Impact of rhomboid intercostal plane block on chronic pain incidence and acute pain scores after oncologic breast surgery: a randomized controlled trial

Background Persistent chronic pain after oncologic breast surgery remains a major clinical problem, affecting approximately 25–60% of patients and significantly impairing quality of life. Although the rhomboid intercostal plane block (RIB) has been shown to reduce acute postoperative pain, its role in preventing chronic postoperative pain remains inadequately investigated. Methods This prospective, single-center, randomized, double-blind, controlled trial included 254 adult women undergoing oncologic breast surgery with or without lymph node dissection. Patients were randomized to receive either a pre-operative ultrasound-guided single-shot RIB using 30 mL of 0.25% bupivacaine or no regional block (control group). All patients received standardized multimodal systemic analgesia. The primary outcome was the incidence of chronic pain at 3 months postoperatively. Secondary outcomes included chronic pain at 6 months, Brief Pain Inventory–Short Form scores at 3 and 6 months, neuropathic pain assessed using the Douleur Neuropathique 4 questionnaire, acute postoperative pain scores, and 24-h postoperative opioid consumption. Results Of the 254 randomized patients, 247 completed the study. Chronic pain incidence was significantly lower in the RIB group at 3 months (17% vs 31%; p = 0.009) and 6 months (13% vs 30%; p < 0.001), with reduced neuropathic pain at 6 months. The RIB group had lower 24-h opioid consumption than controls (p = 0.01). Conclusions Pre-operative single-shot RIB significantly reduced chronic postoperative pain and opioid consumption following oncologic breast surgery, and may be considered as part of multimodal analgesia to decrease chronic pain incidence, neuropathic pain and improve acute postoperative pain control. Trial registration Clinicaltrials.gov (NCT06019325 registered August 17, 2023).