Method and assembly for securing an implantable medical device to a delivery system

Abstract

A method and assembly (104) for securing a crimped medical device (100) to a decompressed balloon (122) of a balloon catheter (120) is provided. The medical device (100) is positioned in its expanded state on the decompressed balloon (122) of the balloon catheter (120) and then crimped on the decompressed balloon (122). The first and second eyelets (135, 136) of the first and second pull wires (121, 131) then pass through first and second rings (105) provided on the medical device (100), respectively. Subsequently, a locking wire (126) advances through a lumen (137) defined between a sheath (123) and a catheter body (124) to exit a distal end of the sheath (123), then advances through the first aperture (135) and the second aperture (136), and into a distal tip (127) of the balloon catheter (120). The sheath (123) then advances across the crimped medical device (100) to the distal tip (127) to completely cover the crimped medical device (100).

Description

Technical Field

[0001] The present invention relates to delivering implantable devices into the human body, and in particular to methods and assemblies for securing an implantable medical device in a delivery system for delivery to a treatment site and placing the implant at the treatment site. Background Art

[0002] Noninvasive placement of certain medical devices has become a routine approach for treating certain diseases. For example, stents and prosthetic heart valves are now delivered to treatment sites within blood vessels and the heart through transcatheter procedures that avoid invasive procedures.

[0003] In order to facilitate delivery to the desired treatment location, for some surgeries, medical devices (e.g., stents and prosthetic heart valves) are crimped onto a depressurized balloon catheter and then passed through an introducer or sheath inserted into the vascular system to reach the target location. The medical device is then expanded to its intended size by the underlying balloon and fixed at the desired treatment location. The balloon is then depressurized and the balloon catheter is withdrawn.

[0004] The medical device is usually fixed to the balloon by using friction, wherein a shoulder is provided on the balloon catheter to prevent the medical device from moving during insertion and delivery. During balloon inflation, the balloon is usually first inflated at both ends to act as a stop to prevent the expanded medical device from moving sideways on the balloon.

[0005] While current crimping and placement of devices often works well for most procedures, balloon expandable medical devices may present some problems in certain circumstances. First, the crimped medical device is exposed to the surrounding environment (e.g., introducer sheath, blood vessel, etc.), which may cause the medical device to experience movement during insertion. When passing through the aortic arch, the exposed medical device tends to open at its distal outer surface, which may cause damage to the artery. Second, the shoulder used to secure the medical device to the balloon may hold the medical device in place, but due to the tendency of the medical device to move and press against the shoulder, there is a risk of puncturing the balloon.

[0006] Therefore, there remains a need for a method and assembly for securing an implantable medical device to a delivery system for delivery to a treatment site, and for positioning the implant at the treatment site in a manner that avoids the above-mentioned disadvantages. Summary of the invention

[0007] In order to achieve the purpose of the present invention, a method and assembly for fixing a curled medical device on a depressurized balloon of a balloon catheter are provided. A medical device is provided, the medical device having a tubular device body, the medical device having a first end and a second end, wherein a first ring is arranged at the first end, and a second ring is arranged at the second end. A balloon catheter is also provided, the balloon catheter comprising a catheter body having a distal tip and a balloon arranged near the proximal side of the distal tip. The balloon catheter also includes a first pull wire and a second pull wire, the first pull wire is fixed to the position of the balloon catheter adjacent to the distal end of the balloon and has a first eyelet, and the second pull wire is fixed to the position of the balloon catheter adjacent to the proximal end of the balloon and has a second eyelet. A sheath is provided for sliding movement on the catheter body and the balloon.

[0008] According to the method of the present invention, the medical device is positioned on the depressurized balloon in its expanded state and then curled on the depressurized balloon. Then, the first eyelet and the second eyelet of the first pull wire and the second pull wire are passed through the first ring and the second ring respectively. Next, the lock wire is advanced through the lumen defined between the sheath and the catheter body to exit the distal end of the sheath and then advanced through the first eyelet and the second eyelet and into the distal tip. The sheath is then advanced over the curled medical device to the distal tip to completely cover the curled medical device.

