A new frequency-doubled double-pulse nd:YAG laser (FREDDY) for laserlithotripsy of gallstones — An interesting new pulsed solid-state laser with an automatic piezo-acoustic stone/tissue detection system (paSTDS)

Abstract

./369 A NEW FREQUENCY-DOUBLED DOUBLE-PULSE Nd:YAG LASER (FREDDY) FOR LASERLITHOTRIPSY OF GALLSTONES AN INTERESTING NEW PULSED SOLID-STATE LASER WITH AN AUTOMATIC PIEZO-ACOUSTIC STONE/TISSUE DETECTION SYSTEM (paSTDS) J. Hochberger, J. Tschepe*, R. Stein, J. Bayer, J. Helfmann*, P. Martus#, S. Tex, C. Ell, D. Schiidel*, E.G. Hahn Dept. of Medicine I, # Inst. Biomed. Statistics, Fr.-Alex.-Univ., Erlangen, *Laser-Medizin-Zentrum, Berlin, Germany Laserlithotripsy using dye laser systems has become a commonly accepted endoscopic treatment modality for the removal of difficult bile duct stones. To date its application is limited, however, to centers because of high costs. In the following we report on our preliminary preclinical experience using a new solid-state laser lithotriptor which seems to combine the advantages of dye and solid state lasers as concerns low price, reliability and effectiveness. A new piezo-acoustic stone/tissue detection system (paSTDS) is integrated in the laser for automatic pulse interruption in case of tissue contact ('smart laser'). Mat.& Meth.: 50 human gallstones (GS) of comparable chem. composition and size [d=9.321.4ram; 5 'mixed groups of 10 GS (10 families of 5 GS)] were disintegrated into sand-grain-like fragments ( 0.1). Conclusions: FREDDY represents an interesting new pulsed laser system with integrated paSTDS which shows a fragmentation capacity comparable to conventional laser systems at 30% of the COSTS. Animal experiments for the paSTDS and first clinical applications are currently under investigation.