The Effect of Pectoral Nerve Blocks on Opioid Use and Postoperative Pain in Masculinizing Mastectomy: A Randomized Controlled Trial.

Background: Bilateral masculinizing mastectomy is the most common gender-affirmation operation performed. Currently, there is lack of data regarding intraoperative and postoperative pain control for this population. It is the authors' aim to study the effects of the pectoral nerve (Pecs) I and II regional nerve blocks in patients undergoing masculinizing mastectomy.

Methods: A randomized, double-blind, placebo-controlled trial was performed. Patients undergoing bilateral gender-affirmation mastectomy were randomized to receive either a Pecs block with ropivacaine or placebo injection. The patient, surgeon, and anesthesia team were blinded to the allocation. Intraoperative and postoperative opioid requirements were collected and recorded as morphine milligram equivalents (MME). Participants recorded postoperative pain scores at specific time points on the day of surgery through postoperative day 7.

Results: Fifty patients were enrolled between July of 2020 and February of 2022. Twenty-seven were randomized to the intervention group and 23 to the control group, with 43 patients undergoing analysis. There was no significant difference in intraoperative MME between the Pecs block group and the control group (9.8 versus 11.1; P = 0.29). In addition, there was no difference in postoperative MME between the groups (37.5 versus 40.0; P = 0.72). Postoperative pain scores were also similar between the groups at each specified time point.

Conclusions: There was no significant reduction in opioid consumption or postoperative pain scores in patients undergoing bilateral gender-affirmation mastectomy who received a regional anesthetic when compared with placebo. In addition, a postoperative opioid-sparing approach may be appropriate for patients undergoing bilateral masculinizing mastectomy.

Clinical Question/level Of Evidence: Therapeutic, I.