Background
We describe the senior authors learning curve for nerve dissection during Targeted Nipple Areola Complex Reinnervation (TNR) in gender affirming mastectomy (GAM) with free nipple grafting (FNG), allowing for primary use of direct coaptation instead of nerve graft. This study explores postoperative sensory outcomes between direct repair and allograft use.
Methods
60 patients who underwent GAM/ FNG at two institutions were prospectively enrolled from November 2021 through April 2023. Three groups with 20 patients each were compared: GAM/FNG + TNR with nerve allograft reconstruction (group 1), GAM/FNG + TNR with direct coaptation (group 2), and a control group GAM/FNG - TNR (group 3). Semmes Weinstein (SW) filament testing was used preoperatively and at 1, 3, 6, 9, and 12 months postoperatively. Pinprick, temperature, vibration, pressure, and 2-point discrimination were tested preoperatively and 12 months postoperatively. Chi-square analysis was used to detect postoperative sensation return differences.
Results
2 ICN branches were used for direct coaptation. Median allograft length was 3.5 cm. Demographics and preoperative sensation were comparable between all groups (p>0.05). At 1 month postoperative, NAC and chest skin SW detection was worse in all groups (p < 0.01). At 3 months, NAC and Chest skin SW values in group 1 and group 2 were improved compared to group 3 (p< 0.05). At 6 months, 82.5% of patients within group 2 demonstrated NAC SW values at baseline, compared to 30% group 1 (p <0.05). 85% of group 2 had chest SW values at baseline, compared to 40% in group 1. At 12 months, sensation levels were comparable between groups 1 and 2 (p>0.05), and SW detection, pinprick, temperature, vibration, pressure, and 2-point discrimination tests were improved in both TNR groups compared to group 3 (p < 0.05).
Conclusion:
After a learning curve, TNR with direct coaptation is efficacious and cost effective in restoring chest wall sensation. Allograft reconstruction and direct repair are feasible options with similar sensory outcomes at 12 months postoperatively.
Figure1. A)Mean NAC Monofilament values for each Group Overtime | B) Mean Chest Monofilament values for each Group Overtime Compared to Baseline | C) 12 month Postoperative NAC and Chest Pinprick values | D) 12 month Postoperative NAC and Chest Two Point Discrimination Values | E) 12 month Postoperative NAC and Chest Vibration Values | F) 12 Month NAC and Chest Pressure Pain Values | G) 12 month Postoperative NAC and Chest Cold Detection Values | H) 12 month Postoperative NAC and Chest Warm Detection Values | I) 12 month Postoperative NAC and Chest Heat Pain Detection | J) Postoperative NAC Monofilament Values as Compared to Preoperative Baseline | K) Postoperative Chest Monofilament Values as Compared to Preoperative Baseline. Asterix represent a statistical difference of p<0.05
