Bifurcated stent graft and method for producing the same

Abstract

The present invention relates to a vascular implant for implantation into a patient's blood vessel, the vascular implant comprising: a hollow cylindrical body having a proximal end and a distal end, a body lumen and a longitudinal axis, and at least one hollow cylindrical side body branching from the body and comprising a side body lumen, the side body lumen being in fluid communication with the body lumen, wherein the hollow cylindrical body and the at least one hollow cylindrical side body are formed in a single piece from a single planar sheet of graft material.

Description

Technical Field

[0001] The present invention relates to a vascular implant for implantation into a branch blood vessel of a patient to restore the patency of the blood vessel. Background Art

[0002] The present invention relates to a vascular implant for implantation into a patient's blood vessel, the vascular implant comprising: a hollow cylindrical body having a proximal end and a distal end, a body lumen and a longitudinal axis, and at least one hollow cylindrical side body branching from the body and comprising a side body lumen, the side body lumen being in fluid communication with the body lumen.

[0003] Such so-called branched vascular implants are known in the prior art. Such vascular implants (which are also referred to as endovascular grafts) are implanted for the treatment of aneurysms, blockages or other injuries in arteries. An aneurysm is understood to be a widening or bulging of an arterial vessel due to congenital or acquired changes in the vessel wall. The bulging may affect the vessel wall as a whole, or, as in the case of a so-called pseudoaneurysm or a so-called dissection, blood may flow out of the arterial lumen between the layers of the vessel wall and may tear these layers apart. Without treating the aneurysm, the blockage or other injury may lead to a late arterial rupture, with the consequence that the patient has internal bleeding.

[0004] To treat aneurysms, blockages or other injuries, grafts are implanted to bridge and / or stabilize the blood vessels to prevent rupture of the blood vessels.

[0005] Such a graft may be applied alone to a blood vessel, or the graft may be supported by metal stents or stent springs that are subsequently placed inside or outside the graft. Such a construction is known as a stent graft.

[0006] The graft or stent-graft is introduced into the vessel by endoluminal techniques using a suitable delivery device to restore vascular patency across the aneurysm.

[0007] At the location of the blood vessel where such a vascular implant is to be inserted, the blood vessel often branches out laterally, which is why when introducing a vascular implant in such a branching location in a blood vessel, there is a risk that these side vessels will be cut off from blood supply by the vascular implant in the main vessel or by the implant material which may not be permeable to blood. Therefore, in these areas, the vascular implant usually has openings, also called "fenestrations", in the graft material in order to guide the blood flowing through the vascular implant through these openings and usually also through the side branches of the vascular implant, which are separately arranged in these openings and are introduced into the side vessels and also into the side vessels branching from the blood vessels. In this way, it is ensured that the area of ​​the body supplied by the side vessels is also supplied with blood.

[0008] In many cases, the vascular implant or graft / stent graft to be introduced at these branching regions has not only fenestrations, but also side branches branching off from the main body of the vascular implant, which are released in the aneurysm sac above the branch vessels and serve, for example, as landing zones for additional stent grafts that are implanted into the side branches and branch vessels to bridge the aneurysm. In this way, it is additionally ensured that the side vessels are also supplied with blood.

[0009] Critical areas in the human vascular system are, for example, the aortic bifurcation area and, in addition, the branches of the iliac arteries to the external and internal iliac arteries. For each of the branches, if the aorta or iliac arteries (e.g. due to an aneurysm) must be treated in this area, it is usually necessary to ensure the blood supply to the branch.

[0010] Vascular implants including side branches known and available in the prior art are usually manufactured by attaching the side branches between stent springs, as described, for example, in US6645242 B. Alternatively, as disclosed, for example, in EP0709066A1, a sidearm graft tube is sutured into the orifice of the main graft tube.

[0011] A disadvantage of the vascular implants known from the prior art that carry side branches is that these vascular implants with side branches usually have accumulations of material in the region of the branch, such as nitinol rings in the side branches (by which the side branches are opened after dilation), or, for example, additionally sewn-in fabric rings of implant material, which in turn require larger insertion systems and can lead to difficulties in handling these vascular implants in narrow vessels. The annular sutures perpendicular to the blood flow can also cause turbulence in the blood flow, thereby increasing the risk of stenosis. Side branches are also usually very unstable and therefore difficult to handle once they have been introduced into a vessel. Summary of the invention

[0012] The object of the present invention is therefore to provide a vascular implant which can be easily and stably inserted into a main vessel and into a side vessel and thus into a branch, whereby accumulation of material is advantageously avoided and an undisturbed blood flow is achieved. A further object is to provide a safe and cost-effective method for producing such a vascular implant.

