Anatomical features of renal artery in a black Kenyan population: Correlation with markers of atherosclerosis

Abstract

Knowledge of anatomical features of the renal artery is important in prediction,  management and control of atherosclerotic renal artery stenosis. These features show population variations but data from black African populations are scarce. The aim of this study was therefore to describe the anatomical features of the renal artery in a black Kenyan population. Six hundred and ten (610) single renal arteries from 305 adult black Kenyans [206 males, 99 females; age range 22 – 79 years] were studied by dissection at Department of Human Anatomy, University of Nairobi, Kenya. Specimens with macroscopic features of stenosis and dilatation were excluded. The implantation angle, length and branching pattern were studied. These features were correlated with intima-media thickness and luminal diameter. The  latter were determined by micrometry on Eosin/hematoxylin stained 5 micron  sections obtained from the proximal segment of the renal artery. Data was analysed by SPSS version 16.0. Student’s t-test, was used to test for statistical significance at 95% confidence interval where P value of < 0.05 was taken as significant. The results are presented in a bar graph, tables and macrographs. The mean  implantation angle was 94⁰±15⁰ (range 58⁰-125⁰). In 26.7% cases, the angle was more than 100⁰. Mean length was 34±1.4 mm with 21.6 % of arteries measuring ≤ 20 mm. Variant branching pattern was present in 40.5 % of cases. It comprised trifurcation (33 %), quadrifurcation (6.6 %) and pentafurcation (0.8 %). Higher implantation angle, short arteries and variant branching were associated with  statistically significant higher intima - media thickness and luminal diameter. These results suggest that higher implantation angle, shorter length and variant branching pattern constitute geometric risk factors for renal artery atherosclerosis.  Ultrasound screening for individuals with suboptimal geometric features for renal artery atherosclerosis is recommended.

Keywords: anatomical risk factors, atherosclerosis, renal artery