Evaluation of Neuroma Perfusion with Indocyanine Green Fluorescence Angiography

Neuromas represent the frustrated regeneration of injured nerve axons encased in a bulbous scar. Symptomatic neuromas are particularly problematic in patients with amputations. Targeted Muscle Reinnervation is a novel surgical approach to neuroma treatment, resulting in improved residual limb pain in amputees. Nevertheless, a subset of Targeted Muscle Reinnervation patients achieve inadequate relief. Incomplete neuroma excision may be of particular concern in such cases, as failure to completely excise the neuroma risks leaving a scarred proximal nerve stump behind. Despite the critical importance of complete neuroma excision, there is no clear definition of a neuroma's "zone of injury". Indeed, intraoperatively determining where to cut a nerve to ensure accurate and complete excision of a neuroma at the time of reconstruction or repair is an unsolved problem in peripheral nerve surgery. The proposed research aims to characterize the perfusion of neuromas using fluorescence angiography. Specifically, we will test the hypothesis that intravascular indocyanine green (ICG) renders visible the perturbations in nerve perfusion associated with neuromas, and that these altered perfusion patterns correlate with the nerve's "zone of injury" as identified by histopathology. Ultimately, indocyanine green (ICG) fluorescence angiography may facilitate intraoperative decision-making at the time of neuroma excision.