Presented by: frederic panthier MD, MSc
Tenon Hospital, APHP-Sorbonne University

Introduction

Holmium:yttrium-aluminium-garnet(Ho:YAG) and Thulium Fiber(TFL) lasers are currently the two laser sources recommended for endocorporeal laser lithotripsy. Recently, the pulsed-Thulium:YAG(Tm:YAG) laser was proposed for ELL, answering to both Ho:YAG and TFL limitations. We aimed to evaluate Tm:YAG in terms of efficiency, safety, and laser settings in laser lithotripsy during retrograde intrarenal surgery (RIRS).

Materials

A prospective study of the first 25 patients with ureteral and renal stones who underwent RIRS using the Thulio(pulsed-Tm:YAG, Dornier©,Germany) was performed in a single center. 272µm laser fibers were used. Stone size, stone density, laser-on time(LOT) and laser settings were recorded. We also assessed the ablation speed(mm³/s), Joules/mm³ and laser power(W) values for each procedure. Postoperative results (stone free rate (SFR<3mm fragments) and zero fragments rate(ZFR)) were also recorded

Results

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A total of 25 patients were analyzed(Table 1). The median(IQR) age was 55(44-72)years old. Median(IQR) stone volume was 2849(916-9153)mm³. Median (IQR) stone density was 1000(600-1174)HU. Median (IQR) pulse energy, pulse rate and total power were 0.6(0.6-0,8)J, 15(15-20)Hz and 12(9-16)W, respectively. All procedures used “Captive Fragmenting” pulse modulation(Table 2). The median(IQR) J/mm³ was 14,8(6-21). The median(IQR) ablation rate was 0,75(0,46-2)mm³/s. One postoperative complications occurred(streinstrasse). SFR and ZFR were 95% and 55%, respectively.

Conclusion

We reported the first clinical experience with pulsed-Tm:YAG, as a safe and effective laser source for lithotripsy during RIRS, using low pulse energy and low pulse frequency, and “Captive Fragmenting” mode as preferred settings. Further comparative studies are required to define its place in the laser sources pipeline.

Funding

None

Lead Authors

Catalina Solano, MD
1 GRC n°20, Groupe de Recherche Clinique sur la Lithiase Urinaire, Hôpital Tenon, Sorbonne Université, 75020, Paris, France. 2 Service d'Urologie, Assistance-Publique Hôpitaux de Paris, Hôpital Tenon, Sorbonne Université, 4 rue de la Chine, 75020, Paris, France. 4Department of endourology, Uroclin SAS Medellin, Colombia

Marie Chicaud, MD
1 GRC n°20, Groupe de Recherche Clinique sur la Lithiase Urinaire, Hôpital Tenon, Sorbonne Université, 75020, Paris, France. 2 Service d'Urologie, Assistance-Publique Hôpitaux de Paris, Hôpital Tenon, Sorbonne Université, 4 rue de la Chine, 75020, Paris, France. 3 PIMM, UMR 8006 CNRS-Arts et Métiers ParisTech, 151 bd de l'Hôpital, F-75013 Paris, France 4Service d’Urologie, CHU Limoges

Stessy Kutchukian, MD
1 GRC n°20, Groupe de Recherche Clinique sur la Lithiase Urinaire, Hôpital Tenon, Sorbonne Université, 75020, Paris, France. 2 Service d'Urologie, Assistance-Publique Hôpitaux de Paris, Hôpital Tenon, Sorbonne Université, 4 rue de la Chine, 75020, Paris, France. 3 PIMM, UMR 8006 CNRS-Arts et Métiers ParisTech, 151 bd de l'Hôpital, F-75013 Paris, France 5 Department of Urology, Poitiers University Hospital, 2 Rue de la Milétrie, 86000 Poitiers, France

Luigi Candela, MD
1 GRC n°20, Groupe de Recherche Clinique sur la Lithiase Urinaire, Hôpital Tenon, Sorbonne Université, 75020, Paris, France. 2 Service d'Urologie, Assistance-Publique Hôpitaux de Paris, Hôpital Tenon, Sorbonne Université, 4 rue de la Chine, 75020, Paris, France. 7Division of experimental oncology/unit of Urology, URI, IRCCS Ospedale San Raffaele, Milan, Italy; Vital-Salute San Raffaele University, Milan, Italy

Steeve Doizi, MD PhD
1 GRC n°20, Groupe de Recherche Clinique sur la Lithiase Urinaire, Hôpital Tenon, Sorbonne Université, 75020, Paris, France. 2 Service d'Urologie, Assistance-Publique Hôpitaux de Paris, Hôpital Tenon, Sorbonne Université, 4 rue de la Chine, 75020, Paris, France. 3 PIMM, UMR 8006 CNRS-Arts et Métiers ParisTech, 151 bd de l'Hôpital, F-75013 Paris, France

Mariela Corrales, MD
1GRC n°20, Groupe de Recherche Clinique sur la Lithiase Urinaire, Hôpital Tenon, Sorbonne Université, 75020, Paris, France. 2Service d'Urologie, Assistance-Publique Hôpitaux de Paris, Hôpital Tenon, Sorbonne Université, 4 rue de la Chine, 75020, Paris, France.

Olivier Traxer, MD
1 GRC n°20, Groupe de Recherche Clinique sur la Lithiase Urinaire, Hôpital Tenon, Sorbonne Université, 75020, Paris, France. 2 Service d'Urologie, Assistance-Publique Hôpitaux de Paris, Hôpital Tenon, Sorbonne Université, 4 rue de la Chine, 75020, Paris, France.