C-reactive protein and its ratio are useful indicators to exclude anastomotic leakage requiring intervention after laparoscopic rectal surgery

The goal of this study was to determine whether C-reactive protein (CRP) levels and its ratios can be used as indicators to exclude postoperative anastomotic leak (AL) requiring intervention in patients undergoing elective laparoscopic total mesorectal excision (TME) without a diverting ileostomy for middle or low rectal cancer. We measured CRP values on postoperative days (POD) 1, 2, and 4 and CRP ratios between two PODs in 1278 consecutive patients undergoing rectal surgery. The incidence of AL requiring intervention was 5.9%, and 92% of AL occurred by POD 4. The CRP levels on POD 4 had a maximal area under the curve (AUC) of 0.956 with a negative predictive value (NPV) of 99.7% when the cutoff was established as 80 mg/l. Also, the ratio between CRP levels on POD 4 and CRP levels on POD 2 (CRP POD 4/2) was the most accurate indicator among the CRP ratios, with an AUC of 0.959 and an NPV of 99.5% when the cutoff was set at one. CRP on POD 4 < 80 mg/l and the ratio of CRP POD 4/2 < 1 can be used to rule out AL requiring intervention in patients undergoing elective laparoscopic TME without a diverting ileostomy for middle or low rectal cancer.