Treatment of urethral stones by retrograde manipulation and extracorporeal shock wave lithotripsy.

Abstract

To assess the effect of retrograde manipulation and extracorporeal shock wave lithotripsy (ESWL) as a monotherapy for urethral stones that are not associated with urethral strictures. Between August 1993 and January 1995, 34 male patients (mean age 38.7 years, range 7-55) presented with urethral stones. No patient had a suggested or past history of urethral stricture. Lidocaine jelly (2%) was instilled and retained inside the urethra for 5 min. A 16 F urethral catheter was advanced gently to push the stone back to the urinary bladder. Twenty patients had ESWL of their stones in the bladder, using a Storz Modulith SL20, in the prone position. Tilting the patient about 15 degrees towards the side with the stone minimized movement of the stone during fragmentation. In-line co-axial echography (3.5 MHz) and intermittent pulsed fluoroscopy were used to monitor stone fragmentation. In situ fragmentation of posterior urethral stones was not possible because localization was difficult and the treatment was painful. Thirteen patients had cysto-urethroscopy and mechanical cystolitholapaxy under general anaesthesia. Stones impacted in the posterior urethra in 31 (91%) patients and in the anterior urethra in three (9%) patients. Stones ranged in size from 7 to 25 mm. One patient expelled an anterior urethral stone after the instillation of 2% lidocaine jelly. The urethral stones were pushed back to the bladder without complication in the remaining 33 patients. All 20 patients except one had their stones fragmented by ESWL in one session. The mean number of shock waves was 3600 +/- 1480 (range 1200-6000) and the generator voltage ranged between 5 kV (560 bar) to 8 kV (940 bar). No patient in the ESWL group required anaesthesia or analgesia. Thirteen patients had successful mechanical cystolitholapaxy with no complications. Both endoscopic lithotripsy and ESWL of urethral stones are safe and effective. However, transurethral lithotripsy requires general anaesthesia and carries a risk of bladder and urethral trauma. This study demonstrated that, in the absence of urethral stricture, urethral stones can be pushed back safely to the urinary bladder and fragmented effectively by ESWL. The success of the treatment depends on adequate anaesthesia of the urethra before inserting the urethral catheter. We propose that this new technique should be considered before resorting to endoscopic or surgical management of urethral stones, particularly in children.