The Influence of Weaving Technologies on the Integral Characteristics of Synthetic Vascular Prostheses

Abstract

The aim of the study is to determine physical and structural properties of woven synthetic prostheses depending on the type of the weave.

Materials and methods: Ten vascular prostheses manufactured at the Science and Technology Park of the BNTU "Polytechnic" (Minsk, Republic of Belarus) have been analyzed. The prostheses differed in the type of weaving, duration and temperature of thermal fixation during crimping. Three samples had a single-layer structure and 7 samples had a double-layer structure. Tests for water permeability, resistance to radial bending, and porosity of the prostheses have been performed.

Results: The single-layer woven prostheses have demonstrated a low level of water permeability: the best result was shown by sample No.1: 80 [77.1; 80.5] ml/min/cm². A strong direct correlation was revealed for these prostheses: the larger the pore diameter, the greater permeability (r=0.778; p=0.05). The single-layer woven prostheses appeared to be most resistant to radial bending, samples No.1 and 3 had no deformations at the minimum radius of the cylinder (r<4 mm), sample No.2 showed deformation on the cylinder with r=5 mm. For the single-layer prostheses, a strong negative correlation was noted (r=‒0.97; p=0.04) between the density of the warp threads and the kinking radius.All double-layer prostheses have demonstrated higher water permeability and weak resistance to deformation during radial bending. Samples No.4 and 8 were found to have minimum and maximum water permeability of 276.5 [258.3; 288.4] and 538.8 [533.3; 564.3] ml/min/cm², respectively. The minimum kinking radius (7 mm) was shown by samples No.9 and 10. The worst results were demonstrated by sample No.6, which was deformed with minimal bending.

Conclusion: Samples with ordinary plain weave have a low level of water permeability and high resistance to radial deformation, which makes them look most promising for the application in vascular surgery.

Keywords: kinking radius; vascular prosthesis; water permeability; woven dacron prostheses.

Figure 1.. Rapports of the main types of textile weaves:

(а) Rwa/Rwe 2/2 plain weave; (b) 2/1 warp twill weave; (c) 4/1 satin weave. The fibers of the warp threads are located vertically, the fibers of the weft threads are horizontal (pattern from site https://www.nicepng.com/maxp/u2w7r5e6i1t4e6e6/)

Figure 2.. Water permeability testing device:

(а) test bench; general view: 1 — air compressor; 2 — distilled water tank; 3 — BD Sensors DMP 331 water pressure sensor, mounted into the holding device; 4 — sample holding device; 5 — monitor for controlling liquid pressure in the system; (b) fixation of the sample in the straightened state with a rubber ring (black arrow) into the 0.78-cm² aperture; (c) continuous monitoring and display of pressure values in the system during testing procedures

Figure 3.. Tests for resistance to radial bending:

(а) cylindrical gauges with the 4.0‒42.5-mm radius and 1.5-mm pitch; (b) loop formation for sample No.1, cylindrical gauge diameter — 8 mm (R=4 mm)

Figure 4.. Prostheses samples:

(а) prosthesis No.1; (b) prosthesis No.2; (c) prosthesis No.3; (d) and (g) prosthesis No.4; (e) and (h) prosthesis No.5; (f) and (i) prosthesis No.6. Arrows show the direction of the warp threads

Figure 5.. Prostheses samples:

(а) and (e) prosthesis No.7; (b) and (f) prosthesis No.8; (c) and (g) prosthesis No.9; (d) and (h) prothesis No.10. Arrows show the direction of the warp threads