SU628911A1 - Blood vessel prosthesis and method of manufacturing same - Google Patents

Description

This invention relates to medicine.

A prosthetic blood vessel containing a tubular textile frame covered outside and inside with layers of silicone rubber is known. The method of obtaining this prosthesis is that the skeleton is impregnated with a solution of a compound based on low molecular weight silicone rubber, followed by substance 1.

A disadvantage of the known prosthesis is low radial elasticity, which leads to deterioration of the functional properties of the prosthesis.

The disadvantage of this method is the difficulty of obtaining from the solution of a film of silicone rubber with a thickness of more than 0.2-0.3 mm. As a result, the elastic properties of the obtained prosthesis are determined only by the properties of the textile skeleton, and the film of a compound based on low molecular weight rubber reduces the flexibility of the skeleton.

As a result, the blood permeability during bending is reduced, and the longitudinal springiness of the prosthesis.

The aim of the invention is to improve the functional properties of the prosthesis by increasing its radial elasticity.

This is achieved by the fact that the prosthesis containing a tubular textile frame, covered on the outside and inside with layers of silicone rubber, is reinforced with a thread of a rigid polymeric material, preferably polypropylene, arranged in a spiral between the textile frame and the outermost organic layer.

The tubular textile frame can be made of a knitted mesh of a fillet weave made of synthetic fiber, mainly lavsan, while the walls of the prosthesis are corrugated, and the reinforcing thread is arranged in the hollows of the corrugations.

The method of obtaining a new prosthesis is that a layer of unvulcanized silicone rubber is successively applied to the mandrel, then a textile carcass layer, after which the resulting billet is wrapped with a string of rigid polymeric material, then a second layer of unvulcanised silicone rubber is applied, after which the billet thermoablative to the vulcanization of rubber and the resulting prosthesis is removed from the mandrel.

The second variant of the method is that the mandrel is taken with a screw thread. After application of the textile frame, the resulting preform is wrapped with thread along the cutting grooves. Before heat treatment, the workpiece is crimped with wire wound over cutting, which is then wound around the heat treatment.

The drawing shows the prosthesis, incision.

The prosthesis contains an inner layer 1 of silicone rubber, a layer of knitted mesh 2, a reinforcing thread 3 and an outer layer 4 of silicone rubber,

Example. A metal mandrel having a cutting with an outer diameter of 30 m.m is wrapped with a single layer uncured

 Medium Save- 1 Save

I diameter, mm I tsya P1zi bend, frame,%

0.6 mm thick silicone rubber and one layer of lavsan mesh of sirloin weave with a cell size of 3 x x 3 mm.

The resulting billet is wrapped around the grooves of the cutting of the metal mandrel with polypropylene thread. Thread diameter 0.5-1.0 mm. Then the top is wrapped with a billet of a layer of m silicone rubber 0.6 mm thick. The corrugations are molded with an external winding of the obtained billet with wire to cut the mandrel.

The resulting corrugated billet is heat treated at 180 ° C for 6 hours, after which the wire is removed and the resulting prosthesis is released from the mandrel.

The properties of the obtained prosthesis in comparison with the properties of a known prosthesis of similar sizes are shown in the table.

KH%

Note: It was determined by the change in the cross-section when bending the prosthesis around the cylinder with a radius equal to I the diameter of the prosthesis.

Claims (4)

 It was determined by the change in the cross section at an internal pressure differential from 100 to -350 mm Hg. Art. Claim 1. A blood vessel prosthesis comprising a tubular textile frame covered outside and inside with layers of silicone rubber, characterized in that, in order to improve its functional properties by increasing the radial elasticity, it is reinforced with a string of rigid polymeric material, preferably polypropylene, located in a spiral between the textile frame and the outer silicone layer. 2. A prosthesis according to claim 1, characterized in that the tubular textile frame is made of a knitted mesh of a fillet weave made of synthetic fiber, preferably polyester, while the walls of the prosthesis are corrugated, and the reinforcing thread is located in each side of the corrugation. 3. A method of manufacturing a prosthesis of a blood vessel according to claim 1, characterized in that a layer of uncured silicone rubber is subsequently applied onto the mandrel, then a layer of textile carcass, after which the resulting blank is wrapped with a string of rigid polymeric material, then a second layer of uncured silicone rubber is applied, after which the workpiece is thermally treated until the rubber is vulcanized and the resulting prosthesis is removed from the mandrel. 4. A method according to claim 3, characterized in that the mandrel is taken with a screw thread, while applying the textile skeleton, the obtained workpiece is wrapped with thread along the grooves of the thread; before the heat treatment, the workpiece is crimped with wire, which is then wound over the thread, which is then wound after heat treatment. Sources of information taken into consideration. Knowledge of the expertise: 1. USSR Author's Certificate No. 562278, cl. A 61 F 1/24, 1975.