Thulium fibre laser lithotripsy, the new standard?

Abstract

Chua et al. present a meta-analysis comparing ureteroscopic laser lithotripsy techniques employing two different energy sources, specifically, holmium and thulium fibre lasers [1]. These authors chose 15 recent studies for comparison and concluded that thulium fibre laser is more efficient, with significantly shorter operative times. The first series of holmium laser lithotripsy was published 25 years ago [2]. Since then, delivery systems have evolved, allowing the surgeon to increase the frequency of delivered pulsatile light energy for dusting, as well as the ability to vary the pulse width, facilitating improved efficiency. Large published series, some now over 20 years old, defined both safety and efficacy [3]. This is underscored by multiple series of large stones and partial staghorn calculi treated successfully, with a meta-analysis published in 2013 in BJUI [4]. Thulium fibre laser is a relatively new energy source delivered via a flexible optical fibre passed through the working channel of the endoscope, not unlike other laser lithotrites [5]. This energy source produces a localized highly thermal ablative effect, significantly different from other stone lasers. This has led to general concern that these thermal spikes would produce a higher ureteric stricture rate [6]. The authors scoured the literature but did not define a higher rate of complications. With the obvious limitations of short-term follow-up associated with a new technology aside, the US Food and Drug Administration recall of the most popular thulium fibre laser system (a result of Manufacturer and User Facility Device Experience [MAUDE] reporting of adverse events sent directly to the US government) underscores this risk and led to software changes to the delivery systems, prohibiting high energy settings when employed in the ureter [7]. Chua et al. allude to this in their review, but it must be underscored. The application of the thulium fibre laser in the upper urinary tract requires significantly more cooling irrigant than holmium, and the endourologist must be keenly aware of the potential thermal risk. That being said, based on the significantly increased efficiency, thulium fibre laser has replaced holmium:YAG as our preferred energy source for laser lithotripsy. None declared.