Control of excimer laser aided tissue ablation via laser-induced fluorescence monitoring

Human atherosclerotic arterial samples were ablated via a fiber with a XeCl excimer laser. The resulting tissue fluorescence was recorded for each ablating pulse. The pulse-to-pulse evolution of the fluorescence intensity at 430 nm was obtained and compared to the histological findings. The characteristic transition observed in such curves exhibited good correlation with the transition from the atheromatous layer to the normal media, as determined by the histological examination. The establishment of such a relation led to the development of a simple computer algorithm able to detect plaque to normal media transitions. The limitations of this approach are discussed.