Intestinal lengthening in rats after massive small intestinal resection

Background Prior studies have demonstrated lengthening of normal small intestinal segments using mechanical expanders. The present study assesses the feasibility of intestinal lengthening in rats that have undergone extensive small intestinal resection. Methods Female rats underwent small intestinal resection. After 6 weeks, the animals underwent the placement of a mechanical expander device with or without gradual mechanical lengthening. After 3 weeks, the intestinal segments were retrieved for analyses. Results Isolated intestinal segments without mechanical lengthening did not change in length, whereas isolated intestinal segments that were mechanically lengthened more than doubled their initial length. The total alkaline phosphatase activity was 2.4 μmol/min in the isolated intestinal segments and 4.9 μmol/min in the mechanically lengthened segments. The total lactase activity was 0.005 μmol/min in the isolated intestinal segments and 0.007 μmol/min in the mechanically lengthened segments. Smooth muscle thickness was 370 μm in the isolated intestinal segments and 530 μm in the mechanically lengthened segments. Conclusion Mechanical small bowel lengthening was achieved in intestinal segments after extensive small intestinal resection. There was an increase in the total alkaline phosphatase activity and preservation of the total lactase activity. Mechanical lengthening may be a useful technique to increase intestinal length in patients with short bowel syndrome.