Medical device system

Abstract

To provide a medical device system.SOLUTION: A medical device system includes a tubular medical device and a diameter reducing arrangement. The tubular medical device includes a tubular graft body having a proximal end and a distal end. The diameter reducing arrangement is configured for constricting the medical device, and includes a strand section having first and second ends and being immovably secured to the medical device at the first end and at the second end. The second end is at a first circumferential distance from the first end by way of a path along the strand section. In a constricted configuration of the medical device, a first portion of the strand section is folded back to form a first double-stranded tail leading to a first loop, the first tail extending circumferentially along the graft body, constricting the medical device by the strand section restricting the first circumferential distance between the first and second ends of the strand section.SELECTED DRAWING: Figure 1A-1D

Description

[Technical field]

[0001] The present disclosure relates to a system and a reduction mechanism for reducing the diameter of a medical device including a tubular graft body, and optionally a stent. [Background technology]

[0002] Aneurysms and ulcers in the thoracic aorta or aortic arch can be treated by inserting an artificial prosthesis such as a stent graft into an appropriate position. Since the aorta is curved, it is desirable to conform the stent graft, especially the proximal end of the stent graft, to the curvature of the aorta. One known stent graft system for conforming the proximal end to the curvature, as disclosed in U.S. Pat. No. 5,399,323, the contents of which are incorporated herein by reference in their entirety, includes a proximal alignment stent and a sealing stent distal to the alignment stent, in which a first end of a reduction loop is attached to the distal end of the sealing stent, the loop extends in a circumferential direction of the stent graft, and a second end of the loop engages with a trigger wire. In particular, two first ends of opposing loops can be attached to the stent, the loops extend in opposite directions around the stent graft, and the second ends of these loops approach each other to contact each other and engage with a release wire. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2022 / 0211482 [Patent Document 2] US Patent Application Publication No. 2009 / 0171437 Summary of the Invention [Means for solving the problem]

[0004] A medical device system is disclosed for at least partially compressing a medical device, including a tubular medical device, the medical device including a tubular graft body having a proximal end and a distal end, and a diameter reduction mechanism configured to compress a diameter of the medical device, the diameter reduction mechanism including a strand piece having a first and second end and secured to the medical device at the first end and the second end, the second end being a first circumferential distance from the first end by a path along the strand piece, and in a contracted configuration of the medical device, a first portion of the strand piece is folded back to form a first double-lined tail that connects to a first loop, the first double-lined tail extending circumferentially relative to the graft body, such that the strand piece contracts the medical device by limiting a first circumferential distance between the first and second ends of the strand piece.

[0005] The first and second ends of the strand piece are fixedly secured to the medical device, and a first portion of the strand piece passes through the first end and extends circumferentially therebeyond in a double line to form a first tail and a first loop. The first circumferential distance is transverse and defines a first circumferential region of the medical device, and in the expanded configuration of the medical device, at least a majority of the strand piece is disposed within the first circumferential region of the medical device. Further, in the expanded configuration of the medical device, at least a majority of the first portion is disposed within the first circumferential region of the medical device. In the contracted configuration, the first circumferential distance is transverse and defines a first circumferential region of the medical device, and in the contracted configuration, the first portion extends outside of the first circumferential region. The first loop is retained by a release mechanism, which may be one or more trigger wires that hold the medical device in the contracted configuration.

[0006] In the expanded configuration, the first and second ends of the strand pieces define mutually exclusive first and second circumferential regions of the stent-graft, the first circumferential region of the stent-graft extending from the first end to the second end of the strand pieces. Further, in the expanded configuration of the medical device, the first circumferential region extends over at least 1 / 7 of the circumference of the medical device, preferably at least 1 / 2 of the circumference of the medical device, and most preferably between 1 / 2 and 5 / 6 of the circumference of the medical device.

[0007] The medical device can be a stent graft including at least one stent attached to a tubular graft body. The stent can be a proximal most body stent and a strand piece can be attached to the tubular graft body at a distal end of the stent. The strand piece engages a distal apex of the stent to constrict the distal end of the stent.

[0008] Further disclosed is a diameter reduction system for a medical device having a tubular graft body having a proximal end and a distal end, the diameter reduction system including a stent disposed about the tubular graft body near the proximal end of the tubular graft body and at least partially overlapping the tubular graft body, and a diameter reduction mechanism configured to reduce a diameter of the stent, the diameter reduction mechanism including a strand piece having a first and second end, the first end attached to the stent at a first point on the stent and the second end attached to the stent at a second point circumferentially spaced from the first point, defining a first circumferential distance from the first end by a path along the strand piece to the second end. In the expanded configuration, the first circumferential distance is laterally spaced and defines a first circumferential region of the tubular graft body within which a majority of the strand pieces are disposed, and in the contracted configuration of the medical device, a first portion of the strand pieces is folded back to form a first double-lined tail that connects to a first loop and a second portion of the strand pieces is folded back to form a second double-lined tail that connects to a second loop. Further, in the contracted configuration, the first double-lined tail and the second double-lined tail extend in opposite circumferential directions near a surface of the graft body to contract the stent and shorten the circumferential distance between the first and second ends of the strand pieces. The first and second loops engage at least one releasable wire, which may be a trigger wire.

[0009] In the contracted configuration, the strand pieces completely surround the tubular graft and in the expanded configuration, they only partially surround the graft. The strand pieces are attached to the tubular graft body with stitches and have a first end permanently and immovably secured to a first apex with a knot and a second end permanently and immovably secured to a second apex with a knot. In the expanded configuration, the stent has a first distal apex within the first circumferential region, a second distal apex within the first circumferential region, and a third distal apex disposed outside the first circumferential region between the first and second distal apexes, with the first end secured to the first distal apex and the second apex secured to the second distal apex.

[0010] The strand piece may be a reduced diameter strand, such as a length of suture, having a first end fixedly attached to the tubular body at a point on the tubular body and a second end fixedly attached to the tubular body at a point circumferentially spaced from the first point to define a length of the reduced diameter strand between the first and second points, in the contracted configuration, a first portion of the reduced diameter strand at the first end is folded back to form a first double-lined tail that leads to a first loop, the reduced diameter strand is disposed circumferentially around the tubular body and the releasable wire engages the first loop, and in the expanded configuration, the reduced diameter strand is disposed circumferentially around only a portion of the body and when the releasable wire is released the first loop is unwound from its looped configuration. In the contracted configuration, a second portion at a second end of the reduced diameter strand is folded back to form a second double-line tail that leads to a second loop that engages the releasable wire, and when the releasable wire is released, the second loop is released from its loop configuration.

