A comparison of metal telescopic dilators and Amplatz dilators for nephrostomy tract dilation in percutaneous nephrolithotomy.

BACKGROUND AND PURPOSE: Nephrostomy tract dilation is one of the important steps in percutaneous renal surgery. We present our experiences with using Amplatz and metal telescopic dilators (Alken) to create a percutaneous tract and compare the advantages and risk factors of both procedures.

PATIENTS AND METHODS: We retrospectively reviewed the medical records of 173 patients who had undergone 188 percutaneous nephrolithotomy procedures between April 2007 and December 2010. The nephrostomy tracts had been created by using Amplatz (67 cases) or Alken dilators (121 cases). Total operative time, scope time, tract formation time, decrease in hemoglobin concentrations, blood transfusion rates, tract dilation failures, and the cost of both systems were compared between the groups.

RESULTS: There were no statistically significant differences in total operative time (103.3 ± 46.5 vs 99.1 ± 44.4 min, P=0.583), scope time (5.23 ± 3.06 vs 5.28 ± 2.52 min, P=0.732), decrease in hemoglobin concentration (-1.5 ± 1.2 vs-1.3 ± 1.1 mg/dL, P=0.230), blood transfusion rates (13.4% vs 11.6%, P=0.709), and tract dilation failure rates (6.0% vs 1.7%, P=0.107) for Amplatz and Alken dilation groups, respectively. A shorter tract formation time (6.56 ± 3.04 vs 5.42 ± 3.07 min, P<0.001) was observed in the Alken dilation group. The approximate costs per each case were $220 and $7.25 for Amplatz and Alken dilation groups, respectively.

CONCLUSIONS: The Alken dilation technique produces similar results to the Amplatz dilators in terms of efficiency, safety, and total operative time. Notwithstanding, it is more cost-effective in comparison.