Vascular prosthesis

Abstract

To provide a vascular prosthesis whose properties match the properties of natural blood vessels, and which has a simple structure and can be implanted by minimally invasive surgery at the same time; and to provide a method for producing such a vascular prosthesis.SOLUTION: A vascular prosthesis 1 includes a volume chamber 2 and connecting portions 3. The volume chamber 2 has, in a blood pressure range below a pressure threshold value D, a pressure-expansion behavior substantially corresponding to the pressure-expansion behavior of a natural blood vessel, while the volume of the volume chamber 2, depending on the pressure, increases by at least 10 cm3 in a blood pressure range above the pressure threshold value D. The vascular prosthesis 1 is configured as a textile tube and includes in the region of the volume chamber 2 an elastic yarn having a core made from silicone yarn around which a yarn made from polyethylene terephthalate (PET) is wrapped.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vascular prosthesis for connection to a natural cardiovascular system, comprising a volume chamber, the volume chamber having a pressure expansion behavior that substantially corresponds to the pressure expansion behavior of a natural blood vessel in a blood pressure range below a pressure threshold D, while the volume of the volume chamber varies in response to pressure by at least 10 cm in a blood pressure range above the pressure threshold. 3 The present invention also relates to a method for producing such a vascular prosthesis. [Background technology]

[0002] Replacing the diseased part of the aorta with a plastic vascular prosthesis in the form of a bridging graft or bypassing the diseased part of the aorta in the form of a bypass is an old surgical method. The prostheses used in this process are usually fabricated as textile tube prostheses by weaving or knitting from synthetic polymers that are not absorbed by the body, such as polytetrafluoroethylene (PTFE), or polyesters, such as polyethylene terephthalate (PET). If necessary, such vascular prostheses can also be configured in a branched manner, as a so-called Y-prosthesis.

[0003] Vascular prostheses in use today are slightly expandable in the longitudinal and transverse directions, by means such as pleating and crimping, but they do not have the elastic properties of the natural aorta or tissue of the natural arteries. In particular, they are unable to adequately mimic the Windkessel function of natural blood vessels. The Windkessel function is understood to be the short-term retention in the elastic arteries of a part of the blood volume ejected from the heart during systole, followed by its continued ejection during diastole, which results in an overall equalization of the blood flow and a reduction in the pressure difference between systole and diastole. In this case, the short-term accumulation and subsequent ejection of the blood volume is mainly caused by the elastic properties of the natural blood vessel walls, which tend to be slightly expanded during systole and to return to their original state during diastole. So far, known vascular prostheses are only able to imitate this property to an insufficient extent.

[0004] When applied to the human body for a long period of time as intended, the lack of elasticity of the vascular prosthesis adversely affects the heart, the aorta and the vascular prosthesis itself. After the replacement of the diseased aortic segment by the insertion of an inelastic vascular prosthesis, a disparity occurs between the volumetric properties of the remaining native aorta and the stiffer vascular prosthesis that is implanted. This disparity is also called compliance disparity. In this case, if the aortic valve was preserved during the aortic replacement, the lack of elasticity of the vascular prosthesis implanted in the region of the ascending aorta close to the heart may affect the function of the aortic valve, which may then become more prone to leakage. In addition, blood pressure is adversely altered in terms of amplitude level and shape due to the lack of elasticity. Loss or impairment of the Windkessel function of the aorta results in adverse hemodynamic changes, including an increase in the steepness of the blood pressure curve with an increase in pulse wave velocity and an overall increase in blood pressure amplitude.

[0005] These adverse blood pressure changes due to compliance disparities can become a permanent stress on the heart, leading to muscle hypertrophy (thickening of the heart walls) and increased functional impairment in the form of heart failure (weakness of the heart). In addition, the increased stress due to blood pressure changes has a negative effect on the connection point between the remaining native aorta and the implanted vascular prosthesis. Here, so-called anastomotic aneurysms can form, i.e. dilations or sacculations in the connection area between the prosthesis and the aorta, which may possibly have to be repaired surgically. Furthermore, the non-physiological blood pressure stresses that occur immediately after the implantation of the prosthesis can sometimes cause a considerable and irreversible increase in the diameter of the prosthesis, which requires subsequent observation and regular monitoring. This is usually done with an annual CT scan, in addition to which radiation exposure is increased. If there are indications that the vascular prosthesis or the connection point is at risk of tearing, the vascular prosthesis must be surgically replaced, which significantly increases the operative risk.

