Extracorporeal shock-wave lithotripsy for small symptomatic renal calculi: is it effective?

Renal calculi with a diameter of less than 5 mm can pass spontaneously. However, some patients have small symptomatic renal calculi for more than 3 months. We evaluated the results of extracorporeal shock-wave lithotripsy in 38 patients with such stones. Patients presented with loin pain, hematuria, infection, or a combination of complaints. Average stone size was 18 mm2. After a wait of 3 months for spontaneous evacuation without success, all patients were treated with a Siemens Lithostar. Three months after treatment, 19 patients (50%) were completely free of stones, but 7 still had complaints; of the 19 patients with residual fragments, 8 (42%) were free of complaints. Both evacuation and resolution of complaints were achieved in only 12 of the 38 patients (32%). We conclude that one should be reluctant to treat small renal calculi, because spontaneous evacuation occurs in about 80% and the results of treatment are restricted.