Quantitative Magnetic Resonance Venography is Correlated With Intravenous Pressures Before and After Venous Sinus Stenting

Abstract

BACKGROUND Endovascular stenting is an effective treatment for patients with clinically significant cerebral venous sinus stenosis. Traditionally, stenting is indicated in patients with elevated intravenous pressures on conventional venography; however, noninvasive monitoring is more desirable. Quantitative magnetic resonance angiography is an imaging modality that allows blood flow assessment noninvasively. Established in the arterial system, applications to the venous sinuses have been limited to date. OBJECTIVE In this study, we examined quantitative magnetic resonance venography (qMRV) flow in patients before and after venous stenting and correlated these results with intravenous pressure measurements and clinical outcomes. METHODS Five patients with intracranial hypertension (IH) secondary to venous sinus stenosis underwent cerebral venous stenting between 2009 and 2013 at a single institution. Preoperatively venous sinus flow was determined using qMRV, and intravenous pressure measured during venography. After stenting, intravenous pressure, qMRV flow, and clinical outcomes were assessed and compared. RESULTS A mean prestenotic intravenous pressure of 45.2 mmHg was recorded before stenting which decreased to 27.4mmHg afterwards (Wilcoxon signed rank test P=.04). Total jugular outflow on qMRV increased by 260.2 ml/min. Analysis of the change in intravenous pressure and qMRV flow identified a linear relationship (Pearson's correlation r= .926). All patients displayed clinical improvement, including vision. CONCLUSION Venous outflow by qMRV increases after endovascular stenting and correlates with significantly improved intravenous pressures. These findings establish qMRV as a useful adjunct to measure venous flow after stenting, and as a potential tool in the selection and postoperative surveillance of the cerebral venous sinus stenosis patient.

Endovascular stenting for idiopathic intracranial hypertension with venous sinus stenosis

“…However, these treatment modalities do not target the primary pathology. Venous sinus stenosis is an important contributor to IIH, as more than 90% of patients with IIH have complications with venous sinus stenosis (Esfahani et al, ). Growing evidence have supported that venous sinus stenting can treat these cases of IIH, because it suppresses stenosis and reduces the pressure gradient across the stenotic segment, which in turn reduces intracranial pressure.…”

“…However, these treatment modalities do not target the primary pathology. Venous sinus stenosis is an important contributor to IIH, as more than 90% of patients with IIH have complications with venous sinus stenosis (Esfahani et al, 2015).…”

Computational Modeling of Venous Sinus Stenosis in Idiopathic Intracranial Hypertension

“…Recent advances in noninvasive quantitative phase-contrast MRV show promise in measuring blood flow through venous sinuses. 20 Applying such measurements as boundary conditions in the current study’s CFD simulation methodology may allow noninvasive, patient-specific and accurate determination of pathologic and non-pathologic stenoses without the need for invasive venography. This method could be used for enhanced screening of IIH patients at the time of diagnosis, and is under investigation by our group.…”

Neurovascular 4DFlow MRI (Phase Contrast MRA): emerging clinical applications

“…This was due to signal loss in regions of complex/turbulent flow, susceptibility artifacts and very slow flow. 4DFlow MRI also missed 10.4 % of thrombosed segments detected by 3D GE T1 weighted imaging [80,81]. One limitation of this comparison is that the authors did not include the magnitude images in the review.…”

“…In this population flow velocity and relative pressure measurement can assist in the monitoring of therapy and assess the results in interventions such as dural sinus stenting. Esfahani et al assessed five patients with intracranial venous hypertension and dural sinus stenosis [81]. The mean pre-stenotic intravenous pressure measured by endovascular catheter placement was 45.2 mm Hg and decreased to 27.4 mm Hg following stenting.…”