Acidic pelvic drainage as a predictive factor for anastomotic leakage after surgery for patients with rectal cancer

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.

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 °) other than leakage were excluded. Mean postoperative values were compared.

Anastomotic leakage was noted in 57 (7.6%) of 753 patients with rectal cancer. The diagnosis of anastomotic leakage 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 and 2 in group AL while a significantly sharp declining 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 (98.7.0%) and specificity (94.7%) in assessing the risk of leakage.

According to these results, an early and persistent declining of pH value of pelvic drainage fluid after rectal surgery with anastomosis, is a marker of AL. A cut-off value of 6.798 on POD3 maximizes sensitivity and specificity.