MMPI drug-eluting IVC filter decreases adhesion between caval wall and filter

The implantation of inferior vena cava (IVC) filter was a safe and effective therapy for preventing fatal pulmonary embolism. However, there are risks associated with long-term implantation of filters. Retrievable filters are designed to be removed, but may also remain permanently. Retrieval can reduce risk of long-term complications. The difficulty or impossibility of retrieval is still an issue of retrieval filter. The major causes of filters retrieval failure were intimal overgrowth and severely tilted filter with apex embedded into the caval wall. Matrix metalloproteinases (MMPs) play a key role in neointimal hyperplasia. It is documented that neointimal hyperplasia can be reduced by inhibiting MMP activity and hence smooth muscle cell migration. MMP inhibitors (MMPI) can potently inhibit the activity of MMPs. We hypothesize that a drug-eluting filter which contains MMPI may inhibit IVC neointimal hyperplasia and decrease the adhesion between vascular wall and filter struts. After implantation of drug-eluting retrieval filter, MMPI is released slowly at the sites where the filter struts are in contact with the caval wall; the activity of MMPs of caval wall will be inhibited, injury in basement membrane is decreased, migration of SMC maybe reduced, and the release of extracellular matrix maybe lessened. Finally, neointimal hyperplasia maybe inhibited, the adhesion between vascular wall and filter maybe weakened, the success rate maybe increased, and the vascular injury during retrieval maybe reduced. The hypothesis might improve the long-term prognosis of venous thromboembolism patients.