Comparison of ileal and jejunal transplantation after 50% proximal intestinal resection

Background. The ileum has a greater adaptive capacity than the jejunum afte r intestinal resection. Transposition studies suggest that this is, in part , related to increased exposure to nutrients. However, there may be regiona l differences in intestinal properties that contribute to this response as well. The aim of this study was to compare the outcome of replacing the jej unum with either ileal or jejunal transplants while preserving an intact il eum after 50% proximal resection. Methods. Twenty-one Lewis rats were included in the study. One group (n = 7 ) served as transection controls (TC). The other two groups (n = 7) had 50% proximal resection with syngeneic transplantation of a similar length of i leum (ITX) or jejunum (JTX). Nutritional status and adaptation were studied at 14 days. Results. JTX animals gained less weight than TC and ITX (104 +/- 2% vs 114 +/- 1 and 108 +/- 2% initial, P < 0.05). ITX and STX groups had lower calor ic intake and serum albumin levels compared with TC (7.4 +/- 0.4 and 7.2 +/ - 0.8% vs 8.8 +/- 0.2% body weight and 2.6 +/- 0.1 and 2.4 +/- 0.9 g/dl vs 3.0 +/- 0.1 g/dl, P < 0.05). Mucosal thickness increased significantly in t he ileal remnant of both ITX and JTX groups (9.2 +/- 2.1 and 8.8 +/- 0.6 mu m vs 6.6 +/- 0.6 mu m, P < 0.05). Transplanted ileum had mucosal thickness similar to that of jejunum. Conclusions. Transplanted ileum achieves an intestinal structure similar to that of the jejunum in the same environment. Modest adaptation of the remn ant occurs with transplantation. Replacing jejunum with ileum rather than j ejunum resulted in better weight gain, suggesting that intrinsic absorptive , motor, or hormonal rather than structural differences are responsible. (C ) 1999 Academic Press.