Efficacy of Intraoperative Voice Monitoring in Cricothyroid Approximation Under Local Anesthesia for Gender Incongruence

Introduction: Cricothyroid approximation (CTA) is a surgical procedure that increases the pitch of the voice. Previous reports have reported that this procedure is often performed under general anesthesia, which reported a lack of postoperative pitch increase or pitch decrease; however, we performed this procedure under local anesthesia and monitored the pitch intraoperatively. Methods: We retrospectively recruited 15 assigned male at birth patients who underwent CTA at our institution between 2019 and 2024. The same surgeon performed all procedures. We performed statistical analyses of the preoperative, intraoperative, 1 month postoperative, 3 months postoperative, and 6 months postoperative standard fundamental frequency (SFF). Results: The mean SFF was 152.1 ± 25.2 Hz preoperatively, 343.4 ± 62.8 Hz intraoperatively, 249.9 ± 40.1 Hz one month postoperatively, 225.9 ± 26.4 Hz three months postoperatively, and 231.3 ± 29.8 Hz 6 months postoperatively. Comparing intraoperative and 6 months postoperative parameters, SFF showed a mean decrease of 112.1 Hz. Intraoperative SFF was significantly increased compared with preoperative SFF (P < 0.05). Compared with intraoperative SFF, SFF at 1 month postoperatively was significantly lower (P < 0.05); compared with SFF at 1 month postoperatively, SFF at 3 months postoperatively was significantly lower (P < 0.05). However, SFF was not significantly lower at 6 months postoperatively compared with 3 months postoperatively (P = 0.26). Compared with preoperative SFF, SFF was still significantly increased after 6 months postoperatively (P < 0.05). Conclusion: CTA under local anesthesia may stabilize with an SFF approximately 100 Hz lower than the intraoperative value at 6 months postoperatively, and it is useful to set the SFF higher than the objective SFF with intraoperative voice monitoring.