Ileal resection enhances jejunal absorptive adaptation for water and electrolytes to extrinsic denervation: Implications for segmental small bowel transplantation

Background/Purpose: Segmental small bowel transplantation (SBT) may be an alternative to whole jeiunoileal SBT. The aim of this study was to evaluate adaptability of extrinsically denervated jejunum after ileectomy. Methods: Baseline absorption of an isomolar, nonnutrient electrolyte solution was measured in an 80-cm in situ jejunal segment. Control (CON) and extrinsically denervated dogs (EXT DEN) then underwent distal 50% enterectomy; EXT DEN dogs also underwent a complete extrinsic denervation of remnant jejunum. Absorption was remeasured 2 and 12 weeks later; jejunal biopsies at 12 weeks were compared with baseline. Results: All dogs experienced weight loss and diarrhea, which resolved by 10 weeks in CON but persisted in EXT DEN dogs. Net absorptive fluxes of water, Na⁺, K⁺, and Cl^-, however, remained unchanged in both groups 2 weeks and 12 weeks after denervation. Morphometric evaluation showed an increase in crypt depth in both groups at the 12-week time-point. Conclusions: Despite a clinical short bowel syndrome, more weight loss, and diarrhea in EXT DEN, there were no temporal differences in net absorptive fluxes of water and electrolytes within or between these 2 groups, and both developed increased crypt depth at 12 weeks. Extrinsic denervation does not blunt jejunal adaptive response to ileectomy.