Defecation properties after coloanal reconstruction in the pig model

Abstract

Defecation properties after coloanal reconstruction in the pig model. Functional aspects after low anterior resection are of major interest. While patients with straight coloanal anastomoses may suffer from disabling stool frequency and incontinence, evacuation difficulties can be a problem in coloanal pouch anastomoses. The aim of the study was to investigate functional results by establishing a standardized defecation protocol after low anterior resection of the rectum in the pig model. 24 adult Göttinger mini pigs were studied. They were randomly assigned to three groups: 8 animals served as control animals (group 1), the remaining 16 underwent low anterior resection with small colon-J-pouch (4-5 cm) reconstruction (n = 8) and large pouch design of 8-9 cm length (n = 8). The animals were investigated after 12 weeks postoperatively. Defecation properties we studied using a Ceruletide-induced defecography (0.3 microgram kgKG) with a 100 ml barium sulfate bolus, placed just above the anastomosis. Evacuation was significantly impaired in the large pouch (45 min.). However, the small pouches evacuated completely after 14 min. which was comparable to the unoperated controls (17.3 min.). Ceruletide-induced defecation reveals reproducible results in pigs. Evacualtion properties are highly depending upon the coloanal reconstruction. A small colon-J-pouch design reveals nearly physiologic results 3 months after surgery.