Percentages and Gender Distribution of Anatomic Variations of Inferior Vena Cava, Renal Veins, and Posterior Lumbar Tributaries of the Left Renal Vein Left Renal Vein Drainage Variations

Objective: The aim of this study was to investigate percentages and gender distribution of the variations of the inferior vena cava (IVC), renal veins, and posterior lumbar tributaries of the left renal vein (LRV). Materials and Methods: For this cross sectional observational study, the computed tomography (CT) images of 1949 patients were evaluated retrospectively. Results: In the present study, percentages of double IVC, left IVC, and IVC interruption with azygos continuation were 0.5%, 0.2%, and 0.1%, respectively; circumaortic left renal vein (CLRV) was 6% and retroaortic left renal vein (RLRV) was 4.2%. Multiple renal vein variations were 24.1% on the right, but none on the left. Posterior lumbar tributaries of the renal veins were 0.15% on the right and 48% on the left. There was no difference between genders in terms of LRV and IVC variations. While the incidence of multiple right renal veins was statistically significantly higher in male patients compared to female patients (p = 0.045), the opposite was true for the posterior lumbar tributaries of the LRV (p = 0.035). Conclusion: The venous system has a wide variety of variations, and the renal venous circulation is supported by number variations on the right in men and collaterals on the left in women.