Small Bowel and Colon Transplantation in Rats Using Porto-Portal Cuff Anastomosis F.H.F. Galvão, R.M.N. Santos, A. Bakonyi Neto, M.A.C. Machado, T. Bacchella, and M.C.C. Machado ABSTRACT Portal versus systemic venous drainage and colon grafting are major controversies in the techniques of intestinal transplantation. The rat is the best animal for research in this field. Nevertheless, this model requires complex microvascular anastomoses that are responsible for the high incidence of technical failures. A cuff technique is an easier anastomosis method than a hand-suture. We describe a simplified rat model of small bowel and colon transplantation using a porto-portal cuff anastomosis. Donor. The entire small bowel, cecum, and ascending colon are harvested on a vascular pedicle, consisting of a long aortomesenteric conduit and portal vein. The right colonic vessels are preserved. The graft is flushed and a cuff device is placed on the end of the portal vein. Recipient. The graft is implanted through an end-to-side aorto-aorta hand-sewn anas- tomosis. A segment between the first and second jejunal branch is isolated between clamps to insert into the portal cuff. After reperfusion, the recipient’s mesentery is divided just below the cuff anastomosis. The recipient jejunum, ileum, and ascending colon are removed en bloc, and the graft is anastomosed in continuity with the remaining naive intestine concluding the operation. This simplified technique surmounts the technical obstacles in rats because it is easily and quickly performed, maintaining the physiological portal drainage, preserving graft ileocecal valve and ascending colon, and reaching acceptable success after a short period of training. T HE RAT is an optimal animal for intestinal transplan- tation research; nevertheless, this model requires complex microvascular anastomoses that impair satisfactory success rates. 1–6 A cuff technique for microvascular anas- tomosis is easier and safer than a hand-suture technique. 2 There is a lack of simplified models to study intestinal transplantation with portal drainage. We describe a simpli- fied model for intestinal transplantation with portal drain- age using a cuff technique. MATERIALS AND METHODS This study was approved by the ethics committee with animals treated according to institutional norms for laboratory animal care. Donor Operation The donor, anesthetized with isoflurane, undergoes a laparotomy using a midline incision. The duodenal vessels are exposed and the mesocolon is carefully separated from the pancreas and epiploics, preserving the right colonic vessels. The middle colic vessels are divided, and the middle and descending colon are separated from the small bowel and ascending colon. The superior mesenteric vein is separated from the mesoduodenum and pancreas. Splenic and pyloric veins are divided, and portal vein dissection continues up to hepatic hilum. The celiac trunk, right renal artery, and lumbar branches are divided. The dissected aorta is clamped below the diaphragm, tied below the mesenteric artery, and cut underneath the clamp and below the tie, performing a long aortomesenteric conduit. The portal vein is cut near the hepatic hilum. The entire small bowel, cecum, and ascending colon are removed, washed, and stored in cold preservation solution at 4°C. A 4-mm length polyethylene catheter with an inner diameter of 1.5 mm is used to make the cuff as described previously 2 with some modifications. Briefly, the vein is introduced into the cuff and everted, covering the outer wall of the cuff. Three equidistant stitches are used to fix the distal part of the everted vein to the base of the cuff. From Transplantation and Liver Surgery Discipline, University of Sao Paulo, Sao Paulo, Brazil. Address reprint requests to Dr. Flavio Galvao, Av. Dr. Arnaldo 455, Transplante e Cirurgia do Fı´gado 3 o  andar sala 11, Sao Paulo-SP, Brazil- 01246-903. E-mail: fgalvao@usp.br 0041-1345/06/$–see front matter © 2006 by Elsevier Inc. All rights reserved. doi:10.1016/j.transproceed.2006.05.062 360 Park Avenue South, New York, NY 10010-1710 1842 Transplantation Proceedings, 38, 1842–1843 (2006)