[0011] Also described is a medical device including a tubular medical device including a tubular graft body having a proximal end and a distal end, and a diameter reduction mechanism configured to reduce a diameter of the medical device, the diameter reduction mechanism including a strand piece, wherein in a reduced configuration of the medical device, a first portion of the strand piece is folded back to form a first double-lined tail that connects to a first loop, the first double-lined tail extending circumferentially relative to the graft body to reduce a diameter of the medical device.

[0012] Selected embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0013] [Figure 1A-1D] 1A-1C each show a partial view of a stent graft having a diameter reducing mechanism from various sides of the stent graft when the stent graft is in an expanded configuration. [Diagram 2] 2 is a cross-sectional view of the proximal end system of a stent graft having a diameter reducing mechanism of FIG. 1 in an expanded configuration. [Diagram 3] 2 is a cross-sectional view of the proximal end of the stent graft having the diameter reducing feature of FIG. 1 in a contracted configuration. [Figure 4] 2 illustrates the connection of the trigger wire to the diameter reducing mechanism of FIG. 1; [Diagram 5] 13A and 13B are diagrams showing other examples of coupling between the trigger wire and the diameter reducing mechanism. [Figure 6] FIG. 2 is a view of the diameter reducing mechanism of FIG. 1 with the stent graft in a contracted configuration and attached to a delivery device. [Figure 7] FIG. 7 is an end view of the diameter reducing mechanism of FIG. 6. [Figure 8] FIG. 13 is an end view of another diameter reducing mechanism of a stent graft in a contracted configuration and attached to a delivery device. [Figure 9] FIG. 7 is a side view of the diameter reducing mechanism of FIG. 6. [Figure 9A] FIG. 13 is an end view of another diameter reducing mechanism of a stent graft in a contracted configuration and attached to a delivery device. [Figure 9B] FIG. 9B is a cross-sectional view of the proximal end of a stent graft according to the embodiment of FIG. 9A in a contracted configuration. [Figure 10A-10D] 1A-1C each show a stent graft having a diameter reducing mechanism according to another embodiment of the present invention. [Figure 11] 11 shows a cross-sectional view of the proximal end of the stent graft of FIG. 10 in an expanded configuration. [Figure 12]11 shows a cross-sectional view of the proximal end of the stent graft of FIG. 10 in a contracted configuration. [Figure 13] FIG. 2 is a cross-sectional view of the proximal end of a stent graft having a diameter reducing feature according to the present invention. [Figure 14] FIG. 2 is a cross-sectional view of the proximal end of a stent graft having a diameter reducing feature according to the present invention. [Figure 15] FIG. 2 is a cross-sectional view of the proximal end of a stent graft having a diameter reducing feature according to the present invention. [Figure 16] FIG. 2 is a cross-sectional view of the proximal end of a stent graft having a diameter reducing feature according to the present invention. [Figure 17] FIG. 2 is a cross-sectional view of the proximal end of a stent graft having a diameter reducing feature according to the present invention. [Figure 18] FIG. 2 is a cross-sectional view of the proximal end of a stent graft having a diameter reducing feature according to the present invention. [Figure 19] FIG. 2 is a cross-sectional view of the proximal end of a stent graft having a diameter reducing feature according to the present invention. [Figure 20] FIG. 2 is a cross-sectional view of the proximal end of a stent graft having a diameter reducing feature according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] FIG. 1 is a schematic diagram of a currently preferred embodiment of the present invention; Various embodiments of the present invention, as will be described in more detail below, help prevent bird's beak formation (stent graft failure) at the curve of the aortic arch, thus increasing the success of the procedure. Additionally, the diameter reducing mechanism of the present invention can be used to contract part or all of the stent graft, allowing it to be rotated, properly positioned, and repositioned.

[0015] Each of Figures 1A, 1B, 1C, and 1D illustrates a diameter reduction system for reducing the diameter of a medical device. As shown, the system 10 includes a tubular medical device in the form of a stent graft 12. The stent graft 12 is for implantation in a human blood vessel, such as the thoracic aorta and / or the aortic arch. Each of Figures 1A, 1B, 1C, and 1D illustrates the stent graft from various sides of the stent graft with the stent graft in a fully expanded state. The stent graft 12 includes a tubular graft body 14 including a proximal open end 16 and a distal open end (not shown), an inner lumen between the proximal and distal ends, and a graft wall. As shown, the stent graft 12 includes a plurality of body stents 18 attached to and supporting the graft body 14. Each of the body stents 18 forms a ring or hollow cylinder for supporting the patency of the lumen of the graft body 14. As shown, the body stent 18 is a Z-stent, having proximal and distal ends, with the struts in a circumferential zigzag pattern connecting multiple proximal apices at the proximal end of the stent to multiple distal apices at the distal end of the stent. However, other types of body stents can be used. The body stent can be inside the stent graft, outside the stent graft, or a combination thereof. Alternatively, the body stent 18 can be eliminated altogether.

[0016] The stent graft includes a sealing stent 20 that sits on and supports the proximal end 16 of the graft body 14. The sealing stent 20 forms a ring or hollow cylinder at the proximal end to support the patency of the lumen of the graft body 14. At least a majority of the sealing stent overlaps the graft body 14. As shown, the sealing stent 20 overlaps entirely with the graft body 14. The sealing stent 20 is a Z-stent having a proximal end and a distal end, with the struts being a circumferential zigzag pattern connecting multiple proximal apices at the proximal end of the stent 20 to multiple distal apices at the distal end of the stent 20. Nevertheless, in other embodiments, other types of stents can be used for the sealing stent. As shown, the sealing stent is an internal stent, but in other embodiments, it can be an external stent. The sealing stent 20 is attached to the graft body 14 by one or more sutures, but in other embodiments, other types of attachments can be used.

[0017] The stent graft 12 may also include an exposed stent 22 as shown, although this is not required in all embodiments. The exposed stent 22 has a proximal end and a distal end, with a zigzag pattern of struts connecting a number of proximal apices at the proximal end of the stent 22 to a number of distal apices at the distal end of the stent 22. The distal apices are attached to the graft body 14 at the proximal end 16 of the graft body 14, and the exposed stent 22 extends proximally of the graft body 14. As shown, the proximal apices of the exposed stent 22 are rounded and have a larger radius of curvature than their distal apices to reduce pressure on the vessel wall when deployed. A stent with proximal and distal apices having different radii of curvature is disclosed in U.S. Patent No. 5,399,992, the disclosure of which is incorporated herein by reference in its entirety. For example, the radius of curvature at the proximal apex may range from about 3.0 mm to about 10.0 mm, and the radius of curvature at the distal apex may range from about 0.5 mm to about 1.75 mm. The stents of the stent graft 12 may be self-expanding, balloon-expandable, or a combination of self-expanding and balloon-expandable stents.

