Surgical Treatment of Thoracic Spinal extradural-Intradural AVM: 2D Microsurgery

Extradural-Intradural arterio-venous malformations (AVM) also referred to as spinal juvenile metameric (Type III) AVM are extremely rare and are mostly reported as case reports. Most cause a progressive neurological deterioration. They are treated by either embolization, surgery or a combination. Most extradural-intradural AVMs are not completely obliterated following treatment. [1-3] Following IRB approval, we present a case of a 71-year-old female, treated by embolization and surgery 40years prior to presentation with progressive thoracic myelopathy. As the surgical video contains no patient identifying information or external features permitting identification, the requirement for patient consent for video publication was waived in accordance with institutional policy. Digital subtraction angiography demonstrated only the paravertebral component, eliminating the option for embolization. Surgical closure utilizing intra-operative monitoring, clipping technique and ICG injection enabled closure of the intradural component visualized by ICG, however, since the pre-operative angio failed to visualize the spinal AVM, postoperative angiography was waived. Post-operative course was uneventful. as. Intramedullary engorged vessels resolved on the two-month follow-up MRI. Angiographically occult intradural AVMs should be explored through a wide surgical exposure with multilevel laminectomy, aided by intraoperative ICG angiography.