Category: Clinical Stones: Equipment (stents, lasers, guidewires, sheaths)

MP27-17 - Virtual Basket technology – Impact on high frequency lithotripsy in a urological simulator

Sun, Sep 23
10:00 AM - 12:00 PM

Introduction & Objective : The aim of current study was to compare the performances of holmium laser fragmentation when using the innovative Virtual Basket technology with respect to conventional standard mode in a lithotripsy simulator setup

Methods : A high power holmium laser (Cyber Ho, Quanta System), together with standard 365µm fibers, was used to fragment artificial stones (BegoStone Plus, average weight: 0.37 ± 0.03 g, 5:1 chalk-water ratio) in the bladder of a stone simulator. Standard mode (S) was compared with Virtual Basket mode (VB), using rigid scope to access the stones in the bladder (allowing easier migration). The two modes were compared at   0.5J @ 30Hz (mode I) and 0,8 J @ 45 Hz (mode II) settings. For each combination of mode and settings, different parameters related to lithotripsy performance were collected, including the degree of stone instability (DSI), based on a Likert scale ranging from 0 - no retropulsion - to grade 4 - high retropulsion). Veri combination was tested 4 times. In a separate test, the user tested 8 emission settings (for both modes) for 10 seconds on fragments < 3mm, being blind to the mode in use and rating their instability degree

Results :

In the first part of the test, VB mode was associated with significantly (p < 0.05) fewer events of major stone migration both for settings I (VB: 2.8 ± 2.2 , S: 12.8 ± 3.9) and settings II (VB: 4.5 ± 1.7 , S: 28.5 ± 3.4). Similarly, the DSI scores were significantly in favor of VB mode for both settings (about 0.75-1 point difference), apart from the beginning of mode I (p=0.21). VB was associated with significantly lower emitted energy in mode II (VB: 5.8 ± 0.7 kJ; S: 8.8 ± 0.6 kJ), with no statistically significant difference for mode I (VB: 6.2 ± 0.9 kJ , S: 5.1 ± 1.0 kJ). Similarly, VB resulted in lower lasing time for mode II (VB: 144.8 ± 17.8s , S: 220.8 ± 156s), but not in mode I (VB: 370 ± 52.7s , S: 304.5 ± 62.5s). S mode with settings II appeared not efficient and quite difficult to use, whereas the same settings with VB mode appeared easier, as demonstrated by previous data. In the second part of the test, when targeting small fragments, VB mode was associated with a 1,38 ± 0,52 score significantly lower (out of a 0-4 range; VB: 2± 0.76 , S: 3.38±0.52), suggesting a strong advantage for pop-corning and for size reduction of residual fragments.

Conclusions : When tested with artificial stones in a simulator setup and with the use of high frequency, the Virtual Basket mode resulted in statistically significant better stone stability, fewer migration events and better performances with high-power settings

Damiano Vizziello

Policlinico San Donato
Milan, Lombardia, Italy

Pietro Acquati

Milan, Lombardia, Italy

Maria Chiara Clementi

Milan, Lombardia, Italy

Gloria Motta

Milan, Lombardia, Italy

Claudia Signorini

IRCCS Policlinico San Donato
Paderno Dugnano, Lombardia, Italy

Sebastiano Nazzani

Milan, Lombardia, Italy

Oskar Blezien

Milan, Lombardia, Italy

Luca Carmignani

Milan, Lombardia, Italy