Introduction Cerebral venous sinus stenting (CVSS) is an effective treatment for idiopathic intracranial hypertension (IIH) secondary to dural venous sinus stenosis. However, sinus stenosis is seen in a very high percentage of IIH patients, often secondary to extrinsic compression of the sinus from elevated intracranial pressure. Microcatheter manometry has traditionally been performed to identify those patients with a true primary dural sinus stenosis, with a high-pressure gradient across the point of stenosis indicative of a more likely treatment response. However, a sufficient pressure gradient to recommend stenting remains a subject of debate, and when treatment is considered, pinpointing the location and degree of stenosis is difficult on single-plane angiography. Here, we present the results of a series of cases utilizing venous phase flat-panel CT (FP-CT) as an adjunct to microcatheter manometry to improve decision-making and precise stent placement during CVSS.

Materials and Methods Ten consecutive patients with IIH and suspected dural sinus stenosis underwent angiography with microcatheter manometry and venous phase FT-CT, with CVSS if indicated by the results. All patients were female, with an age range of 29–47 and a mean BMI of 38.7. The dural sinus stenosis was located at the transverse-sigmoid junction in all patients. The cross-sectional area of the narrowed sinus was obtained on FP-CT before and after stenting, with the exact characterization of the location and degree of stenosis. After the procedure, pressure gradient improvement and clinical symptoms were tracked.

Results There was an exponential correlation between the measured pressure gradient and degree of stenosis calculated using venous FP-CT (figure 1). The patients with both a severe stenosis (>95%) measured by FP-CT and a high pressure gradient across the stenosis were most likely to show clinical benefit from stent placement by the time of follow-up.

Conclusion Here we show that 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, this correlation curve mirrors Spencer’s law, which describes the exponential decrease in flow when stenosis exceeds 80%. Furthermore, patients with both an elevated venous pressure gradient and critical stenosis of the sinus on FP-CT were most likely to show symptomatic improvement after stenting.

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Abstract O-042 Figure 1

Dural sinus pressure vs stenosis by cross-sectional area (DynaCT)

Disclosures P. Theiss: None. E. Nico: None. T. Abou-Mrad: None. M. Tshibangu: None. A. Madapoosi: None. L. McGuire: None. A. Alaraj: None.