Sonographic Evaluation of Carotid Artery Luminal Diameter and Degree of Stenosis in Adult Diabetic Patients in University of Maiduguri Teaching Hospital, North Eastern Nigeria

Abstract

Background: Carotid artery luminal diameter measurements have been used as clinico-radiological index of carotid artery atherosclerosis in patients with diabetes mellitus. Luminal diameter values have also been used in epidemiological and interventional studies as surrogate index of carotid atherosclerosis. However, values for luminal diameter measurements in diabetic patients are scarce in our environment. Objectives: This study evaluates the carotid artery luminal diameter dimensions and degree of stenosis among adult diabetic patients using carotid duplex ultrasonography (CDUS). Methods: This was a cross-sectional study carried out at the University of Maiduguri Teaching Hospital, Nigeria. One hundred and twenty adult diabetic patients aged 20 78 years had CDUS for measurements of carotid artery luminal diameter and degree of stenosis. Measurements were taken at 1cm below and 1cm above the carotid bulb for the common carotid (CCA) and internal carotid arteries (ICA). Pearson’s correlation and Student t-test were used to compare the means between the variables. Results: There were 72 males and 48 female diabetic patients aged 20 to 78 years (mean = 50.03±11.4 years). The mean luminal diameter, in millimeters (mm), for normal (non-stenotic) carotid arteries on the right and left were (CCA=6.58±0.52 and 6.51±0.50; ICA=4.80±0.29 and 4.79±0.31); and abnormal (stenotic) were (CCA=6.41±0.62 and 6.35±0.62; ICA=3.44±0.44 and 3.11±0.29) respectively. A total of 75 patients (62.5% of study population) had no carotid artery stenosis; 38 patients (31.7%) had <50% carotid stenosis; 6 patients (5.0%) had 50-69% carotid stenosis; and 1 patient (0.8%) had 72% carotid stenosis. The prevalence of carotid stenosis in diabetic patients was 37.5% in this study. Negative and significant correlation was noted between percentage degree of stenosis and luminal diameter (r=≥ 0.5; p=<0.05). Conclusion: The findings of this study have indicated the presence of atherosclerotic changes in the carotid arteries of adult diabetic patients in our environment who are at risk of developing stroke from carotid stenosis. CDUS has proved to be a valuable diagnostic and screening tool in the evaluation of these patients because of its safety, low cost, wide availability, and accuracy in detecting carotid artery disease.