The influence of serosal patch size on the growth of small intestinal neomucosa.

Several factors might affect the growth of neomucosa after serosal patching of small intestinal defects. Often only short segments of small intestine can be patched because of limited serosal surface and anatomic factors. The purpose of this study was to determine the influence of patch size on neomucosal growth. Twenty male New Zealand white rabbits underwent patching with colon serosa of either a 2 X 15-cm distal ileal defect (n = 10) or three 2 X 5-cm ileal defects (n = 10). There was significantly greater coverage of the patched defect by neomucosa in the triple patch group (99.4% vs 93.1% P less than 0.005) and significantly more of the smaller defects were completely covered by neomucosa than the larger defects (12 of 15 vs 0 of 5, P less than 0.05) at 8 weeks. The final area of the defect was 27.5 and 32.8% of the initial patched area respectively for the single and triple patches. Microscopically there was no difference in villous height or crypt depth, but crypt density was significantly greater in the triple group (207 +/- 11 vs 186 +/- 17 crypts/mm, P less than 0.05). In vitro glucose uptake and disaccharidase activity were similar in both groups. Patching multiple small intestinal defects results in more rapid neomucosal growth than a single large defect of the same surface area. This might be due to a greater circumference exposed to surrounding normal mucosa with a resultant increase in crypt density. Since function and villous development of the neomucosa are similar, multiple patches should result in a greater increase in absorptive capacity.