Cheng-Hung Lin^1,2, Qi Mao¹, Zuhaib Ibrahim¹, Eric Wimmers¹, Lehao Wu¹, W.P. Andrew Lee¹, Gerald Brandacher¹

¹Department of Plastic and Reconstructive Surgery, The Johns Hopkins University, Baltimore, MD, United States; ²Department of Plastic and Reconstructive Surgery, Chang Gung Memorial Hospital, Taipei, Taiwan

Background: Clinical outcomes after small bowel transplantation are still challenging compared to other solid organs. Therefore, animal models are critical to better understand the immunology and physiology of these grafts. In particular with regards to transplant immunology the mouse is the “gold standard” but the microsurgical techniques involved are extremely technically challenging and limit widespread use. Here we report a simplified, reproducible and reliable mouse model for small bowel transplantation using a non-suture cuff technique.

Materials and Methods: Syngeneic transplants were performed using C57BL6 mice (n=20). A 5-cm segment of the jejunum based on the superior mesenteric artery and portal vein was harvested. The donor artery and vein were mounted with polyimide cuffs (artery cuff: inner diameter: 0.404mm, wall thickness: 0.025mm; vein cuff: inner diameter: 0.455mm, wall thickness: 0.025mm), and subsequently anastomosed to the recipient’s common carotid artery and external jugular vein. Following reperfusion of the graft, the proximal and distal ends of the graft were brought out as stomata.

Results: Success rate of this model was high (90%) with 2/20 graft lossesresulting from postoperative bleeding. No vascular thrombosis occurred. Donor operation lasted 60±12min and recipient operation 45±7min. Warm ischemia time could be limited within 20±2min. Graft biopsies were performed at serial time points and long-term graft survival (>100 days) was confirmed by gross and histological appearances without evidence for chronic pathologic changes.

Conclusion: This represents the first cervical heterotopic small bowel transplantation model using a non-suture cuff technique for revascularization. Advantages are that the high-flow common carotid artery keeps anastomosis patent, and diastolic suction of the heart minimizes the risk of venous stasis and thrombosis resulting in lowmortality and morbidity that is usually associated with laparotomy in a mouse model. This novel technique will be best suited to investigate basic immunology and ischemia-reperfusion-injury in intestinal transplantation.