Abstract
INTRODUCTION: The most frequent malignancy in women is the breast cancer, the rhomboid intercostal and subserratus plane (RISS) block is a novel regional approach. OBJECTIVES: This study evaluated the analgesic efficacy of the RISS block compared to type 2 Pectoral Nerve (PECS II) block in breast cancer patients following breast-conserving surgery (BCS). METHODS: This randomized controlled trial comprised 69 women with breast cancer scheduled for unilateral BCS under general anesthesia, randomly allocated into 3 equal groups. The RISS group had unilateral RISS block using 20 mL of 0.25% bupivacaine between rhomboid major and intercostal muscles and an equal volume between external intercostal and serratus anterior muscles. The PECs Group received a PECS II block using 20 mL of 0.25% bupivacaine between pectoralis major and minor muscles and 10 mL between pectoralis major and serratus muscles. The control group did not get any blocks. The primary outcome was total postoperative morphine consumption within 24 hours. The secondary outcomes were pain score, first request for rescue analgesia, intraoperative fentanyl consumption, and hemodynamics. RESULTS: Requesting rescue morphine analgesia was significantly less frequent in the RISS and PECs groups compared to controls (5, 1, and 23 patients, respectively, P < 0.001). Similar findings were found in the need for extra intraoperative fentanyl (P < 0.001). Pain scores in the RISS and PECs groups were significantly lower than the control group, while RISS and PECs groups had comparable scores throughout the postoperative period. All hemodynamic readings were within the clinically acceptable ranges. CONCLUSION: In patients undergoing BCS, RISS and PECs II block are comparable, safe, and effective regional analgesic alternatives.