Postoperative use of non-steroidal anti-inflammatory drugs in patients with anastomotic leakage requiring reoperation after colorectal resection: cohort study based on prospective data

Objectives To evaluate the effect of postoperative use of non-steroidal anti-inflammatory drugs (NSAIDs) on anastomotic leakage requiring reoperation after colorectal resection. Design Cohort study based on data from a prospective clinical database and electronically registered medical records. Setting Six major colorectal centres in eastern Denmark. Participants 2766 patients (1441 (52%) men) undergoing elective operation for colorectal cancer with colonic or rectal resection and primary anastomosis between 1 January 2006 and 31 December 2009. Median age was 70 years (interquartile range 62-77). Intervention Postoperative use of NSAID (defined as at least two days of NSAID treatment in the first seven days after surgery). Main outcome measures Frequency of clinical anastomotic leakage verified at reoperation; mortality at 30 days. Results Of 2756 patients with available data and included in the final analysis, 1871 (68%) did not receive postoperative NSAID treatment (controls) and 885 (32%) did. In the NSAID group, 655 (74%) patients received ibuprofen and 226 (26%) received diclofenac. Anastomotic leakage verified at reoperation was significantly increased among patients receiving diclofenac and ibuprofen treatment, compared with controls (12.8% and 8.2% v 5.1%; P<0.001). After unadjusted analyses and when compared with controls, more patients had anastomotic leakage after treatment with diclofenac (7.8% (95% confidence interval 3.9% to 12.8%)) and ibuprofen (3.2% (1.0% to 5.7%)). But after multivariate logistic regression analysis, only diclofenac treatment was a risk factor for leakage (odds ratio 7.2 (95% confidence interval 3.8 to 13.4), P<0.001; ibuprofen 1.5 (0.8 to 2.9), P=0.18). Other risk factors for anastomotic leakage were male sex, rectal (v colonic) anastomosis, and blood transfusion. 30 day mortality was comparable in the three groups (diclofenac 1.8% v ibuprofen 4.1% v controls 3.2%; P=0.20). Conclusions Diclofenac treatment could result in an increased proportion of patients with anastomotic leakage after colorectal surgery. Cyclo-oxygenase-2 selective NSAIDs should be used with caution after colorectal resections with primary anastomosis. Large scale, randomised controlled trials are urgently needed.