Renal vasculature: Spectrum of anatomical variations and the significance from a surgeon's standpoint

Background: Renal vasculature is known for having a broad spectrum of variants, and some of them hold important implications at the time of renal surgeries, particularly for the renal transplant. Materials and Methods: This observational study was performed using multidetector computed tomography (MDCT) angiography in patients with various renal and other abdominal disorders and advised for pathologies in which MDCT angiography was indicated. A total of 760 patients were evaluated. Various parameters that have surgical importance were studied. Results: This study includes 123 (16%) patients that had accessory renal artery on right side and 152 (20%) patients that had on the left side. Among the right-side renal artery patients, 72 (58.5%) were hilar and 51 (41.5%) were polar arteries, and of left-side patients, 94 (61.8%) were hilar and 58 (38.2%) were polar arteries. The average diameter of the right and left renal artery was 5.1 and 5.07 mm, respectively. The average diameter of the right and left accessory renal artery was 2.4 and 2.6 mm, respectively. Early segmentary bifurcation of the right renal artery was seen in 651 patients (85.6%) with 319 (42%) being retro-caval, and early segmentary bifurcation of the left renal artery was seen in 94 patients (12.3%). Double right and left renal veins were seen in 96 (12.6%) and 37 (4.8%) patients, respectively. Late right renal vein confluence was seen in 50.6% of patients (340/671). Late left renal vein confluence was seen in 181 out of 700 patients (25.85%); 60 (7.9%) patients had circum-/retro-aortic renal vein. Conclusion: CT angiography is highly accurate modality for evaluation of renal vasculature. Although the increasing number of laparoscopic nephrectomies being performed as part of renal transplant procedure, it is becoming important for the radiologists to better understand the anatomy, its variations, its implications, and to accurately demonstrate vascular anatomy on imaging to the surgical team.