivery system16 in accordance with one embodiment of the present invention. In some embodiments,system16 can be used in one or more percutaneous delivery procedures. For example, in some percutaneous procedures, a valve prosthesis can be compacted and loaded onto a delivery device, such as for example a catheter, for advancement through a patient's vasculature. In some embodiments,system16 can be configured for use in illiofemoral, apical, radial, direct aortic, and subclavian/axillary entry locations.System16 can be configured to allow access from multiple locations per procedure (e.g. bilateral femoral access). In some embodiments,system16 can be configured to delivermedical device10 through an artery or vein, a femoral artery, a femoral vein, a jugular vein, a subclavian artery, an axillary artery, an aorta, an atrium, and/or a ventricle.System16 can be configured to delivermedical device10 via a transfemoral, transapical, transseptal, transatrial, transventrical, or transaortic procedure. In some embodiments, one or more components or portion of components ofsystem16 can be configured to flex to facilitate the traversal ofsystem16 through a body lumen during a delivery procedure. In some embodiments, one or more components ofsystem16 or portions thereof can include a curved outer surface and/or shape to facilitate movement through a curved body lumen.
• As described above, in some embodiments,system16 can be configured for use in a transfemoral delivery procedure. In one example of such a procedure, a delivery device including a prosthetic heart valve can be advanced in a retrograde manner through a patient's femoral artery and into the patient's descending aorta. A catheter can then be advanced under fluoroscopic guidance over the simulated aortic arch, through the ascending aorta, into the left ventricle, and mid-way across the defective aortic valve. Once positioning of the catheter is confirmed, the valve prosthesis can be deployed within the valve annulus. The valve prosthesis can then expand against the simulated annulus. In some embodiments, as the valve prosthesis is expanded, it can trap leaflets against the annulus, which can retain the native valve in a permanently open state.
• As described above, in some embodiments,system16 can be configured for use in a transapical delivery procedure. In one example of such a procedure, a trocar or overtube can be inserted into a patient's left ventricle through an incision created in the apex of the patient's heart. A dilator can be used to aid in the insertion of the trocar. In this approach, the native valve (for example, the mitral valve) can be approached downstream relative to blood flow. The trocar can be retracted sufficiently to release the self-expanding valve prosthesis. The dilator can be presented between the leaflets. The trocar can be rotated and adjusted to align the valve prosthesis in a desired alignment. The dilator can be advanced into the left atrium to begin disengaging the proximal section of the valve prosthesis from the dilator.
• In some embodiments,system16 can be configured for use in a transatrial delivery procedure. In one example of such a procedure, a dilator and trocar can be inserted through an incision made in the wall of the left atrium of the heart. The dilator and trocar can then be advanced through the native valve and into the left ventricle of the heart. The dilator can then be withdrawn from the trocar. A guide wire can be advanced through the trocar to the point where the valve prosthesis comes to the end of the trocar. The valve prosthesis can be advanced sufficiently to release a self-expanding valve prosthesis from the trocar. The trocar can be rotated and adjusted to align the valve prosthesis in a desired alignment. The trocar can be withdrawn completely from the heart such that the valve prosthesis self-expands into position and can assume the function of the native valve.
• The few example procedures described above are not intended to be exhaustive. It is understood that not every act need be performed and additional acts can be included as would be apparent to one of ordinary skill in the art. In addition, the acts can be reordered as desired. Other medical devices and delivery techniques can be used with any of the parts described herein. It is further understood that the above delivery routes are merely exemplary and that other suitable delivery routes can be employed. The terms “delivery” and “delivery system” as used herein is intended to refer broadly to positioning a medical device at a desired location and related systems. Such terms do not necessitate a system that actually deposits a medical device at a site, such as for example a device that can be used to implant a prosthetic heart valve. The term “delivery system” can cover, for example, a system that temporarily positions a medical device at a desired location. For example, the delivery system can be used to position an embolic filter at a desired location within a patient's vascular for a period of time before removing the embolic filter.
