Photodynamische Therapie (PDT) in arteriellenGefäßsegmenten zur Prophylaxe der Zellproliferation nach Gefäßverletzung

Application of photosensitizers in endovascular Photodynamic therapy (PDT) might be a usefull approach to prevent restenosis by locally developing a cytotoxic effects in porcine arterial vessel segments treated by directional atherectomy (DA). Photophrin II (PFII) was used as a photosensitizer, selectively delivered by a porous catheter and activated by adequate monochromatic light irradiation. The efficacy of PDT was tested in a porcine model of restenosis with standardized media laceration. 24 arterial segments of pigs with mean average weight of 30 kg were treated by means of directional atherectomy. 16 vessel segment were removed after 7 days (group 1). 12 vessel segments underwent a selective application of 5mg PFII per treated segment with a porous balloon that allows a circumferential homogenous local application of vasoactive drugs. These 12 vessel segments were exposed to monochromatic light (630 nm) with 100 J/cm2 (group 2). Seven days after this treatment all vessels were explanted and processed for immunohistochemistry and electron microscopy.