Foad Abd-Allah

BACKGROUND: A noninvasive method of visualization of the anterior spinal artery such as ultrasound that can be utilized in emergent or intraoperative settings can reduce the risk of spinal cord ischemia.

OBJECTIVE: We assessed the feasibility of imaging and characterizing blood flow in the anterior spinal artery using ultrasound with concurrent validation using a cadaveric model.

METHODS: We developed a protocol for ultrasonographic assessment of anterior spinal artery based on anatomic, morphologic, and physiologic characteristics of anterior spinal artery and determined the feasibility in 24 healthy research participants using high frequency probe (3-9 MHz) through the left lateral paramedian approach in the area between T8 and T12. We ascertained the detection rate, depth of insonation, and flow parameters, including peak systolic velocity, end diastolic velocity, and resistivity indexes for both segmental arteries and anterior spinal artery within the field of insonation. We validated the anatomical landmarks using simultaneous spinal angiography and simulated anterior spinal artery flow in a cadaveric set-up.

RESULTS: We detected flow in all segmental arteries at different levels of our field of insonation with mean depth (± standard deviation) of insonation at 3.9 ± 0.7 cm identified by characteristic high resistance flow pattern. Anterior spinal artery was detected in 15 (62.5%) research participants at mean depth (± standard deviation) of 6.4 ± 1.2 cm identified by characteristic low resistance bidirectional flow. Age, gender, and body mass index were not correlated with either the detection rate or depth of insonation for anterior spinal artery. Simultaneous spinal angiography and simulated anterior spinal artery flow in a cadaveric set-up confirmed the validity of the anatomic landmarks by demonstrating concordance with results obtained from volunteer research participants.

CONCLUSIONS: The current study describes a technique for noninvasive imaging of spinal vasculature using ultrasound which may enhance our diagnostic capabilities in emergent and intraoperative settings.

BACKGROUND: Atherosclerotic aortic arch plaques (AAP) have been linked to an increased risk of thrombo-embolic events as a cause of acute ischemic stroke of undetermined etiology.

OBJECTIVES: To find out the presence of atherosclerotic plaques in aortic arch and their potential role as a source of embolism in cerebral infarction of undetermined etiology.

METHODS: We performed trans-esophageal echocardiography (TEE) and multislice computerized tomography (MSCT) of the aortic arch on 30 patients with acute ischemic stroke of undetermined cause from a total series of 150 non-selected patients with acute ischemic stroke studied prospectively by clinical evaluation, laboratory investigations, cranial computed tomography, color coded duplex ultrasonography of the carotid arteries and transcranial Doppler (TCD).

RESULTS: Using trans-esophageal echocardiography eight patients (29.6%) had atherosclerotic aortic arch plaques, while using multislice computerized tomography atherosclerotic aortic arch plaques were revealed in twelve patients (40%). Atherosclerotic aortic arch plaques were significantly related to older age, male gender, hypertension, ischemic heart disease and low-grade atherosclerotic carotid lesions. Multislice computerized tomography of the aortic arch was more sensitive than trans-esophageal echocardiography in detecting the site, size and characters of atherosclerotic aortic arch plaques.

CONCLUSION: Atherosclerotic aortic arch plaques are a frequent finding in patients with acute ischemic stroke of undetermined cause supporting the hypothesis that aortic plaques have embolic potential. In addition, multislice computerized tomography is more sensitive than trans-esophageal echocardiography in detecting atherosclerotic aortic arch plaques and better characterization of these plaques especially relevant one.

BACKGROUND AND PURPOSE: The prevalence of carotid artery stenosis has been studied in several cohorts and groups of populations. Prevalence estimates were mostly based on ultrasound studies, because duplex ultrasound is accurate, reproducible and inexpensive to diagnose and follow up patients with arterial disorders. The purpose of our study was to describe the pattern of carotid artery disease in a large sample of Egyptians.

METHODS: We analyzed the data of 4,733 Egyptian subjects, who underwent extracranial carotid duplex scanning at the vascular laboratories of Cairo University Hospitals from January 1, 2003, to January 1, 2008. Demographic, clinical data and causes of referral were correlated with ultrasound findings.

RESULTS: Atherosclerotic carotid artery disease was present in 41% of the study population in the form of intimal thickening in 835 (17.6%), <50% stenosis in 983 (20.8%), 50-69% stenosis in 81 (1.7%), ≥70% stenosis in 38 (0.8%) and occlusion of internal carotid artery in 3 (0.06%) patients. Nonatherosclerotic disease was detected in 9 (0.2%) patients only. Significant and clinically relevant stenosis ≥50% was detected in 19 (2.5%) of the atherosclerotic symptomatic subjects. Multivariate stepwise logistic regression analysis selected age, diabetes mellitus, hypertension, smoking and dyslipidemia as independent predictors of the presence of carotid atherosclerotic disease.

CONCLUSION: Hemodynamically significant and clinically relevant extracranial atherosclerotic carotid disease is rare among Egyptians. Risk factors for carotid atherosclerosis are the same as in societies where carotid disease is more prevalent.