[A technical device for the percutaneous extraction in monobloc of various renal calculi larger than 10 mm].

The authors present a technical device consisting of a modification of the operating channel for stone extraction by percutaneous nephrostomy. For selected stones, widening of the lips of the operating channel allows the stone to be rapidly and entirely removed without the need for ultrasound or hydroelectric fragmentation, which is always associated with a risk of leaving residual fragments. The aim of this technical device is to ensure complete absence of residual fragments with a minimum of risks for the renal parenchyma.