Endoscopic surgery for urolithiasis: what does "stone free" mean in 2012.

There is still an ongoing debate regarding the optimal endourological treatment of upper urinary tract lithiasis, a significant parameter being the stone free rate. However, despite the apparent simplicity of notions such as stone free or success rate, when analyzing the available literature one may discover the complex, intricate and debatable issues behind them. The main problems reside in the heterogeneous way of defining intervention success, the timing at which a patient is considered stone-free and also in the lack of standard postoperative evaluation of patients with urolithiasis. A review of the literature in regard of these notions was performed, in order to identify methods to improve the standardization of these notions.