An Endovascular Approach for Idiopathic Intracranial Hypertension: Assessing Morphometric Candidacy After Venous Sinus Stenting

BACKGROUND AND OBJECTIVE: Current treatments of idiopathic intracranial hypertension (IIH), a disorder of elevated intracranial pressure, include ventriculoperitoneal shunting and venous sinus stenting (VSS). Recently, transvenous endovascular shunting using the CereVasc eShunt system has been proposed as a minimally invasive alternative to drain cerebrospinal fluid into the venous system. The implant is deployed transdurally by the inferior petrosal sinus (IPS) into the cerebellopontine angle cistern (CPAC). This study aimed to radiographically analyze CPAC and IPS morphometrics in IIH patients with associated transverse sinus stenosis to evaluate anatomic eligibility for deployment of the eShunt device. METHODS: High-resolution, T1-weighted, gadolinium-enhanced brain MRIs of IIH patients acquired post-VSS at Tufts Medical Center were analyzed to measure CPAC depth, IPS diameter, and IPS angle bilaterally. eShunt eligibility was established under 3 criteria: stringent (CPAC depth >5 mm), moderate (CPAC depth >4 mm), and permissive (CPAC depth >3 mm). Unobstructed IPS wider than 2.25 mm was also required ipsilaterally. RESULTS: Eighty-four patients (ages 17-77, 75 women) were included. Mean CPAC depth was 4.2 and 4.6 mm, whereas mean IPS diameter was 2.9 and 2.7 mm, and mean IPS angle was 133° and 135°, for right and left sides, respectively. Deployment of the eShunt system was anatomically feasible in 43%, 69%, and 82% of analyzed patients, under stringent, moderate, and permissive criteria, respectively. CPAC depth trended non-significantly higher with age (P = .13) and male sex (P = .11); IPS diameter and angle was not associated with age or sex. Patients with noted cerebellar tonsillar descent had significantly smaller CPAC depths (P = .002) than others, precluding them from eShunt eligibility. CONCLUSION: A significant proportion of patients with IIH currently treated with VSS may be suitable candidates for endovascular cerebrospinal fluid shunting with the eShunt System, warranting further clinical investigation of the device in this population.