Ilioinguinal/iliohypogastric nerve block versus transversus abdominis plane block for pain management following inguinal hernia repair surgery: A systematic review and meta-analysis of randomized controlled trials

Background: Controversy still exists regarding the efficiency and safety of ilioinguinal/iliohypogastric nerve (II/IH) block versus transversus abdominis plane (TAP) block for pain management after inguinal hernia repair. The purpose of the current meta-analysis was to perform a relatively credible and comprehensive assessment to compare the efficiency and safety of II/IH versus TAP for pain management after inguinal hernia repair. Methods: The PUBMED, CENTRAL, and EMBASE were systematically searched. Studies comparing II/IH versus TAP for pain management in adult patients undergoing inguinal herniorrhaphy were included. The results of this study are synthesized and reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Results: Six studies with 632 patients were included in this study. No statistically significant difference was observed between the II/ IH and TAP groups in postoperative opioid use, the time to first request for rescue analgesia, the incidence of postoperative nausea and vomiting (PONV), incidence of complication related with nerve blocks and patient satisfaction. The TAP group had a significantly higher pain score at 6 and 8hours postoperatively (6 hours: mean difference [MD]= 0.94, 95% confidence interval [CI] 0.67-1.22, I2= 0%, P<.01; 8hours: MD= 1.02, 95% CI 0.3-1.74, I2= 59%, P<.01). However, no statistically significant difference was observed at 1, 2, 4, 12, 24, 48hours, and 6 months postoperatively. Conclusions: In general, this meta-analysis revealed that both approaches have similar postoperative opioid consumption and no significant difference in postoperative complication and patient satisfaction. The II/IH block provides excellent analgesic effects at 6 and 8hours after inguinal herniorrhaphy in compared with the TAP block. However, more high-quality randomized controlled trials with long-term follow-up are still required to make the conclusion.