Evaluation of Neuroma Perfusion with Indocyanine Green Fluorescence Angiography

Evaluation of Neuroma Perfusion with Indocyanine Green Fluorescence Angiography

The purpose of this study is to characterize the perfusion of neuromas using 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.

Inclusion Criteria:

• Age > 18 years
• Clinical diagnosis of neuroma
• Scheduled elective surgery for neuroma excision

Exclusion Criteria:

• Minors, or age < 18 years old at the time of surgery
• Unable to provide written, informed consent
• Prisoners and decision-impaired individuals
• Pregnant or lactating women
• History of allergy to indocyanine green
• History of allergy to iodides
• History of allergic asthma
• History of hepatic failure
• History of renal failure
• Patients in whom the planned surgical incision/approach does not include excision of the neuroma
• Patients in whom adequate surgical exposure of the neuroma is unable to be obtained, as determined intraoperatively at the time of surgery by the Investigator or Co-Investigators
• Any subject who, at the discretion of the Investigator or Co-Investigators, is not suitable for inclusion in the study