[0018] The system 10 includes a diameter reducing mechanism for contracting the graft, and in particular the sealing stent 20, although the mechanism is applicable to any stent. The diameter reducing mechanism includes a strand piece 24, for example a length of suture as shown here. The strand piece 24 has a first end 26 and a second end 28, which may be at the same longitudinal height as shown. In other words, the first and second ends 26, 28 are at the same longitudinal height ends of a strand of suture that are disposed at the same longitudinal distance from the proximal edge of the stent graft. The strand piece 24 is preferably immovably secured at the first end 26 and the second end 28, respectively, to the sealing stent 20 by being knotted, although the first and second ends may also be immovably secured to the stent graft in other ways. The first and second ends 26, 28 may also be secured to the graft material only, or to both the graft and the stent. As will be appreciated, the immovable fixation of the strand pieces 24 to the stent graft at the first and second ends 26, 28 prevents the first and second ends 26, 28 from moving relative to the stent graft when the strand pieces are tensioned during use of the device as described herein, but does not necessarily preclude the ends from being removable by external means from the stent graft. The immovable fixation of the strand pieces 24 to the stent graft at the first and second ends 26, 28 serves to retain the ends to the stent graft when the strand pieces are tensioned.

[0019] As shown in Figure 2, when the stent graft is in the expanded configuration, the second end 28 is secured to the stent graft at a point 27 on the stent graft by a path along the strand piece that is a first circumferential distance from the attachment point 25 at the first end 26. In other words, proceeding along the strand piece 24 from the first end 26 to the second end 28 ends up a first circumferential distance away from the first end 26. The first circumferential distance is thereby transverse and defines a first circumferential region 30 of the stent graft, with the strand piece circumferentially surrounding the first circumferential region 30 of the stent graft between the first end 26 and the second end 28. In this manner, when the stent graft is in the expanded configuration, the first and second ends 26, 28 of the strand pieces 24 define mutually exclusive first and second circumferential regions 30 and 30' of the stent graft therebetween, with the first circumferential region 30 of the stent graft being from the first end 26 to the second end 28 of the strand pieces and the second circumferential region 30' being the remaining circumference of the stent graft.

[0020] 2, strand pieces 24 are shown to encircle approximately 4 / 5 of the circumference of the stent graft in the expanded configuration, i.e., first circumferential region 30 extends approximately 4 / 5 of the circumference of the stent graft.

[0021] However, in other embodiments, the strand pieces 24 may encompass a different percentage of the circumference (and the first circumferential region may extend across a different percentage of the circumference) of the stent graft in its expanded configuration, preferably at least 1 / 7 of the circumference, more preferably at least 1 / 2, and most preferably in the range of 1 / 2 to 5 / 6 of the circumference.

[0022] 1, the strand pieces extend circumferentially from a first end 26 to a second end 28. The angle between any radius of the stent graft and the radius of the stent graft up to a point on the strand piece 24 can then be considered to increase monotonically as the point moves along the strand piece 24 from the first end 26 to the second end 28. In other words, in the expanded configuration, the entire strand piece 24 from the first end to the second end is disposed within the first circumferential region 30.

[0023] The first and second ends are at the same longitudinal height so that in the expanded configuration, the strand piece 24 extends in the same plane from the first end 26 to the second end 28. This plane is perpendicular to the longitudinal axis of the stent graft. This minimizes the profile of the device and avoids sagging loops. The strand piece 24 remains loose in the expanded configuration of the stent graft, but is sewn to match the expanded diameter of the graft. In other words, the length of the strand piece 24 is slightly longer (no more than 5%) than the circumferential distance from the first end of the strand piece 24 to the second end of the strand piece 24 when the stent graft is in the expanded configuration. In this way, the strand piece does not block expansion and there is no excess suture.

[0024] The strand pieces 24, including their first and second ends 26, 28, are configured to be positioned on a portion of the sealing stent 20, preferably the distal end of the sealing stent 20, and to constrict it. In particular, the strand pieces 24 are configured to be positioned on the distal apexes of the sealing stent 20 and to constrict it. The strand pieces are positioned around the graft and through most of the distal apexes of the sealing stent 20. For example, the strand pieces are attached to the graft material in a stitched fashion through most of the distal apexes.

[0025] Figure 2 shows a cross-sectional view of the stent graft system 10 of Figure 1 looking in the distal direction in the region of the strand piece 24. As shown in Figures 1 and 2, from the first end 26 to the second end 28, the strand piece 24 generally runs along the outside of the graft body 14, except that at each distal apex of the sealing stent 20 through which it passes, it runs along the inside of a second strut (except for the apex to which the second end 28 is attached), penetrates into the interior of the graft body 14 on one side of the strut, returns to the outside of the graft body 14 on the opposite side of the strut, and then extends to the next apex outside the graft body 14. For the apex to which the second end 28 is attached, the strand piece passes along the inside of the first strut as described above and is then secured to the second strut with a knot.

[0026] As shown in Figures 1-2, in the expanded configuration of the stent graft, the first end 26 and the second end 28 are circumferentially spaced apart, and although not necessary in all embodiments, the length of the strand pieces from the first end 26 to the second end 28 is less than the circumference of the stent graft 12 in the expanded configuration. As a result, in the expanded configuration of the stent graft, some apexes and intervals are devoid of strand pieces. The stent graft of Figure 1 has a diameter of 40-42 mm in its expanded configuration, and the sealing stent 20 has seven distal and seven proximal apices, although any expanded configuration can be used and the number of apices need not be the same in all embodiments, as will be described in more detail below.

[0027] As shown, the six distal apexes of the sealing stent 20 and the five distal inter-apexes therebetween are sewn (herein, a sewn apex / inter-apex is one that is in the first circumferential region 30 in the expanded configuration of the stent-graft and through which a strand piece 24 passes, in the case of an apex, preferably the strand piece is sewn around its strut, as shown in FIG. 2). As also shown in FIG. 2, one distal apex 31 of the sealing stent 20 is free, together with its two adjacent distal inter-apexes 23, 25 (and two proximal apexes) (herein, a free apex / inter-apex is one that is outside the first circumferential region 30 in the expanded configuration of the stent-graft, in other words, within the second circumferential region and that is free of strand pieces, i.e., through which no strand pieces pass). This results in a ratio of the circumferential extent of the first circumferential region to the circumferential extent of the second circumferential region of approximately 5:2.

[0028] As shown in FIG. 2, the first and second ends 26, 28 of the strand piece are adjacent the free distal apex 31 and are secured with knots to the distal apexes on either side thereof, and in particular to the struts adjacent the free distal apex 31.