[0009] The present invention provides a method and assembly for effectively securing an implantable medical device to a delivery system for delivery to a treatment site and for placing the implant at the treatment site so that the medical device undergoes minimal or no movement when in its crimped position on a balloon. In addition, rings are provided at opposite ends of the medical device and are used to receive lock wires passing through the rings, preventing the ends of the medical device from splaying open, thereby minimizing the risk of puncturing the balloon. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1A is an exploded side view of a medical device and a balloon catheter according to one embodiment of the present invention.

[0011] Figure 1B yes Figure 1A A side view of how the medical device is positioned around the balloon of the balloon catheter.

[0012] Figure 2 Shows Figure 1A How the medical device is curled onto the balloon of the balloon catheter.

[0013] Figure 3AIt is shown how the pull wire extends through the loop provided at the end of the medical device.

[0014] Figure 3B Shown is how the lock wire extends from the delivery sheath through the eyelet on the pull wire and into the distal tip.

[0015] Figure 4 The delivery sheath is shown advanced over a medical device.

[0016] Figure 5 The delivery sheath is shown withdrawn to expose the medical device.

[0017] Figure 6 Inflation of the balloon for expanding the medical device is shown.

[0018] Figure 7 The locking wire is shown withdrawn from the eyelet and into the delivery sheath.

[0019] Figure 8 Deflation of the balloon is shown.

[0020] Fig. 9 The withdrawal of the balloon catheter is shown.

[0021] Figure 10-12 Shows Figure 1A Different embodiments of the medical device described in Figure 1A The balloon catheter and Figure 1A-9 method together with the

[0022] Fig.13A is a side view of the medical device crimped on a balloon catheter according to another embodiment of the present invention.

[0023] Fig. 13B yes Fig.13A A cross-sectional side view of the device shown in FIG.

[0024] Fig.14A yes Fig.13A , showing the adjustment line being tightened.

[0025] Fig. 14B yes Fig.14A A cross-sectional side view of the device shown in FIG.

[0026] Fig.15A yes Fig.13A A side view of the device showing the locking wire connected to the intermediate sheath.

[0027] Fig. 15B yes Fig.15A , showing the locking wire being tensioned by the intermediate sheath. DETAILED DESCRIPTION

[0028] The following detailed description is the best mode currently expected to implement the present invention. This description should not be considered as limiting, but is only for the purpose of illustrating the general principles of embodiments of the present invention. The scope of the present invention is best defined by the appended claims.

[0029] Figure 1A 1 is an exploded side view of a medical device 100 and a balloon catheter 120 according to an embodiment of the present invention. The medical device 100 can be any medical device intended to be implanted in a human body, such as a stent, a transcatheter heart valve, a stent graft assembly, a closure device, and a plug, etc. The drawings in the present invention are shown in conjunction with a transcatheter heart valve assembly 104, which can be an expandable stent or a stent framework used with a transcatheter heart valve. The stent heart valve assembly 104 can have a generally cylindrical stent body, the stent body having a plurality of cells 102 defined by struts 103. The stent body can be woven from a single thread or multiple threads, or laser cut from a metal (e.g., nickel-titanium) tube. The assembly 104 has a distal end 106 and a proximal end 107, a plurality of leaflets 108 fixed in the lumen of the stent body, and at least one ring 105 disposed at each of the distal end 106 and the proximal end 107. Other details of the heart valve assembly 104 are well known to those skilled in the art and will not be described in detail here.

[0030] The balloon catheter 120 has a catheter body 124 having a distal tip 127; and a balloon 122 disposed near the distal tip 127. A sheath or sheath 123 is provided for sliding movement on the catheter body 124 and the balloon 122. The distal tip 127 may have a tapered configuration from its proximal end 128 to its most distal end, and a cylindrical connector 129 having a diameter smaller than that of the proximal end 128 may be disposed at the proximal end 128 and extending in a proximal direction. The distal end of the balloon 122 is fixed to the proximal surface of the connector 129, and the proximal end of the balloon is fixed to the distal end 132 of the catheter body 124. A central tube 133 extends through the central cavity of the catheter body 124, and its proximal end is connected to a handle assembly (not shown), and the distal end of the central tube 133 is connected to the connector 129 and extends through the interior of the balloon 122.

