The use of surface oximetry to assess bowel viability.

Tissue depends on perfusion, but tissue oxygenation measurements have been impractical. To develop a method for the clinical evaluation of bowel viability, we studied PO2 on the bowel surface (PSO2). The PSO2 was assessed on the stomach and intestine of 11 dogs. Normal small-bowel PSO2 was 44 +/- 11 mm Hg (mean +/- SD). When bowel vasculature was interrupted PSO2 rapidly decreased. Reductions in PSO2 were related to the degree of ischemia produced. Anastomoses were performed on partially devascularized bowel to determine anastomotic viability at various levels of PSO2. The PSO2 measured just prior to anastomosis predicted viability of the anastomoses at 48 hours. Anastomoses below 30% of predevascularization PSO2 necrosed. Between 30% and 50%, one third of anastomoses leaked. At PSO2 values above 50% of initial normal value all anastomoses healed. Surface oximetry allows accurate intraoperative assessment of bowel perfusion.