Fig. 1

The images of the duplex ultrasound and the left renal venography. a, Right transverse image: Duplex ultrasound demonstrated the compressed left renal vein between the aorta (white arrow) and the superior mesenteric artery (blue arrow), and the left renal vein was pressed like a beak. b, Left transverse image: Duplex ultrasound demonstrated a narrowing of the left renal vein at the aortomesenteric portion and varices of left gonadal vein (green arrow) arising from the left renal vein on the left of aorta (white arrow). c, Before extravascular stenting, left renal venography demonstrated there was obstruction of left renal venous outflow and perihilar varices (red arrow). d, After endovascular stenting (red arrow), left renal venography showed unobstructed blood outflow and full stent expansion without obvious protrusion of the stent in the inferior vena cava