Mastication steal: an unusual precipitant of cerebrovascular insufficiency. (1/215)

An 83-year-old man had episodic dizziness, visual disturbance, and facial and extremity weakness associated with eating. Occlusion of the ipsilateral common carotid artery and stenosis or occlusion of the major collateral sources were demonstrated. We believe this anatomic configuration, combined with increases in demand for external carotid artery blood flow necessitated by the act of chewing, resulted in a vascular steal syndrome. An extended carotid endarterectomy was performed, and there were no additional episodes.  (+info)

Apoptosis and Bcl-xs in the intimal thickening of balloon-injured carotid arteries. (2/215)

We performed balloon injury in the rat carotid artery and identified intimal thickening after injury. Balloon-injured carotid arteries showed maximum thickness of the neointima on the 14th day before complete endothelial cell regeneration. In this lesion we identified apoptosis of vascular smooth muscle cells (VSMCs) by in situ DNA labelling and electron microscopy in the neointima on the 14th day after injury. mRNA expression levels of bcl-2, bax, bcl-x, p53 and caspase-1 were determined by the reverse transcriptase-polymerase chain reaction method both in injured and uninjured carotid arteries. Neither bcl-2 nor bcl-xl mRNA expression was detected in either injured or uninjured arteries, whereas bax and p53 mRNA expression was identified and their mRNA levels were not altered after balloon injury. In contrast, both bcl-xs and caspase-1 mRNA was detected and was markedly induced only in the injured carotid artery. Positive staining for immunoreactive Bcl-x was observed specifically in the injured arterial wall and co-localized with positive staining of nuclei identified by in situ DNA labelling. We conclude that two opposite cellular responses, VSMC proliferation and apoptosis, exist together in the neointima of the rat carotid artery after balloon injury, and selective induction of Bcl-xs expression is a key regulator of VSMC apoptosis in the process of vascular remodelling.  (+info)

Recently occluded intracranial and extracranial carotid arteries. Relevance of the unstable atherosclerotic plaque. (3/215)

BACKGROUND AND PURPOSE: It is now widely accepted that thrombotic coronary artery occlusion usually follows rupture of an unstable atherosclerotic plaque. The significance of such instability in arteries supplying the brain is less well appreciated. We therefore describe the clinical and pathological features of recent, symptomatic internal carotid artery occlusion to examine the pathogenetic role of plaque instability at both extracranial and intracranial sites. METHODS: Cases were selected from a consecutive series of 188 adult neuropathology autopsies. In 90 of these, the principal neuropathological abnormality was cerebral infarction, in 14 cases due to recent occlusion of 1 or more segments of the internal carotid artery. In each case, a full systemic, cardiovascular, and neuropathological autopsy was performed. Plaque instability was assessed by the presence or absence of a large, necrotic, lipid core; a thin, fibrous cap; and superficial inflammation. RESULTS: Of the 14 cases, 3 showed extracranial (carotid sinus), 7 intracranial, and 4 both extracranial and intracranial carotid artery occlusion. In 6 of the 7 occluded carotid sinuses, thrombus overlay an ulcerated, unstable, atherosclerotic plaque. In 1 extracranial and all 11 intracranial occlusions, there was either no atheroma or a mildly stenotic, stable, fibrous plaque, and in these cases, the cause of occlusion was embolism (8 cases), giant-cell arteritis (1 case), and unknown (3 cases). CONCLUSIONS: Coronary-type rupture of an unstable atherosclerotic plaque is the usual cause of fatal occlusion of the carotid sinus, but other causes usually underlie intracranial carotid occlusion. The nature and consequences of intracranial atherosclerosis require further study.  (+info)

Summation of dynamic transfer characteristics of left and right carotid sinus baroreflexes in rabbits. (4/215)

Although interactions among parallel negative-feedback baroreflex systems have been extensively investigated with respect to their steady-state responses, the dynamic interactions remain unknown. In anesthetized, vagotomized, and aortic-denervated rabbits, we perturbed isolated intracarotid sinus pressure (CSP) unilaterally or bilaterally around the physiological operating pressure according to binary white noise. The neural arc transfer function from CSP to cardiac sympathetic nerve activity (SNA) and the peripheral arc transfer function from SNA to aortic pressure were estimated. The gain values of the neural arc at 0.01 Hz estimated by the left (L) and right (R) CSP perturbations were 0.94 +/- 0.31 and 0.96 +/- 0.25, respectively. The gain value increased to 2.17 +/- 0.97 during the bilateral identical CSP perturbation and was not significantly different from L + R. The phase values of the neural arc did not differ among protocols. No significant differences were observed in the peripheral arc transfer functions among protocols. We conclude that summation of the dynamic transfer characteristics of the bilateral carotid sinus baroreflexes around the physiological operating pressure approximates simple addition.  (+info)

