How can I get a renal access if I do not have an ultrasound and cannot opacify the collecting system? Another use of the hydrophilic guide wire

It is well-known that fluoroscopic guidance is the most commonly used imaging technique for percutaneous access to the kidney. However, we might encounter difficulties when attempting to establish the limits of the collecting system for a percutaneous puncture, especially in places where the use of ultrasound guidance in the operating room is limited. We aim to describe the use of a hydrophilic guide wire to delimit the collecting system when this becomes difficult with conventional techniques.