Histological evaluation is the preferred method for examining the in-situ interaction between implanted medical devices and its surrounding tissue. The challenge lies in maintaining the interaction between the device and tissue due to differences in density. This method will present a similar density between the materials, allowing for a clean section through the tissue, device, and the interface. We have specially developed protocols to process, section, and stain devices implanted in tissue.
With this method, it is possible to examine the changes taking place at the interaction site such as scar tissue formation, changes to tissue architecture, changes in collagen and other protein profiles, tissue infiltration into the device and inflammation. Since most medical devices differ in material, our research team will work closely with you to develop specific protocols for your studies. In general, softer devices can be sectioned and deplastinated to obtain the best staining results.
Cutting & Grinding
For harder devices, the cutting & grinding technique is used to obtain 10μm section the best resolution. This sectioning method consist of a precision diamond blade saw and a semi-automated grinder/polisher. The saw is used to cut a think ‘wafer’ out of the resin-embedded tissue block then glued onto a slide. From there it is ground and polished to the required thickness.
Medical Device Tissue Interaction Analysis
The image below highlights surrounding tissue that is interacting with a bare-metal stent, embedded within the arterial wall. Using high powered imaging software, customized reports can be generated to score for pathological analysis.