Holmium laser lithothripsy of ureteral calculi: our initial experience

Correlation between the operation time using two different power settings of a Ho: YAG laser: laser power doesn't influence lithotripsy time

BACKGROUND

This study investigated the correlation between the operation time using two different power settings of a Ho: YAG laser.

FINDINGS

A total of 68 patients underwent cystolithotripsy from April 2010 to October 2011 In Fifty-six of these patients underwent cystolithotripsy by one surgeon using a Ho: YAG laser for bladder calculi. This study assessed these patients in two groups; the 30 W laser generator group with the settings of 2.5 J x 5 Hz (30 W group) and the 100 W laser generator group as the settings of 3.5 J x 5 Hz (100 W group). The operation time in these two groups were assessed.A total of 56 patients including 45 male and 11 female patients that underwent cystolithotripsy using a Ho: YAG laser for bladder calculi by one surgeon were enrolled in this study. The patients' characteristics including age (mean; 68.8 vs 68.4 yr), gender (male; 74.2 vs 88.0%), stone burden (mean; 34.9 vs 41.3 mm), number of stones (mean; 3.2 vs 2.0) and stone's CT density (mean; 981.5 vs 902.0 HU) showed no significant differences. All patients were stone free following treatment. The median total length of the operation was 19 minutes (mean: 34.6 ± 36.1) in the 30 W group and 29 minutes (mean: 44.4 ± 38.8) in the 100 W group, which was not significantly different.

CONCLUSIONS

The results showed that the power settings of Ho: YAG laser show no differences in the operation time for bladder calculi lithotripsy.

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.