Ultrasonographic demonstration of intraneural neovascularization after penetrating nerve injury.

INTRODUCTION: Hypervascularization of nerves has been shown to be a pathological sign in some peripheral nerve disorders, but has not been investigated in nerve trauma.

METHODS: An observational cohort study was performed of the intraneural blood flow of 30 patients (34 nerves) with penetrating nerve injuries, before or after nerve reconstruction. All patients underwent electrophysiological assessment, and B-mode and color Doppler ultrasonography.

RESULTS: Intraneural hypervascularization proximal to the site of injury was found in all nerves, which was typically marked and had a longitudinal extension of several centimeters. In 6 nerves, some blood flow was also present within the injury site or immediately distal to the injury. No correlation was found between the degree of vascularization and age, size of the scar / neuroma, or degree of reinnervation.

DISCUSSION: Neovascularization of nerves proximal to injury sites appears to be an essential element of nerve regeneration after penetrating nerve injuries. Muscle Nerve 57: 994-999, 2018.