Comparison of modified thoracoabdominal nerve block via perichondrial approach with serratus intercostal plane block and rectus sheath block combination in laparoscopic cholecystectomy: a randomized controlled trial

Patients undergoing laparoscopic cholecystectomy (LC) may experience severe postoperative pain. Peripheral nerve blocks, as a component of multimodal analgesia, are now widely employed in postoperative pain management. This study investigated the effects of modified thoracoabdominal nerve block (M-TAPA) compared with the combination of rectus sheath block (RSB) and serratus intercostal plane block (SIPB) on postoperative NRS scores, tramadol consumption, and dermatomal spread. This randomized, assessor-blinded trial enrolled 72 patients scheduled for LC. One group received bilateral M-TAPA (Group 1, n = 35), while the other received a combination of bilateral RSB and right-sided SIPB (Group 2, n = 37). All peripheral nerve blocks were performed following surgery and prior to emergence from general anesthesia, using 0.25% bupivacaine; RSB was administered as 10 mL per side, M-TAPA as 20 mL per side, and SIPB as 20 mL on the right side. The primary outcome was postoperative tramadol consumption within the first 24 h; NRS scores, rescue analgesia requirement, and dermatomal spread were secondary outcomes. Static NRS (Numeric Rating Scale) scores measured at 0, 1, and 6 h differed significantly between groups (mean difference [Group 2 − Group 1] 1.27 [95% CI 0.54–2.00], 0.69 [0.14–1.24], and 0.56 [0.12–1.00], respectively). Dynamic NRS scores assessed at 0, 12, and 18 h were also found to be statistically significant between groups (mean difference 1.06 [95% CI 0.25–1.87], 0.45 [0.05–0.85], and 0.52 [0.05–0.99], respectively). Total tramadol consumption over the first 24 h, the primary outcome, did not differ significantly between groups (92.6 ± 26.3 mg vs. 103.9 ± 39.3 mg; mean difference 11.3 mg, 95% CI − 4.4 to 26.9; p = 0.108); however, tramadol consumption between 12 and 24 h was significantly higher in Group 2 compared to Group 1 (24.0 ± 11.7 mg vs. 31.7 ± 17.3 mg; mean difference 7.6 mg, 95% CI 0.7 to 14.6; p = 0.030). The number of patients requiring rescue analgesia was also significantly greater in Group 2 than in Group 1 (absolute risk reduction 24.4%, 95% CI 2.5% to 46.3%; p = 0.034). Both M-TAPA and the combination of RSB with SIPB provided effective postoperative analgesia following LC. Under the conditions of this trial, M-TAPA was associated with lower NRS scores and lower opioid requirements than the combination of bilateral RSB and unilateral SIPB. The study was registered at ClinicalTrials.gov, NCT06241794, registered on January 28, 2024.