Survival of transferred ileum after ischemia time longer than 1 hour: A Clinical result different from animal studies

Background: The aim of this study was to identify the ischemic tolerance of the ileum. In microvascular transfer of autologous bowel segments, the most critical factor for survival is ischemic time. In earlier animal studies, the tolerance of ischemic time was shorter for the ileum than for the jejunum, and an ischemic time of <1 hour was suggested for microvascular transfer of the ileum. It was believed that there are more bacteria in the ileum than in the jejunum and therefore autolysis and necrosis will be triggered sooner after the initiation of ischemia. However, in a clinical scenario, the tolerance for ischemic time of the ileum has not yet been clarified. Study Design: From 1998 to 2011, eight-four cases of microvascular transfer of intestine containing a segment of the ileum were reviewed. Data collected included the ischemia time during surgery, re-exploration, survival, complications, and postoperative functions. Multivariate analysis with exact logistic regression was used to identify the correlation between the ischemic time and necrosis of the transferred segment, as well as other complications. Results: For segmental ileum transfer, the ischemic time >1 hour (but within 2 hours) at room temperature is not a risk factor for flap loss or complications. This contradicts data from animal studies in the literature. Conclusions: Clinically, the ileum segments can tolerate ischemia well within 2 hours. Segmental ileum transfer can be more widely applied in other fields. Care in each step of transfer is mandatory for functional success.