[0031] The construction of the balloon catheter 120 as described above is similar to the construction of any conventional balloon catheter having a distal tip and a balloon positioned adjacent to the distal tip. The present invention adds two adjustment pull wires 121 and 131, which are used to releasably fix the medical device 100 (i.e., the heart valve assembly 104 in this embodiment) in the position of the balloon 122. Specifically, the pull wire 121 is fixed to the connector 129 and has an eyelet 135, and the pull wire 121 extends from the connector 129 in the proximal direction on the balloon 122. Similarly, the pull wire 131 is fixed to the distal end 132 of the catheter body 124 and has an eyelet 136, and the pull wire 131 extends from the distal end 132 to the balloon 122 in the distal direction.

[0032] The sheath 123 has a proximal end (not shown) operably connected to a handle assembly and is adapted to slide over the catheter body 124 as is known in the art.

[0033] The catheter body 124 can be made of PEBAX, PTFE, nylon, or any other known material for catheter bodies; the sheath 123 can be made of PEBAX, PTFE, nylon, or any other known material for similar slidable sheaths; and the pull wires 121 and 131 can be made of polypropylene suture, braided PET suture, PTFE suture, or any conventional suture. The balloon 122 can be made of any conventional balloon material, such as nylon and PEBAX. TM The ring 105 may be made of metal, for example the same material as the stent body.

[0034] Figure 1A The heart valve assembly 104 is shown advanced on the balloon 122. The heart valve assembly 104 is in its expanded state and the balloon 122 is deflated. Figure 1B The heart valve assembly 104 is shown positioned directly on the deflated balloon 122, and Figure 2 The heart valve assembly 104 is shown crimped onto the balloon 122.

[0035] Reference Figure 3A, the eyelets 135 and 136 of the pull wires 121 and 131 pass through the ring 105 at the distal end 106 and the proximal end 107 of the heart valve assembly 104, respectively. This can be done manually by an individual using a dedicated tool during the assembly process. Once this is done, the lock wire 126 advances through the lock wire lumen 137 defined between the sheath 123 and the catheter body 124 and exits the distal end 138 of the sheath 123. The lock wire 126 can be made of 304 or 316 stainless steel with a PTFE coating.

[0036] Next, if Figure 3B As shown, the lock wire 126 is advanced through the eyelets 135 and 136 and into a hole (not shown) in the distal tip 127 . Figure 3B Position LK in FIG. 1 shows a locking knot where the locking wire 126 passes through the eyelet 135 / 136 after the eyelet 135 / 136 has passed through the ring 105. The hole in the distal tip 127 should have a certain depth so that the locking wire 126 can be securely locked in the distal tip 127. With this assembly and construction, the heart valve assembly 104 is securely restrained on the balloon 122 to prevent any lateral movement, wherein the restraint is provided by the pull wires 121 and 132 and the locking wire 126.

[0037] In the next step, the cuff or sheath 123 is advanced to the distal tip 127 to completely cover the crimped heart valve component 104 and the connector 129. The complete assembly (the sheath 123 covers the balloon catheter 120, and the heart valve component 104 is carried on the balloon 122) is then advanced to the treatment position where the heart valve component 104 is to be implanted. During the delivery and advancement, the heart valve component 104 is firmly constrained on the balloon 122 to avoid any lateral movement.

[0038] Figure 5-9 The release and expansion of the heart valve assembly 104 at the treatment site, and the withdrawal of the balloon catheter 120 are shown. First, since the medical device 100 is the heart valve assembly 104, the treatment site is the annulus where the native heart valve (aortic valve or mitral valve) is located. Figure 5 In the embodiment of the present invention, the sheath 123 is withdrawn to expose or reveal the heart valve assembly 104. Next, in Figure 6 In FIG. 8 , the balloon 122 is inflated, and region 8a shows the interaction between the pull wire eyelets 135 / 136, the locking wire 126, and the ring 105. Figure 5 and Figure 6During the steps shown, the lock wire 126 and the pull wires 121 and 131 restrict movement of the heart valve assembly 104 .

