The most frequent anomalies than can complicate abdominal aortic aneurysms (AAA) repair are: Major venous anomalies: Renal vein anomalies: Retroaortic left renal vein type I or II. Circumaortic left renal vein. Inferior cava vein anomalies: Left-sided inferior vena cava or cava vein transposition Double inferior vena cava: type I, II or III, right double cava. Marsupial cava or preaortic iliac ...