Comparing the Efficacy of a Multimodular Flexible Ureteroscope With Its Conventional Counterpart in the Management of Renal Stones

Abstract

To report our prospective comparison of clinical efficacy between multimodular flexible ureteroscope, PolyScope, and conventional flexible ureteroscope, both combined with holmium laser lithotripsy in managing renal stones<3cm in diameter. Between February 2011 and July 2014, a total of 360 adult patients with renal stones were randomized in a single tertiary-care center trial. For 180 patients in each arm, flexible ureteroscopy and holmium laser lithotripsy were done with either PolyScope or Olympus URF P-5 as control. The primary end points were single-session stone fragmentation rate and stone-free rate. The secondary end points comprised operation time, complication rate, and hospital stay. Demographic and preoperative parameters were comparable between 2 groups. For stones of different locations and sizes, single-session stone fragmentation rate of PolyScope was similar to that of URF P-5. However, for lower calyceal stones, URF P-5 was significantly better than PolyScope (82.0% vs 69.2%; P=.022). No statistically significant difference existed in single-session or overall stone-free rate, complication rate, and hospital stay. Mean operation time of PolyScope group was 92.6±20.2minutes, 9minutes (10.8%) longer than that of URF P-5 group 83.3±17.1minutes (P<.01). PolyScope demonstrates similar overall stone clearance rate to a conventional flexible ureteroscope in managing renal calculi<3cm in diameter, but for lower pole stones, it is of inferior efficacy and it is more skillfully demanding, taking longer operation time.