New arteriovenous access system for hemodialysis and related procedures

Abstract

The invention relates to an arteriovenous access system comprising: - a tubular body (1), - with a slit (2) in the longitudinal direction (3), in relation to the tube shape, which divides the tube body (1) into a left (2a) and a right section (2b) with a symmetry axis (2c) in between, - at least four cutouts (4) in the tube body, of which at least two are arranged in the left section and at least two in the right section, and - a hollow nozzle (5) on the tubular body for connection to a blood vessel, which is connected to the tubular body at an acute angle α of other than 90°, the angle α being measured in the longitudinal direction and • a tube (25) made of mesh, which encloses the nozzle (5) and projects into the tube body (1) through an opening (20), wherein the tube has at least three or four incisions (23) at this projecting end, for opening and applying to the inner wall of the blood vessel, or • which has an outwardly projecting metal ring (24) and has at least three or four incisions (23) at both ends, for insertion into the nozzle (5) until the metal ring (24) stops and for placement against the inner wall of the blood vessel, or • at least three or four flat anchoring elements (21) are attached to the outside of the nozzle (5), which can extend into the interior of the blood vessel through slots between the nozzle (5) and the tubular body (1); and an associated set

Description

[0001] The invention relates to a novel permanent extravascular peripheral arteriovenous access system which can be used in the vessels (arteries, veins, dialysis shunt) for hemodialysis and in related procedures (LJG-JP).

[0002] Extravascular means outside of a blood or lymphatic vessel. A stent (German: Gefäßstütze) is a medical implant used to keep blood vessels or hollow organs open (Wikipedia)

[0003] Established access points in hemodialysis include dialysis cannulas. These are inserted into the dialysis shunt via puncture for each dialysis session. This involves a high number of needle punctures (6 times per week / 52 weeks), which is associated with the disadvantages of puncture trauma, needle dislocation, etc. (see below).

[0004] Other well-known access systems include, for example, temporary and permanent central venous intravascular catheters and port systems, or similar state-of-the-art devices.

[0005] They are designed for insertion inside the blood vessel. Because they obstruct blood flow, they carry the risk of causing deposits in the blood vessel (wall-related thromboses) or even in the heart.

[0006] In addition, these conventional permanent access devices for dialysis and related procedures carry the risk of deposits (clots / thrombi) forming inside (lumens) of these devices or on the outer walls of the catheters and port systems.

[0007] If the clots break off, serious complications (pulmonary embolisms) can occur.

[0008] However, such complications are known with conventional systems (catheters and ports).

[0009] Examples of what is described include: • In CN 1 15 400 278 A an external vascular stent for arteriovenous fistulas, or • In US 2013 / 0041453A1, devices for the physical support of vascular regions, including vascular regions that have an anastomosis area, or • In DE 11 2013 001 846 T5 an auxiliary clamp for use in an anastomosis operation.

[0010] The object of the invention is to provide a new arteriovenous access system for hemodialysis and related procedures.

[0011] The new system is designed to reduce the risk of infection in the heart, blood vessels, and thus throughout the entire body, compared to conventional systems. This is ultimately also beneficial for immunocompromised individuals.

[0012] In particular, the system should be flexible, as it will be anchored in the vessel using pressure balloons. This leads to its temporary expansion.

[0013] The invention is intended to make it possible to do without the previously high number of needle punctures, thus preventing puncture trauma and reducing the amount of contaminated hazardous waste.

[0014] The invention relates to a new access system for blood vessels, comprising: - a tubular body,- with a slit (of the tubular body) in the longitudinal direction (longitudinal direction in relation to the tube shape), which divides the tubular body into a left and a right section with a symmetry axis between them, (the symmetry axis only concerns the tube shape as such, not also the arrangement of cutouts or nozzles described below), - at least four cutouts in the tube body, of which at least two are arranged in the left section and at least two in the right section, and - a hollow (tubular) nozzle on the tubular body, for connection to a blood vessel, which is connected to the tubular body at an acute angle α of non-90° (i.e. a<90°), where the angle α is measured in the longitudinal direction and furthermore comprehensively: • a mesh tube enclosing the nozzle and projecting into the tube body through an opening, the tube having at least three or four incisions at this projecting end for opening and applying to the inner wall of the blood vessel, or • a mesh tube with an outwardly projecting metal ring and at least three or four incisions at both ends, for insertion into the nozzle until the metal ring stops and for placement against the inner wall of the blood vessel, or • at least three or four flat anchoring elements are attached to the outside of the nozzle, which can extend into the interior of the blood vessel through slots between the nozzle and the tubular body.