[0039] refer to Figure 7 When the heart valve assembly 104 is fully expanded, the lock wire 126 is withdrawn and the eyelets 135 / 136 automatically and completely disengage from their corresponding rings 105. Area 8b shows the disengagement between the eyelets 135 / 136 and their rings 105. Next, Figure 8 In the embodiment of the present invention, the locking wire 126 is completely withdrawn and the balloon 122 is depressurized. Fig. 9 In the embodiment of the present invention, the balloon catheter 120 is withdrawn.

[0040] Figure 10-12 Different embodiments of alternatives to the ring 105 are shown. Fig.10 In the embodiment of the present invention, the rings 105a are independent rings, and they can be made of the same or different material as the material of the struts 103. During the assembly of the heart valve assembly 104, the rings 105a are manually attached to the corresponding struts 103. The rings 105a can be made of any conventional suture material (e.g., polypropylene, PTFE) or the same material as the struts 103.

[0041] Fig.11 Another alternative is shown in which the ring 105 is replaced by a rounded or extended tip 105b (also called a "strut ring") of the cell 102, wherein the pull wires 121, 131 are adapted to extend into the space defined by the rounded tip 105b in the same manner as they extend into the opening of the ring 105.

[0042] In yet another embodiment, Fig.12 A hole 115 is shown provided in the vertex 105 c of the cell 102 , wherein the pull wires 121 , 131 are adapted to extend into the hole 115 in the same manner as they extend into the opening of the ring 105 .

[0043] Figures 13A-14BAnother embodiment of the present invention is shown, wherein a connecting wire 140 connects the pull wires 121, 131 to create an adjustable locking knot. The central tube 133 has a first central lumen 141 and a second lumen 142 offset from the first central lumen 141. Openings 143 and 144 are arranged in a spaced-apart manner so that the second lumen 142 communicates with the exterior of the central tube 133, wherein the pull wire 121 extends through the opening 144 and the pull wire 131 extends through the opening 143. The connecting wire 140 extends through the second lumen 142 between the two openings 143 and 144, such that a first end of the connecting wire 140 is connected to the pull wire 121, and an opposite second end of the connecting wire 140 is connected to the pull wire 131. See FIG. Fig. 13B The connecting line 140 may be an extension of the same pull line 131 that exits through the opening 143 .

[0044] As the connecting wire 140 travels toward the distal tip 127 , the pull wires 121 and 131 begin to expose a longer length, which provides enough room or space for the eyelets 135 / 136 to pass through the corresponding loops 105 .

[0045] For example, Fig.13A and 13B The connecting wire 140 is shown in a relaxed state so that the exposed portion of the pull wires 121 and 131 (ie, outside the lumen 142) can be longer. Fig.13A As shown, when the exposed portions of the pull wires 121 and 131 are longer, the curled heart valve component 104 has space to slide back and forth (see the adjustable locking knot 11a), so the fixation is poor.

[0046] However, in Fig. 14B When the connecting wire 140 is tightened, the pull wires 121 and 131 are also tightened, so that the exposed portions of the pull wires 121 and 131 become shorter. Fig.14A As shown, the holes 135 and 136 at the ends of the pull wires 121 and 131 are respectively aligned with the ring 105 on the heart valve component 104 (see the adjustable locking knot 11b), so that the heart valve component 104 is tightly fixed.

[0047] Fig.15A and 15B Another embodiment of the present invention is shown, in which an intermediate sheath 150 is disposed in the lumen 137, surrounding the catheter body 124. The proximal pull wire 131 can be fixed to the distal end of the intermediate sheath 150, and the distal pull wire 121 can be fixed directly to the connector 129 or fixed adjacent to the connector 129. Fig.15AIn the embodiment, the intermediate sheath 150 is advanced in a distal direction toward the balloon 122, wherein the distal end of the intermediate sheath 150 is exposed from the sheath 123 so that the eyelets 135 and 136 can extend through and past the corresponding rings 105. Fig. 15B In the embodiment, the intermediate sheath 150 is then advanced in the proximal direction away from the balloon 122, which causes the pull wires 121 and 131 to be tightened and the eyelets 135 and 136 to lock with the corresponding rings 105. This embodiment 15A and 15B operates under similar principles to the above-described embodiments, except that the intermediate sheath 150 is provided in place of the longer pull wire 131.