• Thedelivery system16 ofFIG. 2 can include ahandle17, one or moreretractable sheaths19 and21, ahub23, anintroducer25, acapsule27, and adilator18. In some embodiments,dilator18 can be configured to dilate a tube, cavity, and/or opening in the body to facilitate introduction ofsystem16 for a delivery procedure. In some embodiments,dilator18 can be configured to facilitate removal ofsystem16 following delivery ofmedical device10.
• In some embodiments,dilator18 can be connected to handle17 via one or more inner shafts (see, for example,shaft29 described below with respect toFIG. 5). In some embodiments, one or more ofhandle17,retractable sheaths19 and21,hub23,introducer25, andcapsule27 can be slidably disposed over one or more of the inner shafts. In some embodiments,capsule27 can be configured to releasably engage withdilator18. In some embodiments, adistal edge33 ofcapsule27 can abut a proximal end ofdilator18.
• In some embodiments,capsule27 can be configured to housemedical device10 for delivery viasystem16.Capsule27 can include a lumen (shown for example inFIG. 5) that is configured to receive the entirety ofmedical device10 or a portion thereof. In some embodiments,capsule27 can be in the form of a tube or another suitable shape. In some embodiments,capsule27 can be in the form of a sheath. In some embodiments, a portion ofcapsule27 can be tapered. For example, in some embodiments, one or both of a proximal and distal end portions ofcapsule27 can be tapered.
• In some embodiments,capsule27 can be configured to move relative tomedical device10 to partially or fully releasemedical device10 for delivery bysystem16. In some embodiments,system16 is configured to movecapsule27 relative tomedical device10 by movingcapsule27 from a first position to a second position whilemedical device10 is relatively stationary. For example, in some embodiments,capsule27 can be configured to move in a proximal direction relative to medical device10 (towards handle17) to partially or fully exposemedical device10 to allow for deliverymedical device10. In some embodiments,system16 is configured to movecapsule27 relative tomedical device10 by movingmedical device10 from a first position to a second position whilecapsule27 is relatively stationary. For example. In some embodiments,medical device10 can be pushed relative tocapsule27 in a distal direction to partially or fully exposemedical device10 for delivery insystem16.
• In some embodiments, movement ofcapsule27 can be automatically or manually actuated. In some embodiments, handle17 can include acontrol knob37 configured to retractcapsule27. In some embodiments, movement ofcapsule27 can be controlled by a user, such as by rotatingcontrol knob37 onhandle17 or via another suitable actuator. In some embodiments, one or more portions ofsystem16 can include a flushingport39, which in some embodiments can be configured to maintain hemostasis during a medical procedure. Flushingport39 can be connected to handle17, or another suitable portion ofsystem16. In some embodiments, one or more portions ofsystem16, such as for example an exterior ofcapsule27 can be coated with a biocompatible lubricant.
• In some embodiments,hub23 can include an integrated hemostasis control feature.Hub23 can be connected tointroducer25 and can be configured to moveintroducer25 by slidinghub23 distally towardsdilator18. In some embodiments,hub23 can include a feature, such as for example a spring-loaded button, that can be configured to avoid accidental movement ofhub23 during a procedure.
• In some embodiments,introducer25 can be in the form of a flexible sheath. In some embodiments,introducer25 can be used to pushcapsule27 againstdilator18 aftermedical device10 has been delivered. In some embodiments,introducer25 can be configured to cover the exposed edges ofcapsule27, which in some embodiments can facilitate retraction through the deployed prosthesis. In some embodiments, oncemedical device10 is released and expands against a body lumen, a user can slidehub23 in a distal direction.System16 can be configured such that distal movement ofhub23 will move introducer25 in a distal direction. In some embodiments,system16 is configured such that distal movement ofintroducer25 will thereby slidecapsule27 to engage a proximal end ofdilator18.
• As described above, in some embodiments,system16 can be configured for use in a percutaneous delivery procedure including a medical device that is compacted and loaded intosystem16 for advancement through a patient's vasculature.FIGS. 3a-cand4a-cillustrate various stages of one example of a delivery procedure. In particular,FIG. 3aillustratesdelivery system16 withmedical device10 fully housed withincapsule27.FIG. 3billustratessheath19 andcapsule27 partially retracted to expose a portion ofmedical device10.FIG. 3cillustratessheath19 andcapsule27 further retracted to further exposemedical device10.FIG. 4aillustratessheath19 andcapsule27 completely retracted to fully exposemedical device10.FIGS. 4band4C illustrate stages ofcapsule27 being returned todilator18 after delivery ofmedical device10. In particular,FIG. 4billustratesdelivery system16 withcapsule27 partially returned todilator18.FIG. 4cillustratesdelivery system16 withcapsule27 engaged withdilator18 withsystem16 ready to be retracted from the body lumen. In some embodiments,capsule27 does not engage withdilator18 beforesystem16 is retracted from the body lumen.
