Posterior nutcracker syndrome: an infrequent cause of hematuria

Abstract

A 44-year-old man presented to the hospital with gross hematuria and left flank pain. His relevant medical history included Marfan syndrome, a DeBakey type 1 aortic dissection repair, and St Jude’s prosthetic aortic valve replacement in 2008 requiring chronic anticoagulation with warfarin. International normalized ratio was 2.9 on admission and warfarin was discontinued. A contrast-enhanced computed tomography scanning of the abdomen and pelvis demonstrated blood in the left renal pelvis. The dissection extended into abdominal aorta, which was dilated. There was symmetric perfusion of both kidneys without evidence of mass or calculus. A prominent left renal vein was noted with a compressed, retroaortic communication with the azygos vein (Figure 1). There was also an anomalous communication between the azygos vein and the inferior vena cava. Urine culture was negative. Cystoscopy showed blood clots in the left collecting system without evidence of malignancy. The patient’s hematuria continued while receiving intravenous heparin. A left renal arteriogram was normal. A selective left renal venogram confirmed extrinsic compression at the aorta with an elevated venous gradient of 6 mm Hg. The left retroaortic renal vein was primarily stented with a 10 by 37 mm biliary express balloon expandable stent with correction of compression and resolution of venous pressure gradient (Figure 2). The hematuria resolved and had not recurred with reinitiating warfarin therapy.