[0015] The "socket" on the tube body serves as a connection between the tube body with its opening to the blood vessel and, sensibly, a connecting hose that directs the blood to the therapy device.

[0016] The nozzle preferably has ring-shaped, cross-shaped or scissor-shaped protrusions on its outer surface, so that the fastening of the connecting hose is improved by increased frictional resistance.

[0017] The access system according to the invention is suitable for blood vessels (arteries and veins) and can be applied from the outside by bending open the slit and placing it (i.e., around the vessels). The slit allows for bending to a certain extent, thereby increasing the diameter of the tubular body.

[0018] Examples of materials used in the body include: metals and alloys such as stainless steel, nickel-titanium alloys (as shape-memory alloys), memory metal, cobalt-chromium, cobalt-nickel alloys, tantalum, titanium, platinum-chromium, alloys of magnesium and iron or with rare earth elements (yttrium, neodymium, gadolinium), or also metallic glass, polylactide (PLA, also called polylactic acid) or polyacetate.

[0019] “Left” and “right section” within the meaning of the invention relates to a view into the interior of the tubular body (in its curved tubular shape) through its slot, so that a basic section is created through the slot and by imagining the tubular body being bent open, which shows the inner surface parts of the tubular body.

[0020] "Left" and "right" are thus clearly dependent on the orientation of the tube body (top and bottom) and always refer to a tube body in a fixed orientation. "Left section" and "right section" should therefore be understood as "a first" and "a second section" and can be equated with this designation.

[0021] The axis of symmetry between them runs parallel to the longitudinal direction of the tubular body and also parallel to the slot, as for example in Fig. 1 shown.

[0022] The at least four "cutouts" are designed as holes in the tubular body and can be, for example, rectangular, round, or 4-, 5- or 6-sided.

[0023] "Stutzen" within the meaning of the invention is a tube with a smaller diameter than the tubular tube body itself.

[0024] The "prong" according to the invention is advantageously connected to the tubular body in such a way that, after the tubular body is placed on the corresponding vessel, blood can flow between the artery or vein via the prong of the access system according to the invention. Advantageously, two such access systems are used during treatment so that blood can flow outside the body via the two prongs.

[0025] This means that in the area where the hollow spigot connects to the tubular body, the tubular body has an opening (more precisely, a rounded oval opening) that has the same dimensions as the inside of the spigot. This prevents unnecessary edges from forming between the inside of the spigot and the inside of the tubular body, where deposits could accumulate over time. Blood can thus flow freely between the blood vessel, the spigot, and the extension of the spigot to the outside (outside the body).

[0026] The shape and size of the rounded oval opening (in the tube body) and the shape and size of the hole (at one end) of the attached fitting at its connection point with the tube body are congruent. The predetermined angle at which the tube body and fitting connect determine the shape and size of the congruent openings of the tube body and fitting (referred to as a hole in the fitting).

[0027] The congruity of both openings allows the unimpeded flow of blood from the vessel into the nozzle or from the nozzle into the vessel.

[0028] The nozzle is therefore hollow; preferably it is round. It is connected to the tubular body, and the tubular body has an opening at this point for the flow of blood.

[0029] The "acute angle α, measured longitudinally" means that it protrudes outwards from the tube body, and that angle α is the smallest angle the fitting can assume in all possible orientations relative to the tube body. The fitting is therefore angled and points downwards or upwards (depending on the orientation of the tube body); in any case, it protrudes longitudinally.

[0030] Geometrically, it follows that the axis in the middle of the tube body (parallel to the longitudinal direction) and the axis in the middle of the hollow nozzle (i.e., the axis of rotation in the middle of the nozzle) must have an intersection point.

[0031] The invention further relates to a set comprising: - the access system according to the invention, - with the mesh tube (for enclosing or inserting into the access system's nozzle), selected from: • (Variant a.:) a mesh tube that can enclose the fitting (It is connected to the outer wall of the fitting according to the state of the art. It projects beyond the fitting where the fitting is connected to the tube body. This allows it to extend from the outer wall of the fitting into the inside of the tube body. The tube has at least three or four incisions at this projecting end, for opening and positioning against the inner wall of the blood vessel.) and (from outside the nozzle to inside the tube body, during manufacturing before joining the nozzle and tube body, e.g. by welding) protrudes through the opening of the tube body (described above) into the tube body, wherein the tube has at least three or four incisions at this protruding end for opening and applying to the inner wall of the blood vessel, or selected from • (Variant b.) a mesh tube which has an outwardly projecting metal ring and has at least three or four incisions at both ends (of the tube) for insertion into the nozzle until the metal ring stops and for placement against the inner wall of the blood vessel. as well as - a connecting hose to be slipped over the outwardly protruding end of the nozzle.

