Ultrasound-guided sacral multifidus plane block for perioperative analgesia: A comprehensive systematic review, meta-analysis, and trial sequential analysis.

Background and Aims: The sacral multifidus plane block (SMPB) is an emerging regional anaesthesia technique targeting the dorsal rami of sacral spinal nerves, with potential applications in lower limb, pelvic, and perineal surgeries. Evidence from randomised controlled trials (RCTs) has not been systematically synthesised. Methods: We conducted a systematic review and meta-analysis following the PRISMA 2020 guidelines, and the study was registered prospectively in PROSPERO. PubMed, Scopus, Cochrane Library, and ClinicalTrials.gov were searched (January 2019-May 2025) for RCTs comparing SMPB with other regional techniques or no block. The primary outcome was time to rescue analgesia. Secondary outcomes included 24-h opioid consumption, postoperative pain scores, patient satisfaction, and adverse events. Data were pooled using a random-effects model; trial sequential analysis (TSA) and GRADE assessment were performed. Results: Twelve RCTs (n = 768; 348 received SMPB) were included. SMPB significantly prolonged time to first rescue analgesia, reduced 24-h opioid consumption, and lowered pain scores at rest and movement during the first postoperative day, particularly during the intermediate (6-12 h) and late (24 h) postoperative periods. Patient satisfaction was generally higher with SMPB, correlating with improved analgesia and reduced opioid use. TSA confirmed the robustness of findings for time to rescue analgesia and opioid consumption, although the required sample size was not reached. No serious block-related complications were reported. Conclusions: SMPB appears to be a safe, effective regional anaesthesia technique, offering opioid-sparing benefits, prolonged analgesia, and high patient satisfaction. However, current evidence is limited by small sample sizes, methodological heterogeneity, and potential publication bias.