Microsurgical Ligation of a Dural Arteriovenous Fistula of the Petrous Apex-A 2-Dimensional Operative Video.

Dural arteriovenous fistulas are rare acquired vascular lesions that represent 15% of the vascular malformations. While endovascular treatment has recently became the first line of treatment, microsurgical ligation may still be indicated in specific cases. We present the case of a 75-year-old patient who presented a progressive tetraparesis culminating in a spastic paraplegia and urinary retention. Cranial and spinal magnetic resonance imaging showed a T2 hypersignal in the cervical spinal cord and lower brainstem associated with flow voids in the subarachnoid space. Brain angiography demonstrated a dural arteriovenous fistula of the right petrous apex fed by the inferior lateral and meningohypophyseal trunks of the right cavernous internal carotid artery and draining in the lateral vein of the pons and the anterior medullary vein. Given the small size and tortuous feeders, endovascular treatment was considered too risky and microsurgical ligation was offered to the patient. The main issue of the microsurgical ligation of the dural arteriovenous fistula is the precise identification of the fistulous point, and therefore a detailed study of the specific vascular anatomy of the cerebellopontine angle is compulsory. Indocyanine green angiography plays a major role in confirming the location of the fistula and its correct occlusion. We discuss the technical nuances of the fistula ligation through a retrosigmoid approach and present Video 1 illustrating these principles. Given the retrospective nature of this report, informed consent was not required.