[0006] Vascular prostheses are already known, which by their specific design are able to at least partially mimic the natural Windkessel function. For example, European Patent No. 2574305 describes a compensatory blood vessel for influencing blood pressure, comprising a volume chamber and connection means for connecting the volume chamber to the natural cardiovascular system, the volume change of the volume chamber being determined by the pressure changes of the cardiovascular system and by the volume change of the volume chamber in a pressure range lower than a pressure threshold of at least 100 mmHg up to 10 cm. 3 and at least 10 cm in the upper pressure range between the pressure threshold and 150 mmHg. 3 and an adaptive means for causing a change in the volume of the volume chamber.

[0007] In this case, the adaptation means comprises a frame and at least one elastic body cooperating with the frame, the frame and the elastic body being arranged outside the volume chamber, the frame comprising two ends and at least three support bars, the support bars connecting the two ends and between which the at least one elastic body extends. The structure of the compensating vessel is relatively intricate and complex. Moreover, the compensating vessel according to EP 2574305 cannot be implanted by minimally invasive surgery. In both cases improvements seem to be necessary. Furthermore, improvements are intended regarding the integration behavior of the vascular prosthesis. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] European Patent No. 2574305 Summary of the Invention [Problem to be solved by the invention]

[0009] The object of the present invention is to provide a vascular prosthesis whose properties correspond more closely to those of natural blood vessels than is the case for vascular prostheses known from the prior art, which has a simple structure and at the same time can be implanted by minimally invasive surgery. Another object of the present invention is to identify a method for producing such a vascular prosthesis. [Means for solving the problem]

[0010] These objects are achieved by a vascular prosthesis having the features of claim 1 and by a method for producing a vascular prosthesis having the features of claim 16. Advantageous embodiments and developments of the invention are the subject of the dependent claims.

[0011] According to claim 1, the invention is a vascular prosthesis for connection to a natural cardiovascular system, comprising a volume chamber, wherein the volume chamber has a pressure expansion behavior that substantially corresponds to the pressure expansion behavior of a natural blood vessel in a blood pressure range below a pressure threshold D, while the volume of the volume chamber varies in response to pressure by at least 10 cm in a blood pressure range above the pressure threshold D. 3 The vascular prosthesis according to the invention is configured as a textile tube, characterized in that in the region of the volume chamber it comprises an elastic thread having a core made of silicone thread around which is wound a thread made of polyethylene terephthalate (PET).

[0012] In other words, the invention is a woven tubular vascular prosthesis, the volume of which increases by radial expansion in the elastic region from a given pressure threshold D, thus providing a given additional volume, where the volume change or radial expansion is approximately reversible and the original unpressurized volume is approximately restored again when the pressure threshold D is lowered. In this case, the vascular prosthesis according to the invention is mainly characterized by the special material from which the volume chamber is completely or partially made. This material includes a special elastic thread formed from a core of silicone threads around which a wrapping thread of polyethylene terephthalate (PET) is wound.

[0013] In this case, the material silicone has excellent elastic properties, which contribute to the volume of the volume chambers, which increases when the pressure increases and decreases again to the same extent when the pressure decreases. The novel vascular prosthesis therefore has an identical compliance to the aorta in the range of physiological blood pressure. By using PET at the same time to encase the silicone thread, the volume of the volume chambers increases significantly only in the case of blood pressures above a pre-determinable pressure threshold D, and this increase in volume is limited overall so that a predefined maximum increase in volume is not exceeded even for very high blood pressures. Due to the high elasticity during expansion of the elastic threads used and the associated restoring forces, all expansions of the volume chambers are reversible, thereby allowing to brilliantly mimic the properties of natural blood vessels.

[0014] According to claim 1, the volume chamber has a pressure expansion behavior that substantially corresponds to the pressure expansion behavior of a natural blood vessel in a blood pressure range below the pressure threshold D. This should be understood to mean that below the pressure threshold D the volume of the volume chamber does not change beyond the minimum expansion necessary to maintain the Windkessel function. In particular, these expansions are reversible due to the elasticity of the material.

