Realtime Ultrasound-guided Percutanous Nephrolithotomy Using The Sonixgps Navigation Guidance Position System

Background and objective: PCNL is the treatment of choice for large renal stones at present. Proper primary access to the renal collecting system can highly influence the complication rate of PCNL and clinical outcomes of the patients. Nevertheless, obtaining an appropriate renal access remains the most difficult step of PCNL for many urologists. Ultrasonography as a common technology for puncture guidance and planning has been widely used. The primary advantages of ultrasonographic guidance include no ionizing radiation, no invasiveness, real-time visualization of surrounding structures, and detection of nopaque stones. Nevertheless, ultrasonographic guidance only offers two dimensional images, and it is difficult to observe the whole length of the puncture needle. The urologist, especially the beginner, may misjudge the position of the needle tip under ultrasonographic guidance, easily causing a deeper puncture than anticipated. The Sonix GPS needle tracking system can display current and predict needle tip position at all times on the ultrasonography screen, thus enabling the operator to optimize the ultrasonographic image for the highest confidence in target visualization during advancement. We report our experience and evaluate the efficacy and safety of real-time ultrasonography-guided PCNL using Sonix GPS navigation in patients with kidney stones and compared it with normal ultrasonography.Materials and Methods: From December 2012 to May 2013 50 patients with kidney stones was performed PCNL in our hospital, the Sonix GPS needle tracking system was used for real-time ultrasonography-guided puncture during PCNL in 25 patients(Sonix GPS group), 25 patients was punctured under normal ultrasonography(normal ultrasonography group). All the patients were under general anesthesia, in prone position; holmium laser lithotripsy was used in all patients after renal access was established.Results: PCNL was performed successfully by a single puncture in all 25 patients in both group. There was no injury to the adjacent organs or vessels in all 50 patients. The puncture time and operation time is shorter in Sonix GPS group than normal ultrasonography group. The complete clearance rate in two group has no significance different.Conclusion:PCNL under the Sonix GPS electromagnetic needle tracking system is safe, reliable, effective and easy to follow, It can help clearly observe the trajectory of the needle during puncture, thus facilitating needle-beam alignment and guidance to the target, which may provides a new choice for PCNL.