Stented Vessels: A Challenge for Histological Preparation and Microscopy

Abstract

Andrea Nolte, Theresa Braun, Sven zur Oven Krockhaus, Adelheid Munz,Ulrich F.ogel, Rainer Kehlbach, Christian Schlensak, Hans P. Wendel Tobias Walker

Objective: The first procedure to treat blocked coronary arteries was coronary artery bypass graft surgery. In 1977, Andreas Grüntzig introduced percutaneous transluminal coronary angioplasty (PTCA). Today, several stent systems exist ranging from bare metal stents (BMS) to various drugeluting stents. Unfortunately, our understanding of the arterial reaction to stent implantation is incomplete – primarily due to technical limitations in the histological study of stented vascular tissue. Methods: In our study, we examined different histological preparation methods based on the embedding material methacrylate. The procedure of embedding and sectioning of stented porcine arteries was optimized for the specific requirements, like histochemistry, immunohistochemistry or pre-stained fluorescence. Furthermore, we used a microscopical technique described as fluorescence intensity decay shape analysis microscopy (FIDSAM) to eliminate auto-fluorescence from fluorescently labeled tissue. Results: The sections were suitable for histochemical and immunohistochemical staining. Additionally, pre-labeled fluorescence in the porcine tissue was not lost by the embedding process. Conclusions: The evaluation of arterial cross sections with FIDSAM technology gives new, very important insights into the examination possibilities of fluorescently labeled tissue. Future studies of the vascular response to a variety of new stent materials will provide important clues to the pathogenesis resulting in restenosis and occlusion of stents.