CN108245279B

CN108245279B - Tectorial membrane support

Info

Publication number: CN108245279B
Application number: CN201611248671.5A
Authority: CN
Inventors: 肖本好; 刘彩萍
Original assignee: Lifetech Scientific Shenzhen Co Ltd
Current assignee: Lifetech Scientific Shenzhen Co Ltd
Priority date: 2016-12-29
Filing date: 2016-12-29
Publication date: 2023-11-21
Anticipated expiration: 2036-12-29
Also published as: CN108245279A

Abstract

The invention discloses a covered stent, which comprises a stent body and a covered film coated on the surface of the stent body, wherein the covered film is of a lumen structure with two open ends, at least one groove for accommodating a branch stent is concavely formed towards the inside of the covered film stent, and the groove penetrates through at least one end of the covered film stent. The covered stent of the invention has the advantages that the grooves for accommodating the branched stent are reserved on the covered stent, the gap between the branched stent and the covered stent is reduced to the greatest extent, and the occurrence rate of I-type internal leakage is reduced.

Description

Tectorial membrane support

Technical Field

The invention relates to a cardiovascular medical instrument, in particular to a covered stent.

Background

CPG technology includes two parts, chimney technology and periscope technology. The proximal side of the stent or stent graft opening is referred to as the chimney technique and the distal side of the opening is referred to as the periscope technique. CPG techniques are often applied in the aortic arch, the visceral region of the abdominal aorta, or the internal iliac arteries. Fig. 1 shows a schematic representation of the reconstruction of bilateral renal arteries using a chimney technique. The abdominal aortic aneurysm 3 is treated by arranging the abdominal main covered stent 2 and the branch stent 1 side by side. Fig. 2 shows a cross-sectional view of the stent graft 2 and the stent graft 1 placed in a blood vessel 4, and the stent graft 2 and the stent graft 1 are unevenly deformed by extrusion with each other due to the radial extrusion force and uneven stress on the circumferential surfaces of the stent graft 2 and the stent graft 1, and this deformation results in a large number of voids 5 between the stent grafts 1 and the stent graft 2, resulting in a clinically I-shaped endoleak.

The grant publication number CN 102641164B shows a stent graft in which a depression 11 is formed in the middle, the depression 11 corresponds to a branching portion of the aortic arch, the depression 11 has three side holes 12, and one end of the three branch stents 2 is connected to the side holes 12, and the other end is placed in a branch artery, thereby reconstructing the branch artery. However, this technique still has the following problems: on the one hand, before the stent graft is inserted into the branch stent 2, a guide wire track is required to be established, and the guide wire access window is very difficult, so that the operation time is long, the occurrence risk of complications such as branch artery injury and stenosis is easy to increase, and a series of brain dysfunction can occur due to cerebral ischemia and hypoxia caused by long-time blocking of the branch artery. On the other hand, the blood flow flows through the lumen of the covered stent and then flows into the divided stent lumens, which tends to bring small thrombi or other particulate matter deposited inside the covered stent lumens into the branched stent, increasing the occurrence probability of complications caused by the thrombi. Even if the proximal end of the branched stent is extended to be flush with the proximal end of the covered stent, there is still a risk that the proximal end of the branched stent will swing under the impact of blood flow, resulting in stent displacement and thrombosis.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides the tectorial membrane bracket which can greatly reduce the occurrence rate of I-type internal leakage.

The technical scheme adopted for solving the technical problems is as follows: the tectorial membrane support comprises a support body and a tectorial membrane coated on the surface of the support body, wherein the tectorial membrane is of a lumen structure with two open ends, at least one groove for accommodating a branch support is formed in the tectorial membrane towards the inner part of the tectorial membrane support in a recessed mode, and the groove penetrates through at least one end of the tectorial membrane support.

In an embodiment of the invention, the groove penetrates only one end of the stent graft.

In an embodiment of the invention, the maximum distance between any two points on the cross section of the groove is 6-18mm.