[0032] “Protruding outwards” in the case of the metal ring of the pipe means, in relation to the diameter, protruding, i.e., the outer diameter of the metal ring is larger than the outer diameter of the pipe.

[0033] Each of the “incisions” leads to individual segments at the end of the pipe, in the form of anchoring elements as described below. Regarding both variants a. and b.:

[0034] The tube preferably has exactly three or four incisions at at least one of its two ends. This creates three or four equally sized segments, which in both variants can be referred to as 3 or 4 anchoring elements, as explained below. These are later pressed against the vessel wall using a balloon.

[0035] The mesh tube preferably projects 2-5 mm inwards into the interior of the tube body. The incisions in the tube at this end are preferably also 2-5 mm deep, so that the anchoring elements are also 2-5 mm long. After placement, the intravascular end, with its opening containing at least four segments (resulting from the at least four incisions), is located within the blood vessel. It thus preferably protrudes 2-5 mm above the vessel wall. In a subsequent step, it can be expanded using a balloon catheter. The segments created by the four incisions are pressed against the vessel wall by the balloon catheter. Regarding variant b.:

[0036] In variant b., the notches are located at both ends. After inserting the pipe into the fitting, these notches are pulled over the metal ring from the outside on the side with the metal ring (see Fig. 8) The tube preferably extends 5-10 mm beyond the metal ring (at the extravascular end) in an outward direction (away from the tube body). This is the direction towards the end of the fitting that points away from the tube body.

[0037] These two variants are particularly distinguished by the inclusion of three or four so-called planar anchoring elements. These anchoring elements are located at the rounded oval opening of the tube body at the point where it connects with the congruent opening of the hollow fitting. They are folded / inserted into the inner lumen of the fitting (i.e., the inside of the fitting). The three to four anchoring elements at the opening of the tube body consist of a mesh-like, flexible grid. As described in variant a., the grid is attached to the outside of the fitting. When the fitting and tube body are connected, the anchoring elements lie directly against the common opening and are then folded into the lumen of the fitting (into the inside of the fitting).

[0038] During the procedure, a sufficiently large connection is first established between the blood vessels and the tubular body. Then, the anchoring elements, which rest on or against the inner lumen of the stub, are inserted from the stub through the opening in the tubular body into the vessel. Finally, they are pressed against the wall of the corresponding vessel using a balloon catheter.

[0039] An additional advantage of the metal ring from variant b is that the mesh tube cannot completely slip through it when the ring is inserted into the fitting. This is prevented by the access system according to the invention. The contact of the metal ring with the fitting end also ensures that the intravascular portion of the tube / tubular hose only protrudes into the vessel to the predetermined depth, so that it can then be pressed against the vessel wall by the balloon catheter.

[0040] By placing the segments created by the four incisions (in the manner of four hose flaps) over the metal ring and the nozzle of the access system according to the invention, it is possible to attach the pipe to the nozzle, whereby it can then be fixed, e.g. by means of binding thread.

[0041] "Wire mesh tube" within the meaning of the invention means that the tube comprises a wire mesh with square or round meshes. It is also possible to encase the wire mesh with a plastic structure so that the meshes would be closed.

[0042] The connecting hose can be sheathed with a mesh or have a mesh incorporated into it.

[0043] Reinforcement of the connecting hose using various braided structures (metals, plastics) is possible. A flexible and kink-resistant design can be achieved by: sheathing the connecting hose with an outer metal spiral or mesh; sheathing a pre-formed spiral or mesh structure (made of fibers or metal) with the corresponding plastics, which are listed below as preferred materials for the connecting hose.

[0044] Introducing or sheathing four opposing fiber or metal filaments in the wall of the connecting hose may be a preferred option.

[0045] The connecting hose can be made of polyurethane or silicone, for example.

[0046] In preferred embodiments: 1.) The lumen of the connecting hose is preferably dimensioned at the connection point to the nozzle and at the (e.g. Luer-Lock) connection point in such a way that the connections can be formed securely here. 2.) In the intermediate tube segment, a smaller tube lumen is preferred, as it runs under the skin, i.e., subcutaneously. 3.) The connecting tube runs subcutaneously until it emerges from the skin. 4.) The connecting hose is equipped with at least one or more so-called Dacron couplings (e.g., central placement (±5cm) for variable connecting hose lengths, e.g., at a distance of 10-15cm from each end of the connecting hose). 5.) The Dacron sleeves serve to firmly heal the tube and thus fix it in place, and they act as an infection barrier.

