Diagnostic value of computed tomographic findings of nutcracker syndrome: correlation with renal venography and renocaval pressure gradients.
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.
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ABSTRACT: To investigate the relationship between the level of left renal vein (LRV) compression and changes in the perfusion of the left kidney in patients with nutcracker syndrome (NCS) by one-stop whole-organ perfusion imaging of bilateral kidneys using 640-slice volume CT. Twelve patients, clinically diagnosed with NCS, were subjected to one-stop examination of kidneys. Angiography and whole-organ perfusion imaging of bilateral kidneys were conducted, and the compression segment of LRV was demonstrated and measured. Information including the results of whole-organ perfusion images of both kidneys in 12 patients was collected. Results of epigastrium dynamic volume scanning by 640-slice volume CT were collected for 12 patients as control group. Left and right renal cortexes were chosen as regions of interest (ROI), and their perfusion values were measured. The perfusion values of the left and right renal cortexes in the control group were 323.8 ml·min(-1)·100 ml(-1) and 322.9 ml·min(-1)·100 ml(-1), respectively. The difference was not statistically significant (t = 1.388, P = 0.193). For NCS patients, the perfusion values of the left and right renal cortexes were 350.8 ml·min(-1)·100 ml(-1) and 391.1 ml·min(-1)·100 ml(-1), respectively. Significantly decreased value was observed in left renal cortex compared to that of the right renal cortex, with the mean decrease of 40.3 ml·min(-1)·100 ml(-1), and the difference was statistically significant (t = -4.204, P = 0.001). As a non-invasive functional imaging technique, whole-organ perfusion imaging of kidneys can be used to evaluate the organ and tissue perfusion status and to accurately reflect the hemodynamic changes of the left renal cortex in the patients with NCS. Whole organ perfusion imaging may also provide the basis for quantitative diagnosis and clinical interventions of NCS.PLoS ONE 01/2013; 8(9):e74365. · 3.73 Impact Factor
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ABSTRACT: Nutcracker syndrome is one of the abdominal venous entrapments, caused by compression of the left renal vein between the superior mesenteric artery and the abdominal aorta. Occasionally a retro-aortic left renal vein is compressed between the aorta and the vertebral body (posterior nutcracker syndrome). The renal vein distal to the compression is dilated and renal venous flow can be diverted toward the pelvis through an incompetent, refluxing, left ovarian or spermatic vein, in addition to drainage through retroperitoneal venous collaterals. In this article, we describe the different surgical and endovascular techniques that are used to treat this syndrome.Seminars in Vascular Surgery 03/2013; 26(1):35-42. · 1.02 Impact Factor
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ABSTRACT: Nutcracker syndrome (NCS), which is caused by compression of the left renal vein between the abdominal aorta and the superior mesenteric artery, leads to a series of clinical symptoms including hematuria, proteinuria, flank pain, and varicocele. The diagnosis of NCS is difficult due to variations in normal anatomy. Treatment, which ranges from observation to nephrectomy, remains controversial. We conducted a review based on the related literature and our experience with hundreds of cases. We summarize the characteristics of NCS, the different measurements used in diagnosis, and the current treatment options. We present our diagnostic criteria and recommend endovascular stenting as the primary option for NCS.Urology 10/2013; · 2.42 Impact Factor