The impact of smoking on inguinal hernia repair outcomes: a meta-analysis of multivariable-adjusted studies.

PURPOSE: While the detrimental effects of smoking on postoperative outcomes are recognized, the extent of its risk for inguinal hernia repair remains unclear. Our study aims to assess the influence of smoking on patients who undergo inguinal hernia repair.

METHODS: We systematically reviewed PubMed, Embase, and Cochrane databases. Our goal was to identify studies that compared postoperative outcomes in smoking and non-smoking patients after inguinal hernia repair, and which employed a multivariate analysis to reduce possible confounding factors. Outcomes were recurrence, postoperative complications, and surgical site infection. Odds ratios (ORs) with 95% confidence intervals (CIs) were computed with the use of a random-effects model. Heterogeneity was examined with I2 statistics. This review was prospectively registered in PROSPERO (CRD42023445513).

RESULTS: Our analysis encompassed 11 studies, involving a total of 577,901 patients. Of these, 77,226 (or 13.4%) identified as smokers, with males constituting 90% of the cohort. In terms of surgical approaches, 58% underwent laparoscopic procedures were most common at 58%, followed by open surgeries at 41%, and 1% used robotic techniques. All included studies had a low risk of bias. Smoking was associated with a higher incidence of hernia recurrence (OR 2.95; 95% CI 2.08 to 4.18; p < 0.001; I2 = 0%). No differences were found in postoperative complication (OR 1.15; 95% CI 1.00 to 1.32; p = 0.05; I2 = 56%) or surgical site infection (OR 2.94; 95% CI 0.80 to 10.88; p = 0.11; I2 = 79%).

CONCLUSION: Smoking was associated with a three-fold increase in recurrence. Further studies are needed to evaluate the impact of preoperative smoking cessation on reducing recurrence.