Smoking is a major risk factor for anastomotic leak in patients undergoing low anterior resection

Aim To examine modifiable risk factors for anastomotic leak in patients undergoing low anterior resection. Method In total 233 patients undergoing low anterior resection for benign and malignant disease over a 10-year period at a single surgical unit were identified from a prospective database. The relationships between anastomotic leak and 17 variables were examined, including patient demographics, operative technique, tumour pathology, preoperative physiological function and smoking status. Results The majority (91%) of operations were carried out for rectal cancers, and 24 procedures (10%) were performed with laparoscopic assistance. The overall anastomotic leak rate was 14% (33/233). Patients with anastomotic leak had higher 30-day mortality (6% vs 1%, P < 0.05) and stayed significantly longer in hospital (median 23 vs 10 days, P < 0.001). On multivariate analysis, current smokers (OR 3.68, 95% CI 1.38-9.82, P = 0.009) and patients with evidence of metastatic malignant disease (OR 3.43, 95% CI 1.29-9.13, P = 0.013) were at increased risk of anastomotic leak. Conclusion Smoking and the presence of metastatic disease are major risk factors for the development of anastomotic leak following low anterior resection.