Effect of Intraoperative PEEP Application on Colonic Anastomoses Healing: An Experimental Animal Study

This study aimed to assess the effect of intraoperative positive end-expiratory pressure (PEEP) intervention on the healing of colonic anastomoses in rabbits. A total of 32 New Zealand type male rabbits were divided into 2 groups of 16 animals each. Following ventilation with tracheostomy, colonic resection and anastomosis were performed in both groups. Although 10 cm of H2O PEEP level was applied in group 1 (PEEP), group 2 [zero end-expiratory pressure (ZEEP)] was ventilated without PEEP throughout the surgery. Half of both the PEEP and ZEEP group animals were killed on the third postoperative day, whereas the remaining half were killed on the seventh. Anastomotic bursting pressures, the tissue concentrations in hydroxyproline, and histologic assessments were performed. Intraoperative oxygen saturation and postoperative arterial blood gas parameters were also compared. On the first postoperative day, both arterial oxygen tension (PO2) and oxygen saturation (SO2) in the PEEP group were significantly higher than in the ZEEP group. On the seventh postoperative day, the bursting pressures of the anastomoses were significantly higher in the PEEP group; however, the hydroxyproline content was significantly lower in the PEEP group than in the ZEEP group. At day 7, the PEEP group was significantly associated with increased neoangiogenesis compared with the ZEEP group. The anastomotic healing process is positively influenced by the intraoperative PEEP application.