Category: New Technology: Stones

MP5-11 - The “Safety distance concept” applied to ureterorenoscopy with a SuperPulsed Thulium Fiber Laser: are all parameters really usable?

Fri, Sep 21
10:00 AM - 12:00 PM

Introduction & Objective :

The costs of flexible ureterorenoscopes (fURSs) and their repair oblige the surgeon to know the proper handling of instruments. Recently, a study has focused on defining distance that the laser fiber should have once out from the ureterorenoscope to avoid instrumental damages observing that when the laser fiber was at ¼ of the screen, the bubble was never touching the fURS tip. In a previous study, our team has shown that the thulium laser produces, at certain energies, an extended stream of bubbles, legitimately posing the question of the risk of material damage with this technology.


Methods :

We performed an in vitro observational study, using a 50W SuperPulsed surgical laser prototype of TFL (IPG Photonics, Oxford, MA). The distance from the laser fiber tip and the fURS camera was established thanks to a micrometric screw.
We used a Photron APX-RS 3000 high-speed camera, with a setting of 15 000 frames per second, to evaluate the impact of the thulium laser bubble according to different fiber distances, an assessment of the size and shape of the bubble created at the tip of the fiber.
We used a high-speed Photron APX-RS 3000 camera, with a 15 000 frames per second setting, to evaluate the impact of thulium laser bubble at different fiber distances, and depending on the material being processed (hard or soft kidney stone phantoms, or pork renal tissue).


Results : As demonstrated for the holmium laser, the output of the 3 mm fiber endoscope (fiber visualized at 1/4 of the screen) seems safe for the treatment of both soft, hard stones or tissue, up to a maximum power of 20W. Beyond that, the fiber can be released from 4 mm to treat hard stones (without exceeding 30W) or tissue. When the fiber is less released (not visible, or first appearance on the screen), the vapor bubble touches the fURS tip.


Conclusions : Although the effect of the return of the vapor bubble on the tip of the endoscope has not been studied, we can assume that it could damage this fragile and expensive device. This study allows us to define certain parameters not to be exceeded with the thulium generator to avoid damaging the endoscope.

Paul H.L. Chiron

MD, FEBU
Sorbonne Université, GRC n°20, Groupe de Recherche Clinique sur la Lithiase Urinaire, AP-HP, Hôpital Tenon, F-75020 Paris, France
Saint Mandé, Ile-de-France, France

Laurent L. Berthe

Paris, Ile-de-France, France

Etienne X. Keller

Fellow of the ES
Sorbonne Université, GRC n°20, Groupe de Recherche Clinique sur la Lithiase Urinaire, AP-HP, Hôpital Tenon, F-75020 Paris, France
Paris, Ile-de-France, France

Vincent De Coninck

Urologist
AZ Klina
Brasschaat, Antwerpen, Belgium

Vincent De Coninck graduated as a medical doctor from the Free University of Brussels, Belgium (VUB) in 2011. He became a certified urologist in 2017 after a training at the University Hospital of Brussels (Prof. Dr. Dirk Michielsen) and OLV Aalst (Prof. Dr. Alex Mottrie), where he developed a special interest in the minimal invasive treatment of benign and malignant pathologies. In the same year, he became Fellow of the European Board of Urology.
In 2018, he completed a one-year fellowship program of the Endourological Society in Paris, France under the supervision of Prof. Dr. Olivier Traxer. During that fellowship, he also obtained a diploma in urolithiasis, organized by Dr. Michel Daudon at the Sorbonne University in Paris, France. Afterwards, he was trained in HoLEP by Dr. Karin Lehrich in Berlin, Germany.
Currently, he is completing a three-month fellowship under the supervision of Dr. Guido Giusti in Milan, Italy. In December 2018, he will start working as an endourologist in AZ Klina, Brasschaat, Belgium. He will focus on the medical and surgical treatment of kidney stones and benign prostatic obstruction (HoLEP) and he will continue publishing articles relating to the management of patients with renal stone disease.

Steeve S. Doizi

Urologist
Sorbonne Université, GRC n°20, Groupe de Recherche Clinique sur la Lithiase Urinaire, AP-HP, Hôpital Tenon, F-75020 Paris, France
Paris, Ile-de-France, France

Olivier O. Traxer

Professor
Sorbonne Universite, GRC n020 Lithiase Renale, AP-HP, Hospital Tenon, F-75020 Paris, France
Paris, Ile-de-France, France