Transcirculation repair of a direct carotid-cavernous fistula in a patient who presented with hydrocephalus: illustrative case.

Background: Direct carotid-cavernous fistulas (CCFs) are relatively rare but dangerous complications of penetrating traumatic brain injury or maxillofacial trauma. A variety of clinical signs have been described, including ophthalmological and neurological ones. In some cases, severely altered cerebral blood flow can present as massive life-threatening bleeding through the nose, subarachnoid hemorrhage, and/or intraparenchymal hemorrhage. Although intuitively it makes sense that the elevation of venous pressure can obstruct the absorption of cerebrospinal fluid after the formation of a CCF, reports of CCFs presenting with acute acquired hydrocephalus do not exist.

Observations: This case illustrates the development of hydrocephalus in a patient with a direct CCF.

Lessons: In the absence of a direct path of access to the cavernous sinus due to occlusion of the carotid artery and difficult venous access, a transcirculation route was used to obliterate the CCF and resolve the hydrocephalus in this patient. https://thejns.org/doi/10.3171/CASE24618.