Tentorial meningioma encroaching the transverse sinuses and sigmoid sinus junction area associated with dural arteriovenous fistulous malformation: a case report. (5/215)

A 62-year-old woman was evaluated for tinnitis and headache. Magnetic resonance imaging and angiography revealed the coexistence of a tentorial tumor encroaching the junction of the right transverse-sigmoid sinuses, and dural arteriovenous fistulous malformation (AVFM) of the right transverse sinus. AVFM was not manipulated at all during the surgery. The pathology was fibroblastic meningioma. Postoperatively, the dural AVFM completely disappeared on follow-up angiography. The fistulas were occluded also after surgery, even though there was no manipulation of the AVFM. It is suggested that the right dominant transverse-sigmoid sinuses are partially occluded by tentorial meningioma, developing the dural arteriovenous fistula of the right transverse sinus. An acquired origin of the dural AVFM was suggested in this case.  (+info)

External carotid endarterectomy with patch angioplasty using internal jugular vein--two case reports. (6/215)

A 59-year-old male and a 74-year-old male presented with occlusion of the right internal carotid artery and stenosis at the origin of the ipsilateral external carotid artery manifesting as cerebral ischemia. External carotid endarterectomy with patch angioplasty using the internal jugular vein was performed. Special care was taken to obliterate the stump of the carotid artery using a Weck clip in one case and plication with non-absorbable sutures in the other. Cerebral blood flow in the affected hemisphere was increased after surgery and the patients remained asymptomatic. External carotid endarterectomy has several special aspects such as patch angioplasty and elimination of the stump which must be understood.  (+info)

Grading internal carotid artery stenosis using B-mode ultrasound (in vivo study) (7/215)

OBJECTIVE: to determine the value of percentage area and diameter reduction in grading ICA stenosis using colour-coded B-mode transverse ultrasonic images. MATERIALS AND METHODS: measurement of the percentage area and diameter reduction of the common carotid, external carotid and internal carotid (at the point of maximum stenosis) were performed, using duplex scanning with colour-flow imaging preoperatively, in 33 patients (six patients were excluded). The duplex measurements were compared to the percentage area and diameter reduction from transverse section of the specimens. Peak systolic (PSV) and end-diastolic velocities (EDV) were measured at the proximal CCA and ICA within the jet of turbulence. A mm scale was placed next to the specimen block, which was captured by video. The area reduction was measured by playing the video and using the same duplex software. RESULTS: linear-regression analysis of the percentage area reduction of the in vivo against the specimen measurements showed a good linear relationship (r=0.9047). The in vivo duplex measurements had 95% confidence interval (CI) of 8% (95% CI of diameter reduction 5%). CONCLUSION: using the gold standard of fixed histological endarterectomy specimen, the results indicate that transverse image obtained with colour B-mode imaging is more appropriate in determining the degree of stenosis.  (+info)

Axillary-to-carotid artery bypass grafting for symptomatic severe common carotid artery occlusive disease. (8/215)

PURPOSE: Revascularization of the internal or external carotid arteries is occasionally indicated for symptomatic atherosclerotic common carotid artery occlusion or long-segment high-grade stenosis beginning at its origin. I report the outcome of axillary artery-based bypass grafts to the distal common, internal, or external carotid arteries. METHODS: Between 1981 and 1997, 29 axillary-to-carotid bypass grafting procedures were performed on 28 patients, 15 men and 13 women, with a mean age of 68 years. Indications were transient ischemia in nine patients, amaurosis fugax in four patients, completed stroke in six patients, and nonlateralizing global ischemia in nine patients. Twenty-three common carotid arteries were totally occluded, and six had long-segment stenosis of 90% or greater beginning at the origin. Saphenous vein grafts were used in 25 procedures, and synthetic grafts were used in four. Grafts were placed to 13 internal, eight distal common, and eight external carotid arteries. RESULTS: There were no perioperative deaths; one stroke occurred (3.4%). No lymphatic or peripheral nerve complications occurred. In a 1- to 11-year follow-up period (mean, 4.5 years), there were no graft occlusions, one restenosis of 50% or greater, and two restenoses of 70% or greater. The 1-year stenosis-free rate for 50% or greater stenosis was 93%, and the 5- and 10-year rates were 87%. No late ipsilateral strokes occurred. The 5- and 10-year survival rates were 64% and 28%, respectively. Coronary artery disease was the major cause of late mortality. CONCLUSION: Axillary-to-carotid bypass grafting for severe symptomatic common carotid occlusive disease is safe, well tolerated, durable, and effective in stroke prevention. There is a high late mortality rate because of coronary artery disease in patients with severe proximal common carotid occlusive disease.  (+info)

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