Five RCTs and seven comparative studies (five retrospective and two prospective studies) were included in the review (n=1,542 patients). All five RCTs were classified as high quality RCTs.
Transabdominal pre-peritoneal mesh repair was associated with a significant increase in the rate of overall hernia recurrence compared with totally extraperitoneal mesh repair (RR 3.25, 95% CI 1.32 to 7.9; three studies). There were no significant differences in the rate of overall hernia recurrence between totally extraperitoneal mesh repair and Lichtenstein open repair, as well as between laparoscopic procedure and Lichtenstein open repair.
Laparoscopic mesh repair was associated with a significant decrease in the rate of haematoma/seroma formation compared with Lichtenstein open repair (OR 0.38, 95% CI 0.15 to 0.96; six studies). There were no significant differences in the rate of haematoma/seroma formation between totally extraperitoneal mesh repair and Lichtenstein open repair, as well as between laparoscopic mesh repair and open pre-peritoneal mesh repair.
There were no significant differences in the rate of early hernia recurrence, urinary retention and wound infection between laparoscopic procedures and Lichtenstein open repair.
Substantial heterogeneity was only observed in the outcome of haematoma/seroma formation when totally extraperitoneal mesh repair was compared with Lichtenstein open repair (I2=75.1%), when laparoscopic procedures were compared with Lichtenstein open repair (I2=64%), and when laparoscopic procedures were compared with open pre-peritoneal mesh repair (I2=74%).
Sensitivity analyses showed that removal of one study (by Alani et al) from the analysis significantly altered the result of haematoma/seroma formation when laparoscopic procedures were compared with open pre-peritoneal mesh repair.
There was no evidence for publication bias.