[0015] Following implantation of the vascular prosthesis according to the invention, the volume chambers of the vascular prosthesis initially expand to the existing aortic diameter due to the diastolic pressure (lower pressure value) occurring in the aorta. Within the context of normal operation of the heart, which includes the ejection of a certain blood volume (stroke volume), the blood pressure of the aorta or of the vascular prosthesis rises until it reaches the systolic pressure (higher pressure value). The vascular prosthesis therefore expands in the region of the elastic volume chambers, converting part of the dynamic ejection energy into potential energy of elastic deformation.

[0016] When the heart relaxes during diastole and the blood pressure falls accordingly, the vascular prosthesis, which is configured to be elastic in the region of the volume chambers, releases the stored energy again under the action of restoring forces and in the process expels the accumulated blood, which corresponds to the normal Windkessel function of the aorta. Thus, the harmful changes in blood pressure status, including an acceleration of the pulse wave velocity, an increase in the blood pressure curve and amplitude, as well as the associated unfavorable long-term consequences that occur after the implantation of a rigid vascular prosthesis, do not occur after the implantation of the elastic vascular prosthesis according to the invention.

[0017] However, the vascular prosthesis according to the invention not only mimics the natural Windkessel function very well. In the presence of hypertension, the vascular prosthesis according to the invention also has a significant blood pressure lowering effect, which can also be attributed to the elastic configuration of the volume chambers of the vascular prosthesis. Due to the specific volumetric characteristics according to the invention, the lowering effect occurs only in the case of hypertension, without further lowering in normal or hypotension. According to the invention, it is provided that below a pressure threshold D, the volume of the volume chambers does not change substantially, and does not change beyond the minimum expansion necessary to maintain the Windkessel function. A substantial and almost reversible radial expansion occurs only above the pressure threshold D.

[0018] In this case, the pressure threshold D may be, for example, 100 mmHg or at least 120 mmHg. The pressure-dependent increase in the volume of the volume chamber when the pressure threshold D is exceeded is between 10 and 80 cm 3 , preferably 40 to 60 cm3 In any case, the upper limit of the predefinable volume increase is not exceeded. This limitation of the volume increase is practically caused by wrapping the silicone yarn in PET. In this connection, and in the predefinition of the pressure threshold D and the possible volume increase, the parameters defining the particular textile tube, such as the yarn count, the number of filaments, the weave structure, etc., play an additional role, which will be explained in more detail below.

[0019] Due to these properties, the application of the elastic vascular prosthesis according to the invention in patients with resistant arterial hypertension, i.e. hypertension that does not respond to drug therapy, can be considered as an interventional long-term alternative to drug therapy. For example, in addition to its use as an aortic replacement, the elastic vascular prosthesis according to the invention can additionally be implanted in the form of an aortic bypass as a permanent measure to reduce blood pressure in patients with resistant hypertension during necessary cardiac surgery. In this case, it is in principle conceivable to carry out the implantation in a minimally invasive manner and, taking into account the indications, can therefore also be considered as a primary intervention for permanently reducing blood pressure.

[0020] The vascular prosthesis according to the invention therefore has highly adaptable properties in that it very closely mimics the natural Windkessel function in natural blood vessels at normal blood pressure and therefore constitutes an excellent substitute for parts of natural blood vessels, and in the case of hypertension also has a significant blood pressure lowering effect due to the additional significant volume increase which occurs only in that case. Due to the materials used, the significant volume change during hypertension is in this case almost reversible, so that below the pressure threshold D the original unpressurized volume of the volume change is again almost restored. The vascular prosthesis according to the invention therefore not only exhibits good distensibility but at the same time also a high level of elasticity.

[0021] Finally, it is also conceivable to use the elastic vascular prosthesis according to the invention as an aortocoronary bypass. A surgically applied aortocoronary bypass bridges an existing narrowed section of the coronary vessel, the so-called coronary stenosis, and directs blood from the aorta behind the coronary stenosis and towards the myocardium, thereby ensuring the blood supply to the myocardium. Up until now, veins from the body's own legs or, due to their elastic properties, preferably the body's own arteries, for example the thoracic arteries, have usually been used.

