Endoscopic Lithotripsy and the FREDDY Laser: Initial Experience

Abstract

Because of the wavelengths used, endoscopic FREDDY laser lithotripsy is an effective and harmless method. This laser can be used as a therapeutic tool because of its moderate cost and ability to be used with flexible ureterorenoscopy. However, it is important to be aware of the FREDDY laser's limited fragmentation capabilities for cystine stones and its inability to treat tissue lesions such as urinary-tract stenosis and tumors.

A comparison of the FREDDY and holmium lasers during ureteroscopic lithotripsy

“…Therefore the distance the fiber is maintained from the stone may have implications for successful lithotripsy. The potential advantage of the FREDDY laser is the stone's preferential absorption of the laser wavelength while the surrounding tissue absorbs only minimal energy, which limits damage to the ureteral wall [4]. While a large amount of data has been accrued on the stone-free rate of the holmium laser, little clinical data exists for the FREDDY.…”

“…Two studies showed the FREDDY laser to have decreased efficacy with certain stone types, including cystine, uric acid, and calcium oxalate monohydrate [4,13]; this is related to the stones' absorption of different wavelengths of energy. Conversely, the holmium has shown excellent effectiveness with all stone types [7].…”

“…Two lasers used for lithotripsy during URS are the frequency-doubled double-pulse neodynium:YAG laser (FREDDY) and holmium:YAG (holmium) lasers. The FREDDY laser combines characteristics of solid state and dye lasers, and fragments stones via generation of a plasma bubble with mechanical shockwave effects [4]. The holmium laser utilizes a photothermal mechanism of action by creating a vapor bubble that transmits laser energy [3].…”

The evolution of lasers in urology

“…Another major advantage is the extremely low risk of damage to the ureteral wall when using this laser [Yates et al 2007]. Unfortunately the 'hard' types of calculi also present a challenge to this laser, as is the case with the pulsed dye lasers [Dubosq et al 2006]. Another problem is that the FREDDY laser is only able to effectively fragment dark or colored stones that absorb the green wavelength.…”

Update on Flexible Ureteroscopy

“…It is reportedly less expensive and easier to maintain than other lasers. Recently, Dubosq et al [23] evaluated its efficacy and role in the ureteroscopic treatment of urinary stones. At 3 months, 69% of the patients were stone-free, and 72.4% of the stones had been treated completely.…”