Direct neurotization of free nipple grafts with cadaveric nerve grafts following mastectomy for gender affirming surgery

Background

Free nipple grafting makes sensory recovery challenging. Permanent decreased sensation to touch and temperature in skin-grafted skin is common. Direct neurotization of the nipple-areolar complex (NAC) graft has been described. However, quantitative data regarding degree of nipple reinnervation possible is unknown. This study aims to quantify and qualify sensation recovery following nerve coaptation to reinnervate the NAC.

Methods

Patients undergoing mastectomy for gender dysphoria from 2020 to 2022 were offered nerve allograft to restore nipple sensation. A lateral intercostal nerve was selected and coapted to allograft which was embedded beneath the nipple graft. Semmes Weinstein testing was used to assess nipple sensation. Assessments were made at visits <1 year and >1 year from surgery. Filaments used represented normal sensation, minor diminished sensation, diminished sensation, loss of protective sensation, and deep pressure sensation only.

Results

A total of 115 patients elected for direct neurotization. Semmes Weinstein testing was limited to 46 patients representing 46 encounters and 92 nipples in the <1 year group and 24 encounters and 48 nipples in the >1 year group. Of the 92 nipples in the <1 year group, 17 (18.5%) noted return of normal sensation and 37 (40.2%) noted minor diminished or diminished sensation, indicating nerve reinnervation. There were 38 (41%) nipples with loss of protective sensation or deep sensation only. There were 48 nipples included in the >1 year group. Of the 48 nipples, 4 (8.3%) noted normal sensation and 30 (62.5%) noted minor diminished or diminished sensation, indicating nerve reinnervation. For the remaining 14 nipples, 14 (29%) noted loss of protective sensation or deep sensation only.

Conclusion

Sensory outcomes in NAC grafts used for reconstruction in patients undergoing double incision mastectomy remain poor. Sensation restoration beyond that expected from full thickness skin grafts can be achieved in the majority of patients with nerve allograft via direct neurotization.