Abnormalities of renal venous system and unexplained renal hematuria.

Since 1968, 152 patients with unexplained renal hematuria have been treated at our clinic. Renal angiography in 46 patients who did not respond to conservative therapy revealed 21 abnormalities of the vascular system. Of these 21 patients 10 had or were suspected to have renal pelvic and ureteral varices, and 8 had congenital anomalies of either the inferior vean cava or the renal vein. Therefore, it was confirmed that vascular abnormalities were associated with the unexplained renal hematuria in these cases. Since these congenital anomalies might easily induce congestion in the renal venous system they might be the predisposing condition of the renal hematuria. Epinephrine-assisted renal phlebography has been a useful technique to detect anomalies of the venous system.