Intraluminal vessel prosthesis for implantation into the heart or cardiac vessels of a patient

0001The present invention relates to an intraluminal vascular prosthesis for implantation into the heart and/or cardiac vessels of a patient, in particular for anchoring in the area of ​​the heart valve leaflets; the vascular prosthesis has a distal and a proximal end, as well as a stent framework and a prosthesis material with which the stent framework is at least partially covered, so that a covered proximal section and a non-covered distal section are formed.

0002In general, intraluminal vascular prostheses are used in the prior art in particular for the treatment of aneurysms or for replacing or supporting natural vessels or even heart valves.

0003An aneurysm is an arterial dilatation or arterial bulging in which the cross-section of blood vessels locally expands in a spindle or sac shape as a result of congenital or acquired wall changes. Vascular prostheses used to treat aneurysms. A distinction is made between a true aneurysm, a false aneurysm and a dissecting aneurysm (<i>Aneurysm dissecans</i>), which occurs as a result of vessel wall dissection. The latter refers to a splitting of the wall layers of the aorta, which is usually caused by a tear in the inner vessel wall, with subsequent bleeding between the layers. The risk factors that can lead to an aortic dissection include structural weakness of the vessel wall and arteriosclerosis.

0004An aortic dissection is usually immediately life-threatening because it can lead to an aortic rupture and acute circulatory disorders in various organs. Immediate diagnosis is therefore crucial for this disease.

0005Statistically speaking, aortic dissections occur most frequently (around 65%) just a few centimeters above the aortic valve, in the ascending section of the aorta (<i>Ascending aorta</i>) on. The second most common (around 20%) is that aortic dissections occur immediately after the departure of the left subclavian artery (<i>Sinister subclavian artery</i>) in the descending section of the aorta (<i>Descending aorta</i>). Furthermore, the aortic arch with 10% or the abdominal aorta (<i>Abdominal aorta</i>) affected by 5%.

0006Depending on the local occurrence of a dissection, it is classified as “A” or “B”, with a strict distinction being made between aortic dissections with and without involvement of the aorta<i>Ascending aorta</i> has enforced. This usually involves dissections in which entry occurs in the area of<i>Ascending aorta</i> is referred to as type A dissections, and dissections in which the entry is distal to the left<i>Subclavian artery</i> lies as type B dissections. As already mentioned, aortic dissection is one of the most urgent emergencies in cardiology and cardiac surgery. The high mortality rate of one to two percent per hour in the acute phase of type A dissection requires immediate clarification of the suspected diagnosis.

0007Against this background, in the case of an acute type A dissection, it is extremely important to quickly eliminate the risk of an aortic rupture, although currently artificial vascular prostheses are usually used for immediate surgical replacement<i>Ascending aorta</i> be used. However, reconstructions of the aortic valve are less common in emergency operations. As a rule, the aortic valve is therefore removed in the event of a dissection of the aortic sections near the valve and in patients with a congenital connective tissue disease and a prosthesis with an integrated valve prosthesis is inserted, to which the coronary arteries are also "connected" again. A basic distinction is made between two types of heart valve prostheses: mechanical valves, which are manufactured artificially and consist largely of metal, and biological valves, which are available as transplants from humans or animals.

0008The artificial prostheses can be used either open surgically or minimally invasively.

0009Correct insertion of the prosthesis into the area to be treated regularly represents a challenge for the treating physician, as even a slight slip of the prosthesis can involve the "decommissioned" bulge back into the bloodstream, thereby re-introducing the risk of rupture. There is a risk of the prosthesis slipping or migrating even after it has been placed, particularly given the natural movement of the heart. For these reasons, the prosthesis is usually fixed to the vessel wall proximally and distally using sutures. However, this suture fixation has the disadvantage that the vessel walls, which are often already impaired, are further stressed. In patients with severely damaged vascular walls, fixation with sutures is also not possible.

0010The<patcit id="pcit0001" dnum="WO0149213A"><text>WO 01/49213</text></patcit> discloses an intraluminal vascular prosthesis for implantation into a patient's heart. The stent framework of the intraluminal vascular prosthesis has a proximal and distal anchoring section, with the vascular prosthesis being covered as a whole.

0011Also the<patcit id="pcit0002" dnum="WO2009094188A2"><text>WO 2009/094188 A2</text></patcit> discloses a fully covered vascular prosthesis with anchoring structures at the proximal end.

0012Against this background, the object of the present invention is to provide a device with which the disadvantages described can be overcome and heart valve prostheses can be securely fixed in the heart, especially in type A dissections.

