Characterization of the site dependency of normal canine arterial fluorescence.
The difference in fluorescence between normal and atherosclerotic artery has been proposed as a feedback mechanism to guide selective laser ablation of atherosclerotic plaque. This fluorescence difference is due to the relative difference in collagen:elastin content of normal artery and atherosclerotic plaque. However, normal arteries have site-dependent variation in collagen: elastin content which may affect their fluorescence spectra. To evaluate the site dependency of normal arterial fluorescence, helium-cadmium (325 nm) laser-induced fluorescence spectra were analyzed in vitro from the ascending aorta, abdominal aorta, and carotid, femoral, renal, and coronary arteries (N = 57) of 12 normal mongrel dogs. Elastin and collagen contents were determined for a subset of these arteries (N = 15). The spectral width of normal arterial Fluorescence varied by site and correlated with the measured collagen:elastin content at each site (r = -0.84, P less than 0.005). Fluorescence spectra were decomposed into collagen and elastin spectral components by using a linear model with a least-squared error criterion fit. The derived collagen and elastin spectral coefficients correlated with the measured collagen and elastin tissue content (r = 0.75 and 0.83 respectively, P less than 0.005). Thus, the fluorescence spectra of normal arteries is site dependent and correlates with the collagen:elastin content. Therefore, spectral feedback algorithms for laser angioplasty guidance must be site specific.
Garrand
T J
TJ
Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06510.
Stetz
M L
ML
O'Brien
K M
KM
Gindi
G R
GR
Laifer
L I
LI
Deckelbaum
L I
LI
D000818:Animals; D001158:Arteries / Q000032:analysis* / Q000033:anatomy & histology; D003094:Collagen / Q000032:analysis*; D004285:Dogs; D004549:Elastin / Q000032:analysis*; D053685:Laser Therapy; D007834:Lasers; D013050:Spectrometry, Fluorescence
D003094:Collagen; D004549:Elastin