[0022] Previously known experiments using artificial vascular prostheses as aortocoronary bypass materials have failed due to lack of elasticity and high occlusion rate of small lumen vascular prostheses. This constraint can be removed with the elastic vascular prosthesis according to the present invention, so that harvesting of autologous veins from the legs or arteries from the inner chest wall is not necessary during aortocoronary bypass surgery. Thus, both surgical trauma and the associated surgical risks (postoperative bleeding, wound healing disorders, and infection at the surgical site) can be minimized, and the operation time can be significantly shortened. In addition to the immediate health benefits for the patient, this will also have a favorable health economics effect.

[0023] In principle, the special properties, i.e. a pressure-dependent increase in the volume of the volume chamber when a pressure threshold D is exceeded and a return of the volume chamber to its initial state when the pressure falls below the pressure threshold D, as well as a pressure expansion behavior exhibited at blood pressures below the pressure threshold D and which corresponds approximately to the pressure expansion behavior of natural blood vessels, are substantially produced by the material combination of silicone and PET in special elastic threads suitable for medical use.

[0024] In this case, the specific volume pressure curve of a given vascular prosthesis can be adjusted by a number of parameters, including variations in the structure and composition of the elastic threads, in particular the silicone threads and PET wrapping threads of the starting material, as well as the PET threads additionally used in the fabrication of the textile tube, as well as variations in the composition of the textile tube, which is fabricated, in particular woven, using the elastic threads.

[0025] According to one embodiment of the present invention, the silicone yarn forming the core of the elastic yarn may be made of silicone having a Shore hardness of 30-70, preferably 40-60.

[0026] The elastic yarn formed of silicone yarn and PET wrapping yarn may have a count of 100-3000 dtex, preferably 200-2000 dtex. The PET wrapping yarn may have a count of 30-150 dtex, preferably 50-110 dtex. In this case, the PET wrapping yarn may be wrapped around the silicone yarn once or multiple times, and in the case of multiple wrapping, there will be several layers of the PET wrapping yarn on the silicone yarn. Thus, in the case of double wrapping, the PET wrapping yarn is placed in two layers on the silicone yarn. The pressure expansion behavior of the elastic yarn can be influenced by the choice of the fineness of the PET wrapping yarn, the number and density of wrapping, and the pitch of wrapping the PET wrapping yarn around the silicone yarn.

[0027] An embodiment of the present invention provides that the vascular prosthesis is configured as a fabric tube, in particular a seamless fabric tube, composed of warp and weft threads, the weft threads in the area of ​​the volume chamber being formed from elastic yarns. The warp threads may be formed, for example, from PET yarns. The PET yarns forming the warp threads may have a count of 50-300 dtex and may be configured, for example, as multifilament yarns composed of 20-300 filaments. In this case, for the purposes of the present invention, flat or textured yarns may be used as PET yarns for the warp threads, and in the area adjacent to the volume chamber, for example in the area of ​​the connection part described in more detail below, flat or high shrinkage yarns may be used for the warp threads. Also, different PET yarns may be used in different parts of the vascular prosthesis, for example PET flat yarns may be used for warping the ground and PET textured yarns for the pile warp threads.

[0028] One of the properties of high shrinkage yarns is that they shrink with the influx of heat, which can be exploited because the use of high shrinkage yarns can cause the woven or knitted fabric or knit that forms the textile tube to be densified by a final heat setting process.

[0029] Alternatively, if the vascular prosthesis is constructed as a fabric tube, it is also conceivable that both the warp and the weft threads in the area of ​​the volume chamber are formed from elastic threads. Different weave structures may form the basis for forming the fabric tube. For example, the fabric tube may be woven in a twill weave or a satin weave or a plain weave or a variant of one of these weave structures. In principle, the fabric tube may be formed in a single weave structure, but the fabric tube may also include parts formed in different weave structures. Among other things, the force expansion behavior of the fabric tube may be influenced by the choice of the weave structure. The force expansion behavior of the fabric tube may also be influenced by the choice of the thread density, i.e. the number of threads per cm, both in the warp and weft direction.

