Impact of BMI on Sensory Recovery after Targeted Nipple Areolar Complex Innervation in Gender Affirming Mastectomy

PURPOSE: Top surgery, which is one of the most common gender-affirming procedures, has been shown to increase body image satisfaction, improve gender congruence, decrease gender dysphoria, and is rarely regretted. Reinnervation techniques have been shown to improve sensation outcomes for the NAC and throughout the chest wall. Historically, Body Mass Index (BMI) has been a challenging topic amongst TGD patients and gender-affirming surgeons as existing research has shown mixed outcomes of BMI impact on E. As such, some providers may hold stringent BMI cutoffs that limit access to life changing procedures. This is the first study to illustrate, in detail, the complications correlated with various BMI groups following reinnervation in female to male gender affirming mastectomy. METHODS: A retrospective chart review was conducted on 122 total patients who underwent FTM gender-affirming mastectomy with targeted NAC innervation. BREASTQ was sent to patients post-operatively. Semmes-Weinstein monofilament testing was used to measure sensation in the nipple, areola, and breast skin within 2cm of the NAC to total 9 segments. RESULTS: A total of 118 patients were included in our chart review. The average BMI of this cohort was 25.1±5.16 kg/m2 (range 18.2 - 49.0). Most patients fell into the healthy weight category (54, 45.8%) or had Class I Obesity (13, 11.0%). Our cohort showed no significant impact of BMI on restoration of sensation in the first 1-6 months, or 12-24 months in any breast region. Log regression results demonstrated that overweight(p=0.51), Class I(p=0.34), and Class 3 (p=0.997) patients did not have significantly lower restoration of sensation than patients in the normal weight class. This trend held up to 24 months post operatively. Furthermore, multivariate regression analysis of BMI class revealed no statistically significant association between BMI class and postoperative complications within the first 30 days(p=0.56) or revision surgeries(p=0.32). CONCLUSIONS: This study demonstrated that BMI is not a significant predictor for restoration of sensation following gender affirming mastectomy with targeted NAC innervation regardless of post-operative time point. It is also consistent with prior research indicating that BMI may not be an accurate predictor of post-operative complications in the setting of adequate patient education. As investigations into optimizing outcomes for gender affirmation surgery continue, our group suggests a wholistic approach to patient evaluation for gender affirming mastectomy.