Arterial spin labeling MR imaging aids to identify cortical venous drainage of dural arteriovenous fistulas

Additional outlet occlusion as an important factor in avoiding retreatment after transvenous embolization for cavernous sinus dural arteriovenous fistulas

BACKGROUND

Transvenous embolization (TVE), such as selective shunt occlusion, is the first line treatment for cavernous sinus dural arteriovenous fistula (CSDAVF). Despite the favorable outcomes of TVE, some cases necessitating retreatment due to recurrence or incomplete occlusion persist. Given the physical, psychological, and financial burden of multiple treatments, understanding the predictive factors for recurrence, spontaneous occlusion, or retreatment is important. However, few reports have addressed these factors, complicating decision making regarding the need for retreatment. This study analyzed predictive factors for retreatment and spontaneous occlusion to offer new insights into CSDAVF management.

METHODS

This retrospective, observational study was conducted in two acute care hospitals. Patients aged 18-100 years undergoing endovascular treatment for CSDAVF from January 2011 to December 2022 were included.

RESULTS

Of 65 patients treated with TVE, 29 experienced immediate complete occlusion. Meanwhile, 22 of 36 patients with incomplete occlusion had spontaneous occlusion, and retreatment was performed in 20% of patients. Additional outlet occlusion was negatively associated with retreatment (P=0.046), and it tended to promote spontaneous occlusion (P=0.056). Favorable functional outcomes were observed in all patients, and approximately 94% of patients showed complete occlusion at the latest follow-up.

CONCLUSION

TVE is an effective treatment for CSDAVF. Outlet occlusion, when immediate complete occlusion is unattainable, is important to reduce retreatment and promote spontaneous occlusion. Substantially reducing shunt flow, carefully assessing dangerous drainage routes, and closely monitoring the residual shunt are crucial for preventing intracranial hemorrhage when outlet occlusion is performed.

Retrograde Flow Into the Internal Jugular Vein in a Hemodialysis Patient Mimicking Dural Arteriovenous Fistula: A Case Report

Arterial spin labeling (ASL) and three-dimensional (3D) time-of-flight (TOF) magnetic resonance angiography (MRA) are sensitive tools to detect dural arteriovenous fistula (DAVF), but hyperintensity in these images is also caused by jugular venous reflux. We present a case of a patient with renal failure on hemodialysis with retrograde flow into the internal jugular vein (IJV) mimicking DAVF. A 74-year-old man with a radial arteriovenous fistula for hemodialysis experienced transient dizziness. The TOF MRA and ASL revealed high signal intensity, suggesting the presence of a DAVF in the left transverse and sigmoid sinuses and the IJV. Digital subtraction angiography (DSA) revealed no evidence of a DAVF but showed retrograde flow into the IJV via his radial shunt. In hemodialysis patients, a high-flow shunt can cause fast retrograde flow into the dural sinuses and might lead to intracranial hypertension. The ASL images are useful for early detection and careful observation.

Clinical applications of arterial spin labeling of the intracranial compartment in vascular anomalies-A case-based review

Arterial spin labeling (ASL) is a magnetic resonance perfusion technique that allows for quantification of cerebral blood flow (CBF) without the use of contrast or radiation. Several applications of ASL have been described in diagnosis of strokes and stroke mimics, intracranial tumors, and other conditions. Various vascular anomalies exhibit specific CBF patterns that correlate with different signal intensities on ASL. In this case-based review, we demonstrate the utility of ASL in diagnosis and surveillance of vascular anomalies in the intracranial compartment.

Arterial Spin Labeling Was Useful for Evaluating the Treatment Response of a Transverse-Sigmoid Sinus Dural Arteriovenous Fistula: A Case Report

Objective

We report the case of a patient in whom arterial spin labeling (ASL) was useful for assessing the effects of treatment for a transverse-sigmoid sinus dural arteriovenous fistula (TSS-dAVF).

Case Presentation

The patient was a 65-year-old man. Cerebral angiography demonstrated an aggressive dAVF involving the TSS, superior sagittal sinus (SSS), and the sinus confluence, with severe cortical and deep venous reflux. We performed multiple transarterial and transvenous embolizations for the TSS and sinus confluence lesion. The shunt disappeared almost completely after embolization. A high signal intensity that had been apparent in the SSS and straight sinus (StS) on ASL imaging before embolization disappeared after embolization. ASL imaging 3 months after embolization revealed slightly a high signal intensity in the StS, which was considered to be due to recurrence of the lesion. Moreover, recurrence of the confluence and TSS-dAVF was observed on cerebral angiography 6 months after embolization. As additional embolization was considered difficult, radiation therapy was recommended, but the patient refused; therefore, follow-up was performed. As ASL imaging findings were consistent with cerebral angiography findings, careful examination and monitoring of changes on ASL imaging were subsequently performed.

Conclusion

Follow-up using ASL imaging is useful to assess the effects of treatment performed for a dAVF.