PURPOSE:In this study, we present our experience using balloon and Amplatz dilatation to establish a percutaneous tract. We also discuss advantages and risk factors of both techniques. MATERIALS AND METHODS:We retrospectively reviewed medical records of 229 patients who had undergone 235 percutaneous nephrolithotomy procedures. The nephrostomy tract had been dilated using a balloon (42 patients) or Amplatz (187 patients) dilator. Total operating time, preoperative and postoperative hemoglobin concentrations, number of tracts required, stone burden, blood transfusion rates, tract dilatation failures, and the cost of the dilatation system were compared between the groups. RESULTS:There were no statistically significant differences in operative time (85.7+/-43.2 v 86.3+/-41.2 minutes; P=0.42), preoperative hemoglobin concentration (14.1+/-1.1 v 13.8+/-1.4 mg/dL; P= .153), postoperative hemoglobin concentration (11.6+/-1.7 v 11.2+/-1.5 mg/dL; P= .601), or blood transfusion rate (18.6% v 21.3%; P= .687) between the two groups. Also, there were no differences in failure rates between the two groups. CONCLUSIONS:The Amplatz dilator is comparable with the balloon dilator with regard to efficacy, speed, and safety. The Amplatz dilator is more cost-effective than the balloon dilator. However, kidney hypermobility may be a significant problem during Amplatz dilatation.