Carotid-related Stroke Research Articles

The need for emergency surgical treatment in carotid-related stroke in evolution and crescendo transient ischemic attack

The purpose of this study was to examine the safety of emergency carotid endarterectomy (CEA) in patients with carotid stenosis and unstable neurological symptoms. This prospective, single-center study involved patients with stroke in evolution (SIE) or fluctuating stroke or crescendo transient ischemic attack (cTIA) related to a carotid stenosis ≥ 50% who underwent emergency surgery. Preoperative workup included National Institute of Health Stroke Scale (NIHSS) neurological assessment on admission, immediately before surgery and at discharge, carotid duplex scan, brain contrast-enhanced head computed tomography (CT) or magnetic resonance imaging (MRI). End points were perioperative (30-day) neurological mortality, NIHSS score variation, and hemorrhagic or ischemic stroke recurrence. Patients were evaluated according to clinical presentation (SIE or cTIA), timing of surgery, and presence of brain infarction on neuroimaging. Between January 2005 and December 2009, 48 patients were submitted to emergency surgery. CEAs were performed from 1 to 24 hours from onset of symptoms (mean, 10.16 ± 7.75). Twenty-six patients presented an SIE with a worsening NIHSS score between admission and surgery, and 22 presented ≥ 3 cTIAs with a normal NIHSS score (= 0) immediately before surgery. An ischemic brain lesion was detected in four patients with SIE and eight patients with cTIA. All patients with cTIA presented a persistent NIHSS normal score before and after surgery. Twenty-five patients with SIE presented an NIHSS score improvement after surgery. Mean NIHSS score was 5.30 ± 2.81 before surgery and 0.54 ± 0.77 at discharge in the SIE group (P < .0001). One patient with SIE had a hemorrhagic transformation of an undetected brain ischemic lesion after surgery, with progressive neurological deterioration and death (2%). Due to the absence of randomized controlled trials of CEA for neurologically unstable patients, data currently available do not support a policy of emergency CEA in those patients. Our results suggest that a fast protocol, including CT scans and carotid duplex ultrasound scans in neurologically unstable patients, could help identify those that can be safely submitted to emergency CEA.

Matrix metalloproteinase-1 and matrix metalloproteinase-3 gene promoter polymorphisms are associated with carotid artery stenosis.

The matrix metalloproteinases (MMPs) are a family of enzymes that are important in the resorption of extracellular matrix and are involved in atherogenesis. Recently, 2 common polymorphisms on MMP-1 (1G/2G) and MMP-3 (5A/6A) gene promoters have been described. The aim of this study was to investigate a possible association between MMP polymorphisms and increased risk of internal carotid artery (ICA) stenosis. We studied 91 patients consecutively recruited for ICA stenosis who had undergone carotid endarterectomy and 133 subjects without ICA stenosis (controls). Polymorphic genotypes were determined by polymerase chain reaction and sequencing analysis. The frequency of the 6A allele was significantly different between cases and controls: 0.62 and 0.50, respectively (odds ratio [OR], 1.58; 95% CI, 1.08 to 2.33; P=0.017). The frequency of 6A/6A genotype was significantly higher in cases with involvement of both carotids (OR, 3.13; 95% CI, 1.14 to 8.5; P=0.026) and in patients with stenosis >70% (OR, 2.55; 95% CI, 1.07 to 6.07; P=0.033). No significant differences were observed in MMP-1 distribution. Patients who were homozygous for both the 6A and 2G alleles had an elevated relative risk of ICA stenosis (OR, 2.66; 95% CI, 1.23 to 5.72; P=0.016). Multiple logistic regression analysis using the common risk factors and the 6A and 2G allele variants revealed that the 6A allele was an independent risk factor for ICA stenosis (P=0.049). When 6A/6A and 2G/2G were combined, the risk factor for ICA stenosis was 3-fold higher (OR, 3.31; 95% CI, 1.48 to 7.42; P=0.004). Homozygosity for the 6A allele of the MMP-3 promoter is associated with carotid stenosis and, in association with MMP-1 2G homozygosity, predicts an increased risk of ICA stenosis. Even if obtained from a relatively limited patient series, these results might have relevant implications for treatment of ICA stenosis and possibly prevention of carotid-related stroke.

