Comparative experimental evaluation of guidewire use in urology.

OBJECTIVES

To evaluate the characteristics and mechanical properties of five different guidewires principally used in urology to provide a guide to the best choice in every situation. This objective was achieved by performing mechanical tests on each guidewire and on the same guidewire in relationship to a real human ureter. Finally, the mechanical properties of a real human ureter were evaluated experimentally.

METHODS

Five different guidewires with a 0.035-in. external diameter were studied to determine their mechanical properties of interest: tip buckling, shaft permanent deformation, guide friction on the human ureter, and the force at which the tip perforated a real human ureter.

RESULTS

Nitinol guidewires with hydrophilic coating had the least dangerous tip in the tip buckling and tip piercing force tests and the lowest friction values on the friction guide test. The shaft of the polytetrafluoroethylene-coated guidewires was stiffer on the bending resistance and plastic deformation tests.

CONCLUSIONS

The ideal endourologic guidewire should be sufficiently flexible and lubricated to negotiate a tortuous ureter and pass possible obstructions. However, high strength against bending is also required when we need to pass a stent or catheter over a guidewire.