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Association Between Di Distance and Left Renal Vein Compression in Nutcracker Syndrome
Zifeng Xu1, Jinbin Xu1, Gengguo Deng1
1Department of Urology, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China (Z.X., J.X., G.D., Z.H., S.C., H.W., J.W., J.D.).
Rationale And Objectives:
To investigate the clinical significance of Di Distance, defined as the projected craniocaudal distance along the inferior vena cava (IVC) between the confluence levels of the left and right renal veins, in patients with Nutcracker Syndrome (NCS) and its potential role in disease pathogenesis.
Materials And Methods:
In this retrospective study from January 2022 to January 2026, 46 patients with NCS confirmed by renal venography and 55 control participants who underwent abdominal CTA/CTV and renal venography but had negative venographic findings, defined as an LRV-IVC pressure gradient of <3 mmHg, were included. Conventional imaging parameters and Di Distance were compared between NCS patients and controls. Diagnostic performance was assessed using ROC analysis.
Results:
Di Distance was significantly larger in patients with NCS than in controls. Incorporating Di Distance improved the diagnostic performance of conventional imaging parameters. These findings suggest that Di Distance may serve as an additional anatomical marker associated with Left renal vein (LRV) compression.
Conclusion:
Di Distance was significantly increased in patients with NCS and may serve as a supplementary anatomical parameter associated with LRV compression. Incorporating Di Distance may improve the diagnostic performance of conventional imaging indicators. These findings suggest a potential anatomical explanation for NCS patients with relatively normal aortomesenteric angles, but further prospective studies integrating hemodynamic validation are required.
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