In an embodiment of the present invention, the groove includes a first curved surface penetrating through the proximal end of the stent graft and extending along the axial direction of the stent graft, and a second curved surface connected to the first curved surface, and orthographic projections of the first curved surface and the second curved surface on a plane parallel to the axis of the stent graft are respectively rectangular and crescent.

In an embodiment of the present invention, the first curved surface is a cylindrical surface, and a cross-sectional shape of the cylindrical surface is inscribed with a cross-sectional shape of the sidewall.

In one embodiment of the invention, the cross-sectional shape of the cylindrical surface is a major arc.

In an embodiment of the present invention, the first curved surface includes two planes disposed opposite to each other and extending toward the inside of the stent graft, and a cylindrical surface connecting edges of the two planes.

In one embodiment of the invention, the cylindrical surface comprises a semi-cylindrical surface or a semi-elliptical arc cylindrical surface.

In an embodiment of the present invention, a generatrix of the semi-cylindrical surface or the semi-elliptical arc cylindrical surface forms an acute angle with an axis of the stent graft.

In an embodiment of the invention, the acute included angle is between 0 ° and 15 °.

In an embodiment of the present invention, the first curved surface includes two first planes which are disposed opposite to each other and extend vertically toward the inside of the stent graft, and a plurality of second planes connected end to end and connecting edges of the two planes.

In an embodiment of the present invention, the covering film has a plurality of the grooves, and the plurality of the grooves are uniformly spaced apart along the circumferential direction of the covering film support.

In an embodiment of the present invention, the second curved surfaces of the plurality of grooves are mutually communicated as a whole.

In an embodiment of the present invention, the stent body includes a plurality of wave rings arranged along an axis of the stent graft, the wave rings include at least one first wave ring for supporting the first curved surface and corresponding to a position of the first curved surface, and at least one second wave ring for supporting the second curved surface and corresponding to a position of the second curved surface, and at least a portion of a waveform of the second wave ring falls on a cross section of the second curved surface.

In an embodiment of the present invention, the stent body further includes a plurality of third waverings arranged along the axial direction of the stent graft from the distal end of the groove, and the wavelengths of the first wavering and the second wavering are smaller than the wavelength of the third wavering.

The covered stent is provided with the grooves for accommodating the branched stent in advance, so that extrusion deformation of the branched stent and the covered stent due to uneven stress is avoided, unsmooth blood flow of the branched stent and the covered stent due to extrusion is prevented, gaps between the branched stent and the covered stent are reduced to the greatest extent, and the occurrence rate of I-type internal leakage is reduced. And the existence of the grooves can shorten the operation time and reduce the occurrence risk of complications such as branch artery injury, stenosis and the like. On the other hand, the groove penetrates through at least one end of the covered stent, blood flows into the branched stent and the lumen of the covered stent at the same time, thrombus in the lumen of the covered stent can be prevented from entering into the branched vessel, and the occurrence probability of complications caused by the thrombus is reduced.

Drawings

The invention will be further described with reference to the accompanying drawings and examples, in which:

FIG. 1 is a schematic diagram of a prior art reconstruction of bilateral renal arteries using chimney technology;

FIG. 2 is a schematic cross-sectional view of FIG. 1;

FIG. 3 is a schematic view of a first embodiment of a stent graft according to the present invention;

FIG. 4 is a left side view of a first embodiment of the stent graft of the present invention;

FIG. 5 is a front view of a stent graft of a first embodiment of the present invention;

FIG. 6 is a top view of the coating shown in FIG. 5;

FIG. 7 is a left side view of the coating shown in FIG. 5;

FIG. 8 is a schematic view showing the structure of a stent body in the first embodiment of the stent graft of the present invention;

FIG. 9 is an expanded view of the first band in the stent body shown in FIG. 8;

FIG. 10 is a left side view of a first wave ring in the stent body shown in FIG. 8;

