Use of Doppler Ultrasound During Surgical Treatment of Intradural Spinal Arteriovenous Fistula.

Abstract

Spinal dural AV fistulas comprise 70% of spinal AVMs. If left untreated, patients typically experience progressive myelopathy, and surgical treatment remains the most definitive and curative strategy. We present an operative video illustrating the use of Doppler ultrasound during clip ligation and disconnection of a spinal AV fistula. A 73-year-old male patient presented with myelopathic symptoms with weakness and diminished sensation in his bilateral lower extremities. Neuroimaging demonstrated spinal cord edema from T6 to the conus with prominent epidural flow voids from T4-T10 on MRI, and an AV fistula with arterial supply from the left T11 segmental artery on DSA, consistent with a type 1 dural AV fistula. Doppler ultrasound was used to identify the location of the AV fistula prior to durotomy, verify the absence of shunting after temporary clip placement on the draining vein, and confirm no residual shunting after clip ligation and disconnection. Post-operatively, the patient was discharged to rehab with full strength in both lower extremities. At six-week and nine-months post-op, the patient remained at full strength, with improvement in myelopathic symptoms. Key features of intraoperative Doppler ultrasound include the ability to measure dAVF hemodynamics, real-time visualization of blood flow, identification of vessels not directly visible under the microscope, and confirmation of fistulous interruption. Compared with existing imaging tools, Doppler ultrasound does not require a dedicated microscope, hybrid operating suite, or injection of a systemic agent. Doppler ultrasound is a readily accessible adjunct surgical tool to localize and confirm obliteration of a spinal dural AV fistula.