[0030] The vascular prosthesis has connection parts at both ends thereof for suturing the vascular prosthesis to the ends of the natural blood vessels. In terms of material and elasticity, these connection parts may be configured to be the same as or different from the volume chambers. For example, it may be provided that the vascular prosthesis includes a connection part adjacent to the volume chamber for connection to the natural cardiovascular system, the connection part having a lower elasticity than the volume chamber. In other words, in this embodiment of the invention, it is provided that the vascular prosthesis has parts with different elasticity, the central part forming the volume chamber having a higher elasticity than the connection parts adjacent to both sides of the volume chamber. In particular, the connection parts may be configured in an inelastic manner. For example, the connection parts may be formed as a woven fabric in which both warp and weft threads are formed from multifilament yarns of PET.

[0031] In contrast to the region of the volume chamber, in this variant no elastic threads are used in the adjacent connecting portions. Alternatively, the end portions of the volume chamber can also serve as connecting portions. In this case, the entire vascular prosthesis can be made of a uniform material and have a substantially uniform elasticity.

[0032] According to one embodiment, the vascular prosthesis according to the invention can have a multi-layer, in particular a two-layer, construction in the region of the connection parts, which increases the tear strength of the sutures, i.e. significantly reduces the possibility of tearing of the sutures connecting the vascular prosthesis to the natural vasculature. The multi-layer construction can be obtained, for example, by turning over or folding and, if necessary, sewing together the textile tube in the region of the connection parts.

[0033] According to one embodiment of the present invention, the vascular prosthesis may have a dumbbell-shaped configuration such that in the unpressurized state, it is conically expanded in the region of the connection portion compared to the central region of the volume chamber. In other words, in the unpressurized state, the vascular prosthesis of this embodiment has a smaller diameter in the region of the volume chamber than in the region of the connection portion, and its diameter expands conically starting from the diameter of the volume chamber towards the end of the vascular prosthesis. In this case, the diameter of the vascular prosthesis in the region of the connection portion may be approximately one third larger than the diameter of the volume chamber in the unpressurized state. It has been found that the natural compliance of the aorta can be particularly well imitated by such a dumbbell-shaped configuration of the vascular prosthesis.

[0034] The vascular prosthesis may have a total length of about 15 cm to 25 cm, the volume chamber may have a length of about 10 cm to 15 cm, and if necessary the length of the connecting parts adjacent to both sides of the volume chamber may be about 3 cm to 8 cm each. As mentioned above, by folding back in the region of the connecting parts, the length of the connecting parts can be varied in this case and adapted to the conditions to a certain extent. The diameter of the vascular prosthesis in the unpressurized state can be 15 mm to 20 mm in the central region of the volume chamber. In one embodiment of the vascular prosthesis with conically expanded connecting parts, the diameter can be expanded to about 25 mm to 33 mm.

[0035] To ensure the initial seal, the vascular prosthesis may be impregnated with cross-linked gelatin or coated with a synthetic polymer such as silicone.

[0036] Finally, the invention according to claim 16 also relates to a method for manufacturing a vascular prosthesis according to the invention, which method comprises the steps of: providing a weft yarn and a warp yarn, the weft yarn being formed from an elastic yarn at least in the region of the volume chamber; warping the ground and pile warps; The process of weaving textile tubes on a shuttle ribbon loom; heat setting the woven textile tube; washing the vascular prosthesis to remove the finishing agent; Includes. Effect of the Invention

[0037] In summary, the vascular prosthesis according to the invention has the advantage, compared to known vascular prostheses, of a very simple construction, since it obtains the required properties mainly from the material from which it is made: for example, the construction of a complex and defect-prone vascular prosthesis having an adaptation means consisting of a frame surrounding a volume chamber from the outside and a clamping spring body can be dispensed with.

[0038] The elasticity and volume capacity (compliance) of the elastic textile vascular prosthesis according to the invention correspond to that of the natural aorta. Thus, the compliance gap between the vascular prosthesis and the aorta that exists in rigid vascular prostheses is eliminated, which has a favorable effect on the heart, the aorta and the vascular prosthesis itself in the designated long-term applications. Thus, the above-mentioned unfavorable consequences for the heart, the aorta and the vascular prosthesis after implantation of the vascular prosthesis can be avoided.

