impact of stone composition on the results of extracorporeal shock wave lithotripsy of renal calculi

ABSTRACT

This retrospective study included 341 patients with renal stones treated on the Dornier MPL9000 lithotriptor utilizing ultrasound localization. The inclusion criteria were solitary renal pelvic stones with a stone burden of 1-2 cm, normal renal functions, absent or minimal dilatation of the pelvicaliceal system and documented stone composition. The patient's demographic data, ESWL parameters, treatment results and any recorded complications were documented. Fragment sizes were measured on the early post ESWL films and by passing the expelled gravels through a metal sieve with 3 mm pore. The X-ray diffraction technique was used for stone analysis. The final success was calculated on the basis of a stone free status at 3 months from the last ESWL treatment. Whewellite and struvite calculi required higher average number of shock waves and treatment sessions, shelved higher rates of residual gravels > 3 mm in diameter and significantly lower stone free rates compared to other stone compositions. Other stones did not show statistically significant difference among each other regarding these parameters