Noninvasive management of obstructing ureteral stones using electromagnetic extracorporeal shock wave lithotripsy

BACKGROUND: Extracorporeal shock wave lithotripsy (ESWL) represents noninvasive management of urolithiasis. Since the first HM3 model, technological progress has improved the efficacy and safety of this treatment. The current study aimed to evaluate the role of ESWL as a first-line emergency therapy of renal colic due to ureteral stone with impaired renal function.

METHODS: This prospective study enrolled all the patients admitted from the emergency room with acute renal colic meeting the following criteria: serum creatinine level ranging from 1.5 to 2.5 mg/dl, hydronephrosis, ureteral stones 6 to 15 mm in size, body mass index less than 30, normal renal function at baseline, and no evidence of urinary tract infection. The patients were submitted to a single-session emergency treatment using Dornier Litothripter S. Follow-up assessment, performed at 24 and 72 h, included radiologic and ultrasound examinations with renal function serum assessment. The end points were a decrease in creatinine level and a stone-free condition.

RESULTS: A total of 40 patients were eligible for the study. The mean creatinine level at admission was 1.93 +/- 0.26 mg/dl. After the treatment, renal function recovery occurred for 34 subjects (85%), with a significant global decrease in creatinine levels (p = 0.00). The global stone-free rate 72 h after SWL was 67.5% (27/40). The patients with residual fragments were managed using re-SWL (n = 7) and endoscopic technique (n = 6).

CONCLUSIONS: Emergency SWL represents an effective tool in the treatment of ureteral stones with hydronephrosis and slight renal impairment. Although complete stone clearance after one treatment still remains a difficult target, the actual role of SWL in the management of acute obstruction is to obtain ureteral canalization and renal function recovery.