Laser-induced fluorescence detection of cardiovascular atherosclerotic deposits via their natural emission and hypocrellin (HA) probing.

In order to develop a reliable laser-induced-fluorescence-guided angioplasty system, fluorescence spectra were recorded during exposure of normal and atherosclerotic cadaveric aortic tissue to He-Cd laser radiation (442 nm). A characteristic increase in the fluorescence signal at 600 nm for atheromatous tissue was observed after treatment of the samples with hypocrellin (HA). This, combined with the spectral distribution of tissue natural fluorescence, allowed the development of simple algorithms, based on the intensity difference and the full width at half-maximum (FWHM), and a subsequent index of discrimination between normal and various atheromatous tissues. Our results suggest that monitoring of this index through the catheter could enhance selective ablation, reducing the risk of normal vessel perforation.