STROKE PREVENTION: Cardiac and Carotid-Related Stroke

The aim of this article is to discuss cardiac sources of stroke as well as the management of symptomatic and asymptomatic carotid stenosis. The authors detail the risks of cardioembolic stroke in the following conditions: aortic arch atheroma, atrial fibrillation, atrial myxoma, atrial septal aneurysm, dilated cardiomyopathy, infective endocarditis, left ventricular thrombus, mitral annular calcification, mitral valve prolapse, patent foramen ovale, prosthetic heart valves, valvular strands, and the optimal medical management for these conditions. The indications for carotid endarterectomy, angioplasty, and stenting are also outlined.

Carotid surgery for prophylaxis of ischemic stroke

Every year more than 250,000 patients suffer from ischemic (80%) or hemorragic (20%) stroke. Some 40,000 of these strokes are induced by stenosis or occlusion of the extracranial carotid artery. Several randomized studies (NASCET, ECST, ACAS, etc.) have proved that operative removal of high-grade carotid stenoses is an effective method in the primary and secondary prophylaxis of ischemic stroke. Operative therapy is significantly better than medical therapy with thrombocyte aggregation inhibitors. The prerequisite for effective operative prophylaxis is a low perioperative stroke rate. Even though the prophylactic value of carotid thrombarterectomy (TEA) is obvious, only about 5% of all carotid-related strokes are prevented by this operation. Essential conditions for increased efficiency in carotid surgery are close cooperation with the neurologist and the internist, screening of patients with a high risk for ischemic stroke, sophisticated, mainly non-invasive diagnostics, and more operative capacity. Interventional methods (stent, PTA) have not yet been proved safe and effective. These methods should be employed only in special cases after interdisciplinary discussions or in randomized studies.

Carotid endarterectomy and intracranial thrombolysis: Simultaneous and staged procedures in ischemic stroke

Purpose: The feasibility and safety of combining carotid surgery and thrombolysis for occlusions of the internal carotid artery (ICA) and the middle cerebral artery (MCA), either as a simultaneous or as a staged procedure in acute ischemic strokes, was studied. Methods: A nonrandomized clinical pilot study, which included patients who had severe hemispheric carotid-related ischemic strokes and acute occlusions of the MCA, was performed between January 1994 and January 1998. Exclusion criteria were cerebral coma and major infarction established by means of cerebral computed tomography scan. Clinical outcome was assessed with the modified Rankin scale. Results: Carotid reconstruction and thrombolysis was performed in 14 of 845 patients (1.7%). The ICA was occluded in 11 patients; occlusions of the MCA (mainstem/major branches/distal branch) or the anterior cerebral artery (ACA) were found in 14 patients. In three of the 14 patients, thrombolysis was performed first, followed by carotid enarterectomy (CEA) after clinical improvement (6 to 21 days). In 11 of 14 patients, 0.15 to 1 mIU urokinase was administered intraoperatively, ie, emergency CEA for acute ischemic stroke (n = 5) or surgical reexploration after elective CEA complicated by perioperative intracerebral embolism (n = 6). Thirteen of 14 intracranial embolic occlusions and 10 of 11 ICA occlusions were recanalized successfully (confirmed with angiography or transcranial Doppler studies). Four patients recovered completely (Rankin 0), six patients sustained a minor stroke (Rankin 2/3), two patients had a major stroke (Rankin 4/5), and two patients died. In one patient, hemorrhagic transformation of an ischemic infarction was detectable postoperatively. Conclusion: Combining carotid surgery with thrombolysis (simultaneous or staged procedure) offers a new therapeutic approach in the emergency management of an acute carotid-related stroke. Its efficacy should be evaluated in interdisciplinary studies. (J Vasc Surg 1999;29:459-71.)