A comparison of arterial measurements between a South African cadaver and living sample as affected by age, sex, height and weight

Abstract

Knowledge of the normal arterial diameter at a given anatomical point is the first step towards quantifying the severity of cardiovascular diseases. According to several studies, parameters such as age, weight, height, Body Mass Index and sex, can explain morphometric variations in arterial anatomy. There is no specific differentiation point between normal age-related arterial changes and pathological changes. Therefore, it remains challenging to distinguish between physiological and pathological processes as structural changes in arteries are bound to occur with the advancement of age. There is no point at which an artery can be said to have stopped growing or developing and started to degenerate or becoming diseased. Hence the knowledge of changes in arterial anatomy with age is vital for understanding arterial pathology. Arterial dimensions studied by other researchers were measured on cadaveric material or diagnostic imaging methodologies such as magnetic resonance imaging, computed tomography and ultrasound. The comparability and compatibility of cadaveric and image diagnostic methodology measurements has often been fiercely debated; repeatedly raising the question on the validity of cadaveric research. The primary purpose of this study was thus to compare the measurements taken on cadaveric material with measurements taken with computed tomography and ultrasound. The aim was to establish whether there is a statistically significant difference between arterial measurements taken via these different approaches. In addition, the study also aimed to examine the effects of various demographic parameters on the arterial diameters of a South African population. Digital arterial measurements were taken on computed tomography images at selected arterial sites and the age and sex of each individual were noted. These computed tomography images, representative of a living South African population, were retrospectively selected from the database of diagnostic images at the Department of Radiology, Steve Biko Academic Hospital. The arterial diameter at the identified arterial sites was measured with the assistance of computer software. Digital measurements of arteries on ultrasound images were also measured at the selected arterial sites and the age, sex, weight, height and Body Mass Index of each individual were noted or calculated. Ultrasound images were taken on volunteers in the Department of Anatomy, University of Pretoria. Demographic information, including age, sex, weight and height, was gathered via a paper-based questionnaire. Body Mass Index was calculated. Newly available cadaveric data was added to the cadaveric database compiled during two pilot studies that took place in the Department of Anatomy at the University of Pretoria. The collected data allowed for the comparison of diameters measured with the different methodologies. The South African sample was divided into comparable age and sex groups that also allowed for the determination of correlations between the changes in arterial diameters and the changes in the demographic parameters. Analyses of these correlations answered questions such as whether arterial diameter increase or decrease with an increase in age, height or weight. This study found that age is a vital demographic parameter when assessing change in arterial dimensions. Age was also found to influence muscular and elastic arteries differently. Even though some sexual dimorphism was noted, sex had a significantly smaller effect on arterial dimensions compared to age. Weight, height and BMI correlated weakly with a change in arterial dimension. Comparisons between the different populations indicated that cadaver measurements compared well to CT measurements as well as ultrasound measurements, but that CT measurements and ultrasound measurements were significantly different. Arterial pathology is a major contributor to cardiovascular disease and mortality. Data on normal arterial dimensions for a South African population is scarce, but essential when evaluating whether a dilatation or stenosis are pathological. Studies on the arterial morphology on a cadaver sample are thus comparable to living populations and support the premise that there is an age-related increase in the dilatation of the arterial lumen. The arterial diameter is a useful indicator of the vascular ageing process. This study provided us with valuable information regarding the validity and comparability of several arterial measuring methodologies as well as vital information regarding arterial changes in a South African population.