Figure 1 (A, B) Intraoperative precision nerve block was administered through the wound for postoperative analgesia. In the precision group, 0.3% ropivacaine (1.5 mL for each nerve) was used through the wound during surgery. At the deep level of the platysma muscle, the ropivacaine was firstly injected upward along the front edge of the sternocleidomastoid muscle to block the lower branch of the transverse cervical nerve, and then was injected along the anterolateral direction of the sternocleidomastoid muscle to block the inner branches of the supraclavicular nerve.