Dados do Trabalho

Título

THULIUM FIBER LASER EFFICIENCY ON STONE ABLATION: DOES FLUID TEMPERATURE PLAY A ROLE?

Introdução e Objetivo

Thulium Fiber Laser (TFL) has recently been introduced for urolithiasis, with a potential improvement in lithotripsy efficiency, specifically for dusting stones. However, there are still many factors that could influence ablation efficiency which has not been previously studied, such as fluid temperature. Our objective was to assess the effect of different fluid temperatures on the efficiency of the ablation of different stone types.

Método

In this in vitro study, 360 stones ranging from 5-10mm were divided into six groups according to the stone composition: calcium oxalate monohydrate and dihydrate, calcium phosphate, cystine, struvite, and uric acid (UA). Stone ablation efficiency was defined as the volume of the ablation cone determined by optical coherence tomography (Figure). Each stone was tested using four different temperatures (25°C, 37°C, 44°C and 60°C) and three energy (0.1 J, 0.5 J, and 1.5 J) using one single pulse of the TFL, and a multivariable model was developed to assess the effect of fluid temperature.

Resultados

Stone type, energy, and fluid temperature were associated with the ablation cone (Table). In all stone types except UA, fluid temperature was directly associated with the depth of the ablation cone (β 0.096, 95% CI 0.060 – 0.133, p < 0.001) after controlling for energy. To increase the ablation efficiency by a similar amount as 0.1 J, the temperature would need to increase by 7°C.  

Conclusão

Fluid temperature plays a significant role in the efficiency of TFL for stone ablation: higher temperatures were associated with more stone ablated for all stone types, except uric acid. More studies are necessary to assess if there might be a benefit of using 37°C instead of room temperature in clinical practice.