SabreSource™: a novel percutaneous nephrolithotomy apparatus to aid collecting system puncture – a preliminary report

Abstract

Background: Successful percutaneous nephrolithotomy (PCNL) relies on a technically challenging, precise needle puncture of the renal collecting system.  We aimed to compare, in an ex vivo model, the use of a real time image guidance system (the SabreSource™) and a mechanical stabilising device with  conventional manual techniques for the accuracy of needle placement.

Methods: The SabreSource™ system (Minrad International Inc.; New York, USA) is a real time image guidance system. The system platform is mounted on  a C-arm fluoroscope. It employs targeting cross hairs on the fluoroscopic image that can be easily positioned to  target the desired renal calyx. The  system directs a visible laser beam onto the patient which is precisely aligned with the cross hairs on the fluoroscopic  image. This provides the correct  “bull’s-eye” angle of approach to the calyx, even after the x-ray source is turned off. The locator then stabilises the needle  in the “bull’s-eye” position so  that only screening for depth is required. Objective assessment using a simulated PCNL puncture was performed by  7 urologic trainees on a kidney  phantom with and without using the SabreSource™. Fluoroscopy screening time (FST) and amount of radiation (mGy) used  to achieve successful  puncture were compared. 

Results: Simulated PCNL puncture was quicker and resulted in reduced radiation exposure when the apparatus was used. The  mean FST for traditional  “bull’s-eye” vs SabreSource™ puncture was 17 vs 5 seconds (p = 0.01), and the mean radiation exposure to puncture was 0.7 vs 0.2 mGy (p = 0.03),  respectively.

Conclusion: The SabreSource™ is a novel assistant to achieving successful PCNL puncture. In combination with “the locator” the preliminary  in vitro testing suggests that the device reduces fluoroscopy exposure and is quicker. The device warrants further evaluation in the clinical setting.