Extracorporeal Shock Wave Lithotripsy Success Rate and Prognostic Factors

Background: Urinary tract stones are common urological problems with a considerable burden worldwide. Management strategies mostly rely on the stone’s characteristics and the patient’s clinical conditions. Extracorporeal shock wave lithotripsy (ESWL) is a method of choice for managing small calculus. However, the success rate of ESWL and the prognostic factor of success widely vary among different studies. The aim of the present study was to evaluate these prognostic factors in an Iranian population undergoing ESWL. Methods: The present retrospective study was conducted in Imam Ali Hospital of Bojnurd, Iran. Every patient who was referred for the ESWL of distal urethral calculus (5-20 mm) and failed to respond to medical treatment enrolled in this study. The prevalence and relationship between various individual factors and ESWL outcomes were evaluated among the study patients. Results: Among 49 patients (24 males and 25 females) who had urinary tract stones, the mean ( ± standard deviation) of age was 42.7 (14.04) years. ESWL could successfully treat urinary tract stones in 43 patients (85%). The kidney stone diameter was not related to having a successful procedure (P = 0.447). Moreover, the stroke number and receiving tamsulosin were not significantly associated with favorable ESWL outcomes (P = 0.909 and P = 0.590, respectively). Twenty-seven patients (45.1%) received pethidine during the procedure. There was a significant relationship between receiving analgesics and favorable ESWL outcomes (P = 0.033). Conclusion: The results demonstrated that 85% of the distal urinary tract stones that are smaller than 20 mm can be successfully managed by ESWL, and providing analgesics was significantly related to better outcomes.