[0047] The outer surface of the connector is advantageously equipped with ring-shaped, cross-shaped, or scissor-shaped protrusions to improve the attachment of the connecting tubing through increased friction. The connection is then secured with a surgical suture. The arterial portion of the access system carries blood from the artery through this connecting tubing via a Luer-lock fitting to the tubing system of a renal replacement therapy machine or related devices. The treated blood is then connected via a counter-rotating tubing system to the venous tubing of the venous portion of a second access system. The venous portion of the access system returns the blood from the machine to the patient's vein. Advantages

[0048] Advantages of the new access system for patients according to the invention, compared to permanent atrial catheters / port systems, are: • Surgery under local anesthesia • Patients who can no longer receive a dialysis shunt for anatomical reasons or due to heart failure, • Patients with needle phobia - no puncture pain, • Home dialysis patients - no self-puncture required, no needle dislocation • No risk of infection of the heart compared to central venous catheters (CVC, port) • No relative change in the position of the access point on the heart due to changes in upper body position - patient lying down intraoperatively but sitting in the dialysis unit (diaphragmatic elevation while sitting), no dislocation (ventricle, papillary muscle) • lower thrombosis rate • higher blood flow rates similar to that of a dialysis shunt • No / lower risk of steal syndrome as with upper arm shunt and pre-existing peripheral arteriosclerosis

[0049] Advantages of the new access system according to the invention for patients with a dialysis shunt are: • no uncontrollable increase in shunt volume • No contraindication for patients with advanced heart failure • Risk reduction for anastomotic stenosis (arterial) and venous stenosis (prosthetic shunt) • No interference from other central units and devices (pacemaker) • Simple diagnostics and therapy for dysfunction (ultrasound, local lysis) • No puncture trauma as with a native shunt and no wear and tear as with a prosthetic shunt • No needle displacement due to movement during dialysis • No compression of the puncture sites by the needles, no "pressure time" • No bleeding / post-bleeding complications at the puncture site • No cosmetic impairment due to puncture-related shunt dilation or aneurysms

[0050] Furthermore, the use of the invention generates less waste and hazardous materials, resulting in cost savings (expensive locking solution and medications for thrombolysis, dialysis needles, special pressure plasters, face masks, dressings, syringes, cannulas, etc.). Access for diagnostics (left and right heart, aorta and its branches) is possible without general anesthesia; a smaller procedure is performed in the left atrium (LA).

[0051] The disadvantages remain unchanged compared to the well-known central venous catheter (CVC) and shunt: • permanent access with a cosmetic aspect • Infections (exit, tunnel, endovascular) • Risk of tampering and trauma to the device

[0052] Since the tubular body is located on the outside of the vessel, thromboses and clots cannot form inside it or on its outer surfaces, which could lead to complications (embolisms), reduced function, or complete loss of function of the system.

[0053] Thus, the known and conventional risk of deposits in the vessel, as well as on and in the systems used, is no longer present in the invention due to the extravascular location, i.e., outside the blood vessels, as is the case with known intravascular systems.

[0054] The new access system is one which, due to its shape and design, flexibly surrounds the vessels (artery and vein) from the outside.

[0055] The invention advantageously generates less contaminated hazardous waste and other waste, as the previously necessary use of numerous needles at short, repeated intervals is no longer required. Furthermore, puncture trauma (which is particularly common in children) is eliminated. Needle dislocations are also a thing of the past.

[0056] Since the invention is "placed" on the vessel from the outside, it no longer presents a flow obstruction within the blood vessel. The risk of wall-bound deposits (clots, thromboses) on vessel walls or even in the heart is significantly reduced or even eliminated after the tubular body is inserted, compared to conventional permanent access devices for dialysis and related procedures.

[0057] The access system according to the invention, or its tubular body, is flexible and less rigid due to its slot and cutouts. This is advantageous for widening (or also for pressing on optionally present three anchoring elements, such as those that may also be present in the set according to the invention, to the opening of the tubular body by means of a pressure balloon).

[0058] Another advantage is that, because the invention can be used outside the blood vessel, the risk of infection during surgery is shifted from inside the vessel to the outside. The invention is therefore particularly suitable for patients with weakened immune systems. Preferred embodiments

[0059] Preferably, the tubular body has four cutouts.

