Success Rate of Stone Recurrence after Extracorporeal Shockwave Lithotripsy and Factors affecting Success of Treatment among Egyptian Patients

Objectives: To evaluate the factors that affect the success rate of ESWL for treatment of renal stones and to estimate the prevalence of stone recurrence during a 1-year period. Materials and Methods: During the period of January, 2010 and December, 2010, prospective study of 142 subjects with single or multiple renal stones (<30 mm, largest diameter) undergone ESWL monotherapyby SiemensLITHOSKOP lithotriptor. The results of treatment were assessedafter a follow-up period of 3 months. Treatment success was a complete clearance of the stones or presence of insignificantresidual fragments<4 millimeters. Correlation of the success rate with the characteristics of the subjects, conditionsof the urinary tract and features of the stone was done. Results: During the 3-months follow-up period, the success rate was 111/142 (78%). Retreatment was needed in 75 patients (52.8%). Post-treatment procedures were done in 12 subjects (8.4%). Post-ESWL complications were observed in 5 subjects (3.5%). Out of 10 prognosticfactors studied, 5 had a powerful influence on the success rate, which are: renal morphology, presence of congenital anomalies, size of stone, site of stone and treated stones number. Other factors including age, sex, nationality, stonenature (de novo or recurrent) and ureteric stenting had no significant impact on the success rate. Conclusions: Prediction of success of treatment with ESWL and the recurrence depends and may be predicted by renal morphology, presence of congenital anomalies, size of stone, site of stone and treated stones number.