• FIG. 5 illustrates a cross-sectional view of a medicaldevice delivery system16 in accordance with one embodiment. As described above,delivery system16 can includemedical device10,dilator18, andcapsule27.System16 can further include ashaft29 and aguide wire22.Dilator18 andshaft29 can includerespective lumens24 and43 formed therein for receivingguide wire22 such thatdilator18 andshaft29 are slidably disposed relative to guidewire22. In some embodiments,medical device10 can be crimped aroundshaft29.
• In some conditions, anedge33 ofcapsule27 can align withdilator18 such that it allows for a substantially continuous surface withdilator18. However, in other conditions, such as while traversing a body lumen, a gap can be created betweendilator18 and edge33 ofcapsule27. In some embodiments, such a gap can be formed as a result ofcapsule27 “fish mouthing”, which can occur when a portion ofedge33 is bent in a shape resembling an open fish mouth. In some cases, a gap betweendilator18 andcapsule27 can undesirably scrape an inside of a body lumen. In some cases, a gap betweendilator18 andcapsule27 can cause damage to one or more ofcapsule27,dilator18,medical device10, or another component ofsystem16.
• In order to avoid complications relating to fish mouthing, or for other advantages,delivery system16 can be configured to cover a gap formed betweencapsule27 anddilator18 or between other components ofsystem16. For example, in some embodiments,dilator18 can includeflaps32 that are configured to coveredge33 ofcapsule27 assystem16 traverses through a body lumen. In some embodiments, flaps32 can be configured to prevent catching or snagging of the system during implantation or removal of the medical device. For example, in some embodiments, a proximal end ofdilator18 can cover an opening formed by a lumen ofcapsule27. In some embodiments, flaps32 can flex down over a portion ofdilator18 to keep a smooth transition betweendilator18 andcapsule27. In some embodiments, flaps32 can be configured so that whenmedical device10 traverses through a body lumen, one offlaps32 can be on the outside curvature ofmedical device10.
• In some embodiments, flaps32 can reduce or eliminate certain effects when recrossing a native valve, such as a native aortic valve, after resheathing. For example, when some dilators recross a native valve, a distal edge of the dilator or another component can flare out. In some cases, the flared dilator can make it difficult for a physician to cross through a native valve. In some embodiments, flaps32 can flex down over a portion ofdilator18. In some embodiments, this can provide a smooth transition betweendilator18 andcapsule27, which in some cases can facilitate tracking through a native valve.
• In some embodiments,dilator18 can be assembled such that flaps32 protrude fromdilator18 at an angle of approximately 90 degrees fromaxial direction64. In some embodiments, flaps32 protrude fromdilator18 at an angle greater than or less than 90 degrees, such as for example approximately 30 degrees, approximately 45 degrees, approximately 120 degrees, or approximately 150 degrees. In some embodiments, one offlaps32 can protrude at a first angle, such as for example, approximately 90 degrees, and another offlaps32 can protrude at a second and different angle, such as for example, approximately 30 degrees. In some embodiments, flaps32 can be made of a thin film of polymer. In some embodiments, flaps32 can be configured so that they are flexible enough to bend towardsfirst portion28 and/orsecond portion30 ofdilator18 whensystem16 is tracked through a body lumen. In some embodiments, flaps32 can be stiff enough so that flaps32 straighten back out to be perpendicular toaxial direction64 when flaps32 are no longer pressed towardsfirst portion28 orsecond portion30.
• In some embodiments, flaps32 are configured to bend so that flaps32 are substantially parallel tocapsule27. As shown for example inFIGS. 9, flaps32 can be configured to bend towards and overcapsule27 whendelivery system16 is moved relative to a body lumen in a first direction, such asaxial direction64. In some embodiments, this direction can correspond to a direction that dilator18 moves whenmedical device10 is being delivered to a delivery site.
• In some embodiments, flaps32 can additionally be configured to bend towardsfirst portion28 whendelivery system16 is moved in a direction opposite to the first direction. In some embodiments, the direction opposite to the first direction can correspond to a direction in which dilator18 moves whendelivery system16 is being retracted from a patient. In some embodiments, an ability offlaps32 to bend towardsfirst portion28 can facilitate removingdilator18 from a body lumen. In some embodiments, flaps32 can bend towardssecond portion30 whendilator18 is moved towards a delivery site and then be inverted to bend towardsfirst portion28 whendilator18 is being retracted. In some embodiments, flaps32 are configured to only bend in one direction.
• FIG. 6 illustrates a cross-sectional view ofdelivery system16 bent within abody lumen31. As shown therein, asdilator18 bends relative tocapsule27,flap32 coversedge33 ofcapsule27.
