The roles of the liver and pancreas in renal nutcracker syndrome

•The presence of the liver and pancreas may influence NCS by compressing SMA against the aorta.•The presence of the liver and pancreas at the level of the LRV is not yet recognized as an independent factor for NCS but should be.•The presence of the liver and the pancreas may allow clinicians to identify NCS patients and may influence the choice of treatment options.

IntroductionTo 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 methodsWe 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.ResultsThe frequencies of group LP, group L, group P, and group O 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 O).ConclusionThe presence of the liver and pancreas at the level of the LRV was frequently found in NCS and was the independent factor for NCS.

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