Abstract No. 197 Using intraoperative neurophysiologic monitoring to prevent peripheral nerve injury during embolization of low-flow vascular malformations

Abstract

To assess the efficacy of intraoperative neurophysiologic monitoring as a method to minimize iatrogenic injury of peripheral nerves during the embolization of low-flow vascular malformations With IRB exemption and HIPAA compliance, the electronic medical record was searched with the search term venous malformation (VM), lymphatic malformation (LM), and mixed vascular malformations (MVM). We derived a study cohort of 50 patients with low-flow vascular malformations treated with percutaneous embolization using sclerosants such as Ethanol, Sotradecol, Bleomycin, and Doxycycline performed from 2004 to 2019 and who received intra-operative nerve monitoring for lesions that are adjacent to one or more peripheral nerve(s). Major complications were defined as those necessitating unplanned hospitalization, prolonging hospital stay, or additional interventions. Minor complications were those managed conservatively without additional treatment. In the study cohort of 50 patients (mean age 30.1 years, range 5-71, 60% female, 59% pediatric) with low-flow vascular malformations (VM 74%, LM 17%, MVM 4%) who underwent percutaneous embolization with intraoperative neurophysiologic monitoring of the adjacent nerve(s), the mean follow-up was 5.56 years (range < 1-14.8 years). Including re-treatments, 319 sites located in the facial (37%), neck (16%), upper extremity (27%), lower extremity (12%), oral cavity (2%), chest (2%), back (2%), and gluteal (2%) regions were targeted by sclerotherapy. There was a minor complication rate of 2.5% (n = 2/80, superficial skin burn), and no major complication. Peripheral nerves with motor and/or somatosensory functions were monitored and included facial (34%), median (15%), ulnar (15%), peroneal (11%), posterior tibial (10%), radial (7%), popliteal (2%), and hypoglossal (2%) nerves and the brachial plexus (2%). Intraoperatively, abnormal neurophysiologic findings were noted in 35% of the treatment sessions and 9% of all sessions were terminated early due to significantly diminished electrophysiologic responses. Ethanol was the sclerosant used in all early terminated sessions (n = 8/85). No patient developed long-term neurologic impairment Intraoperative neuromonitoring may improve the safety of vascular embolization procedures by providing a real-time assessment of any ongoing damage and facilitate intra-procedural planning.