Endovascular Treatment of Cerebral Venous Sinus Stenosis Based on Hemodynamic Assessment Using Pressure Wire

Hemodynamic assessment for intracranial atherosclerosis from angiographic images: a clinical validation study

BACKGROUND

Intracranial atherosclerotic stenosis (ICAS) is one of the leading causes of ischemic stroke. Conventional anatomical analysis by CT angiography, MRI, or digital subtraction angiography can provide valuable information on the anatomical changes of stenosis; however, they are not sufficient to accurately evaluate the hemodynamic severity of ICAS. The goal of this study was to assess the diagnostic performance of the pressure ratio across intracranial stenoses (termed as fractional flow (FF)) derived from cerebral angiography for the diagnosis of hemodynamically significant ICAS defined by pressure wire-derived FF.

METHODS

This retrospective study represents a feasible and reliable method for calculating the FF from cerebral angiography (AccuFFicas). Patients (n=121) who had undergone wire-based measurement of FF and cerebral angiography were recruited. The accuracy of the computed pressure ratio was evaluated using wire-based FF as the reference standard.

RESULTS

The mean value of wire-based FF was 0.78±0.19, while the computed AccuFFicas had an average value of 0.79±0.18. Good correlation (Pearson's correlation coefficient r=0.92, P<0.001) between AccuFFicas and FF was observed. Bland-Altman analysis showed that the mean difference between AccuFFicas and FF was -0.01±0.07, indicating good agreement. The area under the curve (AUC) of AccuFFicas in predicting FF≤0.70, FF≤0.75, and FF≤0.80 was 0.984, 0.986, and 0.962, respectively.

CONCLUSION

Angiography-based FF computed from cerebral angiographic images could be an effective computational tool for evaluating the hemodynamic significance of ICAS.

Arm-only combined transarterial and transvenous access for neurointerventional procedures: a double-center retrospective study

OBJECTIVE

This study aims to share our experience with the arm-only combined transarterial and transvenous access approach for neurointerventional procedures and evaluate its efficacy and safety.

METHODS

The arm-only combined transarterial and transvenous access approach was performed using the right/bilateral proximal radial arteries and the right forearm superficial vein system, guided by ultrasonic guidance. Arterial access closure was achieved using a transradial band radial compression device, while manual compression was utilized for venous approach closure.

RESULTS

Thirteen procedures were successfully performed using the arm-only combined transarterial and transvenous access approach, yielding favorable outcomes. The procedures included dural arteriovenous fistula embolization (seven cases), cerebral arteriovenous malformation embolization (four cases), venous sinus thrombosis catheter-directed thrombolysis and intravenous thrombectomy (one case), and cerebral venous sinus stenosis manometry (one case). All procedures were uneventful, allowing patients to ambulate on the same day. At discharge, all patients exhibited modified Rankin scores of 0-2, without any access site or perioperative complications.

CONCLUSION

This double-center study preliminarily demonstrates the feasibility and safety of arm-only combined transarterial and transvenous access applied in neurointerventional procedures for complicated cerebrovascular diseases. The proximal radial artery and forearm superficial vein are recommended as the primary access sites. Unobstructed compression is strongly recommended for radial approach closure.

ADVANCES IN KNOWLEDGE

This study aimed to add evidence and experience on the arm-only combined transarterial and transvenous access, as a new approach, for neurointerventional treatment that required arteriovenous approaches.

A Comparison Between Pressure Wire and Microcatheter Measurements for Evaluating the Cerebral Venous Pressure Gradient

Introduction: A pressure gradient of over 8 mm Hg across the stenosis (usually located in the transverse-sigmoid junction) is one of the criteria for cerebral venous stenting in idiopathic intracranial hypertension (IIH) patients. The possible inaccuracy of the traditional microcatheter-based pressure measurements has been discussed in previous studies. In the cardiology field, a dual-sensor pressure wire is routinely used for the evaluation of stenotic lesions. Using a pressure wire for cerebral vasculature was previously discussed in a small case series and case reports. In this study, we compared venous pressure measurements obtained using both a microcatheter and a pressure wire in patients who were candidates for stenting. Methods: A retrospective study was conducted, comparing the two methods of pressure measurements in 26 patients with venous stenosis. Altogether, 120 measurements were performed using both methods. Demographic characteristics, medical history, procedural details, medications, indications for the procedure, and complications were collected from the patient charts. Results: Based on an 8-mm Hg pressure gradient cutoff indication, 19 patients were found eligible to go through unilateral venous stenting based on catheter measurements alone. The wire results corroborated the catheter results in detecting all cases indicated for a stent. This finding implies a sensitivity equal to 100% for the wire measurements. There were no wire-related complications, demonstrating its safety. Conclusions: We conclude that the pressure wire is as safe as the microcatheter and can identify cases requiring intervention. A larger-scale study is needed to assess the measurement accuracy of the pressure wire in brain vasculature.

Skull Base Neurointerventional Techniques

Neurodiagnostic and neurointerventional radiology (NIR) play a central role in the diagnosis and treatment of skull base disorders. Noninvasive imaging modalities, including computed tomography and magnetic resonance imaging, are important in lesion localization, evaluation of lesion extent, and diagnosis, but cannot always be definitive. Image-guided skull base biopsy and percutaneous and endovascular treatment options are important tools in the diagnosis and treatment of head, neck, and skull base disorders. NIR plays an important role in the treatment of vascular disorders of the skull base. This article summarizes the imaging evaluation and interventional therapies pertinent to the skull base.

Dural venous sinus stenting in the treatment of idiopathic intracranial hypertension: A systematic review and critique of literature

Idiopathic intracranial hypertension (IIH) is increased intracranial pressure without a known cause. Dural venous sinus stenting (DVSS) is a relatively new intervention for treatment of IIH refractory to medical therapy and lifestyle modifications. In this review, we outline various hypotheses of IIH pathogenesis and describe the role of venous sinus stenosis and the technical details of DVSS. We also present a summary and critique of the available evidence describing the outcomes of DVSS in IIH and review the evidence-based guidelines for this procedure. We conclude that, although many studies have shown generally favorable outcomes of DVSS in patients with IIH, most have serious limitations, the most common one being paucity of pre- and postprocedure ophthalmological data. Thus, there is not enough available evidence to conclude whether DVSS is an effective procedure for treatment of IIH. We also present the most commonly used indications for DVSS as described in the literature and stress the importance of neuro-ophthalmological assessment before and after the procedure to monitor response and potential complications.