[Validation of supra-aortic trunks ultrasound in the diagnosis of atherosclerotic disease of the internal carotid artery. Comparison of the results with angiography]

Abstract

Introduction: Arteriosclerosis of the extra-cranial arteries is believed to be responsible for almost one-third of all ischaemic strokes. The sound diagnosis of the degree of stenosis is essential in deciding the best therapeutic strategy. Although cerebral angiography is considered the reference technique, ultrasound study (UST) is a more readily available, non-invasive and well-established procedure for quantifying carotid stenosis. However, on being a dependent exploratory technique, it is recommended that each laboratory validates its results against angiography.

Objectives: To establish the validity of the neuro-ultrasound study in our laboratory for use in the diagnosis of extracranial atheromatous disease, and determine its capacity to quantify the degree of stenosis in the internal carotid artery.

Material and methods: A retrospective study of patients with extracranial carotid atheromatous disease, in whom the diagnostic process was carried out with carotid ultrasound as well as supra-aortic trunk digital-subtraction angiography.

Results: A total of 254 carotids were evaluated and the degree of stenosis being classified into > 50%, 70-99% and 100%. The UST for the first group had a sensitivity (Se) of 97%, a specificity (Sp) of 90%, a positive predictive value (PPV) of 94.6% and a negative predictive value (NPV) of 94.2%. The second group had an Se of 96.4%, Sp 93%; PPV 94.4% and NPV 95.4%. The respective values for carotid occlusion were, 85%, 96.8%, 80% and 97.8%.

Conclusions: Our data validates the ability of UST performed in our Laboratory to diagnose the degree of carotid stenosis.