[0029] The contracted configuration of the stent graft is shown in Figure 3. In the contracted configuration, the first portion 32 of the strand piece is folded back to form a first double-lined tail 34 which leads to a second loop 36. In particular, from the first circumferential region 30, the first portion 32 extends out of the first circumferential region 30 through the first end 26 into the second circumferential region where it doubles circumferentially beyond the first end 26 to form the first tail 34 and the first loop 36. As shown, the first tail 34 extends circumferentially in a double-lined manner along the graft body, i.e., along the surface of the graft body, in this embodiment along a portion of the outside of the graft body 14, such that the strand piece contracts the stent by limiting the first circumferential distance between the first and second ends 26, 28 of the strand piece 24. In particular, the first portion 32 extends into the second circumferential region, forming a double line, thereby shortening the length of the strand pieces 24 disposed within the first circumferential region 30, thereby forcing the first circumferential region 30 to contract.

[0030] 3, the second portion 38 of the strand piece 24 is folded back to form a second double-lined tail 40 that leads to a second loop 42. In particular, from the first circumferential region 30, the second portion 38 passes through the second end 28, exits the first circumferential region 30, and enters the second circumferential region where it doubles back circumferentially beyond the second end 28 to form the second tail 40 and the second loop 42. Similar to the first tail 34, the second tail 40 extends circumferentially along the graft body 14, i.e., along the surface of the graft body, and in this embodiment, along a portion of the outside of the graft body 14, in a double-lined manner such that the strand piece 24 constricts the stent by limiting the first circumferential distance between the first and second ends 26, 28 of the strand piece. In particular, the second portion 38 extends into the second circumferential region, forming a double line, thereby shortening the length of the strand piece 24 disposed within the first circumferential region 30, thereby forcing the first circumferential region 30 to contract. As shown, a majority of each of the first and second tails 34, 40 is along the exterior surface of the graft body 14. As can be further seen, the first and second tails 34, 40 extend in opposite circumferential directions along the graft body 14, meaning that the distal direction along the first tail 34 toward the first loop 36 is in an opposite circumferential direction from the circumferential direction to the second loop 42 along the second tail 40.

[0031] As shown in FIG. 3, the first and second tails 34, 40 penetrate the wall of the graft body 14 and enter the interior of the graft body, whereby the first and second loops 36, 42 are inside the graft body. As shown, the first and second tails 34, 40 penetrate the wall of the graft body 14 between the struts of the free distal apex 31, which may be referred to as the retention apex 31 because it is there that the tails penetrate and are retained. The retention apex 31 is configured in this embodiment to be on the outside of the curve when the stent graft is deployed in a curved body vessel. As shown in the contracted configuration of the stent graft, each of the distal apices of the sealing stent 20 overlaps with a strand piece, either on the inside or the outside. However, this is preferred but not essential in all embodiments.

[0032] To deploy, the introducer assembly includes a release mechanism including a trigger or release wire 44 that passes through a lumen of the graft body 14. In the contracted configuration of the stent graft, the first and second loops 36, 42 are retained and locked inside the graft body 14 by the trigger wire 44, keeping the stent graft in the contracted configuration. However, the first and second loops 36, 42 may be retained and locked outside the graft body 14 by the trigger wire 44, keeping the stent graft in the contracted configuration. Additionally, the first and second loops 36, 42 may be retained and locked both inside and outside the graft body 14 by the trigger wire 44, keeping the stent graft in the contracted configuration, for example in this case the trigger wire extends along its length both in and out of the graft material of the graft body. As shown in FIG. 4, the trigger wire 44 passes through both loops 36, 42. However, in other embodiments, as shown in FIG. 5, one loop (loop A) can be passed through the other loop (loop B) and the trigger wire can be passed through loop A.

[0033] In Fig. 5, loop A is the first loop 36 and loop B is the second loop 42, although these may be reversed in other embodiments. Figs. 6-7 and 9 show an arrangement including the system of Fig. 1 in a delivery state and an introducer assembly, which includes a delivery device onto which a stent graft is mounted in a collapsed configuration. The delivery device includes a urethane tubing (UAT) 50 and a nose cone 52 coupled to the end of the UAT 50 furthest from the physician during the procedure. The UAT 50 passes through the lumen of the graft body 14, and the stent graft 12 is collapsed around the UAT 50.

[0034] For example, as shown in FIG. 7, the exposed stent 22 is held at its proximal apex in the UAT in a conventional manner using an exposed stent trigger wire 54 that extends through the UAT, out of the UAT, loops around one or more proximal apexes of the UAT, and extends back into the UAT to be secured therein or in the nosecone 52. Here, the trigger wire 44 is separate from the exposed stent trigger wire 54, but in other embodiments, the trigger wire 44 can also serve the function of the exposed stent trigger wire. As shown, the trigger wire 44 is attached to the UAT inside the graft. The trigger wire 44 extends from a control section (not shown) through the UAT, out of the UAT in the region of the stent graft, passing through loops 36, 42 as described above, and extends back into the UAT to be secured therein or in the nosecone 52.

[0035] However, in other embodiments, the trigger wire 44 can be secured to the side of the UAT rather than extending into it, or can be "floating" in that it is not held against or within the UAT, but is independent of the UAT and secured to the nose cone 52 as shown in Figure 8, which is otherwise the same as the arrangement of Figure 7. A "floating" trigger wire allows the trigger wire to optionally hold the first and second loops 36, 42 outside the graft body 14, in which case the first and second tails 34, 40 do not need to penetrate the wall of the graft body. As shown, the trigger wire 44 holds the loops 36, 42 to rest on the outside of the curve as they are introduced into the aorta.

[0036] If the first and / or second loops are held and locked on the outside of the graft body by trigger wires, the trigger wires for holding the first and / or second loops can extend along the outside of the graft body. An example of a system according to such an embodiment is shown in FIG. 9A, which is the same as the embodiment of FIG. 9, except that the first and second loops 236, 242 are outside the graft body 14, and the trigger wires 44' for holding the first and second loops 236, 242 extend lengthwise along the outside of the graft body 14. As can be seen in FIG. 9A, the majority of the trigger wires 44' are outside the graft body 14, but the trigger wires 44' pass inside the graft body 14 at each body stent 18, thereby avoiding the body stents 18 from passing through the graft body and causing the trigger wires 44' to become an obstacle. Additionally, in the embodiment of FIG. 9A, the ends 70 of the trigger wires 44' terminate on and are secured to the surface of the graft body 14, rather than in the UAT or nose cone. Alternatively, the trigger wire 44 ′ can extend into the UAT and be secured within the UAT or within the nosecone 52 .

