Right double inferior vena cava with a retrocaval ureter and preaortic iliac venous confluence: A case report with embryological considerations

With advances in diagnostic imaging, congenital anomalies of the inferior vena cava are being increasingly detected incidentally in asymptomatic patients. Double inferior vena cava is a relatively well-known anomaly, with an estimated prevalence rate of 0.2%–3%. In contrast, right double inferior vena cava—in which two inferior vena cava run parallel on the right side of the abdominal aorta—is extremely rare, with only a handful of reported cases. In this case, the spatial relationship between the two inferior vena cava—which was lateral-to-medial immediately below the renal veins—changed to dorsal-to-ventral at the level of the pelvic inlet. From an embryological perspective, we discuss the spatial relationship between the two inferior vena cava, drawing on previous reports.