Permanent impairment of renal function demonstrated by renographic follow-up in ureterolithiasis

In a prospective study, 358 consecutive patients with radiopaque ureteral stone, verified by intravenous urography were renographically followed up until the stone had left the ureter. Impairment of the renal parenchymal function was revealed in 91 patients. In 24 of them--7% of the total series--the impairment was still demonstrable after the latest examination, on average 17 months after passage of stone. Patients with large stone, or with stone lodged for a long time in the ureter, elderly patients and women predominated in the group with persistent impairment of renal function. The impairment was fairly mild in most cases. In some patients the renal function was severely impaired while the stone remained in the ureter, but subsequently normalized. Increased vigilance to prevent persistent renal damage is recommended, especially in patients with frequently recurrent ureteral stone.