[0013] According to the invention, this object is achieved by developing a vascular implant for implantation into a blood vessel of a patient.

[0014] The object is also achieved by a method for producing a vascular implant.

[0015] Thus, it can be said that the present invention relates to a vascular implant comprising: a hollow cylindrical body having a proximal end and a distal end, a body lumen and a longitudinal axis, and at least one hollow cylindrical side body branching from the body and comprising a side body lumen, the side body lumen being in fluid communication with the body lumen, characterized in that the hollow cylindrical body and the at least one hollow cylindrical side body are formed in a single piece from a single planar sheet of graft material.

[0016] Throughout the specification, the term "proximal" generally refers to a position, direction, or a portion or end of a component of a vascular implant that is located closer to the heart of a patient to be treated. Correspondingly, the term "distal" refers to a position, direction, or a portion or end of a component of a vascular implant according to the present invention that is farther / farthest from the heart of the patient in the direction of blood flow.

[0017] In one embodiment, a single planar sheet forming the vascular implant of the present application comprises a main portion having a width corresponding to the circumference of the body and at least two mirror-image arm portions, at least two mirror-image arm portions extending from the main portion on both sides and having a width corresponding to half the circumference of the side body, or in other words a pair of mirror-image arm portions.

[0018] The angle at which the longitudinal axis of the arm portion is arranged relative to the longitudinal axis of the main portion also defines at least a limited range of angles at which the lateral bodies of the implant are disposed relative to the longitudinal axis of the main portion.

[0019] Therefore, in a preferred embodiment of the vascular implant of the invention, at least one side body branching off from the main body is arranged at an angle α relative to the longitudinal axis of the main body.

[0020] In case the main tube and the side tube are arranged parallel to each other, this angle may be less than 10°. On the other hand, this angle should be less than 90° to avoid increased turbulence in the blood flow near the area of ​​the bifurcation. Preferably, the longitudinal axis of at least one side body projects from the main body at an angle of between 0° and less than 90°, particularly between 20° and 80°, and particularly between 35° and 55°, and particularly in the range of 40° to 50°, and more preferably in the range of between 44° and 46°, and most preferably at an angle of 45°, relative to the longitudinal axis of the main body.

[0021] In the present case, this therefore also explicitly includes all numbers lying between these ranges; it is obvious to a person skilled in the art that the ranges mentioned above in this document also include tolerance bands lying outside the specified range (i.e. above or below the specified range) and within conventional production and measurement tolerances.

[0022] In different embodiments of the invention, a vascular implant according to the invention may comprise one or more side bodies each protruding at a different angle relative to the longitudinal axis of the vascular implant, and thus a single planar sheet may comprise multiple pairs of mirror-image arm portions.

[0023] The vascular implant or its hollow cylindrical body may have a uniform diameter or different diameters over its entire length. This diameter is determined by the width of the main part of the single planar sheet. This also applies to the side body and the mirror image arm portion pairs in the case of a single planar sheet.

[0024] In a further preferred embodiment, the main portion of the single planar sheet forming the vascular implant of the present application is partially separated to form a proximal common main portion and two main portion legs towards the distal end. This embodiment allows a more precise shaping of the body.

[0025] In another embodiment of the present invention, a single planar sheet forming the vascular implant of the present application includes a main portion as described above, which may or may not include a main portion leg and at least two mirrored arm portions extending from the main portion on both sides, wherein at least two of the mirrored arm portions (a mirrored arm portion pair) also include auxiliary side arm portions extending from the arm portion.

[0026] Employing such a sheath leads to an alternative embodiment of the vascular implant according to the present application with one or more auxiliary side bodies branching from the side bodies.

[0027] The angle at which the longitudinal axis of the auxiliary side arm portion is arranged relative to the longitudinal axis of the arm portion also defines at least one limited range of angles at which the longitudinal axis of the auxiliary side body of the implant is arranged relative to the longitudinal axis of the side body. In the case where the side tube and the auxiliary side tube are arranged parallel to each other, this angle may be less than 10°. Preferably, the angle at which the longitudinal axis of at least one auxiliary side body protrudes from the side body relative to the longitudinal axis of the side body is between 0° and 90°, in particular between 20° and 80°, and in particular between 35° and 55°, and in particular in the range of 40° and 50°, and more preferably in the range of between 44° and 46°, and most preferably 45°.

