(Ultrasound Review) The main renal artery diameter and the dimensions of the kidney are related, according to a study in the Journal of Ultrasound in Medicine. This important finding should reduce the problems associated with non-visualization of stenosed and occluded accessory renal arteries. In the general population the incidence of accessory renal artery is 25-30%, they suggested.
Over a 14-month period, a series of 56 patients underwent renal intra-arterial digital subtraction angiography (DSA). Ultrasound imaging was used to measure the renal length. Most patients were either potential renal transplant donors or had suspected renovascular disease causing hypertension. For consistency, the ultrasound and DSA measurements of renal artery diameter were performed at a level 1.0-1.5-cm from the ostium. Renal length was considered normal within a range of 90-120-mm.
"Of 111 kidneys investigated by DSA, 16 (14.41%) had 17 accessory renal arteries detected. Of these kidneys, only 1 (0.9%) was supplied by 3 renal arteries," they reported. Ultrasound visualized 41.8% of the 17 accessory renal arteries found at DSA, and ultrasound was technically successful in 91% of cases overall.
The renal artery diameter for patients without accessory renal arteries was 3.5-6.8-mm compared with 3.0-5.5-mm for patients with accessory renal arteries detected on sonography or DSA. According to the authors, "the highest rates of sensitivity and specificity (80% and 80.5%, respectively) were obtained when the cutoff value was taken as 4.65-mm."
"Our study reveals the statistically significant effect of using this criterion as a clue. Moreover, the sonographic method, because it allows measurement of diameter and size without the problems of magnification and with the advantage of real-time imaging, which provides optimal planes, discloses the renal artery diameters of kidneys with normal dimensions," they concluded. When the renal artery is significantly smaller than expected compared with renal size, an accessory renal artery should be considered.
Correlation between the diameter of the main renal artery and the presence of an accessory renal artery: sonographic and angiographic evaluationAytac, S. K., et. al.
Ankara University, Ibn-i Sina Hospital, Ankara, Turkey
J Ultrasound Med 2003 May; 22:433-439
By Ultrasound Review
July 31, 2003
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