The Efficacy of Ultrasound-guided Type II Pectoral Nerve Blocks in Perioperative Pain Management for Immediate Reconstruction after Modified Radical Mastectomy. A Prospective, Randomized Study.

Objectives:The pectoral nerves (Pecs) II block is a technique that places local anesthetic between the thoracic muscles to block the axillary and breast regions. This study aimed to compare the quality of perioperative analgesia and side effects of the Pecs II block under general anesthesia versus general anesthesia alone in immediate unilateral breast reconstruction with an implant and latissimus dorsi flap after modified radical mastectomy.Materials and Methods:Sixty-four patients scheduled for immediate breast reconstruction after modified radical mastectomy were randomly allocated into the Pecs II block under general anesthesia group (group P, n=32) or the general anesthesia alone group (group G, n=32). After anesthesia induction, patients in group P underwent a Pecs II block. The primary endpoint was postoperative morphine consumption in the first 24 hours in postoperative intensive care unit. Intraoperative fentanyl consumption, visual analog scale scores, shoulder range of motion, and postoperative nausea and vomiting were also assessed.Results:Sixty patients completed the study. There was a significant reduction in postoperative morphine consumption (3.67 mg; 95% confidence interval, 2.91-4.51 mg) and intraoperative fentanyl consumption in group P patients compared with group G patients. Less postoperative nausea and vomiting (relative risk 0.22; 95% confidence interval, 0.05-0.94) and lower visual analog scale scores were also observed in group P. No block-related complications were recorded.Discussion:When patients underwent immediate breast reconstruction with an implant and latissimus dorsi flap, the Pecs II block offers a comprehensive block of associated nerves in the surgical area, and therefore can provide superior analgesia and reduced perioperative opioids use without obvious block-related complications.