Ultrasound-Guided Anterior Quadratus Lumborum Block at Lateral Supra-Arcuate Ligament vs Thoracic Epidural Analgesia after Open Liver Surgery: A Randomized, Controlled, Noninferiority Trial

BACKGROUND: Thoracic epidural analgesia (TEA) has demonstrated great analgesic benefits in open liver surgery. However, the increased risk of postoperative coagulopathy after open liver surgery has promoted interest in alternate analgesic research. We aimed to explore whether ultrasound-guided anterior quadratus lumborum block at the lateral supra-arcuate ligament (LAL-QLB) with intravenous analgesia was noninferior to TEA under multimodal analgesia after open liver surgery. STUDY DESIGN: Seventy-four patients undergoing open liver surgery were randomized (1:1) to the LAL-QLB or TEA group in this open-label study. The primary outcome was the numeric rating scale during coughing at 24 hours postoperatively with a noninferiority limit of 1. RESULTS: The mean difference of numeric rating scale during coughing at 24 hours postoperatively was 0.32 (95% CI –0.03 to 0.68), showing noninferiority. The TEA group had better pain scores at 1 and 6 hours, and the early postoperative pain of the LAL-QLB group was within the clinically acceptable limit with no differences at other time points. The LAL-QLB group received more opioids within 24 hours postoperatively. There were no differences in analgesia-related adverse reactions or rescue analgesia. Postoperative coagulopathy was responsible with 19.4% of delayed epidural removal. TEA outperformed LAL-QLB in terms of ambulation and bowel recovery. There were no differences in hospital stay or 30-day postoperative complications. CONCLUSIONS: LAL-QLB provided noninferior analgesia at 24 hours postoperatively. Despite regarding coagulopathy and delayed epidural removal, TEA was found to be better than LAL-QLB for pain management after open liver surgery. Epidural removal required close coagulation test.