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With the advent of laser lithotripsy and miniscopes for the treatment of ureteral calculi, ultrasonic lithotripsy has lost its function as a universal lithotripsy system, as its probes are not compatible with the miniscopes. Still, laser lithotropsy has its disadvantages: purchase costs are high and the low fragmentation rates make it unsuitable for the primary treatment of bladder calculi and staghorn stones in the kidney. Thus, there is a continuing need for a universal lithotripsy system providing both miniaturized probes and high stone ablation rates.

Insertion of a ureteral stent prior to extracorporeal shock-wave lithotripsy (ESWL) results in a significant decrease in post-procedural morbidity when large stones (>2 cm) are treated (1). As a consequence, indications for ESWL monotherapy have been redefined and extended towards patients with a large stone burden. Moreover, with the introduction of second-generation lithotripters (2) and the upgraded Dornier HM-3 (3), anesthesia-free lithotripsy became available, thus adding further to the attraction of ESWL.

Thirty patients with staghorn stones were treated with a combination of extracorporeal shock wave lithotripsy (ESWL) followed by hemiacidrin irrigation. Following the insertion of one or two small percutaneous nephrostomy catheters and a double-J stent, disintegration of the stone was performed with a Dornier HM lithotripter equipped with a 15.6 cm ellipsoid and standard generator (80 nanofarad) system. Immediately after ESWL, irrigation with 10% solution of hemiacidrin was initiated. Treatment was continued until the patients were either stone free or only had small residual fragments no longer affected by hemiacidrin.

DR GRIFFITH: Our Round Table will focus on secondary stone formation. DR WERNESS (ROCHESTER, Ma. USA) has presented an overview of triamterene stones. Now our discussion will target upon infection stones. There seems to be a general consensus that the bacterial enzyme urease is primarily responsible for struvite and carbonate apatite stones in humans.

Herein we describe the fate of 48 staghorn stones treated primarily with extracorporeal shock wave lithotripsy (ESWL) within an observation period of up to three years. Thirty patients (61%) who became stone free within eight months had two recurrences (6%) and were retreated within two years. Of 18 patients with residual stones, ten became symptomatic and needed auxiliary treatment, and nine eventually were rendered stone free. At 24 months, 84% of the original 48 patients were stone free, and the remainder were free of symptoms. Based on these observations, our approach to staghorn stones has been modified with regard to stone and patient-related parameters, such as stone burden, upper urinary tract anatomy, stone composition, and patient compliance.

The safety and effectiveness of the first-generation Dornier HM3 lithotripter has been well established. The Siemens ‘Lithostar’ is a second-generation machine which produces the shock wave by an electromagnetic induction in a water-filled tube, thereby avoiding the need for a water bath. Stone localization is achieved by bi-planar x-rays.

Extracorporeal shock-wave lithotripsy has revolutionized the management of urinary calculi. The first-generation shock-wave devices with a spark-gap as an energy source still have significant disadvantages. These concern the potential risk to the patients, the need of anesthesia, x-ray exposure, and technical aspects such as mobility, necessity of additional staff, and high running costs. Therefore, a second-generation extracorporeal piezoelectric shock-wave lithotripter (EPL) was designed and developed at the Clinic of Urology, University Homburg/Saar, FRG.