Stone ablation rates using innovative pulse modulation technology: Vapor tunnel, virtual basket, and bubble blast. An in vitro experimental study

Begoña Ballesta Martinez; Angelis Peteinaris; Arman Tsaturyan; Anastasios Natsos; Georgia Koukiou; Athanasios Vagionis; Konstantinos Pagonis; Mohammed Obaidat; Despoina Liourdi; Theofanis Vrettos; Evangelos Liatsikos; Panagiotis Kallidonis

doi:10.1002/lsm.23503

Stone ablation rates using innovative pulse modulation technology: Vapor tunnel, virtual basket, and bubble blast. An in vitro experimental study

Lasers Surg Med. 2022 Apr;54(4):580-587. doi: 10.1002/lsm.23503. Epub 2021 Nov 29.

Affiliations

¹ Department of Urology, University of Patras, Patras, Greece.
² Electronics Laboratory, Physics Department, University of Patras, Patras, Greece.
³ Department of Internal Medicine, Aghios Andreas General Hospital, Patras, Greece.
⁴ Department of Anesthesiology and ICU, University of Patras, Patras, Greece.
⁵ Department of Urology, Medical University of Vienna, Vienna, Austria.
⁶ Institute for Urology and Reproductive Medicine, Sechenov University, Moscow, Russia.

PMID: 34843116
DOI: 10.1002/lsm.23503

Abstract

Introduction and objectives: Virtual Basket^TM , Bubble Blast^TM , and Vapor Tunnel^TM are three laser pulse modulation technologies that modify the holmium: yttrium-aluminum-garnet (Ho:YAG) laser pulse transmission through the creation of bubbles emerging from the fiber tip with different effects on the target stone. The primary outcome of the current study was to test the stone ablation rates for the different pulse modulation modes, Virtual Basket, Bubble Blast, and Vapor Tunnel, using different power, energy, and frequency settings.

Materials and methods: Quanta Cyber: Ho 150 W^TM , a 365 µm Precision^TM fiber, and hard and soft phantom BegoStones^TM were used in an in vitro experimental configuration in a saline bath. In the Virtual Basket mode, the combinations of power, energy and frequency were tested; 10 W = 0.5 J × 20 Hz, 10 W = 0.5 J × 20 Hz, 60 W = 1 J × 60 Hz and 60 W = 2 J × 30 Hz. In the Bubble Blast mode, the combinations, 12 W = 1.2J × 10 Hz, 60 W = 1.2J × 50 Hz and 60 W = 2 J × 30 Hz, were tested. Similarly, the combination of 10 W = 0.5 J × 20 Hz was tested with Vapor Tunnel mode. High-speed camera captures of the bubble formation and regular photographs of the fragmentation pattern were also taken for each mode.

Results: High power lithotripsy was faster and related to higher ablation rates. The Virtual Basket, Bubble Blast, and Vapor Tunnel modalities showed different ablation rates for the same energy and frequency settings. For hard stones, there was an improvement in the ablation rate using 60 W = 2 J × 30 Hz compared with 60 W = 1 J × 60 Hz and 60 W = 1.2 J × 50 Hz. The highest ablation rates were recorded using the Virtual Basket mode with the high-power settings of 2 J of energy and 30 Hz of frequency.

Conclusions: The Virtual Basket^TM pulse-modulation technology was related to the highest ablation rates for both hard and soft stones, compared to the Bubble Blast^TM and the Vapor Tunnel^TM technologies in high-power and low-power lithotripsy respectively. For the same high power settings, higher energy seems to provide higher ablation rates.

Keywords: high power laser; laser lasers; urinary stones.

MeSH terms

Holmium
Lasers, Solid-State* / therapeutic use
Lithotripsy, Laser*
Phantoms, Imaging

Substances

Holmium