To examine temporal-spatial distribution of heat generated upon laser activation in a bench model of renal calyx. To establish reference values for a safety distance between the laser fiber and healthy tissue during laser lithotripsy.
We developed an in-vitro experimental setup employing a glass pipette and laser activation under various intra-operative parameters, such as power and presence of irrigation. A thermal camera was used to monitor both temporal and spatial temperature changes during uninterrupted 60-second laser activation. We computed the thermal dose according to Sapareto and Dewey's formula at different distances from the laser fiber tip, in order to determine a safety distance.
A positive correlation was observed between average power and the highest recorded temperature (Spearman's coefficient 0.94, p < 0.001). Irrigation was found to reduce the highest recorded temperature, with a maximum average reduction of 9.4 °C at 40 W (p = 0.002). A positive correlation existed between average power and safety distance values (Spearman's coefficient 0.86, p = 0.001). A thermal dose indicative of tissue damage was observed at 20 W without irrigation (safety distance 0.93±0.11 mm). While at 40 W, irrigation led to slight reduction in mean safety distance (4.47±0.85 vs. 5.22±0.09 mm, p = 0.08).
Laser settings with an average power greater than 10 W deliver a thermal dose indicative of tissue damage, which increases with higher average power values. According to safety distance values from this study, a maximum of 10 W should be used in the ureter, and a maximum of 20 W should be used in kidney in presence of irrigation.
World journal of urology. 2024 Jul 29*** epublish ***
Eugenio Ventimiglia, Daniele Robesti, Etienne Xavier Keller, Christian Corsini, Andrea Folcia, Margherita Fantin, Luigi Candela, Edoardo Pozzi, Alba Sierra, Amelia Pietropaolo, Bhaskar K Somani, Frederic Panthier, Felipe Pauchard, Ioannis Kartalas Goumas, Luca Villa, Francesco Montorsi, Olivier Traxer, Andrea Salonia, Paola Saccomandi
Vita-Salute San Raffaele University, Milan, Italy. ., Vita-Salute San Raffaele University, Milan, Italy., Young Academic Urologists (YAU), Urolithiasis and Endourology Working Party, Arnhem, The Netherlands., Sorbonne Universite, GRC#20 Lithiase Urinaire, Hôpital Tenon, Paris, Île-de- France, 27063, France., Department of Urology, University Hospital Southampton, Southampton, UK., Progressive Endourological Association for Research and Leading Solutions (PEARLS), Paris, France., Dept. of Urology, Istituto Clinico Beato Matteo, Vigevano, Italy., Department of Mechanical Engineering, Politecnico di Milano, Milan, 20156, Italy.
PubMed http://www.ncbi.nlm.nih.gov/pubmed/39073430