No abstract available.
Intracranial Arteriosclerosis*

No abstract available.
Arteries ; Intracranial Arteriosclerosis

No abstract available.
Cerebral Infarction ; Humans ; Intracranial Arteriosclerosis ; Subarachnoid Hemorrhage

Intracranial atherosclerosis-related occlusion (ICAS-O) is frequently encountered at the time of endovascular revascularization treatment (ERT), especially in Asian countries. However, because baseline angiographic findings are similar between ICAS-O and embolism-related occlusion (EMB-O), it is difficult to differentiate the etiologies before the ERT procedure. Moreover, despite successful randomized trials on ERT, results from studies examining the optimal treatment protocol in ICAS-O patients remain unclear. In this review, we describe the clinical and imaging factors that may possibly differentiate ICAS-O from EMB-O. We will also discuss some current hurdles for treating ICAS-O in the hyperacute period and suggest the optimal ERT strategy for ICAS-O patients.
Asian Continental Ancestry Group ; Clinical Protocols ; Diagnosis ; Endovascular Procedures ; Humans ; Intracranial Arteriosclerosis ; Intracranial Embolism ; Intracranial Thrombosis

Recently, intracranial atherosclerosis has become a major cause of ischemic stroke, appearing more frequently in Koreans than Caucasians. Symptomatic or asymptomatic intracranial atherosclerosis is a disease that could recur readily even during the treatment with anti-platelet agents. When the symptoms develop, ischemic stroke can not be recovered readily. Therefore, aggressive treatments such as endovascular therapy and bypass surgery are required in addition to medical treatment for the intracranial artery stenosis. Recent intracranial stenting and drug eluting stenting have shown as very advanced effective therapeutic modalities. Nevertheless, until now, a randomized controlled study has not been conducted. Regarding bypass surgery, since the failed EC-IC bypass surgery study performed 20 years ago, extensive studies on its efficacy has not been conducted yet, and thus it has to be performed strictly only in hemodynamically compromised patients. Unless breakthrough drugs that suppress the progression of intracranial atherosclerosis and the formation of thrombi, and facilitate the regression of the arterial stenosis, the treatment concept of the recovery of the blood flow of stenotic arterial territory by mechanical recanalization or bypass surgery would be remained for the prevention as well as treatment of ischemic stroke caused by intracranial atherosclerosis.
Arteries ; Constriction, Pathologic ; Humans ; Intracranial Arteriosclerosis ; Stents ; Stroke

PURPOSE: To determine differences in angiographic variations of the circle of Willis between atherosclerosis and normal groups. MATERIALS AND METHODS: In 289 patients we reviewed complete cerebral angiograms obtained using biplane digital subtraction angiography. Atherosclerosis was diagnosed in 189 patients, while 100 were normal. Patients were divided into four subgroups according to the relative size of each segment and the presence of cross-filling of opposite-sided vessels. When the circle was completely present, we determined whether or not it was balanced, and statistically compared variation patterns between the two groups. RESULTS: In the atherosclerosis group, the anterior half of the circle was complete in 74% of cases(139/189), and the posterior half in 38% (72/189). In the normal group, the anterior half was complete in 90% of cases, and the posterior half in 63%. An incomplete circle was more common in the atherosclerosis group than among normal subjects (26% vs 10%, p<.05; 62% vs 37%, p<.001). In the atherosclerosis group with incomplete circle, agenesis was found in the anterior communicating artery in 19% of cases (36/189), the A1 segment in 7% (14/189), the posterior communicating artery in 58% (109/189), and the P1 segment in 7% (14/189). In the normal group with incomplete circle, agenesis was seen in the anterior communicating artery in 9% of cases, in the A1 segment in 1%, in the posterior communicating artery in 36%, and in the P1 segment in 3%. Agenesis of the anterior communicating artery (19% vs 9%, p<.05), the A1 segment (7% vs 1%, p<.05), or the posterior communicating artery (58% vs 36%, p<.001) was more common in the atherosclerosis group than in the normal group. Unbalanced type with a size discrepancy between A1 segments was also more common in the atherosclerosis group (19% vs 8%, p<.05). There was no significant difference between the two groups regarding posterior communicating arteries equal to or larger than the P1 segment (42% vs 27%, p>.05) and agenesis of the P1 segment (7% vs 3%, p>.05). CONCLUSION: An incomplete and unbalanced circle of Willis was more common in the atherosclerosis group than in the normal group. Agenesis of the anterior communicating artery, the A1 segment, or the posterior communicating artery was common in the atherosclerosis group, as was size discrepancy between A1 segments.
Angiography, Digital Subtraction ; Arteries ; Atherosclerosis* ; Circle of Willis* ; Humans ; Intracranial Arteriosclerosis

