A case of secondary hypertension associated with the nutcracker phenomenon.

A 25-year-old Korean woman was referred for uncontrolled hypertension. Laboratory examination revealed increased plasma renin activity and microscopic hematuria. Computed tomography demonstrated compression of the left renal vein (LRV) between the aorta and superior mesenteric artery; however, both renal arteries were intact and there was no adrenal mass. Renal vein catheterization showed external compression with a pressure gradient of up to 8 mm Hg between the LRV and the inferior vena cava. Plasma renin activity in the LRV was almost five times higher than that in the right renal vein. In this patient, renin-dependent hypertension was caused by renal congestion due to LRV obstruction.