0013According to the invention, this is solved by a vascular prosthesis of the type mentioned at the beginning, the vascular prosthesis having at least one to three elongated wire-shaped anchoring structure(s) at the proximal end, which is/are essentially loop-shaped, and which is/are each fixed to the stent framework with two ends and which is/are positioned with its proximal end pointing in the proximal direction in the form of a loop and protruding beyond the proximal end of the stent framework.

0014The object on which the invention is based is completely achieved in this way.

0015The specific anchoring structure of the vascular prosthesis provided at the proximal end ensures that it is securely anchored in the heart without disrupting the natural function of the heart valves. This is achieved by the specific design of the anchoring structure, which extends in a loop-like or arch-like manner in the proximal direction at the proximal end. The vascular prosthesis can be positioned specifically and safely via this anchoring structure.

0016The vascular prosthesis according to the invention then serves as an anchor for a heart valve prosthesis to be inserted separately, which is released at least partially or overlappingly in the vascular prosthesis according to the invention anchored in the vessel, and which serves to support or replace the natural vascular prosthesis.

0017Any heart valve prosthesis can be used over the vascular prosthesis according to the invention, which heart valve prosthesis preferably has a self-expanding framework with valves attached therein. An example is given to the<patcit id="pcit0003" dnum="EP2724690A"><text>EP 2 724 690</text></patcit> referenced, in which examples of heart valves are disclosed. Based on this, it will be clear to the person skilled in the art which heart valves are suitable for use with the vascular prosthesis according to the invention.

0018The anchoring structure ensures that additional suturing of the vascular prosthesis or the heart valve prosthesis to the vessels and thus strain on them can be avoided. The vascular prosthesis according to the invention thus represents a type of anchor structure or receiving structure via which the heart valve prosthesis to be inserted in a second step can be securely anchored in the heart. This also avoids having to provide complicated fixation elements on the heart valve prosthesis itself in order to securely fix it in the heart.

0019The anchoring structure is preferably positioned behind a leaflet of the aortic valve, preferably the noncoronary leaflet or "non coronary cusp "NCC", while the vascular prosthesis itself with the rest of its body is still fixed in the catheter via a retraction sheath or other compression. This can the anchoring structure can be precisely aligned and prevent subsequent proximal migration of the prosthesis.

0020The vascular prosthesis according to the invention is preferably used to treat type A aortic dissections and is introduced in a minimally invasive manner via a catheter-guided application.

0021Basically, in the case of vascular prostheses or endoluminal stent grafts, the terms “distal” and “proximal” are used in general and in this case to designate the respective ends of the vascular prosthesis, whereby the term “distal” refers to the part or end that is in relation to further downstream in the bloodstream. The term "proximal", on the other hand, refers, again in relation to the blood stream, to a part or end that is further upstream in relation to the blood stream. In other words, the term "distal" means in the direction of the blood flow, and the term "proximal" means opposite to the direction of the blood flow. However, in the case of catheters or insertion systems with which the vascular prostheses are introduced into the vessels, the term "distal" refers to the end of the catheter or insertion system that is inserted into the patient. the end that is furthest away from the user, and the term "proximal" means the end that is closer to the user.

0022According to the invention, the division of the base body of the vascular prosthesis into a proximal section and a distal section means that the respective sections differ from one another in their construction, and, for example, have a different number of stent rings or a different length of the stent framework, or whose stent rings/stent framework have different diameters and/or are covered (“covered”) or uncovered (“uncovered/not covered”) by prosthesis material. The prosthesis material can, for example, be sewn or shrunk or otherwise attached to the stent framework, either on the side of the stent framework facing the vessel wall, or on the inside, side facing the blood flow.

0023The "covered" proximal section covered by prosthesis material is intended to bridge the dissection, the uncovered distal section is placed distal to the dissection and serves primarily - like the covered section - to fix the vascular prosthesis in the vessel.

0024A "wire-shaped, substantially loop-shaped" anchoring structure herein means that the structure is formed by bending a wire or wire-like structure into an arch, having two "free" ends and an arch end opposite the two free ends. “Free ends” means that these are not connected to one another directly or in one piece, like the arch section.

0025“Essentially” also means that the anchoring structure does not have to be bent exactly in a loop-shaped round, but should only be guided in the manner of a loop and is still viewed as such by a person skilled in the art.

0026According to the invention, the anchoring structure projects beyond the proximal end of the vascular prosthesis in the proximal direction, with the anchoring structure extending between approximately 1 cm and 3 cm, preferably approximately 1, 1.5, 2, 2.5 or 3 cm above the proximal End of the vascular prosthesis extends.

