Hematoma Prediction in Gender-Affirming Mastectomies: A Single-Surgeon Experience with 267 Patients

Background/Objectives: Gender-affirming mastectomies are a pivotal step in the gender-affirmation process. These procedures represent the concordance between an individual's appearance, as seen by the environment, and his/her perception of themselves. Hematomas are a growing concern in gender-affirming mastectomies, as they carry the risk for reoperation, increased length of hospital stay, and sub-par aesthetic outcomes. Recognition of factors contributing to the development of hematomas in gender-affirming mastectomies can improve surgical outcomes and patient satisfaction. In this study, we hope to shed light on variables potentially contributing to the development of post-operative hematomas in our experience with 267 gender-affirming mastectomies. Methods: Medical records of 267 consecutive gender-affirming mastectomies performed by the senior author were included in this study. Relevant demographic, clinical, and surgical characteristics were collected from patients' medical files. The patients were stratified based on whether they developed post-operative hematomas. Univariate and multivariate analyses were performed to determine the impact of various factors on the risk of the development of post-operative hematomas. Results: The study groups were found to be similar in most baseline demographic and surgical characteristics. Statistically significant differences were seen regarding mean BMI, use of combined TRT and estrogen blockers, surgical technique, previous reduction mammaplasty, and intra-operative tissue resection weight (p-value = 0.007, 0.03, <0.001, 0.02, <0.001). Multivariate logistic regression was performed to predict post-operative hematomas. The covariates in question were statistically significant variables that differed between the groups. Previous reduction mammaplasty was found to be a statistically significant independent predictor of post-operative hematomas, with an OR of 41.55 (95% CI 4.2-408.3), and the "free NAC" surgical technique was found to decrease the incidence of post-operative hematomas, with an OR of 0.015 (95% CI 0.003-0.064). Conclusions: A history of reduction mammaplasty is a substantial risk factor for the development of post-operative hematomas in gender-affirming mastectomies. Of the various surgical techniques, the use of the "free NAC" technique can, to some degree, reduce the risk of hematoma development.