The authors measured flow velocity of intracranial arteries to venrify the patency of the parent arteries and branches after clip placement during aneurysm surgery. Before the clinical study, experimental sonographic recording was done with a feline aorta. The patency was evaluated by recording the flow velocity and pulse waveform using intraoperative microvascular Doppler sonography. The results of the clinical study were summarized as follows: (1) The patency of the parent artery can be proved. (2) The complete clipping of aneurysmal sac can be confirmed. (3) Vasospasm or narrowing of the arterial caliber can be detected. (4) Severe arteriosclerosis may mimic decreased flow velocity. It is suggested that the use of intraoperative microvascular Doppler sonography is an atraumatic and reliable method of testing the optimal clipping of the aneurysm and patency of the parent artery.
Aneurysm ; Aorta ; Arteries ; Arteriosclerosis ; Humans ; Intracranial Aneurysm* ; Parents ; Ultrasonography

Preoperative evaluation of precise aneurysmal geometry is important for the treatment of intracranial aneurysms. We present two cases of unclippable side wall aneurysms due to their extremely low dome height, which appeared as saccular in the preoperative image because of a comparatively narrow atherosclerotic parent arterial lumen. In both cases, a calcified vessel wall was noted preoperatively. Lack of a definitive neck and abrupt discrepancy between the fragile aneurysmal wall and the atherosclerotic parent arterial wall was confirmed intraoperatively in both cases. This study describes an illustrative mechanism for the finding with emphasis on the importance of its preoperative diagnosis. Intracranial atherosclerosis associated with small side walled aneurysms may lead to overestimation of aneurysm height on preoperative imaging of the intravascular compartment.
Aneurysm* ; Angiography* ; Arteries* ; Atherosclerosis ; Diagnosis ; Humans ; Intracranial Aneurysm ; Intracranial Arteriosclerosis ; Neck ; Parents*

BACKGROUND AND PURPOSE: The goal of stent retriever-based thrombectomy is removal of embolic clots in patients with intracranial large artery occlusion. However, outcomes of stent retrieval may differ between acute arterial occlusions due to intracranial atherosclerotic disease (IAD) and those due to embolism. This case series describes the outcomes of stent retriever-based thrombectomy and rescue treatments in 9 patients with IAD-related occlusion. METHODS: Among patients who underwent endovascular treatment for acute intracranial large artery occlusion, those in whom stent retrieval was attempted as first-line treatment were included in this review. IAD was defined as significant fixed focal stenosis at the occlusion site, which was evident on final angiographic assessment or observed during endovascular treatment. RESULTS: Median number of stent retriever passes was 2 (range, 1-3), and temporary bypass was seen in all patients. Immediate partial recanalization (arterial occlusive lesion grade 2-3) was observed in 7 patients. Immediate modified thrombolysis in cerebral infarction grade 2b-3 was seen in 6 patients, but the lesions often required rescue treatment due to reocclusion or flow insufficiency. In terms of rescue treatments, angioplasty and intra-arterial tirofiban infusion seemed to be effective. CONCLUSIONS: Our findings suggest that stent retrieval can effectively remove thrombi from stenotic lesions and achieve partial recanalization despite the tendency toward reocclusion in most patients with IAD-related occlusion. Further research into the use of rescue treatments, such as tirofiban infusion and angioplasty, is warranted.
Angioplasty ; Arteries* ; Cerebral Infarction ; Constriction, Pathologic ; Embolism ; Humans ; Intracranial Arteriosclerosis ; Intracranial Embolism and Thrombosis ; Mechanical Thrombolysis ; Stents* ; Thrombectomy

BACKGROUND AND PURPOSE: The goal of stent retriever-based thrombectomy is removal of embolic clots in patients with intracranial large artery occlusion. However, outcomes of stent retrieval may differ between acute arterial occlusions due to intracranial atherosclerotic disease (IAD) and those due to embolism. This case series describes the outcomes of stent retriever-based thrombectomy and rescue treatments in 9 patients with IAD-related occlusion. METHODS: Among patients who underwent endovascular treatment for acute intracranial large artery occlusion, those in whom stent retrieval was attempted as first-line treatment were included in this review. IAD was defined as significant fixed focal stenosis at the occlusion site, which was evident on final angiographic assessment or observed during endovascular treatment. RESULTS: Median number of stent retriever passes was 2 (range, 1-3), and temporary bypass was seen in all patients. Immediate partial recanalization (arterial occlusive lesion grade 2-3) was observed in 7 patients. Immediate modified thrombolysis in cerebral infarction grade 2b-3 was seen in 6 patients, but the lesions often required rescue treatment due to reocclusion or flow insufficiency. In terms of rescue treatments, angioplasty and intra-arterial tirofiban infusion seemed to be effective. CONCLUSIONS: Our findings suggest that stent retrieval can effectively remove thrombi from stenotic lesions and achieve partial recanalization despite the tendency toward reocclusion in most patients with IAD-related occlusion. Further research into the use of rescue treatments, such as tirofiban infusion and angioplasty, is warranted.
Angioplasty ; Arteries* ; Cerebral Infarction ; Constriction, Pathologic ; Embolism ; Humans ; Intracranial Arteriosclerosis ; Intracranial Embolism and Thrombosis ; Mechanical Thrombolysis ; Stents* ; Thrombectomy