Could titanium oxide coating from a sol-gel process make stone baskets more resistant to laser radiation at 2.1 μm?
BACKGROUND
Stone baskets could be easily destroyed by Holmium:YAG-laser at an endourologic treatment, with respect to this, we try to improve the resistance by coating them with a titanium oxide layer. The layer was established by a sol-gel-process.


METHODS
Six new baskets (Equadus, Opi Med, Ettlingen, Germany) were used: 1.8 Ch. with 4 wires (diameter 0.127 mm). Three baskets were coated with a layer of titanium oxide established by a sol-gel process at the BioCerEntwicklungs GmbH in Bayreuth (~100 nanometres thickness). The lithotripter was a Holmium:YAG laser (Auriga XL, Starmedtec, Starnberg, Germany). 10 uncoated and 10 coated wires were tested with 610 mJ (the minimal clinical setting) and 2 uncoated and 2 coated wires were tested with 110 mJ. The wires were locked in a special holding instrument under water and the laser incident angle was 90°. The endpoint was gross visible damage to the wire and loss of electric conduction.


RESULTS
Only two coated wires resisted two pulses (one in the 610 mJ and one in the 110 mJ setting). All other wires were destroyed after one pulse.


CONCLUSIONS
This was the first attempt at making stone baskets more resistant to a Holmium:YAG laser beam. Titanium oxide deposited by a sol-gel-process on a titanium-nickel alloy did not result in better resistance to laser injuries.
Clinic of Urology, University of Lübeck, University Medical Center Schleswig-Holstein, RatzeburgerAllee 160, D-23538, Lübeck, Germany. Jens.Cordes@uk-sh.de
Jens
J
Cordes
Felix
F
Nguyen
Frank
F
Heidenau
Dieter
D
Jocham
D005782:Gels; D053844:Lasers, Solid-State / Q000009:adverse effects / Q000592:standards*; D008422:Materials Testing / Q000379:methods* / Q000592:standards; D011829:Radiation Dosage; D014025:Titanium / Q000737:chemistry* / Q000528:radiation effects*
D005782:Gels; C009495:titanium dioxide; D014025:Titanium