[0028] Since the vascular implant of the present invention is formed by a single-layer sheet, the edges of the planar sheet are bonded to each other to form the hollow cylindrical structure of the implant, i.e., a hollow cylindrical body and at least one hollow cylindrical side body, and optionally a hollow cylindrical auxiliary side body. Suitable bonding techniques for closing the seams of the implant include welding, gluing, stitching or sewing / suturing, wherein sewing, in particular hand sewing, is preferred. In a preferred embodiment, the bond is impermeable to blood or is liquid-tight.

[0029] Suture materials currently used in the field of surgical operations and stent implantation technology can be used as suture materials for sewing graft materials, and such suture materials are generally composed of polyester, polyurethane, polytetrafluoroethylene, polyethylene, ultra-high molecular weight polyethylene (UHMWPE), and polypropylene.

[0030] In a further preferred embodiment of the present application, the vascular implant of the present invention further comprises a dart at the location where the side body branches, which dart extends from the distal end of the side body opening in the main body along a portion of the proximal end of the side body. Such a dart allows an improved form of a branched vascular implant. It allows a smooth inner surface of the implant and a good hollow cylindrical shape of the main body and the side body. Moreover, by adjusting the width and length of the dart, the angle at which the longitudinal axis of the side body protrudes from the longitudinal axis of the main body can also be adjusted.

[0031] Where the vascular implant further comprises an auxiliary side body, the implant may further comprise a dart at the site where the auxiliary side body branches, wherein the dart extends from a distal end of the auxiliary side body opening in the side body along a portion of the proximal end of the auxiliary side body.

[0032] In one embodiment, a pleat can be formed by folding a portion of the graft material in the distal portion of the branch region in the main tube, wherein the pleat points in the proximal direction to each side of the side tube. In a further preferred embodiment, the fold is fixed by sewing.

[0033] In a further embodiment, the pleats may be formed by cuts into the sheet of graft material at the distal end of the interlayer of the side arms in the main portion substantially parallel to the longitudinal axis of the body. When the tubular member is formed from the sheet of graft material, these cuts are then joined together. In a further preferred embodiment, the cuts are joined by sewing.

[0034] The graft material (i.e. the planar sheet of graft material) can be woven, braided, knitted, electrospun or sputtered. There are many textile fabrics, textile composite materials and medical textiles suitable as graft materials for vascular implants known to the technician. In a preferred embodiment, the planar sheet of graft material of any one of the above-mentioned vascular implants is made of one or more polymers or copolymers thereof selected from polyurethane, polyether, polyester, polyamide, polyethylene terephthalate, polytetrafluoroethylene or expanded polytetrafluoroethylene.

[0035] In a further alternative embodiment, the vascular implant of the present invention has at least one further additional side body branching from the main body or from any one of the side bodies, wherein the additional side body is made of a second piece of graft material, and wherein the proximal end of the additional side body is attached to the circular opening in the graft material of the main body or of any one of the side bodies.

[0036] In a preferred embodiment, the vascular implant of the present invention further comprises one or more stent rings which are arranged successively on the longitudinal axis of at least a portion of the main body and optionally on the longitudinal axis of at least a portion of any one of the side bodies, the stent rings being convertible from a compressed state to a self-expanding state.

[0037] In the present context, "stent ring" refers to any device or structure that provides expansion forces and / or support functions to the prosthesis.

[0038] In a further preferred embodiment, in the vascular implant of the present invention, the stent rings are one-piece stent springs arranged successively on the longitudinal axis of the body and respectively circumferentially meandering perpendicularly relative to the longitudinal axis. The stent springs are connected to the graft material, so that the stent springs are only connected to each other through the graft material, but not to each other.

[0039] Further, the circumferentially meandering support spring has a pointed arch that alternately faces the proximal end and the distal end of the body and is parallel to the longitudinal axis of the body. In the self-stretched state, at least one side body branching from the body is arranged at a certain angle relative to the longitudinal axis of the body, and the angle is stabilized by at least one pointed arch of the support spring of the body that protrudes at an angle relative to the longitudinal axis of the body in a preformed manner in the self-stretched state.

