The 3-finger technique in establishing percutaneous renal access: a new and simple method for junior trainees

Urology trainees may lack experience in gaining renal access during percutaneous nephrolithomy (PCNL). Establishing the correct depth of initial percutaneous needle insertion is one of the major obstacles. As such, we have identified an easy technique, which can be performed, to establish correct depth adjustment allowing easier access.

An initial attempt is made to insert the percutaneous needle into the desired posterior calyx in the antero-posterior (AP) plane. If the needle does not traverse into the desired calyx immediately, it is concluded that the needle track must be too shallow or too deep. The C-arm is then rotated 20 to 30 degrees from the vertical, in the axial plane, towards the operating surgeon and, using the image intensifier, very careful note is made of the end of the needle in this plane, compared with the end of the needle initially in the AP plane, to see if it has moved "medially" or "laterally." The 3-finger technique is then performed by the surgeon, to establish if the needle path is too deep or too shallow. This technique is currently being performed by trainees under direct consultant supervision with 13 successful cases so far.

The 3-finger technique has been successfully used to demonstrate and teach PCNL access to urology trainees. In all 13 cases, percutaneous renal access was achieved successfully by trainees without immediate or late complications. Also, positive and encouraging feedbacks were received from those trainees, and all expressed willingness to continue using the same new technique in the future.

Our new technique is cheap, safe, easy to learn and use, and of particular benefit to junior trainees who are beginning to perform PCNL access.