Comparison of the analgesic efficacy of ultrasound-guided retrolaminar block with serratus anterior plane block in patients undergoing radical mastectomy.

OBJECTIVES

The newly introduced retrolaminar block (RLB) offers anesthesiologists an alternative regional anesthetic technique for radical mastectomy. However, few clinical studies have compared the efficacy of RLB with that of serratus anterior plane block (SAPB). This study aimed to investigate the postoperative analgesia efficacy between ultrasound-guided RLB and SAPB in patients undergoing radical mastectomy.

METHODS

Seventy patients were included in this prospective, randomized controlled trial. Patients were assigned to receive either ultrasound-guided RLB or SAPB. The primary outcome was the visual analogue scale (VAS) score during coughing at 6 hours postoperatively. The secondary indicators included dermatomal spread of sensory block (from T2 to T6 at the medial and lateral nipple lines assessed by acupuncture), intraoperative hemodynamic changes, and analgesia-related adverse reactions.

RESULTS

The median VAS scores during coughing at 6 hours postoperatively were 2 (IQ1-IQ3: 1-3; P = 0.39) in both groups, indicating no significant difference. Similar analgesic effects were observed at other time points within 48 hours post-surgery. RLB provided broader sensory coverage on the medial side of the nipple compared to SAPB (median [IQR]: 3 (3-4) and 2 (1-2)) (P = 0.006). No significant differences in mean arterial pressure (MAP) or heart rate (HR) were observed immediately or 5 minutes after skin incision. The incidence of adverse events did not differ significantly between the two groups.

CONCLUSIONS

Retrolaminar block and Serratus anterior plane block provide comparable postoperative analgesia following radical mastectomy. However, RLB offers a broader sensory block range, particularly over the medial chest wall.