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

Abstract

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). 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. 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. 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 ≥30kg/m 2 and mastectomy weight ≥800g 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. 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.