0027The prosthetic material may include or be formed from a material selected from polyester, polyurethane, polystyrene, polytetrafluoroethylene, ultra-high molecular weight polyethylene (UHMPE), or mixtures thereof.

0028In the present case, a “stent framework” is understood to mean any wire prosthesis in the form of a tube or cylinder made of metal or synthetic fiber, which is preferably self-expanding and forms a lattice or net-like framework to which prosthetic material can be attached if necessary. This can mean, for example, a wire mesh, or so-called stent springs/stent rings arranged one behind the other in a meandering shape, which may be are connected to each other via connecting supports made of wire, or which are only connected to each other via the implant material. The stent framework is usually made of a shape memory material, usually made of Nitinol, which means that the framework can be used after it has been inserted into a vessel²Release can return to the expanded state and the vascular implant can thereby be “clamped”.

0029Accordingly, according to one embodiment of the present invention, the stent framework is a laser-cut stent framework or a braided or woven stent framework, or consists, if necessary only partially, (e.g. in the proximal section or in the distal section) of individual, only via the prosthesis material and not between the stent rings connected to each other (by bars or similar).

0030It will be clear and obvious to the person skilled in the art, taking into account the dissection to be treated and the condition of the vessel, which stent framework is used in order to achieve the best possible implementation of the invention. Accordingly, the proximal section can have a different stent framework structure than the distal section of the vascular prosthesis, or both have the same stent framework.

0031Accordingly, in a preferred embodiment, the stent framework has diamond-shaped cells or consists of circumferential rows of diamond-shaped cells arranged one behind the other, which adjoin one another or are connected to one another via their corners. At the extreme ends of the vascular prosthesis there are free “corners” of the diamond-shaped cells proximally and distally.

0032According to one embodiment of the vascular prosthesis according to the invention, fixing structures are provided at the distal end of the vascular prosthesis, via which the distal end of the vascular prosthesis can be fixed and kept compressed on a release catheter. Preferably, the fixation structures are T-shaped extensions of at least three free corners of the diamond-shaped cells at the distal end. These T-shaped structures can engage corresponding T-shaped receptacles in the delivery catheter. A retraction sleeve, which is then passed over the distal end of the vascular prosthesis, holds the T-shaped fixation structures in the T-shaped receptacles and thus fixes the distal end of the vascular prosthesis to the release catheter. When the retraction sleeve compressing the vascular prosthesis is pulled back beyond the T-shaped receptacle, the T-shaped fixation structures can detach from the receptacles, thereby releasing the distal end of the vascular prosthesis.

0033In one embodiment of the vascular prosthesis according to the invention, it is preferred if the distal ends of the wire-shaped anchoring structure are positioned at immediately adjacent corners of two diamond-shaped cells of the proximal end of the vascular prosthesis.

0034With this embodiment it is achieved that the anchoring structure is stably "stretched" and an enlargement of the loop, which would possibly result in migration of the vascular prosthesis, is avoided. Due to the comparatively tight fixation of the distal ends of the loop, the anchoring structure is given rigidity via the proximal loop, which in turn ensures stable anchoring of the vascular prosthesis.

0035According to the invention it is provided that the wire-shaped anchoring structure comprises a trapezoidal extension at/in its proximal end or end region.

0036The trapezoidal extension gives the anchoring structure additional stability in this area, which further ensures secure anchoring in the vessel wall.

0037According to a further development, it is preferred if the outermost proximal end of the wire-shaped anchoring structure is teardrop-shaped.

0038This embodiment leads to even improved stability of the anchoring structure. “Teardrop-shaped” means a small attached loop pointing in the proximal direction in addition to the basic loop shape.

0039In the intraluminal vascular prosthesis according to the invention, according to one embodiment, it is preferred if the stent framework and the anchoring structure are formed in one piece.

0040“In one piece” means that the stent framework and the anchoring structure were made from the same wire or the same laser-cut tube.

0041In the vascular prosthesis according to the invention, one, two or three anchoring structures are provided at the proximal end of the stent framework.

0042By providing more than one anchoring structure, the vascular prosthesis can be fixed even more securely in the heart. The additional anchoring structures preferably have the same structure and shape, or different shapes; What they all have in common in these cases is the loop-shaped basic structure.

0043According to a further development of the intraluminal vascular prosthesis according to the invention, it is preferred if the stent framework and/or the wire-shaped anchoring structure have hooks or thorns on their side facing away from and/or facing the vessel wall.

0044With these embodiments, the fixation of the vascular prosthesis in the vessel is further strengthened and secured. The hooks and/or thorns can be made of the same material as the anchoring structure or the stent framework, or of different materials.

