Advances in Ureteroscopy: New technologies and current innovations in the era of Tailored Endourological Stone Treatment (TEST)

Abstract

Ureteroscopy has undergone many advances in recent decades. As a result, it is able to treat an increasing range of patient groups including special populations such as pregnancy, anomalous kidneys and extremes of age. Such advances include Holmium laser, high-power systems and pulse modulation. Thulium fibre laser is a more recent introduction to clinical practice. Ureteroscopes have also been improved alongside vision and optics. This article provides an up-to-date guide to these topics as well as disposable scopes, pressure control and developments in operating planning and patient aftercare. These advances allow for a custom strategy to be applied to the individual patient in what we describe using a new term: Tailored endourological stone treatment (TEST). Level of evidence: 5

Innovations in Kidney Stone Removal

“… 7 The enhanced frequency (Hz) and pulse-energy (Joules) settings of new Ho:YAG machines permitted the development of more effective lithotripsy modes such as dusting and pop-dusting, where fine stone particles are produced and are easily expelled from the urinary tract. 8 This enhanced stone disintegration, however, is accompanied by stone retropulsion, most likely due to collapse of the vapor bubble 6 and also damage of the laser fiber tip (“burn back” effect), which leads to longer operative times. 9 Additionally, impairment of the endoscopic view during utilization of high-power settings is commonly encountered (“snowstorm” effect) and can necessitate compensation with an increased irrigation inflow.…”

“… 7 , 13 , 14 This wide range of settings enables TFL to deliver high-power energy through smaller, more flexible fibers of 50 μm, compared to Ho:YAG lower limit of 200 μm. 6 The clinical significance of this difference is the improved scope maneuverability, better irrigation and lower risk of stone retropulsion, which comes not only from smaller fibers and higher frequencies, but also from the creation of smaller water bubbles. 6 , 7 , 11 , 13 It should be emphasized, however, that although these very high frequencies are achievable theoretically, even settings below 50 Hz can create a “blizzard” effect, necessitating the procedure to be paused in order to regain clear vision.…”

“… 17 In vitro experiments suggest that long pulse settings benefit from less retropulsion and fiber damage, although real life clinical outcomes are not yet demonstrated. 6 , 9 , 18 Ho:YAG machines functioning both at short and long pulse settings deliver energy over one pulse, with the majority of energy being consumed during the creation of the vapor bubble. 7 A new characteristic of high-power machines is Moses technology, where the energy is applied with two pulses: the first creates the bubble, whilst the second transfers the energy through the already formed vapor channel to maximize the effect on the stone.…”

Paediatric Ureteroscopy (P-URS) reporting checklist: a new tool to aid studies report the essential items on paediatric ureteroscopy for stone disease

“…Details of the patient positioning and instrumentation should be provided. There is now an increasing use of newer-generation ureteroscopes with smaller diameters as well as single-use ureteroscopes [ 13 ]. These are anticipated to play an increasing role in the future and therefore information regarding the exact instruments used as well as their dimensions is valuable to both assess outcomes and compare them between centres or treatment modalities [ 14 ].…”

Paediatric kidney stone surgery: state-of-the-art review

“…These include next-generation and miniaturised digital scopes, new laser platforms such as thulium fibre laser (TFL) as well as innovations in pulse modulation such as Moses technology. 36 - 38 These developments have contributed to the marked rise in the number of paediatric URS series which have been published, as well as the steady improvement in SFRs, which have been reported over recent years. 7 , 12 , 39 , 40 These advancements have also supported the use of URS for difficult scenarios such as lower pole stones and cystinuria.…”