Comparison of ultrasound-guided modified thoracoabdominal nerve block through perichondrial approach (M-TAPA) and lateral transversus abdominis plane block on postoperative pain and quality of recovery after laparoscopic inguinal hernia repair: a prospective observational comparative study

Background The modified thoracoabdominal nerve block through perichondrial approach (M-TAPA) and the lateral transversus abdominis plane (TAP) block are both used within multimodal analgesia after abdominal surgery, but comparative data in laparoscopic inguinal hernia repair are limited, particularly with regard to patient-reported recovery. We compared the effects of these two blocks on postoperative pain and quality of recovery. Methods This prospective observational comparative study included 63 adults (American Society of Anesthesiologists [ASA] I–III) undergoing elective unilateral laparoscopic total extraperitoneal inguinal hernia repair under general anesthesia. At the end of surgery, patients were allocated to receive either an M-TAPA block ( n = 32) or a lateral TAP block ( n = 31) within a multimodal analgesia regimen; both blocks are used routinely for postoperative analgesia in our department, and the block given to each patient was chosen by the attending anesthesiologist as part of routine clinical care, without a predefined selection rule and independently of patient characteristics; no randomization was performed. Both blocks were performed bilaterally with 20 mL of 0.25% bupivacaine per side under ultrasound guidance. The co-primary outcomes were the resting Numeric Rating Scale (NRS) pain score at 24 h — the time point on which the sample size calculation was based — and quality of recovery assessed with the Quality of Recovery–15 (QoR-15) score at baseline, 24 h, and postoperative day 15. Resting NRS at earlier time points (PACU arrival and 15 and 30 min) and at 2, 4, 6, and 12 h, movement NRS at all time points, 24-h tramadol consumption, rescue medication use, and postoperative nausea and vomiting (PONV) were secondary, exploratory outcomes. Results Baseline characteristics were comparable between groups. Neither co-primary outcome differed significantly between groups: resting NRS at 24 h (median 0 [0–1] in both groups; p = 0.566) and QoR-15 scores at any time point (all p > 0.05), which returned to baseline by day 15. In secondary, exploratory analyses, resting NRS at 15 and 30 min in the PACU was significantly lower in the lateral TAP group ( p = 0.010 and p = 0.013, respectively); NRS did not differ between groups at any other secondary time point. Cumulative 24-h tramadol consumption did not differ significantly between groups (median 50 mg [30–90] in the TAP group vs 107.5 mg [30–147.5] in the M-TAPA group; p = 0.090). PONV incidence and rescue medication use did not differ. No block-related complications occurred. Conclusions On the prespecified co-primary outcomes, ultrasound-guided lateral TAP and M-TAPA blocks provided comparable postoperative analgesia at 24 h and comparable quality of recovery. In secondary, exploratory analyses, the lateral TAP block produced lower NRS scores during the early PACU period, possibly because its injection site lies closer to the surgical area; this finding should be regarded as hypothesis-generating and requires confirmation in adequately powered trials. Both techniques can be considered safe alternatives within a multimodal analgesia regimen. Clinical trial number ClinicalTrials.gov, NCT06753240; retrospectively registered on 22 December 2024, after completion of patient enrollment.