SEGMENTAL SMALL-BOWEL ALLOGRAFT - ISCHEMIC-INJURY AND REGENERATION

Purpose: Small bowel transplantation (SBT) is the ultimate treatment f or intestinal failure. It remains unclear as to which intestinal segme nt is more suitable far use in segmental SET. The current study aims t o assess the susceptibility of various parts of small intestine to isc hemia and reperfusion injury and their capacity for regeneration. Meth ods: Thirty-two segments of pig jejunum and ileum were isolated with i ntact vascular pedicles that were clamped for periods varying from 1/2 to 8 hours. Biopsy specimens were taken im med lately before clamp re lease and 20 minutes afterwards. All segments were anastomosed togethe r before abdominal closure. Laparotomy was performed 24 hours later, a nd biopsy specimens were taken at all segments. All specimens were exa mined histologically by a pathologist. Results: Evidence of injury was detected after 1.5 hours of ischemia at jejunum, but only after 5 hou rs at ileum. More severe injury was noted at the initial period on rep erfusion, but there was no further deterioration at the later period. Complete reepithelialization occurred after 24 hours even where there had been total villous sloughing at reperfusion, but regeneration was impossible when the crypts had been damaged completely. Conclusions: I leum, because it is more resistant to ischemia and reperfusion injury, may be preferred for segmental SET. Regeneration of the bowel epithel ium is fast, provided that the crypts are not damaged completely.