[0037] Figure 9B shows a cross-section of the system of the embodiment of Figure 9A, taken distally through a region of the strand piece of the stent graft system when the stent graft is in a contracted configuration, as can be seen, where the first and second loops 236, 242 are held and locked to the outside of the stent graft by the trigger wire 44'.

[0038] In a method of fabricating the stent graft system, the stent graft is provided in an expanded configuration and the strand pieces are attached to the stent graft using needles or other suitable tools to form the system shown in FIG. 1. Materials and tools for fabricating the stent graft system and for contracting the stent graft can be standard materials and tools for stent graft manufacturing. In this method, when the stent graft is in an expanded configuration, such as shown in FIG. 1, all of the strand pieces are disposed within a first circumferential region 30. The method includes pulling a first portion 32 of the strand piece 24 to form a first loop 36 and a first double-line tail 34 that connects to the first loop 36. The method includes using a conventional stylet or pert (although other tools may be used in other embodiments) to lift the strand piece 24 near the first end 26 from the surface of the graft body 14, thereby creating a loop that forms the first portion 32 and the first loop 36. The first loop 36 is then pulled by the stylet or pert, thereby drawing more of the strand piece 24 into the first section 32 , contracting the stent graft and creating a first tail 34 .

[0039] The method includes further pulling the first loop 36 circumferentially beyond the first end 26 and out of the first circumferential region 30 and into the second circumferential region, and extending the first tail 34 circumferentially along the graft body in the second circumferential region, in this embodiment along an outer portion of the graft body 14. As previously discussed, this limits a first circumferential distance between the first and second ends of the strand piece 24 to contract the stent. The method also includes pulling the second portion 38 of the strand piece 24 to form a second loop 42 and a second double-line tail 40 connected to the second loop 42.

[0040] The method includes using a stylet or pert to lift the strand piece 24 near the second end 28 away from the surface of the graft body 14, thereby forming a loop forming a second portion 38 and a second loop 42. The second loop 42 is then pulled by the stylet or pert, thereby drawing more of the strand piece 24 into the second portion 38, contracting the stent graft and creating a second tail 40.

[0041] Similar to the first loop 36, the method includes pulling the second loop 42 further circumferentially out of the first circumferential region 30 beyond the second end 28 and into the second circumferential region, and extending the second tail 40 circumferentially along the graft body in the second circumferential region, in this embodiment along a portion of the exterior of the graft body 14. As previously described, this limits the first circumferential distance between the first and second ends of the strand piece 24 to contract the stent. The method includes extending the first tail 34 and the second tail 40 through the wall of the graft body into the interior of the graft body, and looping the first loop 36 and the second loop 42 around the trigger wire 44 within the graft body, as previously described.

[0042] In use, the stent graft system is introduced endoluminally in a blood vessel, in this embodiment the aorta, with the stent graft in a contracted configuration in a conventional manner. Once the stent graft has reached a desired deployment location, it can be partially deployed, for example by retracting a sheath (not shown). The stent graft can then be fully deployed and placed in the blood vessel by retracting the trigger wire 44.

[0043] When the trigger wires are pulled back from the loops 36, 44, the sealing stent 20 is free to expand, thereby expanding the stent graft 12 into an expanded configuration and apposition with the vessel wall. This occurs automatically because the stent is a self-expanding stent, although in other embodiments the sealing stent 20 and / or other stents may be expanded using, for example, a balloon.

[0044] As the sealing stent 20 expands, the first and second tails 34, 40 are pulled out from within the graft body 14 and the first and second portions 32, 38 are pulled back into the first circumferential region 30. This pulling back keeps the device in a low profile during expansion while the loops 36, 42 are withdrawn from the interior of the stent graft, thereby reducing the possibility of undesired contact between the strand pieces and loops and other components.

[0045] Each of Figures 10A, 10B, 10C, and 10D shows a system according to another embodiment of the invention, with the stent graft in an expanded configuration. The embodiment of Figures 10A-10D is the same as the embodiment of Figures 1A-1D, including details of manufacture and use, except that the diameter of the stent graft in the expanded configuration is 44-46 mm, and the sealing stent has eight distal apices and eight proximal apices. As with the system of the embodiment of Figures 1A-1D, when the stent graft is in the expanded configuration, there is only one free distal apice (and the two distal inter-apex portions adjacent to it are also free), which means that in this embodiment there are seven sewn distal apices and six sewn distal inter-apex portions, with the ratio of the circumferential extent of the second circumferential region to the circumferential extent of the first circumferential region being 1:3. Figure 11 shows a cross-sectional view of the system of Figure 10 in an expanded configuration. FIG. 11 is a cross-section of the stent graft system of FIG. 10 in the region of the strand pieces, looking distally.

[0046] Figure 12 shows a cross-section of the system of Figures 10A-10D from the same perspective as Figure 11, but with the stent graft in a collapsed configuration. As shown, the collapsed configuration is formed and constructed in a similar manner to the embodiment of Figures 1A-1D.

[0047] FIG. 13 is a cross-sectional view of the system according to the embodiment of FIGS. 1A-1D, through the region of the strand piece of the stent-graft system, looking distally with the stent-graft in the contracted configuration. As shown in FIG. 13 (and FIGS. 14-18), the number of sewn distal apices / inter-apexes of the sealing stent can be varied. In addition, the number of free distal apices / inter-apexes of the sealing stent can also be varied. For example, the sealing stent can have more than one or less than one free distal apices and two free distal inter-apexes. In the expanded configuration of the stent-graft, the ratio of the number of distal apices (i.e., free distal apices) of the sealing stent in the second circumferential region to the number of distal apices (i.e., sewn distal apices) in the first circumferential region can be determined depending on the application. However, preferably, this ratio is in the range of 1:2 to 1:7, as this may cover most applications. A preferred ratio between the circumferential extents of the second and first circumferential regions when the stent graft is in the expanded configuration is 1:2 to 1:5. A preferred ratio between the number of distal apex-to-apex portions of the sealing stent in the second circumferential region and the number of distal apex-to-apex portions of the sealing stent in the first circumferential region when the stent graft is in the expanded configuration is 1:2 to 1:5. This ratio can be achieved in any of the configurations depicted in the accompanying drawings.

[0048] Examples of the number of free distal inter-apex portions (within the second circumferential region) versus sewn distal inter-apex portions (within the first circumferential region) in the expanded configuration of a stent graft for sealing stents with different total numbers of distal apexes are shown in the table below.

