KCR 2020 lecture given in Korean with English subtitle.
Lecturer: Prof. LEE Deok Hee, Department of Radiology, Asan Medican Center, University of Ulsan College of Medicine
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Compared with arterial stroke, venous stroke is much less common and rather vague in clinical presentation. However, clinical consequence of venous stroke could be serious or sometimes fatal in certain situation. The timing of treatment intervention is important in the treatment outcome although the treatment time window is not that narrow as in the arterial stroke.
Regarding symptomatic venous thrombosis, systemic anticoagulation still remains as the most important and effective initial treatment. Endovascular treatment can be considered when the patient symptom and/or signs of acute intracranial hypertension aggravates even on the proper level of anticoagulation. In case of superior sagittal sinus thrombosis, involvement of the dominant lateral sinus or any involvement of the cortical vein could be the causes of anticoagulation failure.
We used to perform venous thrombolysis with local infusion of fibrinolytics within the occluded dural sinuses until various endovascular thrombectomy devices are available due to the recent advent of various thrombectomy devices for the arterial ischemic stroke, such as, stentrievers (stent-like retrievers) and aspiration catheters. Although our experience of applying those devices in the dural sinuses is still limited, it seemed like large-bore aspiration catheters were more effective in the thrombectomy since the diameter of the stentrievers was relatively small to cover rather larger diameter of the occluded dural sinuses. Occasionally, they report immediate and complete recanalization of the major dural sinuses which were extensively occluded with large amount of thrombosis with some exceptions. Procedural outcome of the venous endovascular recanalization becomes improving due to improved lesion access with versatile intermediate catheters which could be used with the large-bore guiding catheters coaxially. Unfortunately, the clinical outcome of these endovascular recanalization remains equivocal despite of the technical improvement. We cannot overemphasize the importance etiologic diagnosis of the thrmbosis and systemic anticoagulation regardless of the procedural outcome for the prevention of recurence.
Recently we experienced technical difficulty in performing mechanical thrombecotmy due to presence of underlying dural sinus steno-occlusive lesions which could be the primary cause of the thrombosis or acquired stenosis secondary to the thrombotic event. Presence of those stenoses, regardless of their nature, could be the source of procedural failure or early thrombotic reocclusion even after laborous thrombectomy. We could manage those lesions by placing a self-expanding stent by eradicating the flow-limting stenosis.
Clinical presentation of the intracranial DAVFs is usually benign, not infrequently however, it could be presented as stroke due to localized venous congestion followed by either venous infarction or hemorrhage. Since DAVFs may present with protean faces not only in clincial features but also in radiologic imaging, the possibility of DAVF should be considered as one of the differential diagnoses in case of unusual infarction and/or hemorrhage.
Due to the complexity of angioarchitecture of these lesions, thorough angiographic evaluation and careful demonstration of the fistulous hole may not be easy or impossible in certain cases, right on the spot during intial angiography, even though control of the shunt seems urgent. To cope with these dilemma, palliative particle embolization, via major arterial feeders to reduce the shunt flow, can be done as a useful temporary measure. Furthermore, reduced shunt help reveal the hidden fistulous hole, which could not be identified before the palliative embolization.
Technical limitations and complications could be limited by careful identification of the embolization target and avoidance of unnecessary occlusion of arterial branches for cranial nerves, violation of the dangerous anastomosis, or occlusion of the normal draining veins or functioning dural sinus. In case of incomplete or partial embolization, late spontaneous occlusion could be expected, however, the drainage pattern of the residual shunt should carefully be analyzed whether the direction is retrograde or not and cortical or not. In case of residual cortical venous drainage, further embolization should be considered. Stereotatic radiation can also be considered in case of otherwise inaccessible situation.
Video editing and subtitles by TheLab291