Comparative efficacy of postoperative analgesia between ultrasound-guided dual transversus abdominis plane and Ilioinguinal/Iliohypogastric nerve blocks for open inguinal hernia repair: An open label prospective randomised comparative clinical trial.

Background and Aims: Transversus abdominis plane (TAP) and Ilioinguinal/Iliohypogastric (IL/IH) nerve blocks have been advocated in reducing postoperative pain and additional analgesic requirement following lower abdominal surgeries with varied effect. The aim of this study was to determine post-operative analgesic efficacy by comparing dual TAP [combining TAP and IL/IH nerve blocks] and IL/IH nerve block alone for open inguinal hernia repair.

Methods: Two hundred patients undergoing elective primary unilateral open inguinal hernia repair with a mesh were included in to this trial. Ultrasound-guided dual TAP (D-TAP Group) or IL/IH (IL/IH Group) nerve block were administered to patients following subarachnoid block according to their group allocation, with 0.5% ropivacaine. Post operatively patients were monitored for visual analogue scale (VAS) scores at rest (at 4, 12, 24 and 48h) and during movement (at 24, 48 h, 3 and 6 months). Pain scores at 3 and 6 months were assessed by telephonic interview, using the DN4 questionnaire for neuropathic pain. The statistics was obtained using Chi-square test for proportions in qualitative data and student's unpaired t test for quantitative data. P value <0.05 was considered significant.

Results: The pain scores at rest (VAS-R) were significantly lower at 12 hours and 24 hours ( P < 0.001) in D-TAP group, while pain scores at movement were significantly lower ( P < 0.001) in D-TAP group at 24 and 48 hours compared to IL/IH group. The mean time required for first rescue analgesic was longer in D-TAP group (5.590 ± 2.386 hr) in comparison to IL/IH group (3.1053 ± 1.1822h).

Conclusion: Ultrasound-guided dual TAP block provides more effective post-operative analgesia in open inguinal hernia repair.