Diagnosis and treatment of acute obstructive ureteral calculi by delayed filling after intravenous urography:report of 39 cases

Objective To summarize the experience of locating ureteral calculi by delayed filling of involved ureter from 4h to 48h after intravenous urography (IVU) and carrying out extracorporeal shockwave lithotripsy (ESWL) under X-ray in patients with renal colic. Methods Thirty-nine patients with acute renal colic, who were found light hydronephrosis by B-ultrasound but not calculi by KUB, were underwent IVU. In 60 min the involved kidneys were not filled with contrast medium or appeared as renal parenchyma visualization. As the ureteral spasm was relieved, renal parenchyma visualization and the following filling of pelvis and ureter above the calculi were observed under X-ray from 4h to 48h after IVU. Then the ureteral calcali were located and lithotritized by ESWL. IVU and B-ultrasound were re-examined after the calculi were discharged to determine whether the involved renal function recovered.Results The calculi of all the 39 patients, which were located poorly or impossibly by IVU, could be quickly located by delayed filling from 4h to 48h after IVU and lithotritized. During lithotripsy contrast medium could be seen clearly to pass the obstruction. Renal colic symptom remissed quickly. All the patients discharged the calculi in 2 weeks. Twenty-three of them re-examined IVU from 2 weeks to 3 months after dischargement and the involved kidneys and ureter were showed no problem.Conclusions The un-filled kidneys caused by acute obstructive ureteral calcali can be filled with contrast medium from 4h to 48h after IVU. Then the obstructive calculi can be located and lithotritized by ESWL, which can remiss the clinical symptom promptly and relieve the obstruction.