CYSTINE STONES - THE EFFICACY OF PERCUTANEOUS AND SHOCK-WAVE LITHOTRIPSY

Cystinuria is a rare cause of renal calculi, whose management presents a complex problem mainly due to the hardness and high recurrence rate of cystine stones. During the period 1987-1991, 28 established cases of cystine calculi were treated by extracorporeal shock wave lithotrip sy (ESWL) and percutaneous nephrolithotripsy (PCNL). These cases were divided into 5 groups, according to the position and size of the stone s, and each group then followed a specific regimen, either ESWL monoth erapy or a combined treatment comprising an initial ESWL treatment fol lowed by PCNL or vice versa. ESWL monotherapy provided satisfactory re sults only in the group with pelvic stones (54.5% success rate), with 2.16 stone treatments/renal unit, and only with calculi smaller than 2 .5 cm. The groups with multiple stones or staghorn calculi were treate d with a combined treatment of ESWL and PCNL and had success rates of 50 and 67%, respectively. However, the group in which PCNL was followe d by ESWL showed a clear advantage over the group in which ESWL was ad ministered before PCNL, since it required a smaller number of ESWL tre atments (1,5 stone treatments/renal unit as compared to 4.3 stone trea tments/renal unit). Finally, attempts for ESWL in situ in the few case s of ureteral stones proved unsuccessful.