Impact of cumulative smoking exposure on morbidity after robot-assisted radical cystectomy

Objectives: To evaluate whether cumulative smoking exposure and time since cessation are associated with perioperative morbidity after robot-assisted radical cystectomy (RARC). Patients and Methods: We retrospectively analysed 475 patients who underwent RARC with urinary diversion at a high-volume tertiary centre between 2004 and 2024. Outcomes of interest were postoperative early complications, postoperative readmission, overall risk of postoperative morbidity according to smoking status, cumulative smoking exposure, and time since smoking cessation. Multivariable logistic regressions were performed to explore the effect of smoking status, cumulative smoking exposure, and time since smoking cessation on perioperative morbidity after RARC. The locally estimated scatterplot smoothing (LOESS) function was used to graphically explore this relationship. Results: Early complications occurred in 60% of current smokers, 50% of former smokers, and 37% of never smokers. Compared with never smokers, former (odds ratio [OR] 3.83, 95% confidence interval [CI] 1.73–9.38) and current smokers (OR 6.75, 95% CI 2.85–12.40) had significantly higher odds of perioperative morbidity. Each 10 additional pack-years increased complication risk (OR 1.20, 95% CI 1.05–1.40), whereas each year since cessation reduced risk (OR 0.84, 95% CI 0.76–0.91). The LOESS curves showed a steadily increasing risk with cumulative exposure and a gradual decline following cessation. Conclusion: Both lifetime smoking burden and time since cessation are strong and independent predictors of perioperative morbidity after RARC. Evaluating smoking exposure as a continuous variable improves risk stratification and provides more accurate information for preoperative counselling in patients undergoing RC.