WOUND TENSILE-STRENGTH AND CONTRACTION RATE ARE NOT AFFECTED BY LAPAROTOMY OR PNEUMOPERITONEUM

Background: Many cellular elements responsible for wound healing are a ffected by laparotomy. The aim of this study was to evaluate the effec ts of laparotomy and CO2 pneumoperitoneum on wound healing. Methods: M ale Sprague Dawley rats were randomly assigned to one of three experim ental groups. Anesthesia control rats underwent no procedure. Pneumope ritoneum group rats were insufflated with CO2 gas. Laparotomy group ra ts underwent a 7-cm midline laparotomy incision. The interventions wer e 30 min long. For the incisional study (n = 30), a 4-cm dorsal full-t hickness skin incision was made on each rat and then closed with stapl es. On postoperative days 7 and 14, an equal number of rats were sacri ficed from each group, and wound tensile strength measurements were pe rformed. For the excisional study (n = 45), each group of 15 rats unde rwent a 2-cm diameter circular dorsal full-thickness skin excision. Bl inded measurements of wound area were performed every other day until wounds closed. Results: Wound tensile strength values were not signifi cantly different among experimental groups at either time point. The s tudy had a power of 80% to find a 30% difference at POD 7 and a power of 80% to find a 23% difference at POD 14 to a confidence level of p < 0.05. Wound contraction data from the excisional model were analyzed with the Generalized Estimation Equations statistical approach. When w e modeled the treatment group as a covariate, no statistical differenc e was found between groups, demonstrating equal slopes across time. Co nclusions: From the results of these studies, we conclude that wound h ealing in this model is not significantly diminished following laparot omy or peritoneal insufflation, as compared to anesthesia control.