[0039] The vascular prosthesis according to the invention is particularly suitable for replacing and bridging diseased parts of the aorta, but also for large, medium and small vessels, as a vascular prosthesis for aortocoronary bypass. [Brief description of the drawings]

[0040] [Figure 1] FIG. 1 is a schematic perspective view showing a first embodiment of an elastic vascular prosthesis. [Diagram 2] FIG. 13 shows a portion from an illustration of a second embodiment of an elastic vascular prosthesis. [Diagram 3] FIG. 13 shows a portion from an illustration of a third embodiment of an elastic vascular prosthesis. [Figure 4] FIG. 13 shows a portion from an illustration of a fourth embodiment of the elastic vascular prosthesis. [Diagram 5] FIG. 13 shows a portion from an illustration of a fifth embodiment of an elastic vascular prosthesis. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0041] The invention is explained in more detail below with reference to exemplary embodiments and the accompanying schematic drawings. In a schematic perspective view, Figure 1 shows a first embodiment of an elastic vascular prosthesis, given in its entirety with the reference number 1. The vascular prosthesis 1 comprises a volume chamber 2 and a connection portion 3 adjacent to the volume chamber 2 for connecting the vascular prosthesis 1 to the natural cardiovascular system, not shown here. The vascular prosthesis 1 is constructed as a seamless textile fabric tube consisting of warp and weft threads, the weft thread in the region of the volume chamber 2 being formed from a highly elastic thread having a core of silicone thread, around which a thread of polyethylene terephthalate wrapping thread is wound once.

[0042] The elastic threads are threads suitable for medical purposes. The warp threads in the area of ​​the volume chamber 2 are made from PET multifilament threads suitable for medical purposes. The end-side connection part 3 of the vascular prosthesis 1 is constructed as a non-elastic woven fabric, both the warp threads and the weft threads being made from PET multifilament threads.

[0043] The vascular prosthesis 1 according to Fig. 1 has a dumbbell-shaped configuration, i.e. in the unpressurized state shown in Fig. 1, it is conically expanded in the region of the connection part 3 as compared to the central region of the volume chamber 2. Here, the maximum diameter D1 in the region of the connection part 3 is approximately one third larger than the diameter D2 in the region of the volume chamber 2, which is shown in Fig. 1 only diagrammatically and not to scale.

[0044] Figure 2 shows a second embodiment of a vascular prosthesis 1 according to the invention, where only half of a symmetrically constructed vascular prosthesis 1 is shown here and also in Figures 3 to 5. The exemplary embodiment of Figure 2 differs from the embodiment of Figure 1 only in that the conical expansion in the region of the connection part 3 is less pronounced. In the example shown here, the maximum diameter in the region of the connection part can be up to a quarter larger than the diameter in the region of the volume chamber in the unpressurized state of the volume chamber.

[0045] Figure 3 shows an embodiment of a vascular prosthesis 1 with a double-layer construction in the region of the connection part 3. For this purpose, the connection part 3 of the vascular prosthesis 1 according to Figure 1 is folded outwards at the end 4 and the outer layer is sewn to the inner layer in a manner not shown in detail with the aim of fixing the outer layer. If such a vascular prosthesis 1 is sutured to a natural blood vessel in the region of the double-layer connection part, tearing of the sutures can be prevented by the double layer.

[0046] 4 shows an embodiment of the vascular prosthesis 1, the diameter of which in the region of the connection portion 3 substantially corresponds to the diameter of the region of the volume chamber 2 in the unpressurized state. At the same time, the vascular prosthesis 1 has a pleated portion 5 in the circumferential direction in the region of the connection portion 3. The pleated portion 5 may be configured in the form of a spiral or a closed ring, providing the vascular prosthesis with a high level of flexibility in the region of the connection portion 3. In particular, the vascular prosthesis 1 can thus avoid kinking in the region of the connection to the natural blood vessel.

[0047] Figure 5 shows another embodiment of the vascular prosthesis 1 according to the invention, in which the end parts of the volume chambers 2 themselves serve as the connecting parts 3. In this case, the entire vascular prosthesis 1 is woven of a uniform elastic material, in the weft elastic threads of silicone yarns with PET wrapping yarns are used, and in the warp PET multifilament yarns are used. In the unpressurized state, the vascular prosthesis 1 has a substantially uniform diameter over its entire length. The volume chambers 2 are configured in a beveled manner in the area of ​​the connecting parts 3.