0045In the embodiment of the hooks/thorns provided on the inside of the vascular prosthesis, it is advantageous that these hooks or thorns further support the anchoring of a heart valve prosthesis to be at least partially inserted therein. Although the partial release and "clamping" of the heart valve prosthesis in the proximal end of the vascular prosthesis according to the invention ensures anchoring of the heart valve in the vascular prosthesis, the thorns and hooks can additionally support the anchoring of the heart valve in the vascular prosthesis.

0046According to a further embodiment of the intraluminal vascular prosthesis according to the invention, it is preferred if the stent framework and/or the wire-shaped anchoring structure comprises X-ray markers.

0047The provision of X-ray markers on the anchoring structure makes it easier for the treating physician to correctly place the anchoring structure and thus also the vascular prosthesis as a whole, since he can thereby precisely place the vascular prosthesis in the heart under X-ray control.

0048The intraluminal vascular prosthesis according to the invention preferably has a total diameter of between approximately 20 mm to approximately 48 mm, preferably between 24 mm to approximately 44 mm.

0049According to one embodiment, the diameter of the vascular prosthesis is essentially constant over its entire length.

0050In a further development of the intraluminal vascular prosthesis according to the invention, it is provided that it further comprises a heart valve prosthesis, the heart valve prosthesis being designed in such a way that its distal end can be released at the proximal end of the intraluminal vascular prosthesis and can be fixed in the area of ​​the heart valves via this.

0051In this embodiment, there are two prostheses, which together represent a system according to the invention for the treatment of an aortic dissection, in particular type A: With the vascular prosthesis according to the invention, as mentioned above, an anchoring structure is provided, which is fixed in the heart in a first step and through which a heart valve prosthesis, which is inserted in a second step, can be securely anchored in the heart. The risk of the heart valve prosthesis slipping or migrating is thereby avoided, and at the same time a relatively simple structure of the system is achieved.

0052Further advantages result from the figures and the following description of preferred exemplary embodiments.

0053It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or alone, without departing from the scope of the present invention.

0054Exemplary embodiments of the invention are shown in the drawing and are explained in more detail in the following description. Show it:<dl id="dl0001"><dt>Fig. 1</dt><dd>a schematic representation of an embodiment of a vascular prosthesis according to the invention, in the non-inserted, expanded state in a view of the long side;</dd><dt>Fig. 2</dt><dd>a schematic representation of the gradual release of the vascular prosthesis<figref idref="f0001">Fig. 1</figref> with a delivery catheter shown schematically; when fully charged (<b>A</b>); with the compression structure partially retracted, but with the proximal and distal ends of the vascular prosthesis still fixed to the delivery catheter (<b>b</b>); and with the proximal end released (<b>C</b>);</dd><dt>Fig. 3</dt><dd>the schematic representation of an embodiment of the vascular prosthesis according to the invention that is completely released in the cardiac vessel;</dd><dt>Fig. 4</dt><dd>the schematic representation of a system according to the invention, with a heart valve prosthesis anchored in a vascular prosthesis according to the invention, the representation being shown outside the cardiac vessel.</dd></dl>

0055In the figures, the same features are given the same reference numerals, although for reasons of clarity not all reference numerals are always indicated in all figures.

0056In the<figref idref="f0001 f0002 f0003 f0004">Figures 1 to 4</figref> 10 denotes a vascular prosthesis according to the invention overall, with a distal end 11 and a proximal end 12. The vascular prosthesis has a tubular stent framework 14, to which a prosthesis material 16 is attached in a proximal section 15, whereby the proximal section 15 is covered. The vascular prosthesis 10 further comprises a distal section 17 which is free of prosthesis material.

0057According to the invention, the stent framework 14 can be a laser-cut stent framework, or a stent framework braided or woven from several wires, or can consist of individual, meandering circumferential stent rings arranged one behind the other, which can only be connected via the prosthesis. material are connected to each other.

0058In the example shown in the figures, the vascular prosthesis 10 has diamond-shaped cells 18 which form the tubular or cylindrical stent framework 14 in rows. At the distal end 11, fixing structures 19 are provided at three free corners of the diamond-shaped cells 18 at the distal end 11, via which the distal end 11 of the vascular prosthesis 10 in a release catheter (not shown) in corresponding recordings or Recesses can be accommodated and fixed to the release catheter via a retraction sleeve (not shown) guided over this. The fixing structures 19 are in the in<figref idref="f0001">Fig. 1</figref> T-shaped embodiment shown.