[0060] In a further preferred embodiment of the invention, the cutouts have a rectangular shape. Most preferably, the tubular body according to the invention has four such cutouts.

[0061] In a particularly preferred embodiment, four rectangular cutouts are enclosed, with a transverse web perpendicular to the longitudinal direction and a longitudinal web extending longitudinally between them (that is, each of the four cutouts is in contact with both the transverse web and the longitudinal web). The transverse and longitudinal webs are thus part of the tube body. The transverse web is understood to be a central web located at the midpoint of the tube body's length. The longitudinal web extends perpendicular to the transverse web.

[0062] In particular, since the cutouts are surrounded on all sides by tubular body material, there is also an edge area made of tubular body material at the upper and lower ends (when the tubular body is aligned longitudinally, so that the aforementioned axis of symmetry runs vertically).

[0063] In a particularly preferred embodiment, four or six holes are provided (in the tubular body material) within one of the two sections of the tubular body according to the invention for fixing it to the vessel wall. These holes are thus clearly excluded at the aforementioned axis of symmetry (between the left and right sections of the tubular body). For fixing, e.g., by sewing, the holes preferably have a diameter of 0.1–0.5 mm. Six holes are particularly preferred, as shown in [reference]. Fig. 2 shown.

[0064] It is advisable to arrange the holes symmetrically on the respective section of the tube body, e.g. 2 on the crossbar and 2 on the upper and 2 on the lower edge area, which is mentioned above.

[0065] In another preferred embodiment with a transverse and longitudinal web, the nozzle is arranged at the intersection of the transverse and longitudinal webs. The intersection is precisely the area where the transverse and longitudinal webs overlap. Preferably, this intersection (when the tube body is in its tubular form) is located opposite the slot.

[0066] It is advantageous if the left and right sections of the tube body have the same dimensions, so that when fixing the nozzle, the flexibility of the left and right sections of the tube body is comparable.

[0067] Furthermore, a preferred variant of the aforementioned design with four rectangular cutouts and transverse and longitudinal ribs is achieved when these rectangular cutouts each have a perpendicular dimension of 11 mm ± 20% and a longitudinal dimension of 2 mm ± 20%. The advantage of this variant is that it provides an optimal balance between the flexibility of the tube body, its pliability (for bending open to place or slip over the corresponding blood vessels), and sufficient stability.

[0068] For all area specifications with relative ranges in the document (e.g. ±20% of the previously mentioned value), these can preferably be closer together, for example ±15% or ±10%; even ±5% is possible.

[0069] Furthermore, it is a preferred variant (of the above-mentioned design with four rectangular cutouts and transverse and longitudinal ribs) if these cutouts each have a distance of 2mm±20% from the slot and / or if the two cutouts located in the same section have a distance of 4mm±20% from each other.

[0070] Thus, the crossbar is formed with a width of 4mm±20% (perpendicular to the longitudinal direction of the tubular body) or an edge area of ​​2mm±20% width along the edges adjacent to the slot.

[0071] In another preferred variant of the embodiment with four rectangular cutouts and transverse and longitudinal webs, the tubular body of the access system according to the invention has different dimensions, depending on whether it is to be used for arteries or for veins and dialysis shunts. - For use in arteries, the tubular body has a (total) width (in the rolled-up, planar state), measured perpendicular to the longitudinal direction, of 30-40 mm, particularly preferably 35 mm ± 20%, and (when viewed in this rolled-up, planar state) there is a distance of 4 mm ± 20% between opposing cutouts of different sections, so that the longitudinal web is formed (consequently with a width of the longitudinal web of 4 mm ± 20%). - For use in veins, however, the tubular body has a (total) width (also in the rolled-up, planar state) of 30mm-60mm (especially preferably 40-50mm) and there is a distance of 4mm-10mm between opposing cutouts of different sections, so that the longitudinal web (in a width of exactly 4-10mm) is formed.

[0072] In both versions (for arterial or venous / dialysis shunts), the margins around the four cutouts are the same. They are preferably 2 mm.

[0073] In a further preferred embodiment of the invention, the cutouts of the system according to the invention have a rectangular or round shape, or a 4-, 5-, or 6-sided shape. Rectangular or round cutouts are particularly preferred. It is preferred in the invention if all cutouts have the same shape.

[0074] In another preferred embodiment of the invention, the slit has a width of 1-2 mm, measured between the left and right sections (in the tubular, i.e., uncoiled state), and wherein the diameter of the tubular body is: 4 mm ± 20% for use in arteries or 3-7.5 mm for use in veins.

