Tobacco smoking and postoperative outcomes after colorectal surgery.

Objective: The aim of this study was to delineate the impact of smoking on postoperative outcomes after colorectal resection for malignant and benign processes.

Background: Studies to date have implicated smoking as a risk factor for increased postoperative complications. However, there is a paucity of data on the effects of smoking after colorectal surgery and in particular for malignant compared with benign processes.

Methods: The American College of Surgeon's National Surgical Quality Improvement Program (2005-2010) database was queried for patients undergoing elective major colorectal resection for colorectal cancer, diverticular disease, or inflammatory bowel disease. Risk-adjusted 30-day outcomes were assessed and compared between patient cohorts identified as never-smokers, ex-smokers, and current smokers. Primary outcomes of incisional infections, infectious and major complications, and mortality were evaluated using regression modeling adjusting for patient characteristics and comorbidities.

Results: A total of 47,574 patients were identified, of which 26,333 had surgery for colorectal cancer, 14,019 for diverticular disease, and 7222 for inflammatory bowel disease. More than 60% of patients had never smoked, 20.4% were current smokers, and 19.2% were ex-smokers. After adjustment, current smokers were at a significantly increased risk of postoperative morbidity [odds ratio (OR), 1.3; 95% confidence interval (CI), 1.21-1.40] and mortality (OR, 1.5; 95% CI, 1.11-1.94) after colorectal surgery. This finding persisted across malignant and benign diagnoses and also demonstrated a significant dose-dependent effect when stratifying by pack-years of smoking.

Conclusions: Smoking increases the risk of complications after all types of major colorectal surgery, with the greatest risk apparent for current smokers. A concerted effort should be made toward promoting smoking cessation in all patients scheduled for elective colorectal surgery.