A PROSPECTIVE TRIAL COMPARING THE EFFICACY AND COMPLICATIONS OF THE MODIFIED DORNIER HN3 AND MFL-5000 LITHOTRIPTORS FOR SOLITARY RENAL CALCULI

A prospective randomized study of 198 patients was conducted to compar e the efficacy of the modified Dornier HM3 lithotriptor to the MFL 500 0 lithotriptor. Entrance criteria included solitary stones at any loca tion within the upper collecting system that had not previously been t reated with lithotripsy. Following lithotripsy the patients were evalu ated by a blinded radiologist with a plain abdominal film, tomograms a nd renal ultrasound at 1, 4 and 12 weeks. Patients were classified at 12 weeks after lithotripsy as failing treatment if any stone fragments were imaged. Of the patients 170 were available for complete 3-month followup, No statistical or clinical difference in stone-free rates wa s apparent for calculi in the ureter or renal pelvis in either group. Of patients with lower caliceal stones 80% had no residual fragments v isualized at 12 weeks when treated with the modified HM3 device versus 56% with the MFL 5000 lithotriptor (p = 0.05). Treatment time on the MFL 5000 unit was significantly prolonged compared with the modified H M3 device (0.7 hours versus 0.4 hours, respectively) resulting in fewe r patients being treated in a given day (p<0.001). No statistical diff erence in complication rates could be found between the 2 machines, St einstrasse were noted in 10% of the patients treated with the modified HM3 device and 6% of the MFL 5000 group, Subcapsular hematomas were n oted in 4% of the MFL 5000 treatment arm compared to 1% in the modifie d HM3 group, Overall, the MFL 5000 lithotriptor was believed to offer no significant clinical advantage over the modified HM3 device in term s of lithotripsy efficacy, although the multifunctional table did offe r more versatility for stone treatment, For a busy lithotripsy center, the modified HM3 lithotriptor is still the most efficacious.