Acidic Pelvic Drainage as a Predictive Factor For Anastomotic Leakage after Surgery for Patients with Rectal Cancer

Purpose: To demonstrate the value of sequential determinations of pelvic drainage in the identification of increased risk of anastomotic leakage (AL) after anterior resection for rectal cancer with a double stapling technique. Patients and Methods: Between January 2004 and December 2011, data for the daily postoperative pH of pelvic drainage fluid in 753 consecutive patients with rectal cancer who initially underwent anterior resection with a double stapling technique were reviewed. All patients experienced a total mesorectal excision. Patients with anastomotic leakage (Group AL, n=57) were compared to patients without leakage (Group nAL, n=696). Patients with perioperatively abdominopelvic implants that were likely to affect pH value (determined at 25 degrees C) other than leakage were excluded. Mean postoperative values were compared. Results: Anastomotic leakage was noted in 57 (7.6%) of 753 patients with rectal cancer. The diagnosis of AL was made between the 6th and 12th postoperative day (POD; mean 8th POD). There was no significance of the daily average values of pH on POD1 & 2 in group AL while a significantly sharp decline mean pH value reached its diagnostic point of AL (p<0.001) on POD3. A cut-off value of 6.978 on the 3rd POD maximized the sensitivity (98.7%) and specificity (94.7%) in assessing the risk of leakage. Conclusion: According to these results, an early and persistent decline of pH value of pelvic drainage fluid after rectal surgery with anastomosis, is a marker of AL. A cut-off value of 6.978 determined at 25 degrees C on POD3 maximizes sensitivity and specificity.