SO19. Top Surgery and Chest Dysphoria Among Transmasculine And Nonbinary Adolescents and Young Adults: A Follow Up Study

PURPOSE: The purpose of this study is to evaluate the effects of top surgery on chest dysphoria, gender congruence, and body image in transgender nonbinary (TGNB) adolescents and young adults (AYA) designated female at birth (DFAB). There is a paucity of prospective research evaluating the impact of top surgery in this population. METHODS: This is a nonrandomized, multicenter, prospective cohort study of TGNB adolescents who underwent top surgery compared to a control group who did not. Patient reported outcomes were obtained via Research Electronic Data Capture preoperatively and at three and twelve months postoperatively. Outcomes included transgender congruence scale (TCS), chest dysphoria measure (CDM), and body image scale (BIS). Primary analyses included inverse probability of treatment weighting (IPTW) with linear mixed effects models (LMM). RESULTS: Overall, 41 patients were in the control group and 41 patients were in the treatment group. IPTW analyses showed a significant improvement in TCS, CDM, and BIS scales at 12 months postoperatively: CDM (-17.86 point; 95% CI -21.97 to -13.74), TCS (6.29 points; 95% CI 4.39 to 8.19), and BIS (-7.9 points; 95% CI -12.65 to -3.16). Improvements were all sustained at study closeout. Subgroup analyses were conducted for patients <18 years with similar results. CONCLUSION: We present the first and largest prospective matched study evaluating quantitative outcomes of top surgery among TGNB DFAB AYA. Surgical intervention is part of the standard of care of gender dysphoria and should not be delayed by arbitrary age restrictions.