FIG. 11 is an expanded view of a second wave ring in the stent body shown in FIG. 8;

FIG. 12 is a left side view of a second wave ring in the stent body shown in FIG. 8;

FIG. 13 is a front view of a stent graft in a second embodiment of the present invention;

FIG. 14 is a top view of the film shown in FIG. 13;

FIG. 15 is a left side view of the coating shown in FIG. 14;

FIG. 16 is a front view of a stent graft in a third embodiment of the present invention;

FIG. 17 is a top view of the coating shown in FIG. 16;

FIG. 18 is a left side view of the coating shown in FIG. 16;

FIG. 19 is a front view of a stent graft in a fourth embodiment of the present invention;

FIG. 20 is a top view of the film shown in FIG. 19;

FIG. 21 is a left side view of the coating shown in FIG. 19;

FIG. 22 is a front view of a stent graft in a fifth embodiment of the present invention;

FIG. 23 is a top view of the coating shown in FIG. 22;

FIG. 24 is a left side view of the cover film of FIG. 22;

FIG. 25 is a schematic view showing the construction of a sixth embodiment of a stent graft according to the present invention;

FIG. 26 is a left side view of the stent graft shown in FIG. 25;

FIG. 27 is a top view of the stent graft shown in FIG. 25;

FIG. 28 is a left side view of the coating of FIG. 27;

FIG. 29 is a schematic view showing the construction of a seventh embodiment of a stent graft of the present invention;

FIG. 30 is a left side view of the stent graft shown in FIG. 29;

FIG. 31 is a front view of the stent graft of FIG. 29;

FIG. 32 is a top view of the film shown in FIG. 31;

FIG. 33 is a left side view of the coating shown in FIG. 32;

FIG. 34 is a schematic view of a stent graft of the present invention implanted in a blood vessel;

fig. 35 is a cross-sectional view of a stent graft of the present invention implanted in a blood vessel.

Detailed Description

For a clearer understanding of technical features, objects and effects of the present invention, a detailed description of embodiments of the present invention will be made with reference to the accompanying drawings.

The "cross section" mentioned in the embodiments of the present invention refers to a section taken in a plane perpendicular to the axis of the stent graft, and the "longitudinal section" refers to a plane taken in a plane parallel to the axis of the stent graft, and will not be described in detail in the following embodiments.

First embodiment:

as shown in fig. 3 and 4, the stent graft of the present invention includes a stent graft segment 10 and a bare stent segment 20 connected to the proximal end of the stent graft 10. The covered stent section 10 comprises a stent body 11 and a covered film 12 coated on the stent body 11. The tectorial membrane stent has radial expansion capability, can be compressed under the action of external force and self-expand after the external force is withdrawn or restore to the original shape and keep the original shape through mechanical expansion (such as balloon expansion) so as to be fixed in the lumen by the radial supporting force of the stent attached to the lumen wall after being implanted in the lumen, thereby playing the roles of reconstructing a blood flow channel and isolating a focus.

As shown in fig. 5 to 7, the covering film 12 has a hollow lumen structure with both ends open, and the lumen structure forms a blood flow channel. The coating 12 itself has a certain thickness, and is generally made of a polymer material having biocompatibility, such as a PET film or a PTFE film. A part of the region of the coating film 12 is recessed toward the inside of the coating film stent to form a groove 121 for accommodating the branch stent. In this embodiment, the groove 121 includes a first curved surface 122 extending through the proximal end of the stent graft and along the axial direction of the stent graft, and a second curved surface 123 connected to the first curved surface 122. In other possible embodiments, the groove 121 may also extend through the distal end of the stent graft or through both the proximal and distal ends of the stent graft. It will be appreciated that the grooves 121 do not have to extend in the axial direction of the stent graft, and their direction of extension is determined primarily by the direction of extension of the branch stent with which they are engaged. The second curved surface 123 is distal to the proximal end of the stent graft compared to the first curved surface 122. The first curved surface 122 is mainly used for accommodating one end of the branched stent, the second curved surface 123 is used for guiding the other end of the branched stent, and the other end is guided to extend in the direction far away from the axial direction of the covered stent so as to enter the branched stent, so that the second curved surface 123 is not a necessary branched stent for the invention. As shown in fig. 6, the orthographic projection of the first curved surface 122 on a plane parallel to the axis of the stent graft is rectangular. The orthographic projection of the second curved surface 123 on a plane parallel to the axis of the stent graft takes the shape of a crescent. In this embodiment, the first curved surface 122 is a non-complete cylindrical surface, and the cross-sectional shape thereof is a major arc, and designing the first curved surface 122 into such a shape can make the recess 121 have better adaptability to the branched stent. As shown in fig. 7, the cross-sectional shape of the first curved surface 122 is inscribed with the cross-sectional shape (circular shape) of the side wall of the coating film 12.