• FIGS. 7-9 illustrate various views ofdilator18 in accordance with one embodiment. In particular,FIG. 7 illustrates a front perspective view ofdilator18,FIG. 8 illustrates a side view ofdilator18, andFIG. 9 illustrates an exploded view ofdilator18. In some embodiments,dilator18 can include adilator body35 having afirst portion28 andsecond portion30.Dilator18 can further include one or more flaps32. In some embodiments,first portion28 is a distal portion ofdilator18 andsecond portion30 is a proximal portion ofdilator18. In some embodiments,first portion28 andsecond portion30 can be two or more pieces attached together. In some embodiments,first portion28 andsecond portion30 can be a monolithic piece of material. In some embodiments, flaps32 can be ends of a monolithic piece of material. In some embodiments,first portion28 andsecond portion30 abut at ajunction34. In some embodiments,first portion28 andsecond portion30 can be removably attached. In some embodiments,first portion28 and/orsecond portion30 can include respective tapered outer surfaces. In some embodiments, an outer surface offirst portion28 can be configured to induce dilation in a body lumen or another site in a patient.
• In some embodiments,first portion28 can include a lumen configured to allowguide wire22 to pass therethrough. In some embodiments,second portion30 can include a lumen configured to allowguide wire22 to pass therethrough. In some embodiments, the lumen offirst portion28 and the lumen ofsecond portion30 can be configured to align to form asingle lumen24 that can allowguide wire22 to pass through bothfirst portion28 andsecond portion30. In some embodiments, only one offirst portion28 andsecond portion30 includes a lumen.
• In some embodiments, such as for example the embodiment shown inFIG. 9, flaps32 can be the ends of asingle piece46 of flap material that protrudes fromdilator18 on either side ofaxis48 ofdilator18. In some embodiments,piece46 can be sandwiched betweenfirst portion28 andsecond portion30 ofdilator18. In some embodiments,piece46 can be hourglass shaped, as shown for example inFIG. 9. In some embodiments, acentral portion50 ofpiece46 can be narrower thanflaps32 such that flaps32 include flared distal ends. In some embodiments,central portion50 can be equal to or wider than flaps32. In some embodiments, a narrower portion ofpiece46 can facilitate the bending offlaps32 aroundfirst portion28 and/orsecond portion30. In some embodiments,piece46 can be substantially rectangular, circular, elliptical, or a suitable non-geometric shape. In some embodiments,piece46 can include anopening52 that corresponds to lumen24 ofdilator18.
• In embodiments includingmultiple flaps32, flaps32 can be formed from separate pieces of flap material. For example, in some embodiments, a left flap can be attached to a left side ofdilator18 and a right flap can be attached to a right side ofdilator18.
• In some embodiments,dilator18 includes only asingle flap32. In some embodiments,dilator18 includes more than two flaps. For example, in some embodiments,piece46 can be X-shaped, with four flaps protruding from an outer surface ofdilator18. In some embodiments, flaps32 can include anend54 that can be substantially flat, shown for example inFIG. 9. In some embodiments, end54 can be rounded, or another desired shape.
• As further shown inFIG. 9, in some embodiments, one or both offirst portion28 andsecond portion30 can include one ormore extensions56 and58 which can correspond to one ormore openings60,62 for securing flaps32. In some embodiments,first portion28 andsecond portion30 are two pieces that are sandwiched around flaps32 and bonded together. In some embodiments,first portion28 andsecond portion30 are molded around flaps32 as one piece. In some embodiments,dilator18 can include recesses whereflaps32 protrude to ensure that whenfirst portion28 is inserted through an introducer, flaps32 can fold down within the recess so thatdilator18 can achieve a desired diameter, such as for example19 Fr or another suitable diameter.
• FIGS. 10-11 illustrate adilator66 in accordance with one embodiment. In particular,FIG. 10 illustrates a perspective cross-sectional view ofdilator66 in a first state andFIG. 11 illustrates a side cross-sectional view ofdilator66 in a second state.Dilator66 can be used, for example, indelivery system16. In some embodiments,dilator66 can be used for another delivery system.Dilator66 can include atip68 and acoupler70. In some embodiments, bothtip68 andcoupler70 includerespective lumens72 and74 formed therein. In some embodiments,lumens72 and74 can be configured to align to allow a guide wire to pass therethrough. In some embodiments,tip68 includes anarm86 that can flex to securely receivecoupler70. In some embodiments,tip68 can include anouter surface90 that is tapered. In some embodiments,tip68 includes acavity88 configured to receivecoupler70. In some embodiments,cavity88 can be configured to partially receivecoupler70. In some embodiments,cavity88 can be configured to receive the entirety ofcoupler70.
