Category: Basic Science: BPH/LUTS

MP3-1 - Tissue effects of different laser fibre diameters using 1.94 µm Tm:fibre lasers in a pig kidney model

Thu, Sep 20
4:00 PM - 6:00 PM

Introduction & Objective : Aim of this study was to evaluate the ablation capacity and coagulation depth of different laser fibre diameters using a high peak power pulsed Thulium (Tm):fibre laser and a continuous wave (cw) Tm:fibre laser in a pig kidney model.


Methods : All soft tissue samples were obtained from a pig kidney and mounted on a motorized translation XY stage to ensure a precise speed of cutting (2 mm/s). A cw Tm:fibre laser (120-W peak power) and a prototype high peak power pulsed Tm:fibre laser (1000-W peak power) both emitting at 1.94 µm were used at the same average power of 60-W and 120-W, respectively. Energy was delivered using a 200 µm and a 600 µm bare-ended fibre. After Lactat Dehydrogenase (LDH)-staining of the embedded specimens, histological evaluation was performed to compare vaporization volume, ablation depth, thermo-mechanical damage zone, coagulation zone and the depth of necrotic tissue layer between both Tm:fibre lasers and fibre diameters, respectively.


Results : Using the cw Tm:fibre laser at 120-W (cutting speed 2 mm/s), no significant differences were seen between both fibre diameters with regard to vaporization volume (24.6 vs. 28.2 mm3/s), ablation depth (5.7 vs. 5.6 mm), thermo-mechanical damage zone (0 vs. 0 mm2) and the coagulation zone (18.1 vs. 11.3 mm2). Regarding the high peak power pulsed Tm:fibre laser, no differences were found between both fibre diameters with regard to vaporization volume (4 vs. 3 mm3/s), ablation depth (2.7 vs. 2.5 mm), thermo-mechanical damage zone (1 vs. 1.3 mm2) and the coagulation zone (3.1 vs. 2.2 mm2) at 120-W, respectively. Regarding the laser fibre diameters, there were also no differences between the histologically measured parameters at 60-W in both Tm:fibre lasers. However, comparing the power of both lasers, the vaporization volume of the cw Tm:fibre laser at 60-W was significantly lower compared to 120-W using 200 and 600 µm fibres, respectively, whereas the high peak power pulsed Tm:fibre laser did not show significant differences at 60-W compared to 120-W with regards to the vaporization volume. 


Conclusions : The laser fibre (200 or 600 µm) diameter did not affect vaporization volume, ablation depth, the thermo-mechanical damage zone and the coagulation zone in cw or high peak power pulsed Tm:fibre lasers. However, the cw Tm:fibre laser produces a coagulation zone five times larger than the high peak power pulsed Tm:fibre laser regardless of the fibre core diameter.

Benedikt Becker

Resident
Asklepios Klinik Barmbek, Department of Urology
Hamburg, Hamburg, Germany

Dr. Becker is a resident of urology in the urological department of the Asklepios Hospital Barmbek in Hamburg, Germany. He studied in Giessen and Lübeck (both Germany). His main scientific interest is the broad spectrum of endourology, especially laser treatment of benign prostatic obstruction. He is an active member of the German Society of Urology (DGU), the German Society of Residents in Urology (GeSRU), and the Endourological Society (WCE). At this time, he is participating in the Two Year fellowship program in Endourology/Stone Surgery.

Christopher Netsch

Consultant
Asklepios Klinik Barmbek, Abteilung für Urologie
Hamburg, Hamburg, Germany

Dr. med. Dr. habil. Christopher Netsch, MD, FEBU is an Assistant Professor of Urology at the Semmelweis University of Budapest/Hungary. He received his medical degree from the University of Mainz/Germany. His training in urology was conducted at the Inselspital Bern/Switzerland, Städtisches Klinikum Karlsruhe/Germany and at the Asklepios Klinik Barmbek/Germany. After his board certification in 2011 (Hamburg/Germany), Dr. Netsch became a consultant urologist at the Asklepios Klinik Barmbek/Germany. Dr. Netsch completed his Endourology Fellowship at the Asklepios Klinik Barmbek in 2012. He was also qualified as a Fellow of the European Board of Urology (FEBU) in 2015.
Dr. Netsch`s research focuses on urolithiasis and minimally-invasive therapies for BPH. He has authored or co-authored over 70 peer-reviewed journal articles and numerous book chapters. He was awarded with the Mauermayer award of the German Society of Urology (DGU) in 2013 and the Hans Marberger award of the European Association of Urology (EAU) in 2014. He is currently an editorial consultant for the World Journal of Urology.
Dr. Netsch is a member of the DGU Urolithiasis Guidelines committee. He is also an active member of numerous national and international societies such as the DGU, EAU, and the Endourological Society. He is also a member of the DGU working group in Endourology and the EAU section of Uro-Technology (ESUT): Lower Tract Section.

Dmitry Enikeev

Deputy Director for Science
Institute for Urology and Reproductive health, Sechenov University
Moscow, Moskva, Russia

Surgical experience:
Experienced in TURP (>300 surgeries).
Experienced in upper urinary tract endosurgery (PCNL >200, RIRS >200).

2008-Present: Multiple upper and lower urinary tract surgeries;
2011-Present: HoLEP (400 surgeries);
2011-Present: En-bloc enucleation of bladder tumor (50 surgeries);
2016-Present: ThuLEP (>400 surgeries);
2016-Present: Thulium en-bloc enucleation of bladder tumor (>80 surgeries);
2016-Present: Brachytherapy (>40 surgeries); prostate cryoablation (70 surgeries), renal cancer cryoablation (30 surgeries);
Apr 2017-Present: Irreversible electroporation (10 surgeries);
Apr 2017-Present: MR-fusion prostate biopsy (80 procedures).

Petr Glybochko

Director
RI for Uronephrology, Sechenov University
Moscow, Moskva, Russia

Leonid Rapoport

Deputy Director
RI for Uronephrology, Sechenov University
Moscow, Moskva, Russia

Mark Taratkin

Researcher
Institute for Urology, Sechenov University
Moscow, Moskva, Russia

Researcher at the Institute for Urology and Reproductive health, Sechenov University.
Head of the laser technology lab.

Andreas J. Gross

Head of Department
Asklepios Klinik Barmbek, Abteilung für Urologie
Hamburg, Hamburg, Germany