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Pulsed holmium laser ablation of cardiac valves
Author(s) -
Lilge Lothar,
Radtke Wolfgang,
Nishioka Norman S.
Publication year - 1989
Publication title -
lasers in surgery and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 112
eISSN - 1096-9101
pISSN - 0196-8092
DOI - 10.1002/lsm.1900090506
Subject(s) - ablation , materials science , holmium , laser , irradiation , laser ablation , optics , biomedical engineering , medicine , physics , nuclear physics , engineering , aerospace engineering
Ablation efficiency and residual thermal damage produced by pulsed holmium laser radiation were investigated in vitro for bovine mitral valves and human calcified and noncalcified cardiac valves. Low‐OH quartz fibers (200 and 600 μm core diameter) were used in direct contact perpendicular to the specimen under saline or blood. Etch rate was measured with a linear motion transducer. Radiant exposure was varied from 0 to 3 kJ/cm 2 . For 200‐μm fibers, the energy of ablation was approximately 5 kJ/cm 3 in noncalcified and 15 kJ/cm 3 in calcified valves. Etch rates were dependent on mechanical tissue properties. Maximum etch rate at 1,000 J/cm 2 was 1–2 mm/pulse at 3 Hz repetition rate. Microscopic examination revealed a zone of thermal damage extending 300 μm lateral into adjacent tissue. Thermal damage was independent of radiant exposure beyond twice threshold.