Current ureteroscopic intracorporeal
lithotripsy devices and stone retrieval technology allow for the treatment of
calculi located throughout the intra-renal collecting system. Difficulty accessing lower pole
calculi, especially when the
holmium laser fiber is utilized, is often encountered. Herein we review our experience where lower pole
renal calculi were ureteroscopically managed by
holmium laser fragmentation, either in situ, or by first displacing the stone into a less dependent position with the aid of a
nitinol stone retrieval device. Lower pole stones less than 20 mm can be primarily treated by ureteroscopic means in patients: that are obese; have a
bleeding diathesis; with stones resistant to shockwave
lithotripsy (SWL); with complicated intra-renal anatomy; or as a salvage procedure after failed SWL. Lower pole
calculi are fragmented with a 200 microm
holmium laser fiber via a 7.5 F flexible
ureteroscope. For those patients where the
laser fiber reduced ureteroscopic deflection, precluding re-entry into the lower pole calyx, a 1.9 F
nitinol basket is used to displace the lower pole
calculus into a more favorable position, thus allowing for easier fragmentation. A
nitinol device passed into the lower pole, through the
ureteroscope, for stone displacement cause only a minimal loss of deflection and no significant impact on irrigation. Eighty-five percent of patients were stone free by IVP or CT scan performed at 3 months. Ureteroscopic management of lower pole
calculi is a reasonable alternative to SWL or
percutaneous nephrolithotomy (PNL) in patients with low volume stone disease. If the stone cannot be fragmented in situ,
nitinol basket or grasper retrieval, through a fully deflected
ureteroscope, allows for repositioning of the stone into a less dependant position, thus facilitating stone fragmentation.