Efficacy of Dretler Stone Cone in the Treatment of Ureteral Stones with Pneumatic Lithotripsy

Introduction: Ureteroscopic pneumatic lithotripsy has been used to treat ureteral calculi for more than 10 years. Owing to its low price and high degree of effectiveness, it has become the most popular ureteroscopic lithotripsy device in use worldwide. The major limitation of the technique is the occurrence of proximal fragment migration during intracorporeal lithotripsy. The Dretler Stone Cone is a new device developed to prevent stone migration during ureteroscopic lithotripsy. The aim of this study was to assess the efficacy and safety of this device during ureteroscopic pneumatic lithotripsy. Patients and Methods: Twenty-three consecutive patients having ureteral stones were treated with a 10-Fr semirigid ureteroscope, a Stone Cone™ Nitinol Retrieval Device, and a pneumatic lithotriptor. In all patients Stone Cones were placed under visual guidance through the working channel of the ureteroscope. Outcomes of this device were then compared with the outcomes of 23 previous patients with stones of similar sizes and locations who had undergone ureteroscopic pneumatic lithotripsy prior to the Stone Cone being available at our clinic. Results: All patients in the study group were stone-free after the procedure. No stone fragments were noted to migrate to proximal segments. Conclusions: The Dretler Stone Cone effectively prevents proximal stone migration and facilitates stone fragmentation during pneumatic lithotripsy with no risk of ureteral injury. It has only a small extra cost.