[0040] In a further preferred embodiment of the invention, the pleat of graft material extends from the distal end of the lateral body opening in the body to a position close to the legs of the ogives of the stent springs protruding at an angle relative to the longitudinal axis of the body. The pleat does not span any of the stent springs.

[0041] The stent ring or stent spring can be attached to the graft material of the vascular implant of the present invention by gluing, welding or sewing. When sewing, the same suture material as described above can be used as the suture material for sewing the stent ring to the graft material.

[0042] At present, a “support spring” is understood to be any one-piece annular element which is compressible due to its material and which can expand again in the manner of a spring after the compression pressure is removed.

[0043] "Meandering" is understood in this case to mean any serpentine or annular shape of a stent spring or stent wire, each stent spring being formed as one part, ie from a stent spring ring in a circumferentially meandering manner.

[0044] In this context, a "circumferentially serpentine one-piece stent spring" is currently an annular stent element that expands and compresses in a spring-like manner and is circumferential and serpentine with alternating phase-forming peaks and troughs.

[0045] A "pointed arch" is formed by two legs and an apex or lowest point between them.

[0046] At least one cusp means that the side body is extended by a projection or extension of a single cusp of the support spring, or else by two or more cusps. In a preferred embodiment, two cusps of the support spring extend. In principle, the circumferentially meandering cusps form the support spring of the body, and the protruding cusp or cusps form the branching point for the side body.

[0047] By definition, stent springs are not directly connected to each other and do not have any connecting legs or struts or similar connecting elements between them. Stent springs are only connected to each other through the implant material or graft material to which the stent springs are attached, thereby forming an "indirect connection" between the stent springs.

[0048] Currently, the expression "stent-graft" is intended to encompass a prosthesis having one or more stents (or stent springs) and also an implant ("graft") material connected thereto that forms a lumen through at least a portion of the prosthesis.

[0049] According to further embodiments of the vascular implant according to the invention, the angle at which at least one side body protrudes / projects from the main body in this case is specially made to match the vessel to be treated or the vessel portion to be treated. This can be precisely defined in advance by the doctor performing the treatment. It goes without saying that, according to further embodiments of the vascular implant according to the invention, the precise angles may differ from vascular implant to vascular implant. In general, since the support spring has at least one pointed arch protruding at a certain angle, the position of the side branch in the body is more flexible than when it is implemented without an angle. There is less risk of kinking of the side branch.

[0050] In a further embodiment of the vascular implant according to the invention, at least one side body has a portion with at least one side body support spring, which is arranged perpendicularly with respect to its side body longitudinal axis and circumferentially meanders, the side body support spring being fixed to the side body graft, wherein the at least one side body support spring and the support spring of the angularly protruding body are connected only by the graft material and are not connected to each other.

[0051] An advantage of this embodiment is that at least one lateral body of the vascular implant according to the invention also has a stented portion, which ensures a secure anchoring for a second stent-graft leading to a branch vessel to bridge the aneurysm sac.

[0052] In the present case, a "stented portion" is understood to cover any portion of a vascular implant which has at least one stent or stent-spring element connected to a prosthetic material.

[0053] In contrast, in the present context, a "non-stented" part is understood to mean any part of the vascular implant which is formed exclusively from prosthetic material.

[0054] According to the development of the vascular implant according to the invention, the support spring is connected to the implant material to which they are indirectly connected, preferably sewn to the implant material. The same applies to the support spring of the side body. In this case, the support spring can be sewn in the inner lumen of the vascular implant (i.e. inside the implant material) or additionally sewn to the implant material externally.

[0055] According to a preferred embodiment of the vascular implant according to the invention, it has one to four, ie one, two, three or four, side branches, which are arranged / protrude from the main body at an angle.

[0056] Therefore, the vascular implant according to the invention can also advantageously be introduced into a vessel portion at which many side vessels branch off. Depending on the respective patient or vessel condition, a person skilled in the art will be able to determine how many side branches are required for the vascular implant to be used.

[0057] It goes without saying that, depending on the location of the branch side blood vessels, a plurality of protruding cusps may be provided on different stent springs.

[0058] The invention also relates to a method for producing a vascular implant according to the invention, the method comprising the following steps:

[0059] (i) providing a planar sheet of graft material, and

[0060] (ii) bonding the edges of the planar sheets to each other by welding, gluing, stitching or sewing to form a hollow cylindrical body and at least one hollow cylindrical side body.