[0049] [Table 1]

[0050] As shown, in the embodiment of FIG. 13, the first and second tails 34, 40 together span two distal inter-apex portions in the contracted configuration of the stent-graft. Preferably, the first and second tails 34, 40 are symmetrically positioned in that, in the contracted configuration of the stent-graft, they extend the same distance along the graft body 14 and overlap the same number of apexes of the sealing stent 20, as in the previously described systems. However, in other embodiments, they can also be asymmetrically positioned. For example, they can extend different lengths along the graft body 14, and / or one of the tails can span all or part of the free distal apexes of the sealing stent 20 while the other tail does not, and / or if there are multiple free distal apexes of the sealing stent 20, one tail can span more free distal apexes than the other tail. One tail can span more free distal inter-apex portions of the sealing stent 20 than the other tail.

[0051] Additionally, while the above embodiment has first and second portions 32, 38 that form first and second tails 34, 40, in some embodiments it is possible to use only one portion to form one tail and loop, and in other embodiments multiple strand pieces along different portions of the circumference of the stent graft, each configured as described herein, can be used such that any number of tails and loops can be created, but preferably with the strand pieces overlapping all of the distal apices of the sealing stent in the contracted configuration of the stent graft.

[0052] An example of a system using one tail and one loop is shown in Figure 14, which is a cross section through a region of strand piece 24' of the stent graft system when the stent is in a contracted configuration, looking distally. The embodiment of Figure 14 is the same as the embodiment of Figure 1 or Figure 10, including details of manufacture and use, with the following differences: As shown, the second portion, second tail, and second loop are absent in this example; the first portion 32, first tail 34, and first loop 36 are the same as the system of Figure 1, but this example does not have a completely free apex.

[0053] As shown in FIG. 14, the retention apex 31' is partially free (in other words, it is partly in the first circumferential region and partly in the second circumferential region). Only one of the distal inter-apex portions of the sealing stent is free, which is adjacent to the retention apex 31'. In particular, the second end 28' of the strand piece 24' is on one strut of the retention apex 31', while the other strut is free. As shown in FIG. 14, in the contracted configuration, the first tail 34 passes through the free distal inter-apex portion on the free strut of the retention apex 31' and passes through the wall of the graft body 14 between the struts of the retention apex 31', where it is retained inside the graft body 14 by the trigger wire 44 (not shown in FIG. 14). Thus, in the contracted configuration of the stent graft, the first tail spans one distal inter-apex portion.

[0054] Figure 15 is a diagram of a system according to the same embodiment as that of Figure 14, including details of manufacture and use, with the following differences: Figure 15 is a cross section through a region of the strand piece of the stent-graft system when the stent-graft is in the contracted configuration, looking in the distal direction. In the system of Figure 15, in addition to the partially free retaining apex 31', there is also a completely free second distal apex 56 between the first end 26 of the strand piece and the retaining apex 31'. There are therefore two free distal inter-apex portions of the sealing stent, both on the same side as the retaining apex 31', one each on each side of the second apex 56. As mentioned above, what is meant by free distal apex / inter-apex portions are those distal apex / inter-apex portions of the sealing stent that are in the second circumferential region and therefore are not reached by the strand piece 24 in the expanded configuration of the stent-graft 12.

[0055] 15, in the contracted configuration of the stent graft 12, the first tail 34' is sewn through the second apex 56. In other words, the majority of the first tail 34' extends from the first end 26 of the strand piece 24 along the outside of the graft body 14 to the retention apex 31', but it passes along the inside of the first strut at the second apex 56, penetrates into the interior of the graft body 14 on one side of the strut, returns to the outside of the graft body 14 on the other side of the strut, and then extends to the retention apex 31' on the outside of the graft body 14. In other words, the first tail 34' spans 1.5 distal apexes and the two inter-apex portions in the contracted configuration of the stent graft.

[0056] Figure 16 is an illustration of a system according to the same embodiment as that of Figure 15, including details of manufacture and use, with the following differences: Figure 16 is a cross section through the region of a strand piece of the stent graft system when the stent graft is in a contracted configuration, looking distally.

[0057] Further to the system of Figure 15, the system of Figure 16 additionally includes the second portion 38, second tail 40, and second loop 42 of the system of Figure 1, with the second end 28 of the strand piece being at the distal apex adjacent the retention apex 31, opposite the second apex 56, in accordance with Figure 1. The first and second loops 36, 42 are retained by a trigger wire (not shown in Figure 16) as described with respect to the system of Figure 1. Thus, in this embodiment, the first and second tails span a combined three distal inter-apex portions of the sealing stent in the contracted configuration of the stent graft.

[0058] Figure 17 is an illustration of a system according to the same embodiment as that of Figure 16, including details of manufacture and use, with the following differences: Figure 17 is a cross section through the region of the strand pieces of the stent graft system when the stent graft is in a contracted configuration, looking distally.

[0059] In the system of FIG. 17, in addition to the retention apex 31″ and second apex 56 which are completely free, there is a third distal apex 58 which is also completely free, which is between the second end 28 of the strand piece and the retention apex 31′ on the opposite side of the retention apex 31″ from the second apex 56. There are therefore four free distal inter-apex portions of the sealing stent, two on each side of the retention apex 31′, one on each side of the second apex 56 and one on each side of the third apex 58. As stated above, what is meant by free distal apexes / inter-apexes are those distal apexes / inter-apexes of the sealing stent which are in the second circumferential region and therefore are not extended by the strand pieces 24 in the expanded configuration of the stent graft 12.

[0060] 17, in the contracted configuration of the stent graft 12, the second tail 40' is sewn through the third apex 58. In other words, the majority of the second tail 40' extends from the second end 28 of the strand piece 24 along the outside of the graft body 14 to the retention apex 31'', but it passes along the inside of the second strut of the third apex 58, penetrates into the interior of the graft body 14 on one side of the strut, returns to the outside of the graft body 14 on the other side of the strut, and then extends to the retention apex 31' on the outside of the graft body 14. In other words, the second tail 40' spans 1.5 distal apexes and two distal apex-to-apex segments in the contracted configuration of the stent graft, which means that the first and second tails span a total of four distal apex-to-apex segments in the contracted configuration of the stent graft.

[0061] As shown in Figure 17, in this system the first tail extends along the inside of the second strut at the second apex 56 (the struts are numbered in a circumferential direction away from the end of the strand piece 24 from which the respective tail extends) rather than the inside of the first strut at the second apex 56 as in Figure 16. However, either strut could be selected where the strand piece 24 and / or tail 34, 40 passes along the inside of a strut at one of the apexes. In addition to the above, in some embodiments the tails can pierce the wall of the graft body at different locations relative to one another.

