1. Introduction
Breast cancer is one of the most common malignant tumors in women [1]. Postoperative pain is a significant concern following modified radical mastectomy (MRM) [2]. Excision of the pectoralis major fascia and extension of the pectoralis muscles to improve surgical access are likely causes of perioperative myofascial pain [3]. Moreover, drain placement may contribute to pain experienced during the postoperative period. In addition to branches of the intercostal nerves, the pectoral, thoracodorsal and long thoracic nerves may also be involved in perioperative pain following radical mastectomy with axillary involvement [2]. Therefore, many different kinds of analgesic techniques have been proposed, including intercostal block, local anesthetic infiltration, erector spinae plane block (ESP), paravertebral block, serratus plane block (SAB block) and rhomboid intercostal block (RIB) block to relieve acute postoperative pain [3-7]. it is still not clear which one is superior to others. The effects of regional block technology needs to be compared by further researches.
Ultrasound-guided erector spinae plane (US-ESP) block is a fascial nerve block technique described for the first time by Forero et al [8]. US-ESP can provide effective postoperative analgesia for patients undergoing modified radical mastectomy [3]. Serratus plane block (SAB) is a new analgesic technique proposed by Blanco et al [9], and provides a good postoperative analgesic effect in patients undergoing MRM [7, 10]. Ultrasound-guided rhomboid intercostal block (US-RIB) is a new fascial block technique discovered by Elsharkawy et al.[11] in 2016. Recently, some clinical studies have reported that RIB can effectively reduce postoperative pain in patients with breast cancer after MRM. However, the comparison of postoperative analgesic effects of RIB, SAB and ESP block on patients undergoing MRM has not been reported. In the current research, we compared the analgesic effects of these three kinds of nerve block after MRM for the first time.
This prospective randomized controlled trial was performed to analyze the postoperative analgesic efects of ultrasound-guided RIB, ESP and SAB block after MRM. The primary hypothesis of this study is that the ultrasound-guided RIB block and ESP block reduced postoperative tramadol consumption and pain scores more efectively than the SAB block in the frst 24 h after MRM.