It will be appreciated that the cross-sectional dimensions of the grooves 121 should be as closely matched to the outside diameter of the lumen of the branched stent as possible. Preferably, the maximum distance between any two points on the cross section of the groove 121 is between 6 and 18mm. In this embodiment, the cross section of the first curved surface 122 for accommodating the branch stent is a major arc, so the maximum distance between any two points on the cross section of the groove 121 is the diameter of the major arc. The cross-sectional dimension of the groove 121 is designed to minimize the gap between the stent graft and the branch stent, thereby avoiding the clinical I-shaped inner leakage. It is envisioned that when the cross-sectional dimensions of groove 121 match the outside diameter of the lumen of the branched stent, an I-shaped endoleak will no longer occur. When the cross section size of the groove 121 is slightly smaller than the outer diameter of the lumen of the branch stent, due to the self-expansion characteristic of the branch stent, gaps between the covered stent and the branch stent can be filled in time, and extrusion deformation generated by the covered stent and the branch stent is uniform at the moment, so that I-shaped internal leakage is avoided, and meanwhile, unsmooth blood flow caused by nonuniform extrusion deformation can be prevented. In addition, the grooves for accommodating the branch stents are reserved on the covering film, so that the operation time can be shortened, and the occurrence risk of complications such as branch artery injury and stenosis can be reduced. This is because the sheath and guide wire can be pre-placed in the groove position, the time for establishing the guide wire track is saved, and the branch stent can be released immediately after the covered stent is released in the blood vessel. The groove penetrates through one end of the covered stent, blood flows into the branched stent and the lumen of the covered stent at the same time, thrombus in the lumen of the covered stent can be prevented from entering into the branched vessel, and the occurrence probability of complications caused by the thrombus is reduced.

As shown in fig. 8, the stent body 11 is composed of a plurality of wave rings arranged along the axial direction of the stent graft, and the wave rings can be connected with the stent graft 12 by stitching. The stent body 11 may be made of a memory alloy material (e.g., nickel-titanium alloy) to provide self-expansion capability. In other possible embodiments, the stent body may also be a mesh formed by braiding wires, or a cut mesh formed by cutting a metal tube. These wave rings include two first wave rings 111 supporting the first curved surface 122, a second wave ring 112 supporting the second curved surface 123, and a third wave ring 113 supporting the portion of the cover film 11 other than the groove 121, the first wave ring 111, the second wave ring 112, and the third wave ring 113 being arranged in this order in a direction pointing distally from the proximal end.

The first wave ring 111 and the second wave ring 112 each include a plurality of peak apexes, a plurality of trough apexes, and a straight support portion connecting the peak apexes and the trough apexes. The first and second wave rings 111 and 112 may be designed as a Z-wave structure or other wave structure that can be compressed into a small diameter. In the present invention, the wavelengths of the first band 111 and the second band 112 are each smaller than the wavelength of the third band 113. The wavelength of the first wave band 111 and the second wave band 112 is designed smaller than that of the third wave band 113 in order to form a better support for the groove 121, and the wave bands with smaller wavelength can be more conveniently stitched with the groove 121 on the cover film 12 when stitching, which is beneficial to assembly and release.

