Purpose After space-occupying lesions and mechanical disruptions of CSF drainage have been excluded, intracranial venous hypertension (ICVH) often is the central mechanism leading to intracranial hypertension and its causes can be categorized into primary venous outflow compromise (PVOC), arteriovenous shunting (AVS) and idiopathic intracranial hypertension syndrome (IIH). We identified pediatric cases of intracranial venous hypertension (ICVH) to investigate the precipitant vascular causes and the role of endovascular intervention.

Materials and methods Following IRB approval, a retrospective pediatric neurointerventional database review identified patients with known ICVH. Cross-sectional imaging and catheter studies were reviewed for direct intravascular pressure measurements and angiographic evidence of disturbed cerebral venous drainage including venous dilation, stenosis, occlusion and abnormal collateral drainage. Demographic data, clinical presentation, type and grade of the underlying vascular lesion, treatment strategy, follow-up imaging and clinical course were obtained accordingly.

Results Eleven patients (3F/8M) with mean age of 4.6 years (range: 20 days - 13 years) at the time of presentation were identified. The presenting signs and symptoms included increased head circumference (IHC) (n = 6), failure to thrive (n = 3), visual disturbance/papilledema (n = 3), seizure (n = 2), prominent scalp and/or facial veins (n = 2), head tilt (n = 1), and cardiovascular/respiratory complications (1). Preprocedural imaging findings included: hydrocephalus (n = 5), ventriculomegaly (n = 4), anatomical sinus variant (n = 4), venous sinus thrombosis (n = 2), and bilateral subdural hematoma (n = 1). ICVH was verified by transcatheter venous pressure measurement in four cases. The underlying vascular lesions leading to ICVH were subclassified into three groups: PVOC, AVS and IIH. Three cases were classified as PVOC including 2 cases of focal web-like stenosis of the dominant sigmoid sinus and 1 case of venous sinus thrombosis. Six cases of AVS included vein of Galen aneurysmal malformation (n = 2), high-flow pial/dural AVF (n = 2) and congenital high-flow torcular arteriovenous fistula (n = 2) with one of the latter complicated by a secondary venous outflow obstruction. Two cases were consistent with IIH. The AVS group comprised younger patients (mean age: 2.6 months) and the most common clinical findings were IHC and hydrocephalus compared with headache, decreased visual acuity and papilledema in IIH. PVOC had a more heterogenous presentation with an overlap of presenting symptoms and signs with the AVS group (IHC and hydrocephalus) and IIH group (headache, papilledema). The endovascular treatment included multiple sessions of endovascular embolization, stent placement, and intra-arterial thrombectomy/thrombolysis depending on lesion type and was technically successful without perioperative complications in all cases. Follow-up imaging and clinical outcome revealed significant improvement in intracranial venous drainage and remarkable clinical and developmental improvement except for one case.

Conclusions Intracranial venous hypertension may be caused by primary outflow obstruction, arteriovenous shunting or idiopathic intracranial hypertension, with significant overlap of clinical presentations as well as hybrid lesions mandating a thorough endovascular work up. Whereas most lesions are amenable to endovascular therapy, the management of idiopathic intracranial hypertension remains controversial.

Disclosures A. Honarmand: None. O. Pasternak-Wise: None. T. Alden: None. R. Bowman: None. M. Hurley: None. S. Ansari: None. A. Shaibani: None.