[Use of specific photo-markers in experimental laser coronary angioplasty]

Research into improving the efficacy of laser in the vaporisation of atheromatous plaques has led to the study of their modes of emission and to attempts at changing the natural absorption properties of the target lesion. This was achieved in vitro by incubation with solutions of derived haematoporphyrin and in vivo by oral administration of therapeutic doses of tetracycline. The selective nature of the coloration produced having been proved, the use of appropriate lasers allowed reduction of 50 to 100 p. 100 of the emitted energy; the exploitation of the fluorescent properties of tetracycline, investigated by laser spectrofluoroscopy in this study, has led to the concept of in situ photodiagnosis of the plaque. These results may open up a new field of research into unknown photobiological characteristics radically different to the thermic energy used at present.