The modified ultra-mini percutaneous nephrolithotomy technique and comparison with standard nephrolithotomy: a randomized prospective study

To compare the success and complications of ultra-mini percutaneous nephrolithotomy (UPNL) and standard percutaneous nephrolithotomy (SPNL) techniques. We prospectively analyzed 50 patients who underwent SPNL, and 47 patients who underwent UPNL. The patients with a stone size equal to or smaller than 25 mm and we used flipping a coin as the randomization technique. The mean stone size was 20.9 ± 3.6 mm in SPNL, and 20.3 ± 3.0 mm in ultra-mini PNL groups. Stone free rates were 88 % (44/50 patients) and 89.3 % (42/47 patients) in SPNL and UPNL groups, respectively, without any significant difference in between (p = 0.33). No major complications were seen in the UPNL group. PNL has been modified into micro PNL and UPNL parallel to the technological advances to decrease the complications of PNL. When performed as we do UPNL may be an alternative method to SPNL without any additional smaller-calibred nephroscope and with a similar high success rate.