Nutcracker syndrome complicated by left renal vein thrombosis and resolution with anticoagulation: A case report and review of the literature

The nutcracker syndrome is the compression of the left renal vein (LRV) between the superior mesenteric artery and the abdominal aorta. LRV thrombosis associated with nutcracker syndrome is extremely rare with only a few cases reported. However, the predisposing factors of LRV thrombosis complicating nutcracker syndrome remain unclear. We report the case of a young woman diagnosed of thalassemia minor and hypothyroidism who received oral contraceptives during 12 months. She presented with acute onset of left side flank pain and a computed tomography (CT) revealed LRV thrombosis caused by local compression by anterior nutcracker syndrome. The patient received bemiparin 5,000 U/day subcutaneously for one week, later converted to oral acenocoumarol. Six months afterwards doppler ultrasound (DU) revealed resolution of her LRV thrombosis. A CT at 9 months confirmed the complete resolution of the thrombus, persistent LRV compression by nutcracker syndrome, left gonadal vein dilatation and pelvic varices. On thrombophilia testing, at 15 months, she was also found to have heterozygous factor V Leiden mutation. After 23 months of anticoagulation, a new CT with three-dimensional reconstruction showed the complete LRV recanalization and a decrease of the left gonadal vein dilation. This case demonstrates that LRV thrombosis should be evaluated for risk factors including thrombophilia conditions. CT and DU were effective in documenting LRV thrombosis, their evolution and the underlying lesions non-invasively and long-term anticoagulation was an efficient and safe treatment. We also reviewed the reported cases of LRV thrombosis complicating nutcracker syndrome and discussed the clinical facts and the management. *Correspondence to: Ramón Peces, Servicio de Nefrología, Hospital Universitario La Paz, Spain, Tel: 34917277151; Fax: Fax: 34917277382; E-mail: ramon.peces@salud.madrid.org