• InFIG. 10,coupler70 is shown disengaged fromtip68. However, as shown for example inFIG. 11,tip68 andcoupler70 can be joined together to restrain movement betweencoupler70 anddilator66. For example, in some embodiments,tip68 andcoupler70 can be joined viathreads76 and78. In some embodiments,tip68 andcoupler70 can include acollet80 having a steppedsurface82 corresponding to anend surface84 ofcoupler70 to prevent removal ofcoupler70 fromtip68. In some embodiments,collet80 can include anangled surface96 which can be configured to facilitate insertion ofcoupler70 intocavity88 oftip68. In some embodiments coupler70 includes anangled surface98 which can be configured to facilitate insertion ofcoupler70 intocavity88 oftip68. As shown for example inFIG. 11,coupler70 can be joined to tip68 via boththreads76 andcollet80. In some embodiments,coupler70 can be bonded to tip68 via adhesives or another suitable bonding technique. In some embodiments,coupler70 can be attached to tip68 via a clip. In some embodiments,coupler70 can be attached to tip68 via a ratchet-style connection. In some embodiments,coupler70 can be over-moulded onto a shaft or another piece withinsystem16.Cavity88 can include a steppedsurface92 configured to abut anend surface94 ofcoupler70 whencoupler70 can be received withincavity88. In some embodiments,tip68 is securely coupled tocoupler70 such thattip68 cannot fall off or be dislodged during delivery ofdilator66.
• In some embodiments, a method of loading a medical device, such asmedical device10 into a delivery catheter can include securingcoupler70 to a delivery catheter shaft, the shaft having a lumen for receivingmedical device10. The method can further include crimpingmedical device10 to a diameter that permitsmedical device10 to be loaded into the shaft lumen. The method can further include loadingmedical device10 into the shaft lumen. The method can further include securingdilator tip68 tocoupler70 aftermedical device10 is loaded into the shaft lumen. In some embodiments,tip68 is secured tocoupler70 by threadingdilator tip68 ontocoupler70, such as viathreads76 and78. In some embodiments,tip68 is secured tocoupler70 via a snap fit between thetip68 and thecoupler70, such as viaarm86 andcollet80. In some embodiments,coupler70 is secured to the delivery catheter shaft via a press fit. In some embodiments,coupler70 is secured to the delivery catheter shaft via adhesive or another suitable fastening means.
• As described above, in some embodiments,tip68 can be configured to attach tocoupler70 after a medical device, such as a valve prosthesis has been inserted into a system. In some embodiments, allowingtip68 to attach tocoupler70 after a medical device has been loaded can increase the options for insertion of the device into the system. In some embodiments, such a configuration can allowtip68 to be easily and securely attached to the system after loading of the device. In some embodiments, such a configuration can allow for variation in tip design for varying anatomy.
• The choice of materials for the various valve prostheses described herein can be informed by the requirements of mechanical properties, temperature sensitivity, biocompatibility, moldability properties, or other factors apparent to a person having ordinary skill in the art. For example, one more of the parts (or a portion of one of the parts) can be made from suitable plastics, such as a suitable thermoplastic, suitable metals, and/or other suitable materials. One or more components or portions of components can be made of the same or similar material as any other component. One or more components or portions of components can be configured such that they are more flexible than another component or portion of component. In some embodiments, one or more components can include radiopaque materials.
• In some embodiments, one or more components can include additional and/or embedded structure configured to provide increased mechanical strength while allowing for increased flexibility. In some embodiments, one or more components, such as forexample capsule27 orintroducer25, can include a metal laser cut tube, a wound coil, braid, or other suitable structure for increasing mechanical strength.
• In some embodiments, one or more components can be entirely or partially constructed using a single material or a composite material and/or a multi-layer material. In some embodiments, one or more of the components can include a material with a low coefficient of friction. In some embodiments, such a material can, for example, assist inloading system16, deliveringmedical device10 and/or withdrawingsystem16 from a body lumen. In some embodiments, one or more components can include a multi-layer design, including for example one or more layers can be made entirely or partially of polymer. In some embodiments, one or more layers can be made entirely or partially of high-density polyethylene (HDPE). In some embodiments, one or more layers can be made entirely or partially of polytetrafluoroethylene (PTFE).
• The foregoing description of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Other modifications and variations can be possible in light of the above teachings. The embodiments and examples were chosen and described in order to best explain the principles of the invention and its practical application and to thereby enable others skilled in the art to best utilize the invention in various embodiments with modifications as are suited to the particular use contemplated. It is intended that the appended claims be construed to include other alternative embodiments of the invention.

