[Techniques for percutaneous access during percutaneous nephrolithotomy.].

The creation of the access is one of the main steps in percutaneous nephrolithotomy, the most complicated for many urologists and the one that limited most the universalization of the technique. From a purely technical point of view, it includes puncture of the excretory tract and dilatation of the percutaneous tract to end with the introduction of an Amplatz type working sheath. The objective of the puncture is to try to access the excretory system through the renal papilla, minimizing the risk of bleeding. The puncture may be guided by ultrasound, fluoroscopy, both, under endoscopic or laparoscopic control, by CT scan or MRI, or even by application of new technologies (Robotic, augmented reality, electromagnetic navigation,...). Due to the versatility and independence involved in having the ability to perform the renal puncture in the operative room, as well as its influence in the results of PCNL, it must be the urologist himself who performs this basic step of percutaneous surgery. The tract may be dilated by Alken type metallic dilators, semirrigid Amplatz type dilators or high pressure balloons. To date, there is no single ideal dilatation method, being the selection based on the endourologist's experience and the knowledge of the advantages and limitations of each option. The objective of this review is to present the main methods for puncture guiding and tract dilatation for PCNL, as well as to provide technical details to improve its result.