Fig. 9 is an expanded view of the first pulsator 111, and fig. 10 is a left side view of the first pulsator 111 after being sewn to the coating film 12, and it can be seen that the first pulsator 111 can be well matched with the sectional shape of the coating film 12. Fig. 11 is an expanded view of the second band 112, and fig. 12 is a left side view of the second band 112 after being sewn to the cover film 12. Since the second curved surface 123 mainly guides the branch frame, at least a part of the waveform of the second wave ring 112 falls on the cross section of the second curved surface 123 in order to better support the second curved surface 123. As can be seen in conjunction with fig. 4 and 13, one of the waveforms of the second wave ring 112 falls within the groove 121, and the trough peaks of this waveform fall on the cross-sectional shape of the second curved surface 123. The wave ring and the tectorial membrane are easier to assemble and have better fatigue performance due to the fact that the wave ring or the semi-wave shape is arranged in the groove. In other possible embodiments, it is also possible that the straight support portion connecting the peak apex and the trough apex falls on the cross-sectional shape of the second curved surface 123.

Second embodiment:

as shown in fig. 13 and 14, in this embodiment, the structure and function of the stent graft are the same as those of the previous embodiment, except that the grooves 21 on the stent graft 20 in this embodiment are different from those of the previous embodiment. The recess 21 still includes a first curved surface 211 extending from the proximal end of the stent graft along the axis of the stent graft and a second curved surface 212 connected to the first curved surface 211. As shown in fig. 15, unlike the previous embodiment, the first curved surface 211 includes two opposite planes 213 extending vertically toward the inside of the stent graft and a semi-cylindrical surface 214 connecting the edges of the two planes 213. The first curved surface 211, which mainly supports the branch bracket, makes the cross-sectional shape of the groove 21U-shaped. In this embodiment, the two planes 213 are disposed in parallel and spaced apart, and the distance between the two planes 213 is equal to the diameter of the semi-cylindrical surface 214, and the distance is the maximum distance between any two points on the groove 21, and the distance is not greater than the outside diameter of the lumen of the branch stent.

Third embodiment:

as shown in fig. 16 to 18, in this embodiment, the structure and function of the stent graft are the same as those of the previous embodiment, except that the grooves 31 on the stent graft 30 in this embodiment are different from those of the previous embodiment. The groove 31 still includes a first curved surface 311 extending from the proximal end of the stent graft along the axis of the stent graft and a second curved surface 312 connected to the first curved surface 311. As shown in fig. 18, unlike the previous embodiment, the first curved surface 311 includes two opposite plane surfaces 313 extending toward the inside of the stent graft and an elliptical cylindrical surface 314 connecting the edges of the two plane surfaces 313. The first curved surface 311, which mainly supports the branch bracket, makes the cross-sectional shape of the groove 31 substantially U-shaped. In this embodiment, the two planes 313 are disposed in parallel and spaced apart, and the distance between the two planes 313 is equal to the length of the major axis of the elliptical cambered surface 214, and the distance is the maximum distance between any two points on the groove 31. The distance is no greater than the outside diameter of the lumen of the branch stent.

Fourth embodiment:

as shown in fig. 19 to 21, in this embodiment, the structure and function of the stent graft are the same as those of the previous embodiment, except that the grooves 41 on the stent graft 40 in this embodiment are different from those of the previous embodiment. The recess 41 still includes a first curved surface 411 extending from the proximal end of the stent graft along the axis of the stent graft and a second curved surface 412 connected to the first curved surface 411. As shown in fig. 21, the first curved surface 411 includes two opposite first flat surfaces 413 extending toward the inside of the stent graft and a plurality of end-to-end second flat surfaces 414 connecting the edges of the two flat surfaces 413. The shape of the second curved surface 412 is the same as in the previous embodiment. It will be appreciated that when there are a sufficient number of second planar surfaces 414, the portion connecting the two first planar surfaces 413 becomes a cambered surface. Although the combination of the plurality of second planes 414 is not as good as the above embodiments, the self-expansion characteristic of the branched stent can fill the gaps mainly appearing at the joint of the two adjacent second planes 414, and still can play a good role in preventing internal leakage.

