Development of trans-1, 4-polyisoprene for sutureless vascular anastomosis

Abstract

Radiation crosslinked trans-1,4-polyisoprene (t-PIP) is shown to be effective as a heat shrinkable connector for severed blood vessels. The sutureless vascular anastomosis system (SVAS) requires a plastic sleeve with the following requirements: biocompatibility, heat shrinkability, melting point 50 to 60°C, and proper mechanical properties. The effects of irradiation by cobalt-60 gammas on pertinent physical properties were determined. The measurements of gel fraction, thermal and mechanical properties demonstrate that at appropriate dose levels t-PIP meets initial SVAS requirements. The ability of processed t-PIP to retain its structural integrity after aging was measured in various oxidizing environments for twenty weeks. The results show no change in the gel fraction and mechanical strength. An in-vitro test of the processed t-PIP with intravenous saline solution demonstrates that the material undergoes no physical property changes after five months. Also, biocompatibility of the crosslinked t-PIP sleeve was established by tests performed at the University of Tennessee. Both in-vitro in in-vivo tests were performed at The Johns Hopkins University. In the in-vivo test, an SVAS operation was performed on the carotid artery of a live dog. The results of all the tests demonstrated that the procedure and the t-PIP sleeve were effective and safe.