Background: There are many factors that affect the safety of gastrointestinal anastomosis.  In this study we aimed to investigate the effect of the stem cells that are derived from adipose tissue on wound healing in rats that are immune-suppressed with mTOR inhibitors
Materials and Methods: 56 rats were used and they were divided 4 groups: Group 1 (control, colonic anastomosis), group 2 (colonic anastomosis+stem cell), group 3 (colonic anasomosis+immunosuppression), and group 4 (colonic anastomosis+immune supression+stem cell). Adhesion, bursting pressure of the colonic anastomosis, tissue hydroxyproline level measurement, histopathologic and marked stem cell detection by florescent microscope examinations were done.
Results: Adhesion was most commonly seen in group 3 and stem cell application caused adhesions to be less visible in group 4. On the seventh day, higher tissue hydroxyproline levels were detected than in the fourth day (p<.001). Immunosuppression caused the tissue to decrease in hydroxyproline level. Stem cell administration caused an increase in the level of hydroxyproline in group 2 (p<.001), whereas group 4 did not cause the same effect. On the fourth and seventh day of anastomoses, the highest bursting pressure was found in group 2 and lowest in group 3.  Although stem cell administration increased the bursting pressure in group 4 on the fourth day, the same effect was not seen on the seventh day. Histopathologic examination revealed a high level of vascular proliferation in the stem cell group (p<.001)
Conclusion:: Subserosal stem cell injections to colonic anastomosis in immunosuppressed rats with everolimus increase the anastomotic resistance, and increase the vascular proliferation.