Biomaterial Database

Laser thrombolysis using long pulse frequency-doubled Nd:YAG lasers. 1999

J A Viator, and S A Prahl

Oregon Graduate Institute, Portland, Oregon 97291, USA.

OBJECTIVE Laser thrombolysis is a means for clearing blood clots in occluded arteries. Many researchers have studied the mechanisms of clot ablation, and research clinicians have used the technique to treat myocardial infarction with a number of different laser systems. Specifically, a 1-microsec pulsed dye laser has been used clinically to remove blood clots in coronary arteries. As a comparative study, the ablation characteristics of lasers with pulse durations in the ranges of 50-150 microsec and 2-10 msec were investigated. Two frequency-doubled Nd:YAG lasers at 532 nm were used in this study. Ablation threshold and ablation efficiency of gel phantoms and thrombus using these two lasers were measured and compared with the results of the pulsed dye laser. The pulsed dye laser in this study operated at 522 nm. METHODS Gelatin samples with 150 cm(-1) absorption coefficient at 532 nm and animal clot were confined to 3-mm silicone tubes to measure ablation parameters. Additional samples with 150 cm(-1) absorption coefficient at 522 nm were prepared for use with the pulsed dye laser. A fluorescence technique and photographic bubble detection were used to determine ablation threshold. A spectrophotometric technique was used to determine ablation efficiency. RESULTS The ablation threshold of the gel phantoms for all three lasers was determined to be 17 +/- 2 mJ/mm(2). Ablation efficiency for the gel phantoms was 1.7 +/- 0.1 microg/mJ. Clot had an ablation efficiency of 2.9 +/- 1.0 microg/mJ. CONCLUSIONS Ablation threshold and efficiency are independent of laser pulse duration for 1-microsec, 50-150-microsec, and 2-10-msec pulses (P < 0.05).

UI	MeSH Term	Description	Entries
D008954	Models, Biological	Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.	Biological Model,Biological Models,Model, Biological,Models, Biologic,Biologic Model,Biologic Models,Model, Biologic
D010781	Photography	Method of making images on a sensitized surface by exposure to light or other radiant energy.	Photographies
D004285	Dogs	The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)	Canis familiaris,Dog
D004396	Coloring Agents	Chemicals and substances that impart color including soluble dyes and insoluble pigments. They are used in INKS; PAINTS; and as INDICATORS AND REAGENTS.	Coloring Agent,Dye,Dyes,Organic Pigment,Stain,Stains,Tissue Stain,Tissue Stains,Organic Pigments,Pigments, Inorganic,Agent, Coloring,Inorganic Pigments,Pigment, Organic,Pigments, Organic,Stain, Tissue,Stains, Tissue
D005780	Gelatin	A product formed from skin, white connective tissue, or bone COLLAGEN. It is used as a protein food adjuvant, plasma substitute, hemostatic, suspending agent in pharmaceutical preparations, and in the manufacturing of capsules and suppositories.	Gelafusal
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D015912	Thrombolytic Therapy	Use of infusions of FIBRINOLYTIC AGENTS to destroy or dissolve thrombi in blood vessels or bypass grafts.	Fibrinolytic Therapy,Thrombolysis, Therapeutic,Therapeutic Thrombolysis,Therapy, Fibrinolytic,Therapy, Thrombolytic,Fibrinolytic Therapies,Therapeutic Thrombolyses,Therapies, Fibrinolytic,Therapies, Thrombolytic,Thrombolyses, Therapeutic,Thrombolytic Therapies
D053685	Laser Therapy	The use of photothermal effects of LASERS to coagulate, incise, vaporize, resect, dissect, or resurface tissue.	Laser Knife,Laser Scalpel,Surgery, Laser,Vaporization, Laser,Laser Ablation,Laser Knives,Laser Photoablation of Tissue,Laser Surgery,Laser Tissue Ablation,Nonablative Laser Treatment,Pulsed Laser Tissue Ablation,Ablation, Laser,Ablation, Laser Tissue,Knife, Laser,Knifes, Laser,Knive, Laser,Knives, Laser,Laser Knifes,Laser Knive,Laser Scalpels,Laser Surgeries,Laser Therapies,Laser Treatment, Nonablative,Laser Treatments, Nonablative,Laser Vaporization,Nonablative Laser Treatments,Scalpel, Laser,Scalpels, Laser,Surgeries, Laser,Therapies, Laser,Therapy, Laser,Tissue Ablation, Laser
D066298	In Vitro Techniques	Methods to study reactions or processes taking place in an artificial environment outside the living organism.	In Vitro Test,In Vitro Testing,In Vitro Tests,In Vitro as Topic,In Vitro,In Vitro Technique,In Vitro Testings,Technique, In Vitro,Techniques, In Vitro,Test, In Vitro,Testing, In Vitro,Testings, In Vitro,Tests, In Vitro,Vitro Testing, In