Tensile testing of tubular vascular grafts produced by thermal compression fusion of flat collagenous materials.

A novel process of fusion bonding for the production of vascular grafts has been investigated. This process, based on the application of pressure and heat in a sophisticated way, has been used for the bonding of the longitudinal edges of flat dermal sheep collagen into tubular forms. The method produces continuous overlapping joints which are expected to overcome the problem of coagulation, as occurs in grafts produced by suturing. The values of the measured shear strength of the bond vary from 750 +/- 30 kPa to 940 +/- 32 kPa, depending on tube diameter and overlap length (n = 5). These values are much higher than calculated values of the stress in thin-walled tubes caused by a high static blood pressure, indicating a high safety factor for the fusion-bonded vascular grafts.