Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2/82—Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2/86—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
  • A61F2/88—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure the wire-like elements formed as helical or spiral coils
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M1/00—Suction or pumping devices for medical purposes; Devices for carrying-off, for treatment of, or for carrying-over, body-liquids; Drainage systems
  • A61M1/36—Other treatment of blood in a by-pass of the natural circulatory system, e.g. temperature adaptation, irradiation ; Extra-corporeal blood circuits
  • A61M1/3621—Extra-corporeal blood circuits
  • A61M1/3653—Interfaces between patient blood circulation and extra-corporal blood circuit
  • A61M1/3655—Arterio-venous shunts or fistulae

Definitions

• the present invention relates to a blood vessel prosthesis of a new type, particularly for use as a coupling piece or by-pass between blood vessels, in particular between vein and artery.
• a blood vessel prosthesis there is usually used a so-called heterograft, i.e. a piece of blood vessel taken from an animal, for example of bovine, ovine or procine origin.
• heterografts treated in a particular way are called xenografts and consist of chemically or physically treated blood vessels from animals for the purpose of enduring long time implantation and for the purpose of constituting a tissue-compatible material.
• Such by-pass is introduced by surgical operation with the one end thereof in an artery and the other end in a vein, for example in the arm of a patient, and it connects in this manner said two blood vessels enabling intermittent drainage of blood, purification of the drained blood and returning same to the blood system of the patient.
• this type of graft for coupling an artery and a vein together there are, however, practical problems, among which the following may be mentioned.
• the by-pass In connection with the drainage of blood the by-pass where it is implanted by operation under the skin of the patient is punctured with a cannula. After repeated drainage the by-pass i loses its elasticity, and when after finished blood treatment the cannula is withdrawn it is required, in the usual manner that pressure is applied to the site of drainage for the purpose of obtaining coagulation of the blood in the same way as in the conventional drainage of blood for blood analysis.
• the present invention has for its purpose to provide a blood vessel prosthesis wherein the above-indicated problems are eliminated or at any rate essentially reduced
• Another purpose of the invention is to provide a process for the application of such blood vessel prostheses operating as a by-pass, particularly for connecting an artery to a vein.
• a blood vessel prosthesis comprising a tubular element of a tissue-compatible material, which blood vessel prosthesis constitutes essential advantages compared to the prior art as indicated above.
• the blood vessel prosthesis according to the invention is provided with an interior elastically resilient support member which at least at one end of the element extends outside said end.
• the said end of the tubular element is connected to the vein and the outwardly extending support member thus extends into the vein for the purpose of maintaining the vein from the inside in an expanded position so as not to disturb the blood circulation.
• the tubular element may be made of any tissue-compatible material of native or synthetic nature.
• tissue-compatible material of native or synthetic nature.
• it is preferred to use in the tubular element such materials which are present in so-called xenografts, which are phemically or physically particularly prepared heterografts.
• synthetic tissue compatible materials may be used, such as polyethylene terephthalate, polytetrafluoro ethylene, polyethylene, polypropylene etc,.
• the support member arranged within the tubular element can be designed in many ways. It may for example consist of a helix-shaped spiral spring which engages the interior wall of the element with an adjusted pressure. As a material in this spiral spring there may be used a tissue compatible metal, for example stainless steel, or a plastic material of sufficient rigidity. Further details concerning such spiral springs are clear from Swedish patent application 8202740-0.
• a flexible tubular body which is composed of several individual rigid but flexible thread elements, each of which extends in helix configuration with the center line of the body as a common axis.
• a number of elements have the same direction of winding but are axially displaced relative to each other.
• the said number of elements having the same direction of winding meet and cross a number of thread elements which also are axially displaced relative to each other but have the opposite direction of winding.
• Such tubular body can be expanded by axial shortage of body or may obtain reduced diameter by axial elongation of the body.
• the diameter of the blood vessel prosthesis may vary within relatively wide limits depending on where it is applied but the most frequent dimension may lie between about 3 and 10 mm.
• the part of the support member extending outside the tubular element has suitably a length of up to about 20 times the inner diameter of the tubular element, particularly about 3-12 times the said diameter to give the desired function. In this manner there is obtained by means of the extending end of the support member a satisfactory supporting function inside the surrounding blood vessel, particularly when the vessel consists of a vein where, as is known, the blood pressure is low and even in some cases may be negative relative to the atmospheric pressure.
• the problems introductorily mentioned are eliminated in a simple and efficient manner.
• the prosthesis for the whole period of implantation maintains a satisfactory elasticity so that blood drainage can take place without problems.
• a further advantage when using a spiral spring or tubular member composed of oppositely directed spiral elements resides is the fact that introducing a cannula in the prosthesis results in widening of the spring material which then after the removal of the cannula and the return of the support member to normal position results in contraction of the opening of the prosthesis caused by the cannula so as to provide for almost autosealing. Thanks to the extending part of the support member also the risk of the formation of stenosis in connection with the application site of a vein will be avoided.
• a blood vessel prosthesis generally indicated 1 according to the invention coupled between an artery 5 and a vein 7.
• the by-pass or blood vessel prosthesis 1 contains as a support member a helix-shaped spiral spring 3 which extends from the site 9 of application of the artery through the tubular element 2 up to and beyond connecting site 11 of the vein 7 a distance 13.
• the tubular element 2 is preferably constituted by a so-called xenograft, for example of bovine origin, i.e. a heterograft treated chemically and/or physically in a suitable manner.
• Spiral spring 3 can be constituted by a medicinally acceptable stainless steel.
• the manner of applying or implanting the blood vessel prosthesis for connecting artery 5 to vein 7 may for example be briefly as follows.
• the vein 7 of the patient is opened by surgical incision, whereafter the tubular element 2, for example the xenograft, is attached to the vein by sewing in a conventional manner.
• spiral spring 3 is inserted from outside into the tubular element 1, which is done by contracting spiral spring 3 in some suitable way, for example by rotating the ends relative to each other, and spiral spring 3 is then positioned in the position shown in the drawing and is subjected to expansion for fixation in this position with a pressure adapted for the purpose.
• the end extending towards vein 7 extends outside the tubular element 1 a suitable distance 13 which, when applied to haemodialysis may be about 3-4 cm.
• the prosthesis After applying the blood vessel prosthesis the prosthesis may now be easily localized and can be easily punctured for drainage of blood.
• the mantle surface of the body consists of a number of individual thread elements. Of these thread elements one set of elements extend in helix configuration axially displaced relative to each other with the center line of the body as a common axis. The other set of element extends in helix configuration in the opposite direction of winding, the thread elements extending in opposite directions crossing each other to form a cylindrical plaited configuration.
• the diameter of a tubular body built up in this manner can be varied by axial displacement of the ends of the body in relation to each other in the direction of the center line.
• the tubular body can be expanded in several ways and it is preferred that the body inherently has the ability of taking expanded position by itself in its released state. This can be provided by using the tension of the material of the body.
• the device of the invention can be used at all times when it is desired by using a so-called by-pass to connect two blood vessels to each other for the purpose of draining blood for the taking of samples, analyses, dialyses etc.
• the process for attaching the blood vessel prosthesis limited to that described above.
• the tubular element is provided in advance with an interior support member, for example a spiral spring, and one must see to it that at least one end of the element of the support member extends outside the end of said element for a certain distance.
• the tubular element provided in advance with a support member is then attached by sewing at the end where the support member extends to the exterior to a vein, whereas the other end of the element is attached to an artery.
• the blood vessel prosthesis after being positioned subcutaneously, for example for use in haemodialysis, will be better attached without rotation or folding which is the case with previously used blood vessel prostheses. Thanks to the interior support member the blood vessel prosthesis obtains an elasticity which makes it safe in operation and easy to use.

