Poster session 5: Nephrolithiasis| Volume 8, ISSUE 8, P682, September 2009

C73 Conventional fiberoptic flexible ureteroscope vs. 4th generation digital flexible ureteroscope: a critical comparison

      Introduction and Objectives

      Development of flexible renoureteroscopy had a significant impact over the diagnosis and treatment of upper urinary tract pathology. During the last decades, a continuous technological improvement of flexible ureteroscopes was encountered. The aim of our study was to compare the performances of a standard fiberoptic flexible ureteroscope with those of a modern digital one.

      Material and Methods

      We compared subjectively and objectively the differences in maneuverability and visibility for a 7.2F Storz 11274AA fiberoptic flexible ureteroscope (FFU) and an 8.5F Olympus URF-Vo digital flexible ureteroscope (DFU). For that, in 44 diagnostic retrograde flexible ureteroscopic procedures (22 with the FFU and 22 with the DFU) the maneuverability and visibility were evaluated by the same urologist with a score ranging from 1 to 5. Also, the maximal deflection and the irrigation flow were measured with the working channel empty and with various accessory instruments inserted through it.


      FFU and DFU received mean scores of 3.64 vs. 4.27 for maneuverability and 3.27 vs. 4.68 for visibility. In 3 cases, approach of the narrow infundibulum was impossible using DFU with a larger diameter at the tip, imposing the use of the FFU. The irrigation flow through FFU and DFU (normal/pressure irrigation) was 54/144 ml/min vs. 60/150 ml/min with an empty working channel, 14/54 ml/min vs. 48/84 ml/min with the 1.6F EHL probe and almost 0 ml/min with 3F instruments inserted. The maximal deflection for FFU and DFU was 162° vs. 275° with the working channel empty, 143° vs. 275° with 1.6 EHL probe, 109° vs. 255° with the 3F triradiate grasper, 80° vs. 217° with the 3F extraction grasper and 149° vs. 257° with the ZeroTip basket.


      The new DFU proved superior maneuverability and visibility, which may translate into improved performances. Larger tip of the DFU may decrease its accessibility, especially in narrow segments of the upper urinary tract. The modern DFU are very useful instruments, with a great potential for future development.