[0061] In a further preferred embodiment, in which the vascular implant is a stent graft, the method for manufacturing the vascular implant according to the invention further comprises the following steps:

[0062] (iii) providing one or more support springs,

[0063] (iv) positioning the stent spring relative to the longitudinal axis of the vascular implant, and

[0064] (v) fixing, preferably suturing, at least one stent ring to the hollow cylindrical body.

[0065] In a more preferred embodiment, the method for manufacturing a vascular implant according to the present invention comprises the following steps:

[0066] (vi) providing a support spring having ogives alternately directed toward the top and bottom of the support spring and parallel to its longitudinal axis and at least one ogive, preferably two adjacent ogives, projecting at an angle relative to the longitudinal axis of the support spring,

[0067] (vii) arranging the stent spring to provide a cusp projecting at an angle relative to a longitudinal axis of the vascular implant and aligning the angled cusp with a side branch also projecting at an angle,

[0068] (viii) fixing, preferably suturing, at least one stent ring to the hollow cylindrical body.

[0069] Further advantages and features can be derived from the following description and the drawings.

[0070] It goes without saying that the features mentioned above and those yet to be explained below can be used not only in the respectively specified combination but also in other combinations or alone, without departing from the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] Exemplary embodiments of the invention are illustrated in the drawings and are described in more detail below with reference to the drawings.

[0072] Figure 1 An exemplary embodiment of a vascular implant of the present invention having a lateral body is shown in a schematic lateral plan view;

[0073] Figure 2 Another exemplary embodiment of a vascular implant according to the invention with a side body and a stent ring is shown in a schematic lateral plan view;

[0074] Figure 3A , Figure 3B and Figure 3C Schematic diagrams showing different embodiments of a single planar sheet of graft material for use in a vascular implant of the present invention.

[0075] Figure 4 A further exemplary embodiment of a vascular implant according to the invention with a bifurcated side body is shown in a schematic lateral plan view.

[0076] Figure 5 Shown for Figure 4 Schematic diagram of an exemplary single planar piece of graft material of an exemplary vascular implant depicted in FIG. DETAILED DESCRIPTION

[0077] Figure 1 An exemplary embodiment of a vascular implant with a side body of the present invention is depicted in a schematic lateral plan view. The vascular implant 1 comprises a hollow cylindrical body 10 having a proximal end 11 and a distal end 12, a body lumen 13 and a longitudinal axis 14, and at least one hollow cylindrical side body 20 branching from the body 10 and comprising a side body lumen 23, the side body lumen 23 being in fluid communication with the body lumen 13.

[0078] exist Figure 1 In the branch graft of the invention, the longitudinal axis 24 of at least one lateral body 20 is arranged at an angle α of about 45° relative to the longitudinal axis 14 of the body. However, it must be noted that this is for illustration only, and the angle may be in the range of between 0° and 90°, preferably between 20° and 90°, preferably between 35° and 55°, preferably between 40° and 50°, and more preferably between 44° and 46°, and is preferably 45°.

[0079] The hollow cylindrical body 10 and the at least one hollow cylindrical side body 20 are formed in a single piece from a single planar sheet 30 of graft material. Figure 1 The vascular implant shown is composed of Figure 3B or Figure 3C A single planar sheet 30 of graft material is shown. Figure 3B and Figure 3C The planar sheet 30 shown in FIG. 1 comprises a main portion 31' having a width corresponding to the circumference of the main body 10 and two mirror-image arm portions 32, 32' extending from the main portion on both sides and having a width corresponding to half the circumference of the side body 20. Further, as Figure 3B and Figure 3C As can be seen, the part forming the main tube is partially divided to form a common main part 31 ' on the proximal side and two main part legs 311, 311' on the distal side. Figure 1 In the implant 1 of FIG. 1 , the edges of the planar sheet 30 are bonded or sealed to each other by sewing edges A and A' together, sewing edges B and B' together, and sewing edges C and C' together. Thus, Figure 1The vascular implant of FIG. 1 shows three longitudinal seams 101 (A-A'), 102 (B-B'), 103 (C-C'). Seam 101 extends longitudinally from the proximal end of the main body 10 to the distal end of the side tube 20. Seam 102 extends longitudinally from the opposite side of the distal end of the side body to the distal end of the main body 10. Seam 103 extends longitudinally from the opposite side of the distal end of the main body 10 to a point away from the proximal end of the main tube 10 and the proximal side of the side tube 20.

