Changes of flow pattern after extracranial intracranial arterial bypass in patients with artherosclerotic cerebral ischemia and moyamoya disease / 대한뇌혈관외과학회지

OBJECTIVE: Extracranial-intracranial arterial bypass (EIAB) has proved to be useful in selected patients with artherosclerotic cerebral ischemia and moyamoya disease. But neurological deterioration (ND) after EIAB has occasionally been reported in spite of successful EIAB. We have performed EIAB in 150 patients with artherosclerotic cerebral ischemia and moyamoya disease during the recent 8 years. We analyzed the patients who exhibited ND after successful EIAB was performed for a selected group of patients with artherosclerotic cerebral ischemia and moyamoya disease. METHODS: Among 150 patients, the cause of the hemodynamic ischemia was atherosclerotic in 90 and moyamoya disease in 60. Eighteen patients experienced ND after successful EIAB. There were 14 patients with temporary neurologic deficit and 5 patients had a permanent deficit. We divided these 18 patients into two groups. Group 1 revealed relative hyperperfusion of a chronically hypoperfused area of the brain after successful EIAB. Group 2 showed hypoperfusion of the brain by the change of the flow pattern after successful EIAB. RESULTS: Of the 18 patients who experienced ND after successful EIAB, 8 patients belonged to group 1 and 10 patients belonged to group 2. We divided group II into four subgroups according to angiographic flow patterns. The first subgroup (2 patients) showed delayed filling of one division out of two divisions of the middle cerebral artery. The second subgroup (3 patients) showed collision between the orthograde flow and the retrograde flow from the grafted vessel, which resulted in more profound hypoperfusion. The third subgroup (2 patients) exhibited a complete occlusion of the preoperative stenotic artery. The fourth subgroup (3 patients) included the cases with marginal hypoperfusion in the periphery of the perfused region from the grafted extracranial artery. CONCLUSION: EIAB is a reliable, reasonably safe method for establishing new pathways of collateral circulation to the brain. However, this operation can have potential complications according to the relative hyperperfusion or hypoperfusion that's due to the altered flow pattern after the bypass.

Effect of Extracranial-Intracranial Bypass on Cerebral Blood Flow and Vasomotor Reactivity in patients with Compromised Cerebral Hemodynamics

BACKGROUND: The obstruction of intracranial arteries causes cerebral hemodynamic impairment. It is now evident that patients with cerebral hemodynamic compromise have a higher risk of stroke than those with normal cerebral blood flow. The purpose of this study is to investigate the changes of cerebral blood flow and vascular reactivity after extra-intracranial arterial bypass (EIAB) surgery in patients with cerebral hemodynamic compromise. METHODS: We enrolled 16 consecutive patients (8 female and 8 male patients) with transient ischemic attack or cerebral infarction resulted from the occlusion of distal internal carotid artery (ICA) or middle cerebral artery (MCA). We measured the relative regional cerebral blood flow (rrCBF) at rest and after Diamox infusion, and vasomotor reactivity by using single photon emission computed tomography (SPECT). We performed extra-intracranial arterial bypass (EIAB) surgery in patients with impaired vasomotor reactivity. Follow-up brain SPECT was done at 3months after EIAB. We compared the rrCBF and vasomotor reactivity before and after EIAB, and evaluated the effect of collateral vessels on the cerebral hemodynamic after surgery. RESULTS: EIAB increases the vasomotor reactivity significantly (-19.6+/-10 before EIAB, 11.2+/-27 after EIAB, p=0.003) but does not increase the cerebral blood flow at rest (70.5% before EIAB, 70.9% after EIAB). The degree of collateral vessel development did not influence on the restoration of vasomotor reactivity. CONCLUSIONS: These results demonstrate that EIAB increases the vasomotor reactivity of the distal part on the occluded ICA or MCA, but does not increase the cerebral blood flow at rest.

Complications of Cerebral Revascularization Surgery / 대한뇌혈관학회지

A variety of procedures have developed for the surgical augmentation of collateral circulation to the brain in some cerebral or cerebellar lesions such as hemodynamic ischemic stroke, giant aneurysm of circle of willis or skull base tumor. Carotid endarterectomy and extracranial-intracranial arterial bypass (EIAB) are included in surgical revascularization (SR), and thrombolysis and transluminal percutaneous angioplasty and/or stenting (PTAS) are included in endovascular revascularization (ER). This article focuses the revascularization procedure related complications in patients treated with surgical or endovascular revascularization.

A Clinical Analysis of Occlussive Cerebrovascular Disease

The author analyzed 352 patients who had been admitted to P.M.C. with clinical signs and symptoms of occlussive stoke from 1973 to 1980. Cerebral angiography was performed on 250 patients and 126 patients of them were confirmed to have angiographical evidence of occlusion. We've analyzed these 126 patients in clinical point of view. As presented above, positive rate of angiography was 50%. The site of lesion was most common at MCA which was somewhat different from other reports, and the side of predelection was left. In majority of cases, the occlusive stroke was occurred in age group between 40 to 60, and man was about 3 times as common as woman. Risk factors, in our series, were hypertension, cardiac problems, diabetes and so on which were similar to other reports. Hypertension, the most common risk factor, correlated well to the peak age incidence but there was not any intimate relationship with the level of serum cholesterol. The outcome of medically treated group(112 patients) was somewhat better than surgery(14 patients). Among 12 of EIAB, TIA noted the best result compared to RIND and SIE. Meticulous selection of patient using CT scanning and measurement of rCBF would promote the benefit of surgery.