Extracorporeal Shock Wave Lithotripsy in Adult Patients: Factors Affecting the Success of the Procedure in Kidney Stones

Aim: Our aim was to investigate the factors affecting the stone-free rate in patients treated with shock wave lithotripsy (SWL) using Dornier Compact Sigma. Methods: The clinical outcomes of 371 patients treated with SWL between March 2007 and June 2008 in our clinic were retrospectively analyzed. We evaluated the effects of patient's age and gender, stone size and localization, use of double-J stent prior to SWL, and previous ipsilateral renal surgery on stone-free rate after SWL. Chi-square, Mann-Whitney U and Student's t-tests were used for statistical analysis. Results: The mean age and stone size were 43.83 +/- 13.79 years and 1.20 +/- 0.41 cm, respectively. Of the stones, 24.5% were less than 1 cm, 66.6% between 1 and 2 cm, and 8.9% were greater than 2 cm. Of these stones, 152 (40.9%), 66 (17.8%), 52 (14.1%), 89 (24%), and 12 (3.2%) were located in the renal pelvis, upper, middle, lower calices, and in the ureteropelvic junction, respectively. While stone-free status was achieved in 291 (78.43%) patients, clinically significant residual stones were observed in 80(21.57%) patients. The mean stone size was 1.18 +/- 0.38 cm in patients who were stone-free and 1.31 +/- 0.44 cm in patients with residual stones after SWL treatment (p=0.008). Conclusion: Success rates are satisfactory after performing SWL using Dornier Compact Sigma. The most important factor affecting the success rate is the stone size. However, auxiliary treatment alternatives are needed in approximately one-tenth of patients.