A 19 year population-based cohort study analysing reoperation for recurrence following laparoscopic and open inguinal hernia repairs

INTRODUCTION: Laparoscopic (LHR) and open (OHR) inguinal hernia repairs are both used to treat primary herniae. This study analyses the rates of operation for recurrence after laparoscopic and open inguinal hernia repair, at a population level, while considering competing risks, such as death and other operative interventions. METHODS: This is a population cohort study in Scotland. All adult patients who had a primary inguinal hernia repair in Scotland between 01/04/1996 and 01/01/2015 were included. The main outcome was recurrent operations. Cumulative incidence functions (CIF) were calculated for competing risks of death. A cox proportional hazards regression model was used to control for confounders of age, gender, bilateral herniae, deprivation and year of procedure. RESULTS: Of 88,590 patients, there were 10,145 LHR and 78,445 OHR. Recurrent operations were required in 1397 (1.8%) OHR and 362 (3.6%). LHR had greater hazard of recurrence than OHR (HR 1.83, 95% CI 1.61–2.08, p < 0.001). Faster time to recurrence was also associated with being older (HR for one year increase: 1.010, 95% CI 1.007–1.013, p < 0.001), being more affluent (HR 1.18, 95% CI 1.01–1.38, p = 0.04) and having a bilateral index operation (HR 2.53, 95% CI 2.22–2.88, p < 0.001). CONCLUSIONS: LHR is becoming more popular in Scotland over the past 2 decades. However, when other key confounding factors are controlled, it is associated with a higher recurrence rate.