[0080] It is obvious to those skilled in the art that Figure 1 The graft depicted in can also be formed from a planar sheet of graft material, such as Figure 3A shown.

[0081] Figure 3A is a schematic diagram of a planar sheet 30 comprising a main portion 31 having a width corresponding to the circumference of the body 10 and two mirror image arm portions 32 , 32 ′ extending from the main portion on both sides and having a width corresponding to half the circumference of the side body 20 .

[0082] When connecting edges A and A' and B and B', the Figure 1 The vascular implant, except that in this case the seam 103 is missing, is because Figure 3A The graft material was not divided laterally.

[0083] exist FIG. 3A to FIG. 3C In the planar sheet, the angle β at which the longitudinal axis of the side portion or arm portion is arranged relative to the longitudinal axis of the main portion is also about 45°.

[0084] It should be understood that this angle may be in the range between 0° and 90°, preferably between 20° and 90°, preferably between 3° and 55°, preferably between 40° and 50°, and more preferably between 44° and 46°, and is preferably 45°.

[0085] Generally speaking, the angle β in the planar sheet also determines a certain range for the angle α in the vascular implant formed from the planar sheath.

[0086] Likewise Figure 1 As shown, the vascular implant further includes a pleat 34 extending from the distal end of the side body opening in the body 51 along a portion of the “virtual” proximal end of the side body 52 .

[0087] Generally speaking, the depth and length of this dart also allows adjustment of the angle α in the vascular implant.

[0088] The pleats 34 can be formed by folding a portion of the graft material in the distal portion of the branch region in the main tube, wherein the pleats are directed in the proximal direction to each side of the side tube. Preferably, the folds are fixed by sewing. When using a method according to, for example, Figure 3A or Figure 3B This embodiment is applicable when the flat sheet is used.

[0089] Alternatively, pleats 34 may be formed by cuts 35 and 35' into the graft material sheet 30 at the distal ends of the interlayer of the side arms in the main portion substantially parallel to the longitudinal axis of the body, as shown. Figure 3C When forming the tubular member from the sheet of graft material, these cutouts 35, 35' are then joined together. Preferably, the cutouts are joined by sewing.

[0090] It must be noted that the hollow cylindrical body 10 of the vascular implant with body lumen 13 has a diameter that may or may not vary with length. Also, the hollow cylindrical body 20 of the vascular implant with body lumen 23 has a diameter that may or may not vary with length.

[0091] Figure 2 A schematic lateral plan view of an exemplary embodiment of a vascular implant 1 according to the invention is shown, wherein, by way of example, five stent rings 60 are arranged one after the other on the longitudinal axis of the vascular implant 1 .

[0092] like Figure 2 As illustrated, the support rings 60 are one-piece support springs 61 which are arranged successively on the longitudinal axis 14 of the body 10 and respectively meander circumferentially perpendicularly relative to the longitudinal axis 14 .

[0093] like Figure 2 As shown in FIG. 6 , the pointed arch 601 with reference to the support spring 61 ′ is formed by two legs 620 , 621 and an apex 601 ′.

[0094] The stent springs are connected to each other indirectly through the graft material, rather than directly through struts or the like. Figure 2 The vascular implant shown in the figure has a "stented" part, or consists of such a part in which the entire graft material 40 is supported by stent springs attached to the implant material at a specific distance from each other. It goes without saying that the vascular implant can also have further parts, which either consist of stent wire mesh or implant material supported by laser-cut stents, or consist of implant material without stents, or consist of stent wire mesh without implant material.

[0095] Back to Figure 2 , Figure 2It is also disclosed that the stent spring has two arranged cusps 602 (of which the second cusp is not shown) which, due to the way they are formed, project laterally at an angle relative to the longitudinal axis of the vascular implant. The other cusps 601 of all stent springs 61 run parallel to the longitudinal axis of the vascular implant. This projection or arrangement of the cusps 602 of the stent spring 630 has the effect of defining a side body or side branch 23a; this side branch 23a provides an anchoring area in the side vessel for the stent graft / stent graft portion (e.g., a covered stent graft / stent graft portion) which is inserted into the side vessel branching from the main vessel.

