Reentrant cannulation of the small intestine in sheep: cannula and surgical method.

The function, design and production of a reentrant cannula for the small intestine of sheep and the corresponding surgical procedure are described. The cannula is molded in one piece from polyvinylchloride plastisol. It consists of a curved intestinal tube joined to a stem with an external elliptical ring on the distal end and a perforated flange that encircles the stem above the intestinal tube. A circular perspex valve with two curved channels was made to fit into the interior of the cannula, making it capable of either a "maintenance" or a "collection" function. The cannula was inserted into the proximal duodenum and(or) terminal ileum of sheep via a 5-cm incision on the antimesenteric side of the intestine. The intestine was attached to the cannula by a Dacron straight arterial graft. This reentrant cannulation method does not require an intestinal transection and a mesenteric incision under the transection. Therefore, little damage was done to the blood and nervous system.