Meta-analysis of the outcomes of Trans Rectus Sheath Extra-Peritoneal Procedure (TREPP) for inguinal hernia

Objectives To evaluate the outcomes of Trans Rectus Sheath Extra-Peritoneal Procedure (TREPP) in patients undergoing elective inguinal hernia repair. Methods In compliance with PRISMA statement standards, electronic databases were searched to identify all studies reporting the outcomes of TREPP in patients undergoing elective inguinal hernia repair. The outcomes of interest included recurrence, chronic pain, haematoma, and wound infection. Proportion meta-analysis model was constructed to quantify the risk of postoperative complications and direct comparison meta-analysis model was constructed to compare the outcomes of TREPP and other open techniques. Random-effects modelling was applied to calculate pooled outcome data. Results Seven studies enrolling 1891 patients undergoing TREPP were included. The mean operative time was 26 min (95% CI 15–36). Pooled analyses showed that TREPP was associated with 3.00% (95% CI 1.00–6.00%) risk of recurrence, 3.00% (95% CI 2.00–6.00%) risk of chronic pain, 8.00% (95% CI 0.00–20.00%) risk of haematoma, and 3.00% (95% CI 0.00–6.00%) risk of wound infection. The results remained consistent through subgroup analysis of patients with primary hernias and those with recurrent hernias. Analysis of a limited number of comparative studies showed no difference between TREPP and Lichtenstein technique in terms of recurrence (OR 1.57, P = 0.26) and chronic pain (OR 1.16, P = 0.59). Conclusions The best available evidence suggests that TREPP may be a promising technique for elective repair of inguinal hernias as indicated by low risks of recurrence, chronic pain, haematoma, and wound infection. The available evidence is limited to studies from a same country conducted by almost the same research group which may affect generalisability of the findings. Moreover, there is a lack of comparative evidence on outcomes of TREPP versus other techniques highlighting a need for high-quality randomised controlled trials for definite conclusions. Although the available evidence is not adequate for definite conclusions, the results of current study can be used for sample size calculation and power analysis in future trials.