Analysis of cerebral venous sinus stenosis by flat panel angiographic CT (FP-CT) to guide treatment for idiopathic intracranial hypertension.

Abstract

Cerebral venous sinus stenting (CVSS) is an effective treatment for idiopathic intracranial hypertension (IIH) secondary to dural venous sinus stenosis. Traditional selection of patients for CVSS has been made by microcatheter manometry, but pressure measurements are often equivocal. Here we present the results of a series of cases in which venous flat-panel CT (FP-CT) was used as an adjunct to microcatheter manometry to improve decision making and precise stent placement during CVSS. Ten consecutive patients with IIH underwent angiography with microcatheter manometry and venous FP-CT, with CVSS if indicated by the results. Cross-sectional measurements of the narrowed sinus were obtained on FP-CT before and after stenting. After the procedure, clinical outcomes were tracked. Follow-up with quantitative MRA with sinus flow measurements was also performed, when available. There was an exponential correlation between measured pressure gradient and degree of stenosis calculated using venous FP-CT. All patients with both a high degree of stenosis measured by FP-CT and a high pressure gradient across the stenosis showed a clinical benefit from stenting. True measurement of the cross-sectional area of the dural sinus, made by venous phase FP-CT, has a high degree of correlation with elevated venous pressure gradient across the point of stenosis. Even in a limited series of cases, we found an exponential decrease in flow with increasing severity of stenosis. Furthermore, patients with both an elevated venous pressure gradient and critical stenosis of the sinus on FP-CT showed symptomatic improvement after stenting.