Prospective Sensory Outcomes for Targeted Nipple Areola Complex Reinnervation (TNR) in Gender-Affirming Double Incision Mastectomy with Free Nipple Grafting.

ABSTRACT

OBJECTIVE: This study analyses the anatomy and sensory outcomes of targeted nipple areola complex reinnervation (TNR) in gender-affirming double incision mastectomy with free nipple grafting (FNG). BACKGROUND: TNR is a novel technique to preserve and reconstruct intercostal nerves (ICN) to improve postoperative sensation. There is little evidence on relevant anatomy and outcomes. METHODS: 25 patients were prospectively enrolled. Data included demographics, surgical technique, and axon/fascicle counts. Quantitative sensory evaluation using monofilaments and qualitative patient reported questionnaires were completed preoperatively, and at one, three, six, nine and twelve months postoperatively. RESULTS: 50 mastectomies were performed. Per mastectomy, the median number of ICN found and used was 2 (1-5). Axon and fascicle counts were not significantly different between ICN branches ( P >0.05). BMI ≥30 kg/m 2 and mastectomy weight ≥800 g were associated with significantly worse preoperative sensation ( P <0.05). Compared to preoperative values, NAC sensation was worse at 1 month ( P <0.01), comparable at 3 months ( P >0.05), and significantly better at 12 months ( P <0.05) postoperatively. Chest sensation was comparable to the preoperative measurements at 1 and 3 months ( P >0.05), and significantly better at 12 months ( P <0.05) postoperatively. NAC sensation was significantly better when direct coaptation was performed compared to use of allograft only ( P <0.05), and with direct coaptation of ≥2 branches compared to direct coaptation of a single branch ( P <0.05). All patients reported return of nipple and chest sensation at one year postoperatively and 88% reported return of some degree of erogenous sensation. CONCLUSION: TNR allows for restoration of NAC and chest sensation within 3 months postoperatively. Use of multiple ICN branches and direct coaptation led to the best sensory outcomes.