(038) Optimizing Innervation in Radial Forearm Phalloplasty: Determination of Ideal Nerve Coaptations via Donor:Recipient Axon Ratios

Abstract Introduction There is currently no standardized approach to innervation in radial forearm phalloplasty. This includes both the number and combination of nerve coaptations that are performed. It also under-recognized executed phalloplasty equivalent sensory transfers. well documented a key component successful transfer sufficient donor:recipient (D:R) axon ratio. Evidence suggests minimum ratio greater than 0.3:1 an optimal or equal 0.7:1 best optimize regeneration outcomes. Axon counts ratios have not yet been performed for nerves used surgery. Objective The purpose this study was obtain donor recipient order calculate each possible transfer. information will inform which most ideal based on ratios. Methods Following IRB approval informed consent, five transmasculine patients who underwent gender-affirming at our institution had specimens (5 mm) taken from different routinely transected during surgery – lateral antebrachial cutaneous (LABC), medial (MABC), posterior (PABC), ilioinguinal, dorsal clitoris. Histomorphometric evaluation determine mean respectively. Donor:recipient were then calculated nerves. Results Mean 6957 1866 1712 (PABC). 2301 (ilioinguinal), 5141 (dorsal clitoris). Calculated D:R as follows: clitoral:LABC 0.739, clitoral:MABC 2.754, clitoral:PABC 3.002, ilioinguinal:LABC 0.331, ilioinguinal:MABC 1.233, ilioinguinal:PABC 1.344. Conclusions Based ratios, clitoral more powerful available should be considered use primary donor. All exceed 0.3:1. However matches clinical size match appear clitorial:LABC ilioingiinal:MABC ilioinuinal:PABC. If using MABC PABC coapt into nerve, there consideration only part prevent unnecessary levels denervation neuroma formation given significant excess axons compared pathways regeneration. ilioinguinal likely under-powered consistently re-innervate LABC. In general, highly favorable functional additional factors beyond may contribute outcomes following Disclosure No