Reinnervation of Free Nipple Grafts Associated With Improved Erection Function.

Background: Most patients undergoing breast surgery with free nipple grafts lose nipple erection (NE) function. This study aimed to evaluate the effect of nerve preservation and reconstruction with targeted nipple-areola complex reinnervation (TNR) on NE following gender-affirming mastectomy with free nipple grafting.

Methods: Patients undergoing gender-affirming mastectomy with free nipple grafts were prospectively enrolled. Subjects who underwent TNR were compared with controls who did not undergo TNR. Postoperative patient-reported NE function was scored using a 4-point Likert scale. Objective NE evaluation consisted of the change in areola circumference and nipple height following cold application using a thermal device and 3-dimensional imaging.

Results: Twenty patients (11 subjects and 9 controls) with comparable age, body mass index, and mastectomy weight were included. At an average follow-up of 16.8 (±7.0) months, significantly more subjects reported NE than controls (72.8% versus 38.9%, P = 0.03), with a higher median NE score (3 [range 1-4] versus 1 [range 1-2], P = 0.0005). Following cold application, subjects had a greater mean reduction in areola circumference (-4.16 ± 3.3 versus -1.67 ± 1.9 mm, P = 0.02) and a greater mean increase in nipple height (+0.86 ± 0.8 versus +0.37±0.3 mm, P = 0.04) compared with controls. Improved patient-reported NE function correlated with better cold detection thresholds (P = 0.01).

Conclusions: TNR was associated with improved patient-reported and objective NE following gender-affirming mastectomy. Improved NE correlated with improved cold detection, suggesting the role of both sensory and autonomic innervation in mediating NE.