Surgical removal of the pancreas with one-step autotransplantation of isolated Langerhans islets into the hepatic portal system in the pig.

Introduction: Autotransplantation of isolated Langerhans islets is regarded as the only way to prevent iatrogenic diabetes in patients who had been scheduled for pancreatectomy due to painful chronic pancreatitis. A sufficient number of Langerhans islets capable of secretory activity need to be transplanted to maintain normoglycemia after the surgical procedure. In order to optimize all stages, including collection, storage, isolation and transplantation of pancreatic islets, a reproducible animal-based experimental model should be developed before a new method is introduced into clinical practice.

Objectives: The aim of the present study was to develop a reproducible autogenic model-based method for collection, conservation and isolation of porcine pancreas so that transplantation of isolated pancreatic islets could be performed and postoperative normoglycemia achieved.

Material And Methods: Pigs were subjected to total pancreatectomy with simultaneous splenectomy and without removal of the duodenum. The collected pancreas was stored in the University of Wisconsin solution with the addition of pentoxifylline (PTX) until the isolation procedure (<4 hours). Efficacy of isolation was evaluated based on the number, quality and viability of obtained islets. Following autotransplantation into the liver, secretory activity of the islets was assessed intravitally by serum glucose monitoring.

Results: The islet yield per gram of pancreas was 1452 (standard deviation [SD] +/- 125) for the PTX group and 384 (SD +/- 115) for the control non-PTX group (p<0.01). Viability of islets for individual isolations did not reveal any statistically significant differences between groups and was estimated at 85-93%. Three out of five animals demonstrated normoglycemia with features of neoangiogenesis in the islets transplanted into the liver, which was confirmed by histological examination. One animal developed hyperglycemia up to 430 mg/dl, and histological image showed intensive apoptosis and degranulation in the transplanted islets.

Conclusions: Efficacy of the isolation method was confirmed by achieving normoglycemia after autotransplantation of pancreatic islets into the liver, while histological examination showed hepatic vascularization to be the most appropriate location for an autogenic graft. PTX presence in the preserving solution for the pancreas storage produced the cytoprotective effect, which directly correlated with the islet yield.