VTE Rate in Transgender Surgery: Is it Safe to Continue Estrogen?

INTRODUCTION: Gender dysphoria is defined as incongruence between expressed and assigned gender. Transfeminine individuals often undergo Gender-Affirming Surgery (GAS) and adopt Estrogen Therapy (ET) for effective gender alignment. Despite the transformative benefits of GAS, a potential increase in risk Venous Thromboembolism (VTE) may be associated with continuation of ET in the peri-operative period. This study aims to assess the rate of venous thromboembolism in GAS patients on ET. METHODS: A retrospective review of transgender patients on ET who underwent GAS was conducted between January 1, 2018, and October 1, 2023. Exclusion criteria were defined as patients with thrombophilia or surgeries lasting less than 30 minutes. Demographics were presented using median and interquartile range or mean ± standard deviation. Sample normality was assessed using the Shapiro-Wilk test. Independent student T-test and Chi-Squared test were employed when appropriate. A p-value of less than 0.05 was set as statistically significant. All analyses were conducted in R (R Open-Source Software, version 4.1.3). Patients were followed up to eight weeks post-operatively. RESULTS: A total of 195 GAS in 123 transfeminine patients were included (mean age: 37.06 ± 14.25 years). Primary vaginoplasty comprised 47% of procedures followed by Orchiectomy (56.4%) and Facial Gender Affirmative Surgery (28%). The most common ET was 17-β-estradiol (47%), whereas the predominant method of administration was oral (46.7%). Eighty-seven procedures (44.5%) were done on patients who stopped ET, and among these patients, 66 (75.86%) stopped ET two weeks prior to surgery. Mean operative times differed between those that continued ET (3.92 ± 2.04 hours) and stopped ET (5.02 ± 2.71 hours, p = 0.002). Thirty-six patients (18.46%) received postoperative VTE chemoprophylaxis, amongst which 13 (12.04%) were in the ET-continued group and 23 (26.43%) in the ET-stopped group. The average Caprini score of our sample was 3.4 (ET-stopped group 3.6 and ET-continued group 3.0). There was a total of 2 VTE events, one in each group, with an overall 1.03% incidence rate. The VTE incidence in patients continuing and discontinuing ET was 1.04% and 1.15%, respectively (p = 0.9447). All VTE events occurred in patients on oral ET, resulting in a 3.3% incidence in patients on oral ET. No statistically significant difference in VTE rate was found in subjects using other forms of administration when compared to oral ET (p = 0.19). CONCLUSION: Based on our cohort of 123 transgender patients, maintaining ET peri-operatively does not elevate the risk of postoperative VTE in patients with low baseline Caprini scores. Oral ET was associated with a relatively higher VTE risk. Further research with a randomized prospective design is imperative to validate these findings and provide comprehensive guidelines for peri-operative management of ET.