Question

Explain the phenomena of thrombogenicity and embolization with respect to medical devices.

Answer 1

Thrombogenicity is nothing but the ability of a material in contact with the blood to produce a clot. It can be a fixed thrombi or an emboli which have become detached and travel through the bloodstream. All materials are considered to be thrombogenic with the exception of the normal state of endothelial cells which line blood vessels. Few medical implants appear non-thrombogenic due to high flow rates of blood past the implant, but in reality all are thrombogenic to a degree. Many surface treatments are available to minimize these thrombogenic effects. The implant can be covered by a fibrous capsule, and the thickness of this capsule can be considered one measure of thrombogenicity, and if extreme can lead to the failure of the implant.

Embolization: Embolization devices allow the occlusion of selective blood vessels by introducing emboli. Patients with congenital heart disorders, embolization devices such as coils have designed for indications, such as ductal, atrial, and patent foramen oval (PFO) defect occluders. This procedure is performed for occluding a vessel with Gelfoam, coils, balloons, polyvinyl alcohol, and various glue-like agents, which are injected as liquids and then solidify in the vessel. It is performed with a specialized intravascular catheter after angiographic evaluation has outlined the area to be treated.