University of Virginia Lithostar Experience: Preliminary Report

Abstract

The Siemens Lithostar system consists of a motorized patient table, two integral electromagnetic shock wave generators, and biplane fluoroscopy for stone localization. Shock wave coupling is through water-filled bellows attached to the shock tubes. Seven of the first 30 patients (21%) required more than one treatment, even though the mean stone size was less than 13 mm. Seven other patients had poor fragmentation: all had 4 mm to 5 mm fragments. The mean number of shock waves delivered was 3,100.

The unit was realigned six weeks after the first patient was treated. Pulverization was excellent in the first 30 patients who were treated after this optimization procedure. Mean stone size was 10 mm, and the mean number of shock waves delivered was 2,700.

The Lithostar can effectively pulverize most upper urinary tract calculi. The modest shock wave pressures minimize the need for anesthesia but may hinder the treatment of impacted ureteral stones or difficult-to-fragment renal calculi.

The first extracorporeal shock wave lithotripter to use electromagnetic shock wave generation was developed by the Siemens Corporation at the Department of Urology of Mainz University under the direction of Prof. Rudolf Hohenfellner.¹ Clinical trials were initiated in 1986 in West Germany. The first two Lithostars in the United States were installed at the Washington University School of Medicine in St. Louis and the University of Virginia School of Medicine in Charlottesville, Virginia. Clinical trials began at the University of Virginia on March 3, 1986.