The impact of smoking on ventral and inguinal hernia repair: a systematic review and meta-analysis

Purpose Individual studies indicate poorer outcomes for smokers after hernia repair. Previous meta-analyses have examined the impact of smoking on specific outcomes such as recurrence and surgical site infection, but there has been a lack of comprehensive consensus or systematic review on this subject. Addressing this gap, our study undertakes a systematic review and meta-analysis to assess the impact of smoking on the outcomes of ventral hernia repair (VHR) and inguinal hernia repair. Source A thorough search of Cochrane Central, Scopus, SciELO, and PubMed/MEDLINE, focusing on studies that examined the effect of smoking on inguinal and VHR outcomes was conducted. Key outcomes evaluated included recurrence, reoperation, surgical site occurrences (SSO), surgical site infection (SSI), and seroma. Principal findings Out of 3296 screened studies, 42 met the inclusion criteria. These comprised 25 studies (69,295 patients) on VHR and 17 studies (204,337 patients) on inguinal hernia repair. The analysis revealed that smokers had significantly higher rates of recurrence (10.4% vs. 9.1%; RR 1.48; 95% CI [1.15; 1.90]; P < 0.01), SSO (13.6% vs. 12.7%; RR 1.44; 95% CI [1.12; 1.86]; P < 0.01) and SSI (6.6% vs. 4.2%; RR 1.64; 95% CI [1.38; 1.94]; P < 0.01) following VHR. Additionally, smokers undergoing inguinal hernia repair showed higher recurrence (9% vs. 8.7%; RR 1.91; 95% CI [1.21; 3.01]; P < 0.01), SSI (0.6% vs. 0.3%; RR 1.6; 95% CI [1.21; 2.0]; P < 0.001), and chronic pain (9.9% vs. 10%; RR 1.24; 95% CI [1.06; 1.45]; P < 0.01) rates. No significant differences were observed in seroma (RR 2.63; 95% CI [0.88; 7.91]; P = 0.084) and reoperation rates (RR 1.48; 95% CI [0.77; 2.85]; P = 0.236) for VHR, and in reoperation rates (RR 0.99; 95% CI [0.51; 1.91]; P = 0.978) for inguinal hernias between smokers and non-smokers. Analysis using funnel plots and Egger's test showed the absence of publication bias in the study outcomes. Conclusion This comprehensive meta-analysis found statistically significant increases in recurrence rates, and immediate postoperative complications, such as SSO and SSI following inguinal and VHR. Also, our subgroup analysis suggests that the MIS approach seems to be protective of adverse outcomes in the smokers group. However, our findings suggest that these findings are not of clinical relevance, so our data do not support the necessity of smoking cessation before hernia surgery. More studies are needed to elucidate the specific consequences of smoking in both inguinal and ventral hernia repair.