Orbital Compartment Syndrome Secondary to Direct Carotid Cavernous Fistula After Carotid Cavernous Aneurysm Rupture: Case Report and Review of Literature.

BACKGROUND: Carotid cavernous aneurysm (CCA) rupture is rare. However, it can result in various complications such as carotid cavernous fistula (CCF), epistaxis, spontaneous thrombosis, and subarachnoid hemorrhage. CASE DESCRIPTION: We report a 65-year-old woman with a history of uncontrolled diabetes who was referred with complaints of acute headache, diplopia, proptosis, and chemosis. Ophthalmic examination revealed elevated intraocular pressure in the right eye, optic disk edema, and retinal venous congestion. Canthotomy was performed based on a diagnosis of orbital compartment syndrome (OCS). Further imaging revealed a dilated superior ophthalmic vein and cavernous sinus, as well as swelling of the extraocular muscles in the right eye. Digital subtraction angiography revealed the fistulous connection between the cavernous part of the internal carotid and cavernous sinus (direct CCF) due to the large ruptured CCA, resulting in retrograde flow through the superior and inferior ophthalmic veins. Successful endovascular coiling of the aneurysm resulted in complete occlusion of the fistula. Postintervention ophthalmic examination demonstrated progressive improvement of ophthalmic signs and symptoms; however, the patient's right eye remained sightless. CONCLUSIONS: In patients with clinical manifestation of OCS with no history of any predisposing risk factors, diagnosis of ruptured cavernous sinus aneurysm and resulting direct CCF should be considered. In such cases, emergent imaging along with early endovascular intervention can resolve OCS and prevent permanent ocular injury and vision loss.

Pial Arteriovenous Fistula with Multiple Venous Aneurysms Resembling a Vein of Galen Aneurysmal Malformation; Case Report and Review of Literature.

BACKGROUND: Pial arteriovenous fistulas are abnormal vascular connections between arteries and the cranial venous system on the surface of the brain in the pia mater. In contrast to vein of Galen aneurysmal malformations, they lack a true vascular nidus and may only indirectly involve the vein of Galen. CASE DESCRIPTION: An 18-month-old boy was referred to us with a history of seizures, drowsiness, bulging cephalic veins, and cranial nerves palsy identified as vein of Galen aneurysmal malformation according to initial magnetic resonance imaging. Digital subtraction angiography showed a vertebrobasilar junction pial high-flow fistula between the basilar artery and anterior pontomesencephalic vein, causing retrograde flow, dilation, and tortuosity of the lateral and posterior mesencephalic vein as well as the vein of Galen. Endovascular treatment, including coil embolization of fistula site, was done successfully without complication resulting in recovery from previous symptoms and signs. CONCLUSIONS: If cerebral venous dilations are encountered, one must keep in mind that the location of the fistula may not be in close proximity to the dilated veins, especially when there is a suspicion for vein of Galen aneurysmal malformation. Other pathologies, such as pial arteriovenous fistula, in a region away from the site of the vein of Galen must be considered.