Delineation of Inferior Vena Caval Anatomy With 3-Dimensional Computerized Tomography Reconstruction

Abstract

A55-year-old female presented with a history of intermittent, painful gross hematuria. On examination she was afebrile with stable vital signs and right costovertebral angle tenderness with deep palpation. Hemoglobin, blood differential, blood chemistry studies and urinalysis were unremarkable. Multiphasic helical computerized tomography demonstrated an enhancing 3 5 cm right lower pole mass suspicious for malignancy. Post-processing 3-dimensional reconstructions of the arterial phase computerized tomogram displayed aberrant vena caval anatomy with a left inferior vena cava (IVC) (see figure). Preoperative review of the abdominal venous anatomy enabled an uncomplicated laparoscopic right radical nephrectomy to be performed. Final pathological diagnosis was stage 1b, Fuhrman grade 3, clear cell renal cell carcinoma. Embryologically the abdominal venous drainage system develops from the posterior cardinal, subcardinal and supracardinal veins. 1 These systems, formed by 8 weeks of gestation, communicate with each other, anastomose, and eventually degenerate to leave a right IVC, a short right renal vein and a single ventral left renal vein among other tributaries. The IVC develops from the right subcardinal vein above the level of the renal veins and the vena cava develops from the right supracardinal vein below the renal veins. Anomalies occur with the persistence of additional or other embryonic segments. Persistence of the left supracardinal vein with regression of the right vein results in a left IVC (see figure). Left IVCs cross over the aorta (part B of figure, arrow) and mirror normal vena caval anatomy with the left adrenal and gonadal veins emptying directly into the IVC, while the right adrenal and gonadal veins empty into the right renal vein (part A of figure, arrow). 1 Below the level of the renal veins the aberrant IVC is to the left of the aorta (part C of figure, arrow). Persistence of both supracardinal veins results in a double IVC and can lead to symptoms including renal obstruction/ stones, lumbar/flank pain, hypertension, venous stasis or varicocele. Anomalies of the subcardinal vein can result in interruption of the IVC with azygous/hemiazygous continuation. Persistence of the posterior cardinal veins results in retrocaval/ circumcaval ureters. Although some patients with anomalous abdominal venous drainage may present with symptoms, many are asymptomatic and the aberrant anatomy is discovered incidentally on radiographic evaluation or surgical exploration.