[0075] In another preferred embodiment of the invention, the material of the tube body (or of the access system as a whole) is selected from stainless steel and nickel-titanium alloys (such as Nitinol (a nickel-titanium alloy with 55% nickel and 45% titanium), memory alloys, memory metal, cobalt-chromium, cobalt-nickel alloys, tantalum, titanium, platinum-chromium, alloys of magnesium and iron or with rare earths (yttrium, neodymium, gadolinium), as well as: metallic glass, polylactide (PLA, also called polylactic acid) or polyacetate.

[0076] It is further preferred if, in the invention, the hollow fitting is a round, tubular fitting with a length of 1-2 cm (measured from the apex of angle 'a' to the end of the fitting pointing away from the tube body). This length is sufficient for a secure connection without creating excessive leverage, which could lead to significant movement of the tube body when inserted into the body.

[0077] Advantageously, the hollow nozzle according to the invention has a straight end, i.e., at the end pointing away from the tube body, a vertical cut perpendicular to the longitudinal axis of the hollow nozzle.

[0078] In the invention, it is preferred that the inner diameter of the nozzle is 1.10-1.90mm (preferably also 1.2-1.5mm or 1.3-1.4mm) and the outer diameter is 1.25-2.10mm (preferably 1.4-1.7mm or also 1.5-1.6mm), and that the nozzle has a material thickness of 0.15-0.21mm.

[0079] Particularly preferred is the combination of these two embodiments mentioned above, i.e. as a round tubular nozzle of this length with the described inner and outer diameter and material thickness.

[0080] In a further preferred embodiment of the invention, three flat anchoring elements are attached to the outside of the nozzle. That is, in the area of ​​the connection between the hollow nozzle and the tube body, the tube body has an opening (a hole).

[0081] In order to allow the anchoring elements to pass from the outside of the nozzle into the interior of the pipe body, slots are sensibly provided between the nozzle and the pipe body in this design, through which the anchoring elements can be guided.

[0082] "Flat" means that the thickness of the anchoring elements is significantly less than the length of the individual outer edges. The material thickness of the anchoring elements can, for example, be in the range of the material thicknesses of the spigot specified above.

[0083] Regarding the length dimensions of the anchoring elements, it is preferred if two of the three anchoring elements are short and one (the one arranged in the middle) is longer, as for example in... Fig. 9, long. The long anchoring element preferably has a length of 2-5mm and the two short ones a length of 2-3mm.

[0084] These three anchoring elements are therefore located in the area of ​​the hole of the nozzle (that is, at the rounded oval opening of the tube body at the point where it connects with the congruent opening of the hollow nozzle).

[0085] The anchoring elements can have a grid structure, meaning they can, for example, be a mesh.

[0086] The anchoring elements are preferably made of a material selected from metals and alloys (such as stainless steel, cobalt-chromium, cobalt-nickel alloys, tantalum, titanium, platinum-chromium, alloys of magnesium and iron or with rare earths (yttrium, neodymium, gadolinium), nickel-titanium alloys (as shape-memory alloy or memory metal)), and metallic glass, polylactide (PLA, also called polylactic acid) or polyacetate.

[0087] The anchoring elements are preferably attached to the nozzle by welding, pressing or pressing with a fold.

[0088] Regarding insertion during surgery, the following should be noted: The three to four anchoring elements at the opening of the tubular body initially rest against the inner lumen of the hollow catheter. First, a sufficiently large connection is established between the blood vessels (artery and vein) and the tubular body. Then, the anchoring elements, which rest against the inner lumen of the catheter, are advanced from the catheter through the opening in the tubular body into the corresponding vessel. Finally, they are pressed against the wall of the corresponding vessel using a balloon catheter.

[0089] In further preferred embodiments of the invention, the angle α is 20-40°, particularly preferably 25-35° or even 20-30° or even 25°±3°.

[0090] In a preferred embodiment of the set according to the invention, the connecting hose can have a rectangular or parallelogram shape in its longitudinal cross-section, i.e., the ends can be cut straight or at an angle.

[0091] In one embodiment of the set according to the invention with connecting hose, the material of the connecting hose is selected from: silicone, elastomers or thermoplastic polymers (such as polyurethane, polyamide, polyisobutylene, polyethylene terephthalate (PET, Dacron), polyhydroxyalkanoates (PHA), polyhydroxybutyrate (PHB), polyvinyl chloride (PVC), Ultem, polyetherimide and polyvinylidene fluoride (PVDF).

