As current endourologic treatment for upper urinary tract stones has been dramatically improving, first standard treatment for over 2cm renal stone still remains percutaneous nephrolithotomy (PNL). The current instruments of PNL have changed and developed to miniaturization such as mini-PNL, ultramini-PNL, and micro- PNL. However, even if tract sheath size used in PNL is smaller, it is possible to occur various complications when you make a false step to perform the procedure. The first critical step in PNL is definitely “percutaneous puncture” with needle. It’s no exaggeration to say that the success of PNL procedure is influenced by the skill of percutaneous puncture.
