An open approach versus ultrasound approach for deep serratus anterior plane block for postoperative analgesia after modified radical mastectomy: A randomized controlled trial.

Background And Aims: Ultrasound-guided deep serratus anterior plane (SAP) block has recently gained popularity as an analgesic technique in breast surgery. However, the effectiveness of ultrasound depends largely on the quality of the equipment used, and the technique can be complicated by patient-related factors such as obesity. We hypothesized that the simpler open approach to deep SAP block would be non-inferior to the ultrasound-guided approach in providing analgesia for modified radical mastectomy.

Method: A non-inferiority, randomized controlled study was performed in 100 patients aged 18-60 years who underwent modified radical mastectomy. In the open approach group (n = 50), 30 ml of 0.25% bupivacaine was injected deep to the serratus anterior muscle after breast resection and rib palpation. In the ultrasound-guided group (n = 50), 30 ml of 0.25% bupivacaine was injected deep to the serratus anterior muscle under ultrasound guidance before the skin incision. The primary outcome was total morphine consumption in the first 24 postoperative hours. Secondary outcome measures included time to first request for rescue analgesia (duration of SAP block), postoperative visual analogue scale (VAS) score, and the incidence of adverse effects.

Results: Median (interquartile range) morphine requirement in the first 24 hours was similar in both groups (P = 0.81), and the time to first request for analgesia was also similar (P = 0.81). Evaluation of VAS scores during the initial 24 hours after surgery showed no statistically significant differences between groups (P > 0.05), except at 4 postoperative hours, when the score was significantly higher in the ultrasound group (P < 0.001). No complications were observed in either group.

Conclusion: The open approach to deep SAP block is comparable to the ultrasound-guided approach in providing postoperative analgesia in female patients undergoing modified radical mastectomy.