Renovascular anatomic variants at CT angiography.

The aim of this paper was to assess the origin and course variations of vessels forming the renal vascular pedicle. METHODS: The IRB approved study retrospectively evaluated 921 consecutive patients (503 females, 418 males; mean age, 54 years), who underwent multidetector computed tomographic (MDCT) of the abdomen for various purposes at our Department of Radiology, between January 2012 and December 2013. Multiplanar and volumetric reformations were performed in all cases. For each set of images, the locations of renal artery origins and renal venous drainage, such as all renal vessels variations, including division variations and presence of extrarenal vessels, were investigated. RESULTS: The tract of the aorta between the upper margin of L1 and the lower margin of L2 originated 96% of main renal arteries and 72% of extra renal arteries. The most common location for renal artery origin was the L1- L2 intervertebral disc level. Sixty-nine percent of patients showed a single renal artery, with multiple arteries in 31%, bilateral multiple arteries in 11%, and early division in 6% of cases. Additional renal arteries were detected on the right side in 5% and on the left side in 12% of cases. With regard to the venous drainage, 89.8% of patients showed a single renal vein, with multiple vein in 10.2%, while 23.8% showed a retro-aortic course of the renal vein. CONCLUSION: Renal arteries and veins variations of origin and course are not infrequent. Extrarenal vessels may compromise renal surgery. The awareness of any possible renovascular anomaly is crucial in case of a non-invasive diagnostic search for renal artery stenosis, and when renal surgery related to renal arteries is performed, such as in case of interventional radiological procedures, urological and vascular operations, and renal transplantation.