Radiopaque Laser Fiber for Holmium: Yttrium-Aluminum-Garnet Laser Lithotripsy: Critical Evaluation

Optimizing use of the holmium:YAG laser for surgical management of urinary lithiasis

The holmium:yttrium aluminum garnet (Ho:YAG, holmium) laser is an intracorporeal lithotrite that is widely used in the surgical management of urinary lithiasis. The Ho:YAG laser is capable of fragmenting urinary stones of all compositions while maintaining a wide margin of safety. The 2140-nm wavelength of energy is transmitted from the generator to the stone using specialized silica optical fibers. The effectiveness of the laser can be impacted by the type of laser fiber used, the pulse energy and frequency settings, and the composition of the stone. This paper provides an overview of Ho:YAG laser fibers utilized for lithotripsy during ureteroscopy. We will also review current data regarding optimal energy settings and discuss our experience with different fragmentation techniques.

Superiority of the EF-120-00-3F biopsy forceps in the histopathological evaluation of upper urinary tract specimens

PURPOSE

The purpose of this study was to analyze the efficacy of two different biopsy forceps with respect to their functionality and quality for histological assessment of upper urinary tract biopsies.

METHODS

We compared flow rates, active deflection angle and histological quality of specimens taken from upper urinary tract biopsies of 40 consecutively treated patients between October 2011 and October 2012. Two different biopsy forceps [group A = 20 patients: "Piranha (®) " (Boston Scientific, Natick, USA) versus group B = 20 patients: "EF-120-00-3F" (Euromedical GmbH, Siegsdorf, GER)] were assessed.

RESULTS

The specimens obtained with the "EF-120-00-3F" were superior in terms of tissue preservation such as intact urothelium/tissue fragmentation and the prevention of artifacts due to tissue compression (existence of artifacts/nucleus evaluation). Furthermore, due to superiority of tissue preservation, tissues obtained with the "EF-120-00-3F" showed better tissue orientation in the sense of anatomic evaluation of invasion and deep layer involvement. Irrigation flow rates did not differ significantly while deflection angle was more impaired with the "Piranha" biopsy forceps. No difference was observed with the handling of both biopsy forceps.

CONCLUSIONS

We conclude that the "EF-120-00-3F" biopsy forceps represent a valuable modification of antegradely insertable instruments that qualifies for improved and correct staging as well as diagnosis of upper urinary specimens in comparison with standard biopsy forcipes.

Intracorporeal laser lithotripsy

Objectives

To review the current literature on intracorporeal laser lithotripsy.

Methods

We searched PubMed for relevant reports up to January 2012, using the keywords ‘laser’, ‘lithotripsy’ and ‘intracorporeal’.

Results

We studied 125 relevant reports of studies with various levels of evidence. Efficient lithotripsy depends on the laser variables (wavelength, pulse duration and pulse energy) and the physical properties of the stones (optical, mechanical and chemical). The most efficient laser for stones in all locations and of all mineral compositions is the holmium yttrium–aluminium–garnet laser (Ho:YAG). The frequency-doubled double-pulse Nd:YAG laser functions through the generation of a plasma bubble. New laser systems, such as the erbium:YAG and the thulium laser, are under evaluation. Laser protection systems have also been developed for the novel digital flexible ureteroscopes. Although complications are rare, a high relevant clinical suspicion is necessary.

Conclusions

Laser lithotripsy technology is continuously developing, while the Ho:YAG laser remains the reference standard for intracorporeal lithotripsy.