Claims (20)

1. A medical device delivery system comprising:

a dilator; and

a flap that radially protrudes from the dilator, wherein the flap is configured to bend against a body lumen to cover at least a portion of the delivery system when the dilator is tracked through the body lumen.

2. The system ofclaim 1, wherein the flap is configured to bend in a first direction when the dilator is tracked through the body lumen in a first direction.

3. The system ofclaim 1, further comprising:

a capsule disposed adjacent to the dilator, wherein the capsule is configured to house a medical device for use with the medical device delivery system,

wherein the flap is configured to cover at least an edge of the capsule when the flap is bent against a body lumen.

4. The system ofclaim 1, wherein the flap protrudes from the dilator at an angle of approximately 90 degrees.

5. The system ofclaim 1, wherein the system includes two flaps that radially protrude from the dilator.

6. The system ofclaim 5, wherein the two flaps are formed from a single piece of flap material that passes through the dilator.

7. The system ofclaim 6, wherein the piece of flap material is sandwiched between a first portion of the dilator and a second portion of the dilator.

8. A medical device delivery system comprising:

a dilator including a tip having a lumen and a coupler having a lumen,

wherein the coupler is configured to securely connect to the tip such that the lumen of the tip is aligned with the lumen of the coupler to allow a guide wire to pass therethrough.

9. The system ofclaim 8, wherein the coupler and tip include mating threaded surfaces configured to securely attach the coupler to the dilator.

10. The system ofclaim 8, wherein the tip and the coupler are connected via a snap fit configured to substantially prevent the coupler from being removed from the tip.

11. The system ofclaim 8, wherein the tip includes a cavity formed therein configured to receive the coupler.

12. The system ofclaim 11, wherein the coupler includes a flared end that is configured to engage with a portion of the tip to prevent removal of the coupler from the cavity of the tip.

13. The system ofclaim 11, wherein the tip includes an arm that can flex to securely receive the coupler.

14. The system ofclaim 8, wherein the system is configured to allow the tip to be attached to the coupler after a medical device is inserted in the system.

15. The system ofclaim 8, further comprising:

a flap that radially protrudes from the tip, wherein the flap is configured to bend against a body lumen to cover at least a portion of the delivery system when the dilator is tracked through the body lumen.

16. A method of loading a medical device into a delivery catheter, the method comprising:

securing a coupler to a delivery catheter shaft, the shaft having a lumen for receiving the medical device;

crimping the medical device to a diameter permitting the medical device to be loaded into the shaft lumen;

loading the medical device into the shaft lumen; and

securing a dilator tip to the coupler after the medical device is loaded into the shaft lumen.

17. The method ofclaim 16, wherein the dilator tip is secured to the coupler by threading the dilator tip onto the coupler.

18. The method ofclaim 16, wherein the dilator tip is secured to the coupler via a snap fit between the dilator tip and the coupler.

19. The method ofclaim 16, wherein the coupler is secured to the delivery catheter shaft via a press fit.

20. The method ofclaim 16, wherein the coupler is secured to the delivery catheter shaft via adhesive.

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