[0096] exist Figure 2 In the example shown in , the side body 20 also has its own side body support spring 640, which therefore does not form the support spring of the main body 10 of the vascular implant 1. The side body support spring 640 is indirectly connected to the protruding ogive 602 of the support spring 630 of the main body 10 via the graft material.

[0097] exist Figure 2 In the example shown in , the support springs 61 , 630 and the side body support spring 640 are sewn to the graft material 40 composed of the sheet material 30 .

[0098] The stent ring or spring can be made of any material suitable for allowing the stent ring or spring to provide expansion force and / or support function. Preferred materials are metal alloys, such as stainless steel, nickel titanium alloy, tantalum, cobalt chromium alloy and magnesium alloy. The preferred material for the stent ring or spring is Nitinol (nickel titanium alloy), which gives the stent ring or spring self-expansion properties.

[0099] Return to reference Figure 2 The pleat 34 or seam located at the distal side of the side body 20 branching from the main body 10 of the vascular implant 1 extends from the distal end of the side body opening in the main body 51 to a position adjacent to the leg 603 of the pointed arch 602 protruding at an angle relative to the longitudinal axis of the main body of the support spring 630, but does not contact the support spring. This is to provide good support for the vascular implant in the area of ​​the branch and excellent shape and smoothness of the internal lumen, thereby avoiding multiple material overlaps or even folds.

[0100] exist Figure 4 In FIG. 1 , a vascular implant 1 according to the invention is shown, which comprises a side body with branches. This vascular implant is generally based on Figure 1 The vascular implant 1 depicted in FIG. 1 is constructed with Figure 1 1 , but with an additional branch or auxiliary side body having one or more auxiliary side bodies 70 branching from the side body 20.

[0101] exist Figure 4 In the branched graft, the longitudinal axis of the auxiliary side body 70 or the auxiliary side body 74, respectively, is arranged at an angle γ of about 45° relative to the longitudinal axis 24 of the side body. However, it must be noted that this is for illustration only, and the angle may be between 0° and 90°, preferably between 20° and 90°, preferably between 35° and 55°, preferably between 40° and 50°, and more preferably between 44° and 46°, and preferably 45°.

[0102] The hollow cylindrical body 10, the hollow cylindrical side body 20 and the hollow cylindrical auxiliary side body 70 are formed in a single piece from a single planar sheet 30 of graft material. Figure 4 The vascular implant shown is composed of Figure 5 Schematically shown in FIG. 1 is a single planar sheet 30 of graft material. Figure 5 The planar sheet 30 shown in FIG. 1 includes a main portion 31' having a width corresponding to the circumference of the main body 10 and two mirror-image arm portions 33, 33' extending from the auxiliary portions 32, 32' at a predetermined angle and having a width corresponding to half of the circumference of the auxiliary side main body 70. Further, the main body portion 31 is partially divided to form a common main portion 31' on the proximal side and two main portion leg portions 311, 311' on the distal side.

[0103] exist Figure 4 In the implant 1, the edges of the planar sheet 30 are bonded or sealed to each other by sewing edges A and A' together, sewing B and B' together, sewing C and C' together, and sewing D and D' together. Figure 4 The vascular implant of the present invention thus shows four longitudinal seams 101 (A-A'), 102 (B-B'), 103 (C-C') and 104 (D-D'). Seam 101 extends longitudinally from the proximal end of the main body 10 to the distal end of the side tube 20. Seam 102 extends longitudinally from the opposite side of the distal end of the auxiliary side body to the distal end of the main body 10. Seam 103 extends longitudinally from the opposite side of the distal end of the main body 10 to a point away from the proximal end of the main tube 10 and the proximal side of the side tube 20. Seam 104 extends longitudinally from the distal end of the side body to the distal end of the auxiliary side body.

[0104] Further, if Figure 4 As depicted, the vascular implant has pleats 34, 34' at each interlayer of the graft, with a first pleat 34 extending from the distal end of a side body opening in the body 51 along a portion of the "virtual" proximal end of the side body 52, and a second pleat 34' extending from the distal end of a second side body opening in the side body 51 along a portion of the "virtual" proximal end of the second side body.

[0105] The vascular implant according to any one of the defined embodiments of the present invention is easy to produce, because the graft is made of a single piece of graft material and the joints or sutures are straight. This allows for more efficient material preparation and more efficient and safe joints. Moreover, the resulting graft is safer to produce, simply because the branches cannot be pulled out of the main body. Another advantage is its smoothness in the area where the branches connect, because there are no joints or material accumulations in the graft perpendicular to the blood flow.

