Diagnostic value of computed tomographic findings of nutcracker syndrome: Correlation with renal venography and renocaval pressure gradients

Department of Radiology, Seoul National University Hospital, and Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea.
European journal of radiology (Impact Factor: 2.16). 12/2011; 80(3):648-54. DOI: 10.1016/j.ejrad.2010.08.044
Source: PubMed

ABSTRACT To evaluate the diagnostic values of CT findings of nutcracker syndrome (NCS).
Twenty seven subjects that underwent CT and renal venography, were divided into three groups based on the venographic renocaval pressure gradient (PG) and collateral veins of the left renal vein (LRV): non-compensated NCS patients with PG≥3 mm Hg (group 1, n=12), partially compensated NCS patients with borderline PG (1<3 mm Hg) and collateral veins (group 2, n=6), and control group with low PG (0-1 mm Hg) without collateral veins (group 3, n=9). The CT findings were analyzed with regard to abrupt narrowing of the LRV with an acute angle (beak sign), aortomesenteric angle between the superior mesenteric artery and aorta on sagittal images, and LRV diameter ratio (hilar-aortomesenteric).
Beak sign of the LRV was found in 91.7% (11/12) of group 1, 50% (3/6) of group 2, and in 11.1% (1/9) of group 3 with the significant difference between groups 1 and 3 (P<.05, χ2 test). Mean values of all quantitative CT parameters differed significantly only between groups 1 and 3 (P<.05, one-way ANOVA test). For differentiating the non-compensated NCS from the control group, the beak sign showed 91.7% sensitivity and 88.9% specificity. Of the various CT parameters, the beak sign and LRV diameter ratio of ≥4.9 showed the greatest diagnostic accuracy (AUC 0.903, ROC analysis).
Beak sign of the LRV and CT findings can be useful in diagnosing the non-compensated NCS.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Introduction: To assess the frequency and significance of presence of the liver and pancreas at the left renal vein (LRV) level in patients with suspected renal nutcracker syndrome (NCS). Materials and methods: We included 101 patients with hematuria who underwent urography three-dimensional CT between April 2009 and November 2013. These patients were divided into NCS (n = 25) and non-NCS (n = 76) patients according to the following CT criteria: (1) the presence of beak sign and (2) hilar-aortomesenteric left renal vein diameter ratio >4. Patients were grouped according to the presence of the liver and pancreas at the LRV: group LP (both liver and pancreas), group L (only liver), group P (only pancreas), and group O (neither liver nor pancreas). The difference in the frequencies of groups was analyzed between NCS and non-NCS patients. Multivariate analysis was used to determine the independent factors between NCS and non-NCS patients. Results: The frequencies of group LP, group L, group P, and group 0 in NCS vs. non-NCS were 88% vs. 5.3% (p < 0.001), 4.0% vs. 2.6% (p = 0.75), 4.0% vs. 11.8% (p = 0.45), 4.0% vs. 80.3% (p < 0.001), respectively. Multivariate analysis demonstrated that group was a predictor for differential diagnosis between NCS and non-NCS (p = 0.022), and group LP was an independent factor for the presence of NCS (odds ratio, 43.8; 95% confidence interval, 3.8-500.3; p < 0.002; reference, group 0). Conclusion: The presence of the liver and pancreas at the level of the LRV was frequently found in NCS and was the independent factor for NCS.
    European Journal of Radiology 10/2014; 83(10). DOI:10.1016/j.ejrad.2014.07.011 · 2.16 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Nutcracker syndrome (NCS) is a rare pathology, caused by compression of the left renal vein (LRV) between the abdominal aorta (AA) and the superior mesenteric artery (SMA), due to reduction of the angle between AA and SMA. This leads to LRV varices, left gonadal vein varices and therefore, the pelvic congestion syndrome. For this reason, coexistence of NCS and pelvic congestion syndrome has been described. It manifests by hematuria, proteinuria, and nonspecific pelvic pain secondary to pelvic congestion, dyspareunia and persistent genital arousal. We report a 27-year-old woman who experienced hematuria and left flank pain. The diagnosis of NCS accompanied by pelvic congestion syndrome was missed initially, but later on the diagnosis was made by color Doppler ultrasound, abdominal computed tomography (CT) and CT angiography that were later performed. She refused interventional and surgical treatments, and was lost to follow up. Implication for health policy/practice/research/medical education: Nutcracker syndrome accompanying pelvic congestion syndrome is a rare, but treatable clinical condition. Inclusion of this entity in the differential diagnosis of patients with an unknown cause of hematuria and flank pain can achieve efficient management of this condition. In addition, in our case, the angle between the aorta and the superior mesenteric artery was approximately 14.5 degrees, which is almost the lowest angle in comparison with previous studies and reported cases in the literature.
    Iranian Journal of Radiology 06/2014; 11(2). DOI:10.5812/iranjradiol.11075 · 0.18 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The nutcracker phenomenon [left renal vein (LRV) entrapment syndrome] refers to compression of the LRV most commonly between abdominal aorta and superior mesenteric artery. Term of nutcracker syndrome (NCS) is used for patients with clinical symptoms associated with nutcracker anatomy. LRV entrapment divided into 2 types: anterior and posterior. Posterior and right-sided NCSs are rare conditions. The symptoms vary from asymptomatic hematuria to severe pelvic congestion. Symptoms include hematuria, orthostatic proteinuria, flank pain, abdominal pain, varicocele, dyspareunia, dysmenorrhea, fatigue and orthostatic intolerance. Existence of the clinical features constitutes a basis for the diagnosis. Several imaging methods such as Doppler ultrasonography, computed tomography angiography, magnetic resonance angiography and retrograde venography are used to diagnose NCS. The management of NCS depends upon the clinical presentation and the severity of the LRV hypertension. The treatment options are ranged from surveillance to nephrectomy. Treatment decision should be based on the severity of symptoms and their expected reversibility with regard to patient's age and the stage of the syndrome.