In vivo intravascular laser photodynamic therapy in rabbit atherosclerotic lesions using a lateral direction fiber

Abstract

This study was performed to evaluate the possibility of inducing regression of atherosclerotic foci by photodynamic therapy (PDT) using hematoporphyrin derivative (HpD). Atherosclerotic rabbits were divided into four groups: A (n = 6) and C (n = 6) were given 5 mg/kg of HpD intravenously; Groups B (n = 4) and D (n = 4) were not. Twenty-four hours after HpD administration, the aortae of groups A and B were exposed to 200 mw output argon dye laser beam at 630 nm for 10 minutes; groups C and D were exposed to 400 mw for 5 minutes. Three rabbits from groups A and C and two rabbits from groups B and D were sacrificed immediately after laser photoradiation, being named groups A 0, C 0 and groups B 0, D 0, respectively. Groups A 7, C 7, and Groups B 7, D 7 were sacrificed 7 days after the photoradiation. In groups A 7 and C 7, most intimal cells and endothelial cells had become necrotic and disappeared, and a loss of intima was observed. No such changes were found in groups B 7, D 7. The above data suggest that PDT caused effective regression of the atherosclerotic lesions.