[0092] Regarding the invention: • (as described above as variant a.) is a tube made of mesh which encloses the nozzle (first on the outside) and projects into the tube body through an opening in the tube body (after the connection of nozzle and tube body), wherein the tube has at least three or four incisions at this projecting end, for opening and applying pressure to the inner wall of the blood vessel, or • (as described above as variant b.) comprises a tube made of mesh, which has an outwardly projecting metal ring and at least three or four incisions at both ends, for insertion into the nozzle until the metal ring stops and for positioning against the inner wall of the blood vessel, or • Three or four flat anchoring elements are attached to the outside of the nozzle, which can extend into the interior of the blood vessel through slots between the nozzle and the tube body. Fig. Figure 1 shows a preferred embodiment of the invention according to embodiment 1 with rectangular cutouts 4 and with six holes 6 on one of the two sections (“left or right section”, 2a, 2b) for sewing onto an artery or vein from one side. Fig. Figure 2 illustrates the six holes for sewing. Fig. 1. Fig. Figure 3 shows a sketch of this embodiment from embodiment 1 in various views (left: oblique view / / center: from behind looking at the nozzle 5 in the area of ​​the mirror axis 2c / / right: from the front looking at the slot 2, which divides the tube body 1 into a left section 2a and a right section 2b). A transverse web 7 and a longitudinal web 8 located between the cutouts 4 are indicated. Fig. Figure 4 shows a partial basic section resulting from the unfolding of the tubular body 1, starting at the slit 2. The holes 6 for sewing are not shown. The transverse rib 7 and longitudinal rib 8 are also indicated here. Fig. Figure 5 shows the transverse web 7 and longitudinal web 8 resulting from four rectangular cutouts 4. Fig. Figure 6 shows embodiment 1 in sketch form during use, after “coating” a vessel. Fig. Figure 7 shows two further possible embodiments of the invention (left: with round cutouts 4 / / right: with hexagonal cutouts 4). In the Fig. Figures 1 to 7 clearly show the mesh tube or the anchoring elements not shown. Fig. Figure 8 shows (right) the tube 25 provided in the set according to the invention, with a metal ring 24 and with four incisions 23 at both ends of the tube. The tube 25 (in this embodiment with metal ring) is designed to be inserted into the nozzle 5 of the new access system according to the invention. Fig. Figure 8 (left) shows the symmetrical distribution of the incisions 23 at both ends. Fig. Figure 9 shows a embodiment of the nozzle with three anchoring elements 21 (in a cutaway, planar view of the inner surface of the nozzle 5). The upper edge in Fig. 9 forms hole 20 of the fitting 5. Fig. Figure 10 shows this design on the hollow spigot 5 from the outside. Here, the three anchoring elements 21 were placed on the outside. They are visibly connected to the spigot 5 on the outside.

[0093] Unless otherwise specified, it is advisable to combine the different embodiments.

[0094] The invention will now be explained in more detail with reference to several preferred embodiments. These embodiments are not intended to limit the invention. Examples of implementation Example 1:

[0095] Exemplary embodiment 1 is in Fig. Figure 1 shows the component. It has four rectangular cutouts 4. The nozzle is connected to the tube body 1 in the region of the axis of symmetry 2c, with the acute angle α between the nozzle and the axis of symmetry 2c of the tube body being 30°. Within one of the two sections, six holes 6 are provided for fixing by sewing. Examples 2 and 3:

[0096] Exemplary embodiments 2 and 3 are in Fig. Figure 7 shows round cutouts on the left and hexagonal cutouts on the right. The number of cutouts is variable and is only sketched in; the number shown is not exhaustive. There may be more or fewer. The angle of the stub is also not accurately represented. Example 4 as a set:

[0097] One version as a set is partially available in Fig. Figure 8 on the right shows the connecting hose 22 already inserted into the pipe 25. Example 5 (spigot with anchoring elements):

[0098] Fig. Figure 9 shows a sketch of the hollow nozzle 5 of a version in cut-open planar form with a view of the inner surface of the nozzle.

