Material and Structures for Gastrointestinal Stents

Stents are used to counteract and relieve in-vivo duct or vessel obstructions. The purpose of the current study is to select a biocompatible, biodegradable material for use in the manufacture of stents to counteract anastomotic leakage following gastrointestinal surgery. Chitosan a biocompatible, biodegradable environmentally friendly natural polysaccharide was blended with polycaprolactone, a versatile synthetic polymer. This material was fabricated in the form of sheets by moulding and curing blends of chitosan / polycaprolactone. The tensile strength of chitosan and chitosan / polycaprolactone blends were investigated. These tensile tests were carried out on chitosan and chitosan / polycaprolactone blends of 50/50, 40/60, 30/70 and 20/80 wt/wt %, cured in 5% sodium hydroxide. The chitosan / polycaprolactone blends were then formed into stents. The sheet mouldings were wound around a stainless steel stent former while fixing the layers together with un-cured chitosan / polycaprolactone blend and subsequently curing the layers together with sodium hydroxide, producing the stent shape.

This research concluded that the chitosan / polycaprolactone blends of various compositions show a wide range of strain at failure and mechanical strengths. Furthermore the fabrication of the chitosan / polycaprolactone stents show that the blends can be formed into thin films wound into tubular stent structures. This indicates that the material blends are suitable materials for the further development of biodegradable stents designed to counteract gastrointestinal leakage.