Claims

1. A vascular implant (1) for implantation into a patient's blood vessel, the vascular implant comprising: A hollow cylindrical body having a proximal end (11) and a distal end (12), a body lumen (13) and a longitudinal axis, and at least one hollow cylindrical side body branching from the body and comprising a side body lumen (23), the side body lumen (23) being in fluid communication with the body lumen (13), characterised in that the hollow cylindrical body and the at least one hollow cylindrical side body are formed in a single piece from a single planar sheet (30) of graft material, wherein the single planar sheet (30) comprises a main portion (31) having a width corresponding to the circumference of the main body and at least two mirror image arm portions (32, 32') extending from the main portion on both sides and having a width corresponding to half the circumference of the side body, wherein at least two mirror-image arm portions (32, 32') further include auxiliary side arm portions (33, 33') extending from the arm portions (32, 32'), The vascular implant further includes a dart (34) extending from a distal end of the side body opening in the body along a portion of a proximal end of the side body.

2. The vascular implant (1) according to claim 1, wherein the main part is partially divided to form a common main part (31') and two main part legs.

3. The vascular implant (1) according to any one of claims 1 to 2, wherein the edges (A, A', B, B', C, C') of the planar sheet are bonded to each other by welding, gluing, stitching or sewing to form the hollow cylindrical body and the at least one hollow cylindrical side body.

4. The vascular implant (1) according to any one of claims 1 to 2, wherein the planar sheet of graft material is woven, braided, knitted, electrospun or sputtered.

5. The vascular implant (1) according to any one of claims 1 to 2, wherein the planar sheet of graft material is made of one or more polymers selected from polyurethane, polyether, polyester, polyamide, polyethylene terephthalate, polytetrafluoroethylene or expanded polytetrafluoroethylene, or copolymers thereof.

6. The vascular implant (1) according to any one of claims 1 to 2, wherein the vascular implant has one or more auxiliary side bodies (70) branching from the side bodies.

7. A vascular implant (1) according to any one of claims 1 to 2, wherein the vascular implant has at least one further additional side body, which branches off from the main body or from any of the side bodies, wherein the additional side body is made of a second piece of graft material, and wherein the proximal end of the additional side body is attached to the circumference of the orifice in the graft material of the main body or of any of the side bodies.

8. The vascular implant (1) according to any one of claims 1 to 2, wherein the longitudinal axis of at least one side body branching from the main body is arranged at an angle α relative to the longitudinal axis of the main body.

9. The vascular implant (1) according to any one of claims 1 to 2, further comprising one or more support rings (60), which are arranged successively on the longitudinal axis of at least a part of the main body and optionally on the longitudinal axis of at least a part of any one of the side bodies, and the support rings (60) are capable of changing from a compressed state to a self-expanded state.

10. The vascular implant (1) according to claim 9, wherein the stent rings (60) are single-piece stent springs (61) arranged successively above the longitudinal axis of the main body and respectively winding circumferentially perpendicularly relative to the longitudinal axis, the stent springs (61) being connected to the graft material (40) of any one of the main body and / or the side body, the stent springs being connected to each other only through the graft material, and not to each other, and wherein the circumferentially meandering stent spring has ogives that face alternately toward the proximal and distal ends of the body and parallel to the longitudinal axis of the body, It is characterized in that In the self-extending state, the longitudinal axis of at least one side body branching from the main body is set at an angle α relative to the longitudinal axis of the main body, and the angle is stabilized by at least one pointed arch of the support spring of the main body that protrudes at an angle in a preformed manner relative to the longitudinal axis of the main body in the self-extending state.

11. The vascular implant (1) according to claim 10, wherein the vascular implant further comprises a dart (34) extending from the distal end of the side body opening in the body along a portion of the proximal end of the side body, the dart (34) extending from the distal end of the side body opening in the body to a position close to the leg of the pointed arch of the support spring protruding at an angle relative to the longitudinal axis of the body.

12. A method for producing a vascular implant (1) according to any one of claims 1 to 11, the method comprising the following steps: (i) providing a planar sheet (30) of graft material, and (ii) bonding the edges (A, A', B, B', C, C') of the planar sheets to each other by welding, gluing, stitching or sewing to form the hollow cylindrical body and the at least one hollow cylindrical side body.

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