Fifth embodiment:

this embodiment is a modification of the second embodiment, as shown in fig. 22-24. The groove 51 includes a first curved surface 511 and a second curved surface 512 connected to the first curved surface 511. The first curved surface 511 is formed by two parallel, spaced-apart flat surfaces 513 and a cylindrical surface 514 connecting the edges of the two flat surfaces 513. Wherein, the generatrix of the cylindrical surface 514 forms an acute included angle alpha with the axis of the tectorial membrane bracket, and the angle of the acute included angle alpha is between 0 DEG and 15 deg. Specifically, the generatrix of the cylindrical surface 514 is inclined in a direction from the distal end toward the proximal end. The bus of the cylindrical surface 514 is designed to form an acute angle with the axis of the film covered bracket, so that the branch bracket can more easily extend into the branch pipe cavity. It will be appreciated that the generatrix of the incomplete cylinder in the first embodiment, and the generatrix of the elliptical cylinder in the third embodiment, may also be designed to form an acute angle with the axis of the stent graft.

Sixth embodiment:

as shown in fig. 25-26, the stent graft of the present invention includes a stent graft segment and a bare stent segment 60 connected to the proximal end of the stent graft. The covered stent section comprises a stent body and a cover 70 covering the stent body. The structure of the bracket body is the same as that of the above embodiments, and will not be described again here.

As shown in fig. 27 to 28, the cover 70 has a hollow lumen structure surrounded by a side wall and having both ends open, and a groove 71 for accommodating the branch stent is formed in the cover 70 so as to be recessed toward the inside of the cover stent. In the present embodiment, three grooves 71 are provided on the cover film 70 at regular intervals along the circumferential direction thereof, and the structures of the three grooves 71 are the same. It should be noted that the number of the grooves 71 may be designed according to the requirements of the branch stent, and the arrangement of the grooves 71 in the circumferential direction of the coating film 70 is not necessarily uniform, and may be specifically adjusted according to the installation position of the branch stent. As in the previous embodiments, the recess 71 includes a first curved surface 711 extending through the proximal end of the stent graft and along the axial direction of the stent graft, and a second curved surface 712 connected to the first curved surface 711. The primary housing for the branch brackets is a first curved surface 711,

the cross-sectional shape of the first curved surface 711 may be the same as any of the five embodiments described above. As shown in fig. 28, in the present embodiment, the cross-sectional shape of the first curved surface 711 is the same as that in the second and third embodiments, each has a U-shape,

seventh embodiment:

as shown in fig. 29-30, the stent graft of the present invention includes a stent graft segment and a bare stent segment 80 connected to the proximal end of the stent graft. The covered stent section includes a stent body and a cover 90 covering the stent body. The structure of the bracket body is the same as that of the above embodiments, and will not be described again here.

As shown in fig. 31 to 33, the cover 90 has a hollow lumen structure surrounded by a side wall and having both ends open, and a groove 91 for accommodating the branch stent is formed in the cover 90 so as to be recessed toward the inside of the cover stent. In the present embodiment, three grooves 91 are provided on the cover film 90 at regular intervals in the circumferential direction thereof, and the structures of the three grooves 91 are the same. It should be noted that the number of the grooves 91 may be designed according to the requirements of the branch stent, and the arrangement of the grooves 91 in the circumferential direction of the covering film 90 is not necessarily uniform, and may be specifically adjusted according to the installation position of the branch stent. As with the previous embodiments, the recess 91 includes a first curved surface 911 extending through the proximal end of the stent graft and along the axial direction of the stent graft and a second curved surface 912 connected to the first curved surface 911. Unlike the above embodiments, in this embodiment, the plurality of second curved surfaces 912 are connected to each other to form a single body.

