Evaluation of the Best Power Setting of Laser Waves in Pancreatic Surgery: ECHO ND-YAG Laser Ablation on Bovine Pancreatic Tissue

Abstract

Research ABSTRACTBackground: Pancreatic surgery is one of the most difficult and life-threatening surgical therapy especially during necrotizing pancreatitis and advanced solid neoplasms. Aim of the study: To evaluate the possibility to use ECHO Neodymium-Doped Yttrium Aluminium Garnet (ND-YAG) laser in pancreatic surgery and to establish the best power setting for the application on pancreatic tissue. Methods: An ECHO Laser ND-YAG 1064 nm, at the constant fluence of 1800 J/cm 2 was used. The laser waves were inserted inside of the samples with optical fibers of 500 micron diameter for a pre-established timing (11 min, 6 min, 4 min) in order to reach the constant fluence. Samples were, then, prepared for hystological examination. Results: At 3W power setting, the pancreatic tissue was not macroscopically modified except for an increased cutting consistency. Histological examination showed no substantial microscopical differences in pancreatic cells that appeared only partially burnt (in fact, nuclei and membranes are still recognizable). The vessels in the surrounding area have the normal morphological aspects. At 5W, macroscopically the presence of a completely burnt area, corresponding to the site of direct interaction of laser and tissue, was found and the surrounding tissue did not appear substantially modified. Histological examination showed the complete absence of cells in the burnt area and an important heat damage of the surrounding cells till the 2 th centimeter from the site of laser application. The vessels in the heat damage area appeared completely coagulated. At the power of 7 W, the burnt area was about twice than in the previous setting and histological examination showed the complete absence of cells in the burnt area and a larger heat damage of the nearest cells (till the 4 th centimeter from the application site). The vessels in heat damage area were found completely coagulated. Conclusions: A power setting between 4 and 6 W have been found as the best one for laser application on pancreatic tissue because a complete destruction of the cells in the site of application but a limited heat damage in the surrounding healthy cells have been obtained.

Effect of scanning speed on continuous wave laser scribing of metal thin films: theory and experiment

“…According to (13), half-width of the laser beam in the perpend icular ( x σ ) and parallel direction ( y σ ), appears directly and indirectly respectively.…”

“…Laser ablation [1] and specifically scribing [2] have widespread applications in pioneering science [3][4][5][6][7], industry [8][9][10][11] and medicine [12][13][14][15][16][17]. Generally, this phenomenon could be investigated in both bulk and thin film materials.…”