[0062] FIG. 18 is a diagram of a system according to the same embodiment as that of FIG. 1, including details of manufacture and use, with the following differences: FIG. 18 is a cross section through a region of a strand piece of the stent-graft system when the stent-graft is in a contracted configuration, looking in a distal direction. As shown in FIG. 18, in this system there is a first retention apex 31a and a second retention apex 31b in the second circumferential region. In this embodiment, these are two adjacent distal apices of the sealing stent, but in other embodiments they may also be separated by another intermediate distal apex. A first tail 34'' penetrates the wall of the graft body 14 between the struts of the first retention apex 31a, and a second tail 40'' penetrates the wall of the graft body 14 between the struts of the second retention apex 31b. The first and second loops 36'', 42'' are retained by trigger wires as described above. Thus, in this embodiment, in the contracted configuration of the stent-graft, the first and second tails together span three distal inter-apex portions.

[0063] In some embodiments, the first and second loops can be held by different trigger wires, however, they are preferably held by the same trigger wire to provide symmetric expansion of the sealing stent 20. While in the embodiment described above the strand piece is configured to contract the sealing stent, in other embodiments it can be configured to contract other stents along the graft body.

[0064] As mentioned above, the first and / or second tails extend along a portion of the outside of the graft body in the contracted configuration, although in some embodiments it is not excluded that they extend along the inner surface of the graft body, e.g., such that a majority of each of the first and / or second tails extends along the inner surface of the graft body.

[0065] Although the first and second tails are shown extending from the first and second ends of the strand piece, in other embodiments the first and second tails can extend from other points of attachment of the strand piece to the stent graft, such as the points where the strand piece loops around the struts at the apexes of the sealing stent. This can be done, for example, by pulling the loops of the strand piece circumferentially past these points. In these embodiments, the strand piece is tripled in the region of the tails. The attachment points of the strand piece to the stent graft from which the first or second tails extend can act as retainers to hold the strand piece to a point on the medical device, such that in the contracted configuration of the medical device, a first portion of the strand piece extends circumferentially to a first side of the retainer and a second portion of the strand piece extends circumferentially to a second side of the retainer, the first and second sides being circumferentially opposite, the second portion of the strand piece providing the first or second tail as described above.

[0066] While the strand piece is shown positioned at the distal end of the stent to be contracted, in other embodiments it can be positioned at any longitudinal location of the stent to be contracted or even longitudinally offset from the stent to be contracted. Additionally, while all of the strand piece from the first end to the second end is positioned within the first circumferential region in the expanded configuration, this is not required in all embodiments. In some embodiments, it is possible but not desirable for the first and / or second portions to extend, as having all of the strand piece within the first circumferential region allows for a lower profile device. Preferably, at least a majority of the strand piece is positioned within the first circumferential region of the stent-graft in the expanded configuration, including a majority of the first and / or second portions.

[0067] It is not necessary in all embodiments for the ends of the strand pieces to be fixedly secured to the stent graft, as they may be held from coming loose when the strand pieces are pulled. In some embodiments, the strand pieces may be continuous or substantially continuous around the circumference of the stent graft. For example, in the embodiment of FIG. 19, the first and second ends of the strand pieces are attached to one another and the strand pieces are substantially continuous around the circumference of the stent graft.

[0068] In the embodiment of Figure 19, the features, methods of manufacture and use are as described for the embodiment of Figure 14 with the same modifications, except that the strand pieces are substantially continuous around the circumference of the stent graft rather than being fixedly secured to the stent graft at the first and second ends.

[0069] In the embodiment of FIG. 19, the strand piece includes a first length 124 extending from a first point 126 on the strand piece to a second point 128 on the strand piece, the first and second points 126, 128 defining and delimiting the first length 124. It should be noted that in these embodiments, the first length 124 is only a portion of the strand piece. In addition to defining the first length 124, the first and second points 126 and 128 are also interconnected by the remaining portion 60 of the strand piece, such that the strand piece is substantially continuous around the circumference of the stent graft as previously described. Both the first length 124 and the remaining portion 60 of the strand piece can be configured to thread through the graft body and struts in the same manner as described for the strand piece of the embodiment of FIG.

[0070] For purposes of describing the diameter reduction mechanism, the first length 124 can be considered to correspond to the strand piece 24 of the embodiment of FIG. 14, and the first and second points 126, 128 can be considered to correspond to the first and second ends 26, 28 of the embodiment of FIG. 14, and contraction is achieved in a similar manner, with the difference of course that the first and second points 126, 128 are not fixedly fixed to the stent graft but may move circumferentially relative to the stent graft, and contraction is achieved by tightening the continuous strand piece around the circumference of the stent graft.

[0071] When the stent graft is in the expanded configuration, the second point 128 is a first circumferential distance away from the first point 126 by a path along the first length 124 of the strand piece. In other words, moving from the first point 126 to the second point 128 along the first length 124 of the strand piece ends up a first circumferential distance away from the first point 126. The first circumferential distance is thereby transverse and defines a first circumferential region 30 of the stent graft, where the first length 124 of the strand piece circumferentially surrounds the first circumferential region 30 of the stent graft between the first point 126 and the second point 128. In this manner, when the stent graft is in the expanded configuration, the first and second points 126, 128 of the first length 124 of the strand piece define therebetween mutually exclusive first and second circumferential regions 30, 30' of the stent graft, the first circumferential region 30 of the stent graft being from the first point 126 to the second point 128 of the first length 124 of the strand piece, and the second circumferential region 30' being the remainder of the circumference of the stent graft. Of course, it should be understood that in this embodiment, the first and / or second points 126, 128 may move relative to the stent graft, and so the relative circumferential lengths and positions of the first and second circumferential regions 30, 30' may change accordingly.

[0072] In the contracted configuration, the attachment point of the strand piece to the stent graft, in this case the point 62 where the strand piece loops around the strut at the apex of the sealing stent, acts as a retainer to hold the strand piece at that point on the stent graft, whereby a first portion 64 of the strand piece extends circumferentially on a first side of the retainer and a second portion 66 of the strand piece is pulled from the first side and over the retainer to extend circumferentially on a second side of the retainer, with the second portion folded back to form a first double-line tail 134 that extends circumferentially from the retainer and joins a first loop 136, the first tail 134 extending circumferentially along the graft body to contract the medical device. The first and first sides are circumferentially opposed. The first tail and first loop are configured similarly to the embodiment of FIG. 14.

[0073] The contracted configuration can also be described as follows: a first portion 132 of the first length 124 of strand piece is folded back to form a first double-lined tail 134 that connects to a first loop 136. In particular, from the first circumferential region 30, the first portion 132 passes through a first point 126 and extends out of the first circumferential region 30 into a second circumferential region where it doubles circumferentially beyond the first point 126 to form a first tail 134 and a first loop 136. As can be seen, in this embodiment, the first point 126 is at the retainer 62 in the contracted configuration and the first tail extends from the retainer 62. As shown, the first tail 134 extends circumferentially along the graft body in a double-lined manner as described in the previous embodiment, contracting the stent graft by the first length 124 of the strand piece and limiting the first circumferential distance between the first and second points 126, 128 of the first length 124 of the strand piece 24. In this embodiment, this causes the continuous strand pieces to gather around the circumference of the stent graft, contracting the stent graft.

