Evaluation of the longitudinal musculature of segments of the distal coloninterposed following extended jejunum-ileum resection

Several morbid conditions may necessitate extensive intestinal resection, l eading to short-bower syndrome. When clinical treatment becomes inefficient , a surgical approach is necessary. Distal colon interposition is one of th e viable techniques. The interposition of colon segments between remnants o f the small bower improved lifestyle, increased transit time, and diminishe d diarrhea. The aim of this study is to observe the longitudinal muscular c ontractions after distal colon interposition. Sixteen male Wistar rats (EPM -1) were submitted to an 80% small bowel resection associated with a partia l colectomy of the distal colon immediately after the bifurcation of the mi ddle colic artery followed by a 3-cm isoperistaltic distal colon interposit ion. After 70 days, the animals were submitted to euthanasia and segments o f the jejunum, ileum, remnant colon, and interposed colon were prepared for pharmacological tests. The isometric contractions were measured by a polig raph. After 30 minutes, the dose/effect curves were obtained for both metac holine and barium chloride stimulation through the extraluminal surface (se rosa). After this period, we observed a significant increase in the length, diameter, and thickness of the intestinal wall. Regarding the sensibility (pD(2)), no difference was found (interposed colon = 7.21 +/- 0.2; remnant colon = 7.65 +/- 0.1; remnant jejunum 7.46 +/- 0.1, and remnant ileum 7.57 +/- 0.1), even though the animals were submitted to different procedures. I n relation to the maximal effect (E-max), the longitudinal muscle contracti on responses (interposed colon = 11.79 +/- 0.1; remnant jejunum = 15.42 +/- 0.2; and remnant ileum = 11.48 +/- 0.2) were lower than those of the remna nt colon (E-max = 22.42 +/- 0.1). This means that there was a possible adap tation of colonic segments to their new location. (C) 1999 Wiley-Liss, Inc.