The Efficacy of a Combined Pneumatic/Ultrasound Device in Percutaneous Nepholithotripsy

Purpose. Percutaneous nephrolithotripsy (PCNL) is widely accepted as the procedure of choice for removing large, complex renal calculi. A ”2 in 1” pneumatic/ultrasonic intracorporeal lithotriptor has been developed for PCNL procedures. It combines the stone clearing efficiency of an ultrasonic device with the fragmentation strength of a pneumatic probe into a single handheld unit. We present our clinical experience with this device in a prospective randomized comparison of the combined lithotriptor ”2 in 1” ”Swiss Lithoclast Master” with individual ultrasonic and pneumatic devices in performing lithotripsy. Methods. A total of 40 consecutive patients aged 48 to 71 years (mean: 59.9 yr; 28 men and 12 women) underwent PCNL to treat symptomatic calculi from April 2003 to August 2004. Patients were randomized into two comparable groups; 20 patients in group one underwent PCNL with the combined pneumatic/ultrasonic device while 20 patients in group two underwent PCNL with individual ultrasonic and pneumatic components. The stone burden was assessed before and after the operative procedure. The stone clearance rate in mm^2 per minute was calculated for these two groups. Complications and stone-free rates were also compared between the groups. Results. There were no significant differences in stone location or stone composition between the two groups of patients. The duration of the operation for complete stone clearance was considerably less with the combined device (40.5±10.1 vs 65.5±24.7 mm, p=0.01). Furthermore, the stone clearance rate was much higher with the new ”2-in-1” lithotriptor (23.5±10.1 vs 12.4±5.0 mm^2/min, p=0.006). Hydrothorax was noted in one patient who underwent treatment with the ”Swiss Lithoclast Master”, but it was not attributed to the device. Conclusions. The new combined lithotriptor ”2 in 1” ”Swiss Lithoclast Master” is able to disintegrate and extract stone material more rapidly than individual ultrasonic and pneumatic devices. The Swiss Lithoclast Master appears to be efficacious and safe for removing large renal calculi.