The Effect of Ultrasound-Guided Low Serratus Anterior Plane Block on Analgesia and Quality of Recovery After Robot-Assisted Thymectomy via Subxiphoid Approach: Study Protocol for a Randomized Controlled Trial

Purpose: It is pivotal to optimize perioperative analgesia in order to fit a transition in the surgical approach for removing mediastinal tumors, from sternotomy to trans-subxiphoid robotic thymectomy (TRT). Serratus anterior plane block (SAPB) is a safe, effective and easy to perform analgesic technology, which could provide analgesia in thoracic and upper abdominal surgery. However, the efficacy of SAPB analgesia in the patients undergoing TRT is unclear and has never been described in scientific literature. Therefore, this study aimed to determine the effect of ultrasonic-guided low SAPB on analgesia and the quality of recovery (QoR) following the TRT. Study Design and Methods: In this prospective double-blind, randomized controlled design trial, 40 adults scheduled for TRT will be randomly allocated to the low SAPB group (Group S) and placebo control group (Group C). The patient of Group S will be performed SAPB bilaterally at the level of T8-T9 under ultrasound guidance with 40 mL 0.375% ropivacaine after anesthesia induction. Group C will be administered normal saline at the same volume and timing. The primary study outcome is the global Quality of Recovery-40 (QoR-40) score on postoperative days (POD) 1. The secondary endpoints are numeric rating scale (NRS) scores and sufentanil consumption at different time points after surgery, QoR-40 scores on POD 2, 30 and 90, chronic pain at POD 90, and the incidence of perioperative adverse events. Discussion: This is the first prospective trial to shed light on the efficacy of ultrasonic-guided low SAPB on postoperative pain and recovery after TRT. The findings will provide a new strategy of perioperative pain management for TRT.