[0074] The first tail 134 penetrates the wall of the graft body and enters the interior of the graft body, and the first loop 136 can be held and locked by a trigger wire, similar to the embodiment of FIG.

[0075] The embodiment of Figure 20 is similar to the embodiment of Figure 19, except that the diameter reducing mechanism also includes a second tail 140 extending from the second retainer 68, i.e., from another point where the strand piece loops around the strut at the apex of the sealing stent, and leading to a second loop 142. The second tail 140 is configured with respect to the second point 128 and the second retainer 68 and is configured and functions similarly to the first tail 134, except that it extends in the opposite direction to the first tail 134. The opposite orientation of the first and second tails is consistent with the embodiment of Figure 13. The second tail 140 passes through the wall of the graft body and is retained and locked by a trigger wire, similar to the embodiment of Figure 13.

[0076] Of course, the embodiment of Figures 19 and 20 can be modified such that the trigger wires hold and lock the first and / or second loops outside the graft body, as described for the embodiment of Figures 9A-9B.

[0077] Although the tubular medical device to be contracted is disclosed as a stent graft including a stent, this is not required in all embodiments, and the diameter reduction mechanism may be used to contract any tubular medical device from one diameter to a smaller diameter.

[0078] All optional and preferred features and modifications of the above-described embodiments and dependent claims can be used in all aspects of the invention taught herein. Moreover, individual features of the dependent claims and all optional and preferred features and modifications of the above-described embodiments can be combined with each other and substituted with each other.

[0079] The disclosures in the Abstract accompanying this application are incorporated herein by reference. Although embodiments are described separately, features of one embodiment may be included in other embodiments. [Explanation of symbols]

[0080] 12 Stent graft 14 Graft body 16 Proximal end of graft body 18 Main body stent 20 Sealing stent 22 Exposed stent 23 Distal intervertex 24 Strand Pieces 25 Distal interapical portion 26 First end of strand piece 28 Second end of strand piece 30 First circumferential region 30' Second circumferential region 31 Distal apex 32 First Part 34 First Tail 36 First Loop 40 Second Tail 42 Second Loop 44 Trigger Wire 50 Urethane tube 52 Nosecone 54 Trigger wire 56 The Second Peak 58 The Third Vertex 60 Remaining strand pieces 62 Retainer 124 First length of strand piece 126 First point of strand piece 128 Second point of strand piece 134 First Tail 136 First Loop 140 Second Tail 142 Second Loop 236 First Loop 242 Second Loop

Claims

1. In medical equipment systems, a tubular medical device including a tubular graft body having a proximal end and a distal end; a diameter reduction mechanism configured to reduce a diameter of the medical device, the diameter reduction mechanism including a strand piece, a first length of the strand piece extending from a first point on the strand piece to a second point on the strand piece, the second point on the strand piece being a first circumferential distance from the first point on the strand piece by a path along the first length of the strand piece; Including, In a contracted configuration of the medical device, a first portion of the first length of the strand piece is folded back to form a first double-lined tail that connects to a first loop, the first double-lined tail extending circumferentially along the graft body, the strand piece contracting the medical device by limiting the first circumferential distance between the first and second points of the strand piece.

2. 2. The medical device system of claim 1, wherein the first point of the strand piece is a first end of the strand piece and the second point of the strand piece is a second end of the strand piece, and the first and second ends of the strand piece are optionally retained to the medical device at the first and second ends.

3. The medical device system of claim 2 , wherein the first and second ends of the strand piece are fixedly secured to the medical device.

4. The system of any one of claims 1 to 3, wherein in the contracted configuration, the first tail extends circumferentially in a double line along an outer portion of the graft body.

5. 5. The medical device system of claim 1, wherein the first portion of the strand piece passes through and circumferentially beyond the first point in a double line to form the first tail and a first loop.

6. 6. The medical device system of claim 1, wherein the first circumferential distance is transverse and defines a first circumferential region of the medical device, and wherein in an expanded configuration of the medical device, at least a majority of the strand pieces are disposed within the first circumferential region of the medical device.

7. 7. The medical device system of claim 1, wherein the first circumferential distance is transverse and defines a first circumferential region of the medical device, and wherein in an expanded configuration of the medical device, at least a majority of the first portion is disposed within the first circumferential region of the medical device.

8. 8. The medical device system of claim 1, wherein the first circumferential distance is transverse and defines a first circumferential region of the medical device, and in the contracted configuration, the first portion extends outside of the first circumferential region.

9. The medical device system of any one of claims 1 to 8, wherein the first loop is retained by a release mechanism to retain the medical device in the contracted configuration.

10. The medical device system of any one of claims 1 to 9, wherein the medical device is a stent graft optionally including at least one stent attached to the proximal end of the tubular graft body.

11. The system of any one of claims 1 to 10, wherein the first tail penetrates the wall of the graft body and the first loop is retained within the graft body by a release mechanism.

12. 12. The system of claim 1, wherein in a contracted configuration of the medical device, a second portion of the strand piece is folded back to form a second double-lined tail that connects to a second loop, the second double-lined tail extending circumferentially along the graft body and contracting the medical device by limiting the first circumferential distance between the first and second points of the strand piece.

13. 1. A method for collapsing a tubular medical device, comprising: the medical device includes a tubular graft body having a proximal end and a distal end; a diameter reducing mechanism including a strand piece, a first length of the strand piece extending from a first point on the strand piece to a second point on the strand piece, the second point on the strand piece being a first circumferential distance from the first point on the strand piece around the medical device by a path along the first length of the strand piece; the method comprising: tensioning a first portion of the first length of the strand piece to form a first loop and a first double-line tail connected to the first loop; and contracting the medical device by extending the first tail circumferentially along the graft body to limit the first circumferential distance between the first and second points of the strand piece.

14. 14. The method of claim 13, comprising: pulling a second portion of the first length of the strand piece to form a second loop and a second double-line tail connected to the second loop; and extending the second tail circumferentially along the graft body to constrict the medical device by limiting the first circumferential distance between the first and second points of the strand piece.

15. 15. The method of any one of claims 13 to 14, comprising extending the first tail and / or the second tail along a portion of the exterior of the graft body and then through a wall of the graft body into the interior of the graft body, and looping the first loop and / or the second loop around a trigger wire within the interior of the graft body.

Images