Landscapes

• Health & Medical Sciences (AREA)
• Heart & Thoracic Surgery (AREA)
• Engineering & Computer Science (AREA)
• Biomedical Technology (AREA)
• Vascular Medicine (AREA)
• Veterinary Medicine (AREA)
• Cardiology (AREA)
• Public Health (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Oral & Maxillofacial Surgery (AREA)
• Transplantation (AREA)
• Anesthesiology (AREA)
• Hematology (AREA)
• Prostheses (AREA)
• External Artificial Organs (AREA)
• Materials For Medical Uses (AREA)
• Investigating Or Analysing Biological Materials (AREA)

Applications Claiming Priority (1)

Publications (1)

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ID=20349888

Family Applications (1)

Country Status (5)

Cited By (45)

Families Citing this family (3)

Citations (6)

Family Cites Families (4)

• 1983
  • 1983-02-03 SE SE8300578A patent/SE446372B/sv not_active IP Right Cessation
• 1984
  • 1984-01-26 WO PCT/SE1984/000025 patent/WO1984003036A1/en unknown
  • 1984-01-26 CH CH5073/84A patent/CH660299A5/fr not_active IP Right Cessation
  • 1984-01-26 JP JP59500679A patent/JPS60500520A/ja active Granted
  • 1984-02-02 FR FR8401634A patent/FR2540379A1/fr active Pending

Patent Citations (6)

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