Determining Embolus Trapping Efficiency of an Inferior Vena Cava Filter during Exercise

Restricted (Penn State Only)
Author:
Riley, Joshua Mackey
Area of Honors:
Biomedical Engineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Keefe B Manning, Thesis Supervisor
  • William O Hancock, Honors Advisor
  • Peter J Butler, Faculty Reader
Keywords:
  • Inferior Vena Cava Filter
  • IVC Filter
  • Pulmonary Embolism
  • Trapping Efficiency
Abstract:
Deep vein thrombosis (DVT) and pulmonary embolism (PE) affect 1 in 1,000 people in the US annually. Inferior vena cava (IVC) filter placement is performed when patients cannot undergo anticoagulation therapies for DVT/PE. IVC filters capture thromboemboli traveling through the IVC to prevent PE. Many factors can affect the trapping efficiency of an IVC filter, including filter orientation with respect to the IVC axis, IVC orientation in relationship to gravity, and ratio of clot to fluid density. To study these factors, researchers at the U.S. Food and Drug Administration (FDA) recently designed a generic IVC filter for research purposes. The objective of this study is to characterize the embolus trapping efficiency of the FDA’s generic IVC filter and to generate data to validate computational simulations of the device. This study measured the FDA generic IVC filter’s trapping efficiency using rigid beads of 3.2 mm, 4.8 mm., and 6.4 mm diameters under exercise conditions. Deformable emboli, created by the coagulation of bovine whole blood, of similar sizes and shape were also tested. A Reynolds number of 1470 was chosen for infrarenal IVC flow in coordination with pre-existing literature regarding the anatomical IVC model used in this experiment. This study characterized the embolus trapping efficiency of the FDA generic IVC filter. The trapping efficiency depends on embolus size and the iliac vein from which the embolus originates. There is a significant difference (p < 0.05) in the trapping efficiency of 4.8 mm diameter deformable and rigid spheres. There is also a significant difference (p < 0.01) in the trapping efficiency between the left and right iliac of rigid small clots and deformable small and medium clots. These results are important for the verification of existing computational models. With verification, the accuracy of patient-specific models will better predict IVC filter success and improve patient outcomes.