When is ESWL of small calyceal stones indicated?

PURPOSE: To evaluate the indications for and the outcomes of extracorporeal shock wave lithotripsy (ESWL) of calyceal stones <5 mm, we prospectively studied a series of 25 patients scheduled for treatment. MATERIALS AND METHODS: Between January 1994 and June 1995, 15 males and 10 females with a mean age of 44 years (median 43; range 4 to 70 years) underwent ESWL of calyceal stones <5 mm using an unmodified HM3 Dornier lithotriptor. RESULTS: Indications for ESWL included 17 patients (68%) suffering from back and flank pain, 3 patients (12%) with gross hematuria and 1 patient (4%) with recurrent episodes of pyelonephritis. Six patients (24%) were asymptomatic. Evaluation 3 months after ESWL revealed that of the 17 patients with flank pain, 13 (76%) had complete resolution of pain and 4 (24%) had partial resolution of pain and there had been no further episodes of gross hematuria or pyelonephritis in the previously affected patients. At 3-month follow-up, of the 31 kidneys treated, plain radiography were available in 29; 20 (69%) were clear and 9 (31%) had small residual fragments. CONCLUSIONS: Calyceal stones <5 mm in maximum diameter can cause significant symptoms such as pain, hematuria and infection and should not be dismissed as inconsequential. When no other obvious cause is apparent, these small stones should be treated with a high likelihood of resolution of symptoms and clearance. ESWL should not be withheld in patients with small asymptomatic calculi who request or require treatment for fear of unexpected colic or stone growth.