Estimation of trapped thrombus volumes in retrievable inferior vena cava filters: a visual scale.
OBJECTIVE
To establish a visual, objective scale for estimating trapped thrombus volumes in five types of retrievable inferior vena cava filters.


METHODS
Silicone-based radiopaque polymer volumes of 0.25, 0.5, 1.0, 1.5, 2.0, 3.0, and 4.0 mL were created. Both sphere and cone shapes were used. Polymer volumes were confirmed by means of the water displacement method. The volumes were then positioned to simulate trapped thrombus in five retrievable filters: Recovery and G2 (Bard Peripheral Vascular, Tempe, Ariz), Günther Tulip and Celect (Cook, Bloomington, Ind), and OptEase (Cordis Endovascular, Warren, NJ). Radiographs were obtained by using conventional parameters. Visual scales of thrombus volume were created for each filter type.


RESULTS
Visual scales for each retrievable filter type were created with simulated thrombi in typical trapping positions.


CONCLUSIONS
The authors developed a visual, objective scale for estimating trapped thrombus volume in five types of retrievable IVC filters. This could facilitate standardized reporting of thrombus volumes in studies of optional vena cava filters.
Wang
Stephen L
SL
Dotter Interventional Institute, Oregon Health and Sciences University, 3181 SW Sam Jackson Park Rd, Portland, OR 97239, USA. stephen.wang@alumni.duke.edu
Timmermans
Hans A
HA
Kaufman
John A
JA
D006801:Humans; D008954:Models, Biological; D011108:Polymers; D011859:Radiography; D012828:Silicones; D013927:Thrombosis / Q000000981:diagnostic imaging*; D016306:Vena Cava Filters
D011108:Polymers; D012828:Silicones