[0048] The angle of the bevel is approximately 45° relative to the longitudinal axis L of the vascular prosthesis 1. Such a vascular prosthesis 1 is therefore particularly suitable for being implanted as a bypass. Such a vascular prosthesis 1 can be produced from an unbroken corresponding textile tube by simply cutting it to length and providing a bevel in the region of the cut edges. In this case, the beveled cut may be performed, for example, by laser cutting. In this way, particularly smooth cut edges without fraying can be achieved. A vascular prosthesis configured in this way has a particularly simple structure and is particularly easy to manufacture. [Explanation of symbols]

[0049] 1 Vascular prosthesis 2 Volume chamber 3 Connection part 4 End 5 Pleated section

Claims

1. a volume chamber, the volume chamber having a pressure expansion behavior that substantially corresponds to the pressure expansion behavior of a natural blood vessel in a blood pressure range below a pressure threshold D, while the volume of the volume chamber varies in response to pressure by at least 10 cm in a blood pressure range above the pressure threshold D. ３ A vascular prosthesis for connection to the natural cardiovascular system, characterized in that the vascular prosthesis is configured as a textile tube, which in the region of the volume chamber comprises an elastic thread having a core made of silicone thread around which is wound a thread made of polyethylene terephthalate (PET).

2. 2. The vascular prosthesis according to claim 1, characterized in that the core of the elastic thread is a highly elastic silicone thread.

3. Vascular prosthesis according to claim 1 or 2, characterized in that the silicone thread is constructed as a monofilament made from silicone having a Shore hardness of 30-70, preferably 40-60.

4. Vascular prosthesis according to any one of claims 1 to 3, characterized in that the elastic threads have a count of 100 to 3000 dtex, preferably 200 to 2000 dtex.

5. 5. The vascular prosthesis according to claim 1, characterized in that the vascular prosthesis is constructed as a fabric tube made up of warp and weft threads, the weft threads in the region of the volume chamber being formed from the elastic threads.

6. 6. The vascular prosthesis according to claim 5, characterized in that the warp threads are made of PET threads.

7. 7. Vascular prosthesis according to claim 6, characterized in that the PET yarns forming the warp threads have a count of 50 to 300 dtex.

8. 8. Vascular prosthesis according to claim 6 or 7, characterized in that the PET yarns forming the warp threads are configured as multifilament yarns consisting of 20 to 300 filaments.

9. Vascular prosthesis according to any one of claims 6 to 8, characterized in that the PET yarns forming the warp threads are configured as flat yarns or textured yarns.

10. Vascular prosthesis according to any one of claims 5 to 9, characterized in that the fabric tube is woven in a twill or satin or plain weave.

11. The vascular prosthesis according to any one of claims 1 to 10, characterized in that the vascular prosthesis comprises a connection portion adjacent to the volume chamber for connection to the natural cardiovascular system, the connection portion having a lower elasticity than the volume chamber.

12. 12. The vascular prosthesis according to claim 11, characterized in that the connecting portion is configured as a woven fabric and includes warp and weft threads made of PET configured as multifilament yarns, the weft threads being configured as flat yarns or high shrinkage yarns.

13. A vascular prosthesis according to any one of claims 1 to 10, characterized in that an end portion of the volume chamber serves as a connecting portion for connecting to the natural cardiovascular system, and the vascular prosthesis has a uniform elasticity in the area of ​​the volume chamber including the connecting portion.

14. Vascular prosthesis according to any one of claims 11 to 13, characterized in that the vascular prosthesis has a double layer construction in the region of the connection parts.

15. 15. The vascular prosthesis according to claim 11, characterized in that in a non-pressurized state, the vascular prosthesis has a dumbbell-shaped configuration such that it is conically expanded in the region of the connection portion compared to the central region of the volume chamber.

16. providing a weft thread and a warp thread, the weft thread being formed from the elastic thread at least in the region of the volume chamber; warping the ground and pile warp yarns; weaving the textile tube on a shuttle ribbon loom; heat setting the woven textile tube; washing the vascular prosthesis to remove the finishing agent; A method for producing a vascular prosthesis according to any one of claims 1 to 15, comprising:

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