Roux-en-Y gastric bypass: the impact of tobacco nicotine, nontobacco nicotine, and marijuana use on postoperative outcomes.

BACKGROUND: Nontobacco nicotine products and cannabis use are increasingly prevalent, yet their effects on outcomes following Roux-en-Y gastric bypass (RYGB) remain poorly understood. OBJECTIVES: This study evaluates postoperative complications among patients undergoing RYGB using tobacco nicotine, nontobacco nicotine, or marijuana compared with nonusers. SETTING: United States. METHODS: This retrospective cohort study was conducted using the TriNetX Research Network. Adults (>18 years) undergoing RYGB were stratified into 4 propensity-matched cohorts based on documented preoperative substance use within 90 days of surgery: tobacco nicotine, nontobacco nicotine, marijuana, and nonusers. One-year outcomes included infection, readmission, seroma, anastomotic leak, deep vein thrombosis, internal hernia, marginal ulcer, and nutritional deficiencies. Risk ratios (RRs), 95% confidence intervals, and P values (P < .05) were calculated. RESULTS: Tobacco nicotine users showed increased readmission (RR 1.29), internal hernia (RR 1.29), marginal ulcer (RR 1.69), and nutritional deficiency (RR 1.04), with fewer anastomotic leaks (RR .65). Nontobacco nicotine users showed increases in readmission (RR 1.29), internal hernia (RR 1.30), and marginal ulcer (RR 1.57), with reduced leaks (RR .71). Marijuana users had increased marginal ulcers (RR 1.74), but no significant differences in readmission. No clinically meaningful differences were observed between nicotine groups or between marijuana and nicotine users. CONCLUSIONS: Tobacco nicotine, nontobacco nicotine, and marijuana use all increased morbidity across several markers, suggesting that various forms of substance use impact postoperative complications. These findings highlight the need for umbrella preoperative cessation recommendations and prospective studies on how nicotine and cannabis influence postoperative outcomes.