Objectives: To determine whether mechanical percussion combined with inversion (MPI) therapy and forced diuresis can move stone fragments out of the lower pole of the kidney.
Methods: Twelve patients with lower pole residual stone fragments at least 2 weeks after shock wave lithotripsy were treated using the following protocol. Eleven patients received 20 mg of furosemide before MPI therapy. Patients were treated in the prone Trendelenberg position on a pivoting stretcher and given 10 minutes of percussion over the flank using a mechanical chest physiotherapy percussor. Stone location was documented with plain abdominal radiographs before, immediately after, and 2 weeks following MPI therapy. Voided urine was strained immediately after MPI therapy and throughout the study period.
Results: Abdominal radiographs before and after treatment demonstrated movement of fragments out of the lower pole in 11 patients. In 8 patients, the lower pole appeared entirely clear of fragments on the immediate post-treatment film. Four patients passed stone fragments in their first voided urine. Ten patients passed stone fragments during the 2-week follow-up period.
Conclusions: MPI therapy combined with diuresis can effectively mobilize stone fragments out of the lower pole calyces and appears to aid in the passage of fragments.