IN-VIVO INTRAVASCULAR LASER PHOTODYNAMIC THERAPY IN RABBIT ATHEROSCLEROTIC LESIONS USING A LATERAL DIRECTION FIBER

Background and Objective: This study was performed to evaluate the pos sibility of inducing regression of atherosclerotic foci by photodynami c therapy (PDT) using hematoporphyrin derivative (HpD). Study Design/M aterials and Methods: Atherosclerotic rabbits were divided into four g roups. Groups A (n = 6) and C (n 6) were given 5 mg/kg of HpD intraven ously; Groups B (n = 4) and D (n = 4) were not. Twenty-four hours afte r 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 a nd C and two rabbits from groups B and D were sacrificed immediately a fter 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 sacrifice d 7 days after the photoradiation. Results: In groups A 7 and C 7, mos t intimal cells and endothelial cells had become necrotic and disappea red, and a loss of intima was observed. No such changes were found in groups B 7, D 7. Conclusion: The above data suggest that PDT caused ef fective regression of the atherosclerotic lesions. (C) 1997 Wiley-Liss , Inc.