Clinical outcomes of inferior vena cava filter placement in patients with renal vein anomalies

Background To investigate the clinical outcomes in patients with renal vein anomalies who undergo inferior vena cava (IVC) filter placement. Methods Contrast-enhanced computed tomography images of 410 patients who underwent IVC filter placement were retrospectively reviewed to detect renal vein anomalies. Clinical outcomes involving de novo pulmonary embolism and worsening of renal function were compared between patients with the location of filters placed in relation to the anomalous renal veins versus not in relation to any renal veins. Results A total of 97 (23.7%) renal vein anomalies were identified: 62 (15.1%) multiple right renal veins, 23 (5.6%) circumaortic left renal veins, 10 (2.4%) retroaortic left renal veins, and 2 (0.5%) accessory left renal veins. Frequency of de novo pulmonary embolism in patients with circumaortic left renal veins who had filters placed at or in between the 2 left renal veins was not significantly different from patients who underwent infra- or suprarenal filter placement (5.9% [1/17] vs. 3.1% [12/387]; P = 0.433). The frequency of patients who had a >25% decrease in estimated glomerular filtration rate after IVC filter placement was not significantly different whether the filter was placed in an infrarenal location or at or above the level of the anomalous renal veins (11.0% [37/335] vs. 17.6% [6/34]; P = 0.261). Conclusions Clinical outcomes involving the frequency of de novo pulmonary embolism and worsening of renal function are not dependent on location of IVC filter placement in patients with renal vein anomalies.