Unusual collecting system anatomy, in particular infundibular stenosis, often precludes successful elimination of stone fragments following ESWL and URSLL, again making PCNL the better choice.

Finally, congenitally abnormal kidneys, such as horseshoe kidneys and pelvic kidneys, usually have anteriorly located ureteropelvic junctions, which can make spontaneous passage of stones after ESWL and ureteral extraction of stones during URSLL very challenging. The unusual position of the ureteropelvic junction, along with the collecting system dilation that often accompanies these ectopic kidneys, makes PCNL the preferred choice.

TECHNIQUE

Patients scheduled for PCNL must have a documented sterile urine culture because PCNL in the setting of urinary tract infection can lead to urosepsis. The procedure is performed under general anesthesia, and the patient is typically prone. More recently, however, techniques have been described in which PCNL is performed in the supine and flank positions.