Surgical aspects of islet cell transplantation

Abstract

In this study, the initial experience of the authors using the lower rectum as a novel site for transplantation of free islets is reported. The reasons for selecting the rectum as a potential site are, firstly, that there is a rich plexus of veins draining into the portal venous system, secondly, that it is safe and convenient for access, both for grafting procedures and biopsies and thirdly, that repeat procedures are possible. About 1500 intact islets from three donor PVG rat pancreases were implanted, using an injection technique,into the submucosa of the lower rectum circumferentially above the dentate line of recipient syngeneic PVG rats (n=31). Biopsy of these transplanted islets showed revascularisation of islet clusters in the submucosa of the rectum for greater than 60 days. Clinical trials of islet cell grafting have commenced worldwide over the last 18 months, and this study describes a simple technique for islet cell grafting which could potentially be applied in diabetic patients. These data document for the first time the feasibility of the rectum as a novel site for transplantation of free islet cells.