Exaggerated primary endoscope deflection: initial clinical experience with prototype flexible ureteroscopes

Abstract

The arrival of the flexible ureteroscope has been of great value to urologists, allowing access to virtually all parts of the collecting system. Authors from two centres in the New York area and Taiwan write in this section about their experience with new types of flexible ureteroscopes. Their views are sure to be of interest to readers.OBJECTIVETo increase the clinical usefulness of the actively deflectable flexible ureteroscope by making sequential changes in design and then using these prototypes clinically; and to develop a clinical series using the optimum prototype and contrast it with an extensive database of patients treated with the traditional flexible ureteroscope.METHODSA series of prototypic flexible ureteroscopes was developed and used clinically. The active deflection of the prototype ureteroscope was evaluated with and with no accessories in the working channel, and compared with a standard 7.5 F ureteroscope. Clinical data were then accrued and compared with a previously published database.RESULTSThe progression of prototypes led to a final version which incorporated > 300° primary active deflection, shaft miniaturization (8.4 F) and an increase in endoscope shaft stiffness. The prototype flexible ureteroscope had significantly greater active deflection than the standard ureteroscope, especially when working channel accessories were used. In all, 115 endoscopic procedures were carried out, the indications for which included endoscopic lithotripsy for distal calculi (51), treatment of upper tract urothelial carcinoma (27), diagnostic endoscopy (26) and retrograde endopyelotomy (three). No guidewire was required to place the flexible ureteroscope into the upper urinary tract in 27% of patients. Active intramural dilatation for access was only required in 3% of the procedures. All lower pole calyces were accessed with this instrument.CONCLUSIONSAdding exaggerated deflection is a timely advance in flexible ureteropyeloscopy. This and the other changes in design facilitated complex retrograde endoscopic procedures and increased the therapeutic potential of the instrument.

Comparison of Percutaneous Nephrolithotomy, Shock Wave Lithotripsy, and Retrograde Intrarenal Surgery for Lower Pole Renal Calculi 10-20 mm

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Ureteroscopy for Stone Treatment Using New 270° Semiflexible Endoscope: In Vitro, Ex Vivo, and Clinical Application

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