Twenty-seven RCTs with 8,751 randomised participants (range 50 to 1,537) were included. Quality scores on the Jadad scale ranged from 1 to 5 (median 3). Twelve trials reported a power calculation, 20 described the method of randomisation and 15 described withdrawals in detail. Follow-up ranged from 0.5 to 70 months.
Hernia recurrence: Laparoscopic repair was associated with a statistically significant doubling of the risk of recurrence compared with open repair (RR 2.06, 95% CI 1.26 to 3.37; 18 RCTs). Substantial heterogeneity was present (Ι²=50.9%). In subgroup analyses, totally extraperitoneal repair was associated with an increased risk of recurrence compared with open repair (RR 3.82, 95% CI 1.66 to 8.35; 10 RCTs; Ι²=38.2%). There was no statistically significant difference between transabdominal preperitoneal repair and open repair (RR 1.14, 95% CI 0.78 to 1.68; 11 RCTs; Ι²=0%).
Perioperative morbidity: Laparoscopic repair was associated with a statistically significant 22% increase in the risk of perioperative morbidity compared with open repair (RR 1.22, 95% CI 1.04 to 1.42; 18 RCTs; Ι²=0%). In subgroup analyses, transabdominal preperitoneal repair was associated with an increased risk compared with open repair (RR 1.47, 95% CI 1.18 to 1.84; 13 RCTs; Ι²=0%) but totally extraperitoneal repair was not (RR 1.05, 95% CI 0.85 to 1.30; eight RCTs; Ι²=0%).
Postoperative complications: Laparoscopic repair was associated with statistically significant reductions in risk of both chronic groin pain (RR 0.66, 95% CI 0.51 to 0.87; 13 RCTs; Ι²=27.7%) and chronic numbness (RR 0.27, 95% CI 0.12 to 0.58; eight RCTs; Ι²=28%) compared with open repair. Results of subgroup analyses were reported.