Tissue oxygen saturation during colorectal surgery measured by near-infrared spectroscopy: Pilot study to predict anastomotic complications

Introduction: We investigated the relation between tissue oxygen saturation measured by near-infrared spectroscopy (NIRS) and anastomotic complications associated with colorectal surgery. Methods: A series of 20 patients with colorectal cancer underwent radical surgery with enteric anastomosis. Measurements of tissue oxygen saturation (StO(2)) were performed at both the proximal and distal portions of the anastomotic site; in cases of anterior resection, we measured StO(2) only in the proximal portion. Reults: Two anastomotic complications (one leakage, one stenosis) occurred in the 20 cases. The StO(2) in patients with anastomotic complications was 58.0%, and that in patients without complications was 71.0%. Altogether, 18 patients had StO(2) values > 66%, and none of them had anastomotic complications. In contrast, 2 patients had StO(2) values < 60%, and both had anastomotic complications. Conclusions The StO(2) of the anastomotic site can be safely and reliably measured by NIRS during colorectal surgery. Low StO(2) on both sides of the anastomosis may indicate an increased risk of anastomotic complications. Further study is needed to determine the cutoff value for StO(2) required to prevent serious complications.