Comparison of Extracorporeal Shock Wave Lithotripsy and Percutaneous Nephrostolithotomy for the Treatment of Renal Calculi in Lower Pole Calices

Abstract

Lower pole calyceal calculi can be treated by percutaneous nephrostolithotomy (PCNL) or by extracorporeal shock wave lithotripsy (ESWL^†). In previous studies investigators have noted that stones in lower calices treated with ESWL have a poor clearance rate. This study compared PCNL and ESWL treatments for solitary lower calyceal stones. Thirty-five patients with lower pole calyceal stones were treated with ESWL (Dornier HM3), and 29 patients were treated with PCNL between March 1983 and January 1988. Pretreatment intravenous pyelograms of the ESWL patients were examined, and the length and width of the lower pole infundibulum were recorded. The mean stone diameter was 9 mm (range, 3 mm to 30 mm) in the ESWL group and 10 mm (range, 4 mm to 27 mm) in the PCNL group. All patients in the ESWL group had adequate stone fragmentation (particles < 4 mm). Stone composition was similar for the two groups. A KUB was obtained at a median follow-up of 13 months in 94% of ESWL patients and 90% of PCNL patients. There was a 59% stone-free rate for the ESWL group and an 85% stone-free rate for the PCNL group. The ESWL stone-free rate did not correlate with infundibular width or infundibular length. The ESWL patients spent 2.5 days in the hospital y 6.1 days for the PCNL patients. The PCNL patients had a two-fold greater recovery time (19.3 days y 10 days). Interestingly, there was no difference between the two treatment groups in regard to recurrent stone disease; 10% of ESWL patients had a recurrence within 18 months, and 11% of PCNL patients had a recurrence with 22 months following treatment.

PCNL for calyceal stones is more invasive, has a higher morbidity, and is associated with more serious complications than ESWL. Thus, PCNL should be reserved for patients with small stones who fail primary ESWL therapy.