Regional anesthesia in breast surgery: An Italian expert consensus - Part 2: Results from a network meta-analysis evaluating 103 randomized controlled trials on regional anesthesia techniques for mastectomy with or without axillary clearance.

Regional anesthesia techniques are increasingly used to improve analgesia and reduce opioid consumption after breast surgery. Several approaches have been proposed, including paravertebral block and different fascial plane blocks, but their comparative effectiveness remains uncertain. This network meta-analysis (NMA) aimed to compare the efficacy and safety of regional anesthesia techniques in patients undergoing mastectomy with or without axillary clearance. A systematic review and NMA of randomized controlled trials were conducted according to established methodological guidelines. Studies evaluating regional anesthesia techniques in patients undergoing mastectomy were included. Outcomes assessed were intraoperative opioid consumption, 24-hour postoperative morphine milligram equivalents (MMEs), pain at rest and with movement at 12 and 24 hours, postoperative nausea and vomiting (PONV), use of rescue analgesics, and the incidence of complications such as pneumothorax and local anesthetic systemic toxicity (LAST). Regional anesthesia techniques were associated with improved analgesic outcomes compared with LA infiltration or no regional block. Paravertebral block showed the most consistent benefit across outcomes, particularly for opioid consumption and postoperative pain. Fascial plane blocks demonstrated comparable performance to paravertebral blocks for most outcomes, although paravertebral blocks showed superior results for pain on movement. LA infiltration alone or the absence of regional anesthesia performed worse across most outcomes. Serious complications were rarely reported. Paravertebral block appears to provide the most consistent analgesic benefit for mastectomy when performed by experienced practitioners. Fascial plane blocks represent a reasonable alternative when a paravertebral block is not feasible. Simple surgical infiltration alone appears insufficient for optimal analgesia in major breast surgery.