The cross-sectional shape of the first curved surface 911 may be the same as any of the above-described five embodiments. As shown in fig. 33, in the present embodiment, the cross-sectional shape of the first curved surface 911 is U-shaped,

fig. 34 and 35 show a specific application of the present invention, fig. 34 is a schematic view of the structure in which the stent graft of the present invention is implanted in a lumen, and fig. 35 is a cross-sectional view of fig. 34. In actual operation, the covered stent 6 is implanted into the lumen 7, then the guide wire passes through the concave structure of the covered stent 6, and then the branch stent 8 is implanted, so that reconstruction of three branches on the bow is realized. As shown in fig. 35, the branch stent 8 is completely wrapped in the concave structure of the stent graft 6, thereby preventing the formation of an I-shaped endoleak between the branch stent 8 and the stent graft 6.

The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims

1. The covered stent comprises a stent body and a covered film coated on the surface of the stent body, wherein the covered film is of a lumen structure with two open ends, and is characterized in that the covered film is concavely formed towards the inside of the covered stent to form at least one groove for accommodating a branch stent, and the groove only penetrates through one end of the covered stent; the groove comprises a first curved surface penetrating through the proximal end of the tectorial membrane bracket and extending along the axial direction of the tectorial membrane bracket, and a second curved surface connected with the first curved surface, and orthographic projections of the first curved surface and the second curved surface on a plane parallel to the axis of the tectorial membrane bracket are respectively rectangular and crescent.

2. The covered stent of claim 1, wherein the cover is a PET film or a PTFE film.

3. The stent graft of claim 1, wherein the maximum distance between any two points on the cross-section of said groove is between 6 mm and 18mm.

4. The stent graft of claim 1, wherein said stent body is made of a memory alloy material.

5. The stent graft of claim 4, wherein said first curved surface is a cylindrical surface having a cross-sectional shape inscribed with a cross-sectional shape of said stent graft sidewall.

6. The stent graft of claim 5, wherein the cross-sectional shape of said cylindrical surface is a major arc.

7. The stent graft of claim 4, wherein said first curved surface comprises two oppositely disposed planar surfaces extending inwardly of said stent graft and a cylindrical surface connecting the edges of said planar surfaces.

8. The stent graft of claim 7, wherein said cylindrical surface comprises a semi-cylindrical surface or a semi-elliptical cylindrical surface.

9. The stent graft of claim 8, wherein the generatrix of said semi-cylindrical surface or said semi-elliptical cylindrical surface forms an acute included angle with the axis of said stent graft.

10. The stent graft of claim 9, wherein said acute included angle is between 0 ° and 15 °.

11. The stent graft of claim 4, wherein said first curved surface comprises two oppositely disposed first planar surfaces extending vertically toward the interior of said stent graft and a plurality of end-to-end second planar surfaces connecting the edges of said planar surfaces.

12. The stent graft of claim 4, wherein said stent graft has a plurality of said grooves, said plurality of grooves being circumferentially spaced about said stent graft.

13. The stent graft in accordance with claim 12, wherein the second curved surfaces of said plurality of grooves are integrally connected to one another.

14. The stent graft of any one of claims 4-13, wherein said stent body comprises a plurality of bands aligned along an axis of said stent graft, said bands comprising at least one first band for supporting said first curved surface and corresponding to a location of said first curved surface, and at least one second band for supporting said second curved surface and corresponding to a location of said second curved surface, said second band having a waveform at least a portion of which falls on a cross-section of said second curved surface.

15. The stent graft of claim 14, wherein said stent body further comprises a plurality of third wavelength bands disposed axially of said stent graft from a distal end of said groove, and wherein said first wavelength band and said second wavelength band are each less than a wavelength of said third wavelength band.