The superficial branch of the radial nerve and sensory disturbance in the radial forearm flap donor-site

INTRODUCTION: Sensory disturbance due to injury of the superficial branch of the radial nerve (SBRN) is a donor-site morbidity of the radial forearm (RF) flap. The relationship between the SBRN preservation method and the post-operative sensation at the flap donor-site was retrospectively investigated. METHODS: We included 39 patients who underwent head and neck reconstruction with a free RF flap at Hyogo Cancer Center between April 2014 and March 2018. The patients were classified into the following three groups according to the SBRN preservation method: group 1, zero preservation, excision of the entire SBRN; group 2, main trunk preservation, excision of all branches except the main trunk of the SBRN; and group 3, complete preservation, preservation of the entire SBRN. Objective sensations and subjective symptoms at the flap donor-site were analyzed. RESULTS: The mean objective sensory scores were 3.18, 2.97, and 1.78 in groups 1, 2, and 3, respectively. Differences between groups 1 and 3 and between groups 2 and 3 were significant (p = 0.0035 and p = 0.037, respectively). The mean subjective symptom scores were 2.40, 1.33, and 1.40 in groups 1, 2, and 3, respectively. Differences between groups 1 and 2, and between groups 1 and 3 were significant (p = 0.032 and p = 0.019, respectively). CONCLUSIONS: Zero preservation method had a higher risk of subjective symptoms and objective hypoesthesia development at the flap donor-site than the complete preservation method. Despite inevitable objective hypoesthesia, the main trunk preservation prevented the development of subjective symptoms. Complete preservation is optimal for RF flap harvest; however, in case of perforator crossing, main trunk preservation is another option.