Is the guideline the cause of structural failure in current polyester vascular prostheses? An experimental study.

To evaluate the impact of the guideline on the structural failure of current polyester vascular prostheses, we studied seven unsealed polyester vascular prostheses. An accelerated time test was used for assessing degradation of polymeric medical materials at pH 7.4 in phosphate buffer at a temperature of 95 degrees C. Probe burst strength was determined on the guideline and on standard parts of the prostheses during the accelerated time test. Weight-average molecular weights of the guideline and of the standard parts in all knitted grafts during the accelerated time test were measured. The guideline was significantly weaker than the standard parts in most prostheses. The guideline had significantly lower values of weight-average molecular weights than the standard parts in most knitted grafts. This study showed that guideline degeneration was one factor responsible for the structural failure of some current polyester vascular prostheses.