Superior vena cava (SVC) filters placed over central lines - analysis of line trapping and difficulties with line retrieval: an in-vitro experimental study.
BACKGROUND
Placement of superior vena cava (SVC) filters has been shown to be both safe and effective in preventing symptomatic pulmonary embolism in patients with upper extremity deep venous thrombosis that have contraindications to anticoagulation therapy. In many patients, existing central lines pose a challenge to SVC filter placement due to the theoretical risk of line displacement and/or entrapment.


OBJECTIVE
To assess the risk of catheter entrapment by filter legs during SVC filter deployment and the risk of subsequent filter migration during catheter removal.


METHODS
A model was created by placing a 22 mm vascular graft inside a plastic tube and submerged in a warm saline bath. Five types of filters were deployed under fluoroscopic guidance over different types of central lines of varying calibers (5-14 Fr). Each filter was deployed five times over each type of central line. The positioning of the legs of the filters in relationship to the central lines was studied by fluoroscopic and direct inspection. The lines were then removed under fluoroscopic guidance noting any line trapping, migration, and/or tilting of the filters.


RESULTS
Movement of the lines during filter expansion was commonly seen after deployment of all filters with varying frequencies. During line removal slight resistance was encountered with the Celect filter (10%) and the Option filter (5%), while significant resistance was only encountered when using the OptEase filter (20%). Filter migration was only observed when the OptEase filter was deployed over large (>10 Fr) caliber lines (10%).


CONCLUSIONS
When SVC filters are placed over existing central lines, the risk of catheter entrapment is very low in this in-vitro model. Filter migration during line retrieval was only observed when the OptEase filter was placed over >10 Fr caliber lines.
Department of Radiology, UT Health Science Center at San Antonio, San Antonio, TX, USA Lopera@uthsca.edu.
Jorge E
JE
Lopera
Department of Radiology, UT Health Science Center at San Antonio, San Antonio, TX, USA.
Murray
M
Shapiro
Nova Southeastern University College of Osteopathic Medicine, FL, USