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Pulsed holmium laser ablation of cardiac valves

โœ Scribed by Lothar Lilge; Dr. Wolfgang Radtke; Norman S. Nishioka

Publisher
John Wiley and Sons
Year
1989
Tongue
English
Weight
536 KB
Volume
9
Category
Article
ISSN
0196-8092

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โœฆ Synopsis

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 pm 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/cm2. For 200-pm fibers, the energy of ablation was approximately 5 kJ/cm3 in noncalcified and 15 kJ/cm3 in calcified valves. Etch rates were dependent on mechanical tissue properties. Maximum etch rate at 1,000 J/cm2 was 1-2 mmipulse at 3 Hz repetition rate. Microscopic examination revealed a zone of thermal damage extending 300 pm lateral into adjacent tissue. Thermal damage was independent of radiant exposure beyond twice threshold.

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