Showing papers on "Cerebral Revascularization published in 1995"

Late patency of long saphenous vein bypass grafts to the anterior and posterior cerebral circulation.

Abstract: ✓ To evaluate the late results and the natural history of long saphenous vein bypass grafts (SVGs) between the extracranial and intracranial circulation, the authors retrospectively analyzed 202 consecutive SVGs performed at the Mayo Clinic from 1979 to 1992 The distal anastomosis was to the vertebrobasilar system in 98 patients and to the carotid artery system in 103 patients Surgical indications were advanced cerebroocclusive disease in 63% (127 cases), giant aneurysm in 37% (74 cases), and neoplasm in one patient In 125 patent SVGs follow-up information was obtained for longer than 1 year and in 23 patent SVGs it was over 10 years (maximum 13 years, median 65 years) Most of the graft failures (76%) occurred during the 1st year after surgery, with 42% of all graft failures found during the first 24 hours after operation Late graft attrition occurred in only 10 patients (8%) Cumulative patency at 1 year was 86% ± 3%, at 5 years 82% ± 4%, and at 13 years 73% ± 19% Neurological worsening at the tim

Regional cerebral hemodynamics in childhood moyamoya disease.

Abstract: Regional cerebral blood flow (rCBF) and its reactivity to acetazolamide were analyzed in a series of 15 cases of childhood moyamoya disease, using the xenon-133 inhalation method and single photon emission CT (SPECT). Most of the patients had normal mean hemispheric cerebral blood flow (mCBF), comparable to that of age-matched healthy children. However, they had abnormal rCBF distribution and disturbed reactivity to acetazolamide in the territory of the internal carotid artery, especially in the frontal lobe. Surgical revascularization for the anterior circulation, which consisted of STA-MCA anastomosis and indirect synangiosis, dramatically improved these cerebral hemodynamics in the anterior circulation, including the frontal lobe, and reactivity to acetazolamide in the whole brain. These results suggest that surgical revascularization for the anterior circulation should be carried out in order to improve cerebral hemodynamics as widely as possible, especially in the frontal lobe, and may improve cerebral perfusion reserve in the posterior circulation.

Dementia associated with bilateral carotid occlusions: neuropsychological and haemodynamic course after extracranial to intracranial bypass surgery.

Abstract: A 55 year old man with bilateral internal carotid and unilateral vertebral artery occlusions presented subacutely with profound behavioural and cognitive changes featuring frontal lobe deficits. Neuropsychological testing showed severe cognitive impairment compatible with dementia. Anatomical imaging showed only a small right superior frontal infarction. Cerebral blood flow was severely reduced, with profound hypofrontality and limited hypercapnic reactivity, and cerebral metabolism was reduced primarily in the medial frontal lobes. After right sided extracranial to intracranial cerebral bypass surgery, both flow and metabolism improved, as did behavioural and neuropsychological deficits. Perfusion insufficiency from bilateral carotid occlusions, with secondarily reduced metabolism in the frontal zones bilaterally, may be an unusual cause of a reversible frontal dementia syndrome.

Assessment of intracranial primary collaterals using transcranial color-coded real-time sonography.

Abstract: Transcranial color-coded sonography (TCCS) was used to assess primary willisian collaterals in 100 patients with extracranial internal carotid artery (ICA) stenosis. Their importance was determined during carotid endarterectomy (CEA) by transcranial Doppler measurement of blood flow velocity in the ipsilateral middle cerebral artery (MCAV) before and after carotid clamping. All patients had unilateral ICA disease of at least 60% stenosis. Twenty-nine ICAs (14.5%) were occluded, 70 vessels (35%) were stenosed by 80 to 99%, 43 vessels (21.5%) were stenosed by 60 to 79%, and 53 ICAs had stenosis of less than 60%. Temporal hyperostosis precluded TCCS in 15 patients (15%). Anterior cerebral/communicating artery collaterals were detected in 40 patients (49%) and posterior cerebral/communicating artery collaterals were detected in 22 patients (27%). No patients with ICA stenosis of less than 80% had established collateral pathways. Patients with willisian collaterals showed higher postclamp MCAVs as a proportion of the preclamp value during CEA (72% [62-81]; median with 95% confidence interval) than did those without primary collaterals (46% [34-58], p = 0.02). TCCS allows noninvasive assessment of intracranial primary collaterals whose functional importance is recognized during abrupt hemodynamic challenge. It may determine which patients are at greatest risk of ischemia during cerebral revascularization.

Management of Radiation-Induced Extracranial Arterial Occlusions at Multiple levels A Case Report

Abstract: Extracranial arterial occlusion can occur secondary to external beam irradiation of the cervical region. The authors present a case of radiation-induced occlusion of bilateral common carotid, bilateral internal carotid, and unilateral vertebral arteries. Management issues are discussed, with particular focus on radiation-induced arterial injury and the external carotid artery as a means to cerebral revascularization.

Acute revascularization for bihemispheric anterior cerebral artery thrombosis--case report.

Abstract: A 65-year-old male presented with rapidly progressive paraparesis and akinetic mutism due to occlusion of the bihemispheric anterior cerebral artery (ACA). He was treated by intra-arterial thrombolytic therapy but reocclusion of the arteriosclerotic lesion occurred. Bilateral superficial temporal artery (STA)-ACA anastomoses achieved lasting neurological improvement. Bilateral STA-ACA anastomoses are quite effective to prevent ischemia of the bilateral ACA territories.