[0099] In this embodiment, the three anchoring elements 21 are visibly attached to the outside of the nozzle. When the access system is placed on blood vessels, the anchoring elements, which were previously placed over the edge into the interior of the nozzle, can be folded outwards by means of a pressure balloon and bent against the blood vessel wall. Fig. Figure 10 shows an exterior view, with the anchoring elements 21 placed on the outside. Reference sign 1 tubular body 2 slots 2a left section (of the tube body) 2b right section (of the tube body) 2c Mirror axis (between left and right sections) 3 Longitudinal direction (of the tube body) 4 cutouts (in the tubular body) 5 hollow nozzles (on the tube body) 6 holes (for sewing) 7 Crossbar (of the tube body) 8 Longitudinal web (of the tubular body) 20 Opening of the tube body (corresponds to the hole of the nozzle) 21 anchoring elements (of the nozzle) 23 cuts in the pipe 24 metal rings 25 mesh tubes

Claims

[1] Arteriovenous access system for blood vessels, comprising: • a tubular body (1), • with a slit (2) in the longitudinal direction (3), with respect to the tube shape, which divides the tube body (1) into a left (2a) and a right section (2b) with a symmetry axis (2c) between them, • at least four cutouts (4) in the tube body (1), of which at least two are arranged in the left (2a) and at least two in the right section (2b), and • a hollow nozzle (5) on the tubular body for connection to a blood vessel, which is connected to the tubular body (1) at an acute angle α of other than 90°, wherein the angle α is measured in the longitudinal direction, and further comprising: • a tube (25) made of mesh, which encloses the nozzle (5) and projects into the tube body (1) through an opening (20), wherein the tube has at least three or four incisions (23) at this projecting end, for opening and applying to the inner wall of the blood vessel, or • a tube (25) made of mesh, which has an outwardly projecting metal ring (24) and has at least three or four incisions (23) at both ends, for insertion into the nozzle (5) up to the stop of the metal ring (24) and for placement against the inner wall of the blood vessel, or • at least three or four flat anchoring elements (21) are attached to the outside of the nozzle (5), which can extend into the interior of the blood vessel through slots between the nozzle (5) and the tubular body (1). [2] Access system according to claim 1, wherein the cutouts (4) have a rectangular shape. [3] Access system according to claim 2, comprising four such rectangular cutouts (4) with a transverse web (7) perpendicular to the longitudinal direction (3) and a longitudinal web (8) in the longitudinal direction (3) between them. [4] Access system according to claim 3, wherein four or six holes (6) are provided within one of the two sections (2a, 2b) for fixing to the vessel wall. [5] Access system according to one of claims 3 or 4, wherein the nozzle (5) is arranged in the intersection area of ​​the transverse web (7) and longitudinal web (8). [6] Access system according to one of claims 3 to 5, wherein the rectangular cutouts (4) each have an extent perpendicular to the longitudinal direction (3) of 11mm±20% and in the longitudinal direction (3) of 2mm±20%. [7] Access system according to one of claims 3 to 6, wherein the rectangular cutouts (4) each have a distance of 2mm±20% to the slot (2) and wherein the two cutouts (4) located in the same section (2a, 2b) each have a distance of 4mm±20% from each other, so that the crossbar (7) is formed. [8] Access system according to claims 3 to 7, wherein the tubular tube body (1) has a width, measured perpendicular to the longitudinal direction (3) in the rolled-up planar state: - for use with arteries of 30-40mm and between opposing cutouts (4) of different sections (2a, 2b) there is a distance of 4mm±20%, so that the longitudinal rib (8) is formed, or - for use with veins of 30mm-60mm and between opposing cutouts (4) of different sections (2a, 2b) there is a distance of 4mm-10mm, so that the longitudinal rib (8) is formed. [9] Access system according to claim 1, wherein the cutouts (4) have a round shape or a 4-, 5- or 6-sided shape. [10] Access system according to any one of claims 1 to 9, wherein the slot (2) has a width of 1-2 mm, measured between the left and right sections (2a, 2b), and wherein the diameter of the tubular body (1) is: - for use in arteries at 4mm±20% or - for use in veins between 3-7.5mm. [11] Access system according to any one of claims 1 to 10, wherein the material of the access system is selected from stainless steel, nickel-titanium alloys and metallic glass or polylactide. [12] Access system according to any one of claims 1 to 11, wherein the hollow nozzle (5) is a round tubular nozzle and has a length of 1-2 cm, measured from the apex of the angle α to the end of the nozzle (5) which points away from the tubular body (1). [13] Access system according to any one of claims 1 to 12, wherein the angle a is between 20-40°. [14] Set, comprising: - an access system according to one of claims 1 to 13 comprising the tube (25) for enclosing or inserting into the nozzle (5) of the access system, as well as - a connecting hose (22) to be placed over the outwardly protruding end of the nozzle.

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