CS272674B1 - Vascular prosthesis at least partly wrapped and method of its production - Google Patents

Abstract

The solution deals with the arterial prosthesis, where rows with different material consumption per one link with folding arrangement perpendicular to its longitudinal axis alternate. The production method of this arterial prosthesis includes alternate creation of rows with different material consumption per one link concerning tubular fabric, while these rows, by putting the fabric on the tube and by its subsequent tucking up, form foldings with perpendicular orientation to the longitudinal axis of the arterial prosthesis. So adapted tubular fabric is subsequently fixed.

Description

The present invention relates to a vascular prosthesis in the form of a knitted tubing provided with shaped scraps and to a process for its manufacture.

In vascular surgery, in addition to smooth vascular prostheses, also corrugated vascular prostheses are used, the application of which is advantageous especially in the case of their bending, because even in a bent shape they retain a circular cross-section, which ensures better blood flow.

The classical production of crimped vascular prostheses is basically divided into several successive basic procedures. In the first stage of production, a smooth tube of the desired diameter is knitted and, in the second stage of production, is threaded onto a forming rod provided with a helical groove. By pushing the tubing into the groove with a line, wrinkles are formed on the tubing surface and subsequently thermally fixed. After fixation, the line must be unwound and the corrugated tubing must be unscrewed.

A characteristic external feature of such a crimped vascular prosthesis is a regular helix with a small pitch on its surface. As a result of the crimping process, the direction of the shaped corrugations on the stitch pillars of the braided tubing is not perpendicular, but deviated from the perpendicular to the longitudinal axis, for example by 15 °, depending on the helix pitch. The described, well-known multi-step production of crimped vascular prostheses based on knitting, mechanical threading of the tubing onto the forming rod, the formation of corrugations on the crimping device and the heat treatment is laborious and inefficient due to the manual work required. It is demanding on the skill of the operator.

The aforementioned drawbacks are eliminated by a vascular prosthesis, at least in part corrugated, in particular knitted, according to the invention, which consists in that it alternates rows with different material consumption per eyelet and the wrinkles are oriented perpendicular to the longitudinal axis of the vascular prosthesis. The principle of the vascular prosthesis according to the invention is that alternating rows are formed on the tubular article with different material consumption for the loop, and these rows, after stretching the article onto the tube and subsequently summing it, into wraps with a perpendicular orientation to its longitudinal axis. whereupon the tubular article thus treated fixes.

The advantages of a vascular prosthesis according to the invention are, in particular, that the manufacturing effort and difficulty are reduced. The new manufacturing technology allows the wrecks to be oriented perpendicular to the longitudinal axis of the vascular prosthesis. As a result, the vascular prostheses according to the invention do not rotate in the direction of their longitudinal axis when applied; thereby facilitating both implantation into the human body and the patency of the vascular prosthesis. The difference in the permeability of rows with different material consumption per loop is minimal and fully complies with the given standards for permeability of vascular prostheses.

Lines of different material consumption per loop can be formed, for example, by varying the rate of stitch formation during knitting, i.e., by the speed of the knitting machine, or by changing the amount of yarns fed. It is also possible to achieve rows with different mesh material consumption by changing the knitted fabric bond, possibly also by changing the physical or mechanical properties of the suture material used. In a similar manner, a vascular prosthesis can be produced by a weaving technique, i.e. also with a perpendicular orientation of the sprains to its longitudinal axis.

CS 272674 Bl

He did

The vascular prosthesis of tubular continuous shape of the same diameter was made on a double rasp Mayer DR 10-16 EEW, division 30 E in jersey-cloth binding. Synthetic threads in full sleeve were processed in the following set:

leotard - PES h 84 dtex 48 f, smooth with higher shrinkage cloth - PES h 100 dtex 48 f, KK NR joint - PES h 50 dtex 24 f, KK NR

Rows with different eyelet material consumption were created in this case by changing the knitting speed. In slowing the machine run, a larger yarn supply and a longer withdrawal time were used to create control lines and vice versa to create denser rapid run lines of the machine with less yarn supply in conjunction with a shorter withdrawal time. The looser rows predetermined the location in which the tubular knitted fabric was formed into the corrugations. Subsequent physical treatment consisted of stretching the braided hose onto a metal tube and, after summarizing it, fixing the wraps with a perpendicular orientation to the longitudinal axis of the hose assembly.

Example2

A vascular prosthesis in the form of a bifurcated branching formation was made on the same knitting machine using the weave and material of Example 1. Two narrower branches of 9 mm diameter coupled to one common wider branch of 19 mm diameter were formed under the same row forming conditions with different consumption of the staple material as in Example 1, with only a different row ratio when speeding and slowing the machine. Physical treatment identical to Example 1.

Claims (2)

A vascular prosthesis, at least partially crimped, in particular knitted, characterized in that rows with different consumption of material per loop alternate on it when the spars are arranged perpendicular to its longitudinal axis. 2. A method of manufacturing a knitted prosthesis, at least partially corrugated in accordance with claim 1, characterized in that rows of different loop material consumption are alternately formed on the tubular article, after which the rows are stretched on the tube and stretched thereafter. it creates wrecks with a perpendicular orientation to the longitudinal axis of the vascular prosthesis, whereupon the thus treated tubular article is fixed.