Intestinal transplantation using cuff‐glue sutureless technique for microanastomosis in rats

The rat model is the most suitable for intestinal transplantation. Nevertheless, it is hampered by the need of complex microvascular anastomoses. New techniques have been proposed to simplify this procedure, such as the small bowel and ascending colon transplantation model using graft portal drainage by cuff anastomosis. It is well known that cuff may ground foreign body reaction in anastomosis site. Due to this inconvenience, our group has recently described a simplified sutureless microanastomosis technique, using cuff and glue, in which the cuff is removed from anastomosis. In this letter, we describe a model of intestinal transplantation in the rat using this innovative technique, called cuff-glue, in anastomoses of portal vein and intestines. In the donor, we divide the right renal artery next to the superior mesenteric artery. The mesocolon and superior mesenteric vein are carefully separated from the pancreas and mesoduodenum, preserving the right colonic vessels. The splenic, pyloric, and inferior mesenteric veins are divided and portal vein dissection continues up to hepatic hilum. We dissect a segment of abdominal aorta including the superior mesenteric artery. After heparinization, we remove the graft, containing the small bowel and ascending colon in continuity with an aortomesenteric conduit and portal vein. Three polyethylene cuffs of 4 mm 3 1.5 mm, 8 mm 3 4 mm, and 10 mm 3 6 mm (length 3 inner diameter) are placed at portal vein, jejunum, and colon, respectively. Two equidistant stitches fix the vein and intestines to the base of the respective cuff as previously described. The donor is sacrificed by exsanguination. In the recipient, a continuous 10-0 nylon end-to-side hand-sewn microanastomosis is performed between recipient’s infrarenal aorta and the aortomesenteric conduit. A superior mesenteric vein segment is dissected and cut. The native jejunum, ileum, cecum, and ascending colon are removed en bloc. The portal cuff is introduced in the proximal recipient’s superior mesenteric vein and an encircling 7-0 ligature is placed to fix both margins to the cuff. The recipient vein below the ligature is pulled up and everted, exposing both donor and recipient’s intimae, which are dried and covered with cyanoacrylate. The proximal margin is then pulled down, and the borders are attached, sealing the anastomosis. After convenient adherence, we cut the ligatures fixing the cuff and remove it from the vessel (Fig. 1A). Intestinal reconstruction is performed by jejunal and colonic graft-recipient anastomosis using the same adhesive technique (Fig. 1B). The advantage of the current model includes the use of simpler sutureless anastomosis, in which the cuff is removed. Furthermore, by maintaining the cecum and ascending colon, it raises the possibility of translational studies assessing graft motility with the presence of ileocecal valve. Also, it is an easier way to reconstitute physiologic portal graft drainage, since the hand-sewn technique achieves an elevate failure rate. The commonest microanastomosis technique still uses thread and needle that traumatizes tissues and requires costly and extensive practice. Xue et al. published their experience with the 3-cuff model, demonstrating the usefulness of the cuff technique. However, Nakao et al. reported foreign body reaction and thrombosis in 40% of *Correspondence to: Flávio Henrique Ferreira Galvão, M.D., Ph.D., Rua Arthur Prado, 538, Apt 22, São Paulo, SP, CEP 01322-000. E-mail: fgalvao@usp.br