Effect of Adipose-Derived Stem Cells on Colonic Anastomosis in Rats Immunosuppressed With Everolimus: An Experimental Study.

Abstract

Immunosuppressed patients sometimes require colorectal surgery. We investigated whether adipose tissue-derived stem cells contributed to anastomosis healing in rats immunosuppressed with the mTOR inhibitor everolimus. Sixty male Sprague-Dawley rats were randomly divided into 4 groups of 14 each, with all groups undergoing descending colon anastomosis; the 4 remaining rats were used for stem cell retrieval. Group 1 (control) underwent surgery only, group 2 received stem cell injection, group 3 received everolimus only, and group 4 received everolimus plus stem cell injection. After treatment, each group was randomly divided into 2 equal subgroups according to the day of euthanasia (posttreatment day 4 or day 7). We measured anastomosis bursting pressure and tissue hydroxyproline level and performed histopathological evaluation. At both posttreatment days 4 and 7, median weight loss in group 3 was higher than in group 1, group 3 had higher severity of intraabdominal adhesion than group 4, and group 2 had mean hydroxyproline level higher than the other groups. At posttreatment day 4, mean bursting pressure was significantly different in group 1 versus groups 2 and 4 (P = .002) and group 2 versus groups 3 and 4 (P < .001). No significant differences were shown in pathological analysis except for vascular proliferation on day 7 (P = .003). Injection of adipose tissue-derived stem cells in the anastomosis site prevented anastomosis leakage by contributing to healing. Injection of adipose tissue-derived stem cells in the anastomosis region, especially in the early period after solid-organ transplant in recipients and after gastrointestinal surgery in immunosuppressed patients, may help reduce mortality and morbidity.