Integrated Microscopy Techniques for Analyzing Postmortem Intravascular Stents.
Fred J Clubb, Stephen D Darrouzet, Aaron W Roberts, Brad R Weeks, Maximilian Buja. Texas A&M University, College Station; Texas Heart Institute, Houston
Background: The use of intravascular stents in treatment of coronary artery disease represents a major means for treating coronary artery disease. Coronary stents are implanted in thousands of patients every year in the United States (650,000 in 2006). While there are many reasons for a physician to implant a stent, they, like all implanted medical devices, carry a potential for failure. Current technologies for direct evaluation of vessels with stents include radiography and light microscopy (paraffin or plastic embedding). Though these techniques are fraught with limitations. We have developed a method of integrating micro-computed tomography (microCT) with microground tissue sectioning. By integrating these two techniques, we developed an efficient and a cost effective means of examining postmortem intravascular stent implants.
Design: Human autopsy samples were collected from patients with stents implanted in the coronary arteries (n = 6). The samples were processed for high-resolution radiographs and then microCT scans performed. The vessels were then processed for microgrinding using the data from the microCT scan acquire sections in the area of interest. These microground sections allow processing to occur without decalcification of plaques or removal of the stent struts prior to sectioning, providing a clear and complete view of the state of the tissue in the area of interest. The resulting histology was then compared to the three dimensional volume.
Results: The high resolution scans of the metallic stents allow for detection of fractures in the stent struts as well as calcified plaques within the vascular wall. Such areas of interest can then be localized, allowing the pathologist exclude the vast majority of tissue from processing for histology. In all six cases, the microCT scans demonstrated complications with the stent deployment or problems that arose post-implant, which were then verified by the corresponding histology.
Conclusions: High-resolution microCT (voxel size of ∼13µm) allows efficient identification of areas of interest in coronary vessels with implanted stents in a non-destructive manner. Employing MicroCT for precision-guided microground sections eliminates the need for serial sections on coronary tissue and allows for rapid localization of complications followed by microground light microscopy histology sections for examination.
Monday, February 28, 2011 11:15 AM
Platform Session: Section G 2, Monday Morning