Pre-peritoneal local anaesthetic does not reduce post-operative pain in laparoscopic total extra-peritoneal inguinal hernia repair: double-blinded randomized controlled trial

Purpose Laparoscopic total extra-peritoneal hernia repair (TEP) is associated with less post-operative pain and earlier return to normal activity compared to open hernia repair (OHP). Despite this, post-operative pain remains a major issue. The aim of this double-blinded randomized controlled trial was to identify whether the instillation of local anaesthetic in the pre-peritoneal space improves pain scores following TEP. Methods One hundred patients undergoing laparoscopic total pre-peritoneal hernia repair (TEP) between the years of 2009–2014 were included. Patients were randomly assigned to receive either 20 mL of normal saline or 0.25% bupivacaine with adrenaline. Visual analogue scores (VAS 0–10) were recorded post-operatively at the 4 h, 1 day, 2 weeks, and 6 week mark. Secondary endpoints included complications, time to discharge, and return to normal activity. Results 51 patients were allocated to the local group. 49 patients were allocated to the placebo group. The baseline characteristics and demographics of patients in both groups were comparable. Patients in the local group had similar VAS scores compared to the placebo group at both 4 h (1.1 vs. 1.4, respectively; p = 0.19) and 24 h (2.1 vs. 2.3; p = 0.63). No statistically significant difference noted in other primary and secondary outcomes. Conclusion Although the concept of pre-peritoneal local anaesthetic instillation following laparoscopic TEP is attractive, this appropriately powered study has failed to show any advantage in pain scores at 4 and 24 h. The pain scores recorded, however, were remarkably low in both groups.