Relationship between Microscopic Hematuria and Inferior Vena Cava Reflux on Color Doppler Ultrasonography

Abstract

We examined the relationship between microscopic hematuria and inferior vena cava (IVC) reflux. Transabdominal color Doppler ultrasonography of the IVC was performed in the supine position with the convex probe positioned perpendicular to the upper abdominal wall, and the extent of reflux into the IVC with each heart beat was examined near the diaphragm. A total of 171 patients were studied who had no diseases that could cause hematuria, and no symptomatic gross hematuria. The relationship between the existence and severity of IVC reflux and urine occult blood was examined. The 98 males included 50 subjects without IVC reflux and 48 with reflux, while the 73 females included 24 without IVC reflux and 49 with IVC reflux, respectively. The occurrence of IVC reflux was unrelated to age, but the prevalence of reflux was significantly higher in females than males. As the grade of IVC reflux increased, there was an increase in the prevalence and the severity of hematuria in both males and females. In conclusion, IVC reflux could be related to the occurrence of microscopic hematuria . Renal or urinary tract congestion secondary to IVC reflux may be one of the factors contributing to hematuria.