Microsurgical techniques in rat heterotopic small bowel transplantation: analysis of 450 cases

We sought to review 450 rat small bowel transplantation (SBT) operations having a modified microsurgical technique to discuss the key steps for a successful operation.

Four hundred fifty rat heterotopic small bowel transplantations were performed in 3 stages: the first 80 cases were a training stage, the following 330 cases were for formal experiments, and, in the last stage, 40 cases were to analyze the relationship between the duration of cold preservation and recipient mortality. For all cases, revascularization of the graft was accomplished by an end-to-side anastomosis between the donor superior mesenteric artery or aorta and the recipient infra-renal aorta, and cuffed end-to-end anastomosis between the donor portal vein and the left renal vein of the recipient. The duration of each operation, graft warm ischemia time, and recipient survival rate were compared.

In the first stage, the graft warm ischemia time was about 90 minutes where as it was only 35 minutes in the second stage. The longterm survival rates (>5 days) of recipients were 8.8% and 97.3%, respectively. In the 3rd stage, long cold preservation period significantly increased recipient mortality.

Graft warm ischemia time was a key issue associated with recipient mortality; a well-trained, simplified microsurgical anastomosis between graft superior mesenteric artery and recipient aorta accomplished in a shorter time rendered intravenous transfusion not essential for the recipient.