[0048] The present invention provides a method and assembly for effectively securing an implantable medical device to a delivery system for delivery to a treatment site, and for placing an implant at the treatment site so that the medical device undergoes minimal or no movement in its crimped position on the balloon. The rings 105 are arranged at opposite ends of the medical device, the pull wires 121 and 131 are used to receive a lock wire 126 passing through these rings 105, and the medical device is covered with a sheath, which together locks the medical device on the depressurized balloon and prevents the ends of the medical device from opening, thereby minimizing the risk of puncturing the balloon.

[0049] Although the above description relates to specific embodiments of the present invention, it should be understood that various modifications can be made without departing from the spirit thereof. The appended claims are intended to cover such modifications as fall within the true scope and spirit of the present invention.

Claims

1. Implantable medical device components, including: A medical device having a tubular device body, the medical device including a first end and a second end, the medical device including a first ring disposed at the first end, and a second ring disposed at the second end; Medical device delivery systems, including: A balloon catheter comprising a catheter body having a distal tip and a balloon disposed proximally of the distal tip, the balloon having a distal end and a proximal end; The balloon catheter further comprises a first pull wire and a second pull wire, wherein the first pull wire is fixed to the balloon catheter at a position adjacent to the distal end of the balloon and has a first eyelet, and the second pull wire is fixed to the balloon catheter at a position adjacent to the proximal end of the balloon and has a second eyelet; It is characterized in that the medical device assembly also includes: A locking wire is provided to limit the movement of the medical device.

2. The assembly according to claim 1, characterized in that The first eyelet of the first pull wire and the second eyelet of the second pull wire pass through the first ring and the second ring respectively; the locking wire passes through the first eyelet and the second eyelet.

3. The assembly according to claim 1, characterized in that A sheath is also included, wherein the sheath can be slid on the catheter body and the balloon, and the sheath can completely cover the curled medical device.

4. The assembly according to claim 1, characterized in that The catheter body comprises a distal tip, a connecting piece is disposed at the proximal end of the distal tip, and the first pull wire is fixed to the connecting piece; The second pull wire is fixed to the distal end of the catheter body.

5. The assembly according to claim 1, characterized in that The balloon catheter also includes a connecting wire connecting the first pull wire and the second pull wire.

6. The assembly according to claim 5, characterized in that A first end of the connecting wire is connected to the first pull wire, and an opposite second end of the connecting wire is connected to the second pull wire.

7. The assembly according to claim 6, characterized in that The connecting wire connects the first pull wire and the second pull wire to produce an adjustable locking knot, When the connecting line is tightened, the first pull line and the second pull line are also tightened, and the adjustable locking head is shortened; when the connecting line is in a relaxed state, the adjustable locking head is lengthened.

8. The assembly according to claim 1, characterized in that The balloon catheter also includes: A central tube extends through the catheter body, one end of the central tube extends toward the proximal end of the delivery system, and the other end of the central tube passes through the balloon body and is connected to the connector.

9. The assembly according to claim 8, characterized in that The central tube includes a first central lumen and a second lumen offset from the first central lumen, and a connecting line extending in the second lumen; And, two openings are provided on the second tube cavity, and the first pull wire and the second pull wire extend out of the central tube through the respective openings.

10. An implantable medical device, comprising a plurality of cells and a tubular device body, the medical device comprising a first end and a second end, the first end of the medical device being provided with a first ring, the second end being provided with a second ring, It is characterized in that At least one of the first and second rings is connected to the medical device as an independent ring; or is configured as a rounded tip at the first and second ends of the medical device; or is configured as an opening in the vertex at the first and second ends of the medical device.

11. Balloon catheter, including: a catheter body having a distal tip and a balloon disposed proximally of the distal tip, the balloon having a distal end and a proximal end; a central tube extending through the central lumen of the catheter body; It is characterized in that The balloon catheter also includes a first pull wire and a second pull wire, wherein the first pull wire is fixed to the balloon catheter at a position adjacent to the distal end of the balloon and has a first eyelet, and the second pull wire is fixed to the balloon catheter at a position adjacent to the proximal end of the balloon and has a second eyelet.

12. The balloon catheter according to claim 10, characterized in that: The distal end of the central tube is connected to the connector and extends through the interior of the balloon.

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