Comparison of the Postoperative Analgesic Effects of TAP and M-TAPA Blocks in Laparoscopic Appendectomy: A Pilot Randomized Controlled Trial

Purpose: Effective postoperative pain management is essential following laparoscopic appendectomy. This exploratory pilot randomized controlled trial aimed to compare the postoperative analgesic efficacy of the transversus abdominis plane (TAP) block and the modified thoracoabdominal nerve block through the perichondrial approach (M-TAPA) in patients undergoing laparoscopic appendectomy. Patients and Methods: This prospective, double-blind, single-center exploratory pilot randomized controlled trial included 30 adult patients (ASA I-III) scheduled for laparoscopic appendectomy due to uncomplicated acute appendicitis. Patients were randomly allocated to receive either bilateral TAP block (Group T, n = 15) or bilateral M-TAPA block (Group M, n = 15) under ultrasound guidance following induction of general anesthesia. Both groups received standardized multimodal analgesia. Postoperative pain intensity assessed by Numeric Rating Scale (NRS) was the primary outcome. Secondary outcomes included 24-hour tramadol consumption, Quality of Recovery-15 (QoR-15) scores, and adverse events. Pain assessments were performed at 1, 6, 12, 18, and 24 hours postoperatively by a blinded assessor. Results: All randomized patients completed the study. Demographic and clinical characteristics did not differ significantly between groups. Resting and dynamic NRS scores did not differ significantly between the TAP and M-TAPA groups at any postoperative time point (all p > 0.05). Median 24-hour tramadol consumption was 50 mg (0-50) in both groups. No statistically significant difference was detected in QoR-15 scores between groups (p = 0.51). No block-related complications or opioid-related adverse effects were observed. Conclusion: In this exploratory pilot randomized controlled trial, M-TAPA did not demonstrate superiority over the TAP block with respect to postoperative pain intensity, opioid consumption, or quality of recovery following laparoscopic appendectomy. Within a standardized multimodal analgesia regimen, both techniques were associated with low pain scores and minimal opioid requirements. Larger, adequately powered randomized trials are warranted to confirm these preliminary findings.