1 Department of Nephrology, Chang Gung Memorial Hospital, Taipei, 2 Department of Radiology, Chang Gung Memorial Hospital, Keelung, Taiwan and 3 Histopathology Unit, Cancer Research UK, London Research Institute, London, UK
Correspondence and offprint requests to: Tzung-Hai Yen, MD, Department of Nephrology, Chang Gung Memorial Hospital, 199, Tung Hwa North Road, Taipei 105, Taiwan. Email: m19570{at}adm.cgmh.org.tw
Keywords: nutcracker syndrome; haematuria; magnetic resonance angiography
The nutcracker phenomenon refers to compression of the left renal vein between the aorta and superior mesenteric artery. This phenomenon with its associated symptoms and signs is defined as nutcracker syndrome [1]. It occurs in relatively young and previously healthy people. The compression leads to left renal vein hypertension, which may result in rupture of the thin walled vein into the renal calyceal fornix with the clinical presentation of intermittent gross or microscopic haematuria. There can also be collateral venous circulation formation such as a prominent left ovarian vein or testicular vein with its associated symptoms, such as vulvar varices in females or varicoele in males [2].
A 37-year-old female was referred to our hospital with a 3 year history of symptoms of intermittent gross haematuria and painful left flank. Her past medical and family histories were normal. All blood tests including complete blood cell count, biochemistry, blood clotting profile, serum immunoglobulin electrophoresis and antinuclear antibody were within normal limits. Urinary analysis revealed numerous red blood cells without dysmorphic changes. Renal ultrasound was also normal. Magnetic resonance imaging revealed a dilated left renal vein after passing between the aorta and superior mesenteric artery (Figure 1a). Magnetic resonance angiography (MRA) showed that the diameter of the left renal vein was larger in the left part adjacent to the aorta compared with the right adjacent part. A prominent left ovarian vein, implicating formation of a collateral circulation, was also noted (Figure 1b). Digital subtraction MRA found the impingement of the left renal vein between the aorta and superior mesenteric artery (Figure 1c). Nutcracker syndrome was diagnosed by the combination of clinical and MRA findings. The patient received no surgical treatment and has remained stable over the subsequent 3 years.
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Conflict of interest statement. None declared.
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