Bozzini G, Aydogan TB, Müller A, et al. - A prospective multicenter randomized comparison among Percutaneous Lithotripsy (PCNL), MiniPerc (MP) and UltraMiniPerc (UMP) for lower calyceal stones between 1 and 2 cm according to CT scan was conducted to assess the safety and effectiveness of these procedures. One hundred thirty-two consecutive patients with single lower calyceal stone were recruited between January 2015 and June 2018. Study participants were randomized in three groups; A: PCNL; B: MP; C: UMP. Patient characteristics, stone free rates (SFR) s, complications and re-treatment rates have been analyzed. The mean stone size in Group A, B and C were 16.38, 16.82 and 15.23 mm, respectively. PCNL and MP demonstrated greater effectiveness to achieve a better SFR than UMP. The auxiliary and re-treatment rates in UMP were higher. On the other hand, PCNL had more complications for this kind of stone. The overall assessment favors MP in stones 1–2 cm in size as a better indicator.