title: Application of the 1-microsecond pulsed-dye laser to the treatment of experimental cerebral vasospasm.
abstract: Laser energy of 480 nm was applied in 1-microsecond pulses varying between 2.2 and 10 mJ to in vitro and in vivo models of cerebral vasospasm. First, the pulsed-dye laser was applied intravascularly via a 320-microns fiber to basilar artery segments from six dogs. The segments were mounted in a vessel-perfusion apparatus and constricted to, on average, 70% of resting diameter by superfusion with dog hemolysate. Immediate increase in basilar artery diameter occurred to a mean of 83% of control. In a second model, the basilar artery was exposed transclivally in the rabbit. In three normal animals, superfusion of the artery with rabbit hemolysate resulted in a reduction of mean vessel diameter to 81% of control. Following extravascular application of the laser, vessels returned to an average of 106% of the resting state. In six rabbits, the basilar artery was constricted by two intracisternal injections of autologous blood. 3 days apart. Two to 4 days after the second injection, the basilar artery was exposed. Extravascular laser treatment from a quartz fiber placed perpendicular to the vessel adventitia resulted in an immediate 53% average increase in caliber to an estimated 107% of control. No reconstriction was observed over a period of up to 5 hours. Morphologically, damage to the arterial wall was slight. This preliminary investigation suggests that the 1-microsecond pulsed-dye laser may be of benefit in the treatment of cerebral vasospasm.
authors.affiliation: Wellman Laboratories of Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston.
authors.forename: A
authors.initials: A
authors.lastname: Teramura
authors.forename: R
authors.initials: R
authors.lastname: Macfarlane
authors.forename: C J
authors.initials: CJ
authors.lastname: Owen
authors.forename: R
authors.initials: R
authors.lastname: de la Torre
authors.forename: K W
authors.initials: KW
authors.lastname: Gregory
authors.forename: R
authors.initials: R
authors.lastname: Birngruber
authors.forename: J A
authors.initials: JA
authors.lastname: Parrish
authors.forename: J W
authors.initials: JW
authors.lastname: Peterson
authors.forename: N T
authors.initials: NT
authors.lastname: Zervas
mesh_terms: D000818:Animals; D001488:Basilar Artery / Q000601:surgery / Q000648:ultrastructure; D004285:Dogs; D004730:Endothelium, Vascular / Q000648:ultrastructure; D005260:Female; D066298:In Vitro Techniques; D002546:Ischemic Attack, Transient / Q000473:pathology / Q000601:surgery*; D053685:Laser Therapy; D008297:Male; D008855:Microscopy, Electron, Scanning; D011817:Rabbits; D014664:Vasodilation