Renal stone fragments following shock wave lithotripsy

We describe a select group of asymptomatic patients with fragments and dust 3 months after extracorporeal treatment, who were followed to evaluate the long-term outcome and therapeutic implications.

A total of 129 patients with dust and residual fragments (less than 4 mm.) at 3 months was re-examined at 12 months, and 95 were also evaluated at 24 months. Followup examinations consisted of radiographic studies, renal ultrasonography and urine culture. Dust and residual fragments were sought, and patients were defined as free or as having persistent lithiasis or stone regrowth. At 24 months recurrences in the patients stone-free at 12 months also were considered.

At the 12-month followup 60 patients (46.5%) were stone-free and 56 (43.5%) still had dust or residual fragments. The localization of the stones or fragments at 3 months and their sizes did not have a significant influence on the stone-free rate but regrowth was greater in patients with stones larger than 10 mm. (11 of 40 patients, 27.5% versus 2 of 89, 2.2%, p = 0.001). The probability of eliminating residual lithiasis at 12 months was significantly greater in patients with dust than in those with residual fragments (42 of 79 patients, 58% versus 18 of 50, 36%, p = 0.026). Regrowth of residual lithiasis was observed in 13 patients (10%).

Based on our results, we do not believe that patients with fragments require systematic re-treatment in the short term but they may be followed long term and re-treated if symptoms persist or stones recur.