0059At the proximal end 12 of the vascular prosthesis 10, a wire-shaped anchoring structure 20 is provided, which forms a loop 21 in the proximal direction 12 '. The anchoring structure 20 extends approximately 1/3 of the total length of the vascular prosthesis 10 beyond its proximal end 12.

0060The anchoring structure 20 has a proximal end 22, in the area of ​​which the loop 21 is formed. The anchoring structure 20 further comprises two distal ends 23 and 24, which are fixed to two free corners 18 ', 18 "of the diamond-shaped cells 18 at the proximal end 12 of the vascular prosthesis or are formed in one piece with them.

0061How<figref idref="f0001">Fig. 1</figref> As can be seen, the distal ends 23, 24 of the anchoring structure 20 are attached to/are provided in one piece with immediately adjacent corners of the diamond-shaped cells 18 at the proximal end 12 of the vascular prosthesis 10.

0062“Free ends” of the diamond-shaped cells mean, as for any other embodiment of the vascular prosthesis according to the invention, that these corners are not connected to another diamond-shaped cell, but rather protrude freely in the distal direction 11 'or proximal direction 12'.

0063<figref idref="f0001">Fig. 1</figref> It can also be seen that the anchoring structure 20 has a trapezoidal extension 25 to the outside in the area of ​​the loop 21. This means that the distance between the distal ends 23, 24 of the anchoring structure 20 in the area of ​​its fixation/attachment to the proximal end 12 of the vascular prosthesis 10 is smaller than the distance between the opposing wires of the loop 21 in the proximal area 22.

0064The anchoring structure 20 points, as further shown in<figref idref="f0001">Fig. 1</figref> is shown, in its loop 21 an outermost teardrop-shaped proximal end 26.

0065The anchoring structure 20 and the stent framework 14 can be formed in one piece, for example by laser cutting a corresponding tube or cylinder.

0066The anchoring structure 20 and/or the stent framework can have hooks or thorns (not shown) on the side facing away from the vessel wall, as well as one or more X-ray markers.

0067The diameter d of the vascular prosthesis according to the invention is preferably between 20 mm and 48 mm, preferably between approximately 24 mm and approximately 44 mm.

0068In<figref idref="f0002">Fig. 2</figref> The release of a vascular prosthesis 10 according to the invention loaded onto a release catheter 30 is shown schematically. The vascular prosthesis 10 is fixed at its distal end 11 via the fixing structures 19 provided there on the release catheter in appropriate receptacles and by covering a retraction cover 31. The vascular prosthesis 10 is also releasably fixed via its proximal end 12 to the release catheter 30 via a corresponding system (not shown). The completely fixed and compressed state of the vascular prosthesis 10 is in<figref idref="f0002">Fig. 2A</figref> shown.

0069After the retraction sleeve 31, which keeps the vascular prosthesis compressed, is retracted, a central region of the vascular prosthesis 10 expands in a balloon shape, while the proximal and distal ends 12, 11 of the vascular prosthesis 10 are still fixed to the release catheter 30 (see<figref idref="f0002">Fig. 2B</figref>).

0070After the release of the proximal end 12 of the vascular prosthesis 10, it can expand, whereas the distal end 11 of the vascular prosthesis 10 is still fixed and compressed on the release catheter 30 and by the retraction sheath 31 (see<figref idref="f0002">Fig. 2C</figref>). In this state, the vascular prosthesis 10 according to the invention can be released and positioned at the desired location, preferably behind a leaflet of the aortic valve (see also<figref idref="f0003">Fig. 3</figref>), preferably positioned behind the noncoronary cusp "NCC". This allows the anchoring structure 20 to be precisely aligned and prevent later proximal migration of the vascular prosthesis.

0071If the positioning of the anchoring structure 20 is secured, the remaining vascular prosthesis can be released by completely retracting the retraction sheath 31. The state of the vascular prosthesis 10 that is completely released in a heart 70 is in<figref idref="f0003">Fig. 3</figref> shown, in which figure the vascular prosthesis is shown in dashed lines for better clarity. It can be seen here that anchoring structure 20 is positioned behind a leaflet of the aortic valve 71 while the rest of the vascular prosthesis 10 extends distally into the ascending aorta 72.

0072<figref idref="f0004">Fig. 4</figref> finally shows a system 50 according to the invention consisting of a vascular prosthesis 10 and a heart valve prosthesis 40 in assembled form, specifically outside the heart for better clarity.

0073As soon as the vascular prosthesis 10 is positioned as an anchor in the heart, the heart valve prosthesis 40 can be inserted via it and released in such a way that the heart valve prosthesis 40 with its distal end 41 in the vascular prosthesis 10 at least partially gets caught at its proximal end 12 or already through expansion fixed there.