Neomucosal growth in serosa lined intestinal tunnels

Functional intestinal mucosa, termed neomucosa, will grow in patched intestinal defects, but intestinal patching does not result in significantly increased intestinal surface area. Our aim was to determine if neomucosal growth would occur longitudinally in serosa-lined tunnels and to evaluate the optimal type of tunnel construction. Thirty rabbits had serosa-lined intestinal tunnels 1.5 cm in diameter and 5 cm in length interposed in the ileum. Group I (n = 5) had the tunnel formed from adjacent colon segments. Group II (n = 15) had a similar tunnel created with placement of an intraluminal latex stent. Group III (n = 5) had the tunnel formed by imbricating the cecum. Group IV (n = 5) had the tunnel formed by imbrication plus the intraluminal stent. Only Group II animals survived beyond 7 days (12 of 15 vs 0 of 5, P < 0.05) and were sacrificed at 1 week (n = 3), 2 weeks (n = 3), 3 weeks (n = 2), 4 weeks (n = 2), and 6 weeks (n = 2). All other animals died from intestinal obstruction or peritonitis. Neomucosal growth occurred from proximal and distal margins. Forty percent of the tunnel was epithelialized at 6 weeks and the 5 cm tunnel contracted to 3 cm. In vitro glucose uptake was similar in neomucosa and normal mucosa but disaccharidase activity (sucrase and maltase) was significantly less in neomucosa at 6 weeks (28 ± 35 vs 84 ± 12 and 72 ± 51 vs 471 ± 84, P < 0.05). Although not clinically obstructed, the survivors lost 15% body weight and proximal intestinal diameter increased. Neomucosal growth will occur longitudinally in a surgically constructed serosa-lined tunnel. However, these tunnels contract significantly which limits the surface area gained. Formation of the tunnel from adjacent colon segments employing an intraluminal stent was the best configuration.