Effect of perineural bupivacaine infiltration on reducing inguinodynia in patients undergoing inguinal meshplasty - a randomized controlled trial

Introduction Inguinodynia after inguinal meshplasty is a notable complication with an incidence of 13-37%. We wanted to determine if a perineural infiltration of bupivacaine given intraoperatively would reduce the incidence of immediate postoperative pain and inguinodynia. Methodology We have conducted a single-blinded randomized controlled trial including 100 patients with inguinal hernia. Patients in the control group received only spinal anaesthesia. The intervention group received perineural bupivacaine infiltration in addition to spinal anaesthesia. Intraoperatively Ilioinguinal, iliohypogastric, and genital branch of the genitofemoral nerve was identified and 2 mL of 0.5% bupivacaine was given perineurally along these identified nerves. Presence of inguinodynia, immediate post-operative pain scores using the Wong-Baker faces pain scale, duration of analgesics use, use of additional analgesics along with Paracetamol 500 mg tablet, and the length of hospital stay between the groups were recorded. Results 100 patients were randomized in the study, 49 in control and 51 in the intervention group. Both the group was comparable in terms of demographic characteristics. The intervention group had significantly lower median pain score at 3 h [4 +/- 1.662 vs. 6 +/- 1.55; p = .0001] and 6 h [4 +/- 1.33 vs. 6 +/- 1.307; p = .0001]. The incidence of inguinodynia did not significantly differ between the two groups (p-value = .12). Conclusion Intraoperative Perineural bupivacaine infiltration significantly reduces the immediate postoperative pain. However, there was no significant reduction in the incidence of inguinodynia or additional analgesic requirement.