Mechanical percussion inversion can result in relocation of lower pole stone fragments after shock wave lithotripsy

Objectives. To determine whether mechanical percussion combined with invers ion (MPI) therapy and forced diuresis can move stone fragments out of the l ower 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 proto col. Eleven patients received 20 mg of furosemide before MPI therapy. Patie nts were treated in the prone Trendelenberg position on a pivoting stretche r and given 10 minutes of percussion over the flank using a mechanical ches t physiotherapy percussor. Stone location was documented with plain abdomin al radiographs before, immediately after, and 2 weeks following MPI therapy . Voided urine was strained immediately after MPI therapy and throughout th e study period. Results. Abdominal radiographs before and after treatment demonstrated move ment 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-treat ment film. Four patients passed stone fragments in their first voided urine . Ten patients passed stone fragments during the a-week follow-up period. Conclusions. MPI therapy combined with diuresis can effectively mobilize st one fragments out of the lower pole calyces and appears to aid in the passa ge of fragments. (C) 2000, Elsevier Science Inc.