Biomechanics of human common carotid artery and design of novel hybrid textile compliant vascular grafts

Abstract

The mechanical properties and structure of a human common carotid artery were studied in order to develop criteria for designing and manufacturing compliant textile vascular grafts. The arterial wall comprised a composite of elastin and collagen fibers with the collagen fibers crimped. This structure led to a unique pressure-circumferential stretch ratio curve, the slope of which increased with an increase in strain. The increase in slope was particularly rapid at a stretch ratio above 1.4 or pressure above 120 mmHg. Based on the knowledge gained, a criteria for the design of biomechanically compliant arterial grafts was developed. An elastomeric prestretched polyurethane monofilament yarn with a low modulus of elasticity and a bulked polyester multifilament yarn with a high modulus of elasticity were combined and used as threads in the manufacture of grafts. Tubular structures of diameters in the range 4-6 mm were made by weaving. Transverse compliance and morphological and permeability properties of these grafts were determined and compared with those of a currently available woven commercial grafts and human carotid arteries. Results indicated that the compliance values of the hybrid grafts were comparable with those of the human carotid artery. Preliminary in vivo studies in dogs showed promising results: a thin, stable neointima developed within 6 months of implantation on the flow surface.

Influence of fabrication process on the final properties of natural-rubber latex tubes for vascular prosthesis

“…The elastic moduli (Young's Modulus) of the first tested tubes are 270kPa, 210kPa, and 160kPa, respectively from the thickest to the thinnest. Comparing these preliminary values with results by Gupta and Kasyanov [16], for the Human Carotid Artery (83.36kPa), two different Textile Hybrid Vascular Grafts (HGV1: 61.81kPa and HGV2: 87.78kPa) and a Commercial Polyester Graft (1074.64kPa), we note that the rubber tubes present an intermediary elastic modulus. The elastic moduli of the rubber tubes are about 2 to 3 times larger than in the case of the Human Carotid Artery, even though these values are better than in the Commercial Polyester Graft.…”

“…The fact that the standard deviation is equal to the caliper error (0,01mm) means that the tubes were regular and uniform. Regarding the dimensions of the tubes, they might be applicable in substituting arteries and veins such as femoral, coronary, renal, carotid, portions of aorta with small caliber, vena cava etc [16,17].…”

Resorbable elastomeric networks prepared by photocrosslinking of high-molecular-weight poly(trimethylene carbonate) with photoinitiators and poly(trimethylene carbonate) macromers as crosslinking aids

“…This is most important, as these networks are intended to be used in medical applications involving soft tissues. The elastic modulus values of smooth muscle [40], carotid artery [41] and myocardium [42] range from 6 to 500 kPa, whereas for heart valves [43] and articular cartilage [44] they range from 2 to 20 MPa.…”

Small diameter Polyurethane vascular graft reinforced by elastic weft-knitted tubular fabric of polyester/spandex

“…The porosity of commercially available polyester (Dacron) knitted vascular grafts can be reduced by coating or sealing with a novel ionic urethane, to improve their blood-proof property. The mechanical properties of coated vascular grafts have been found to be comparable with, or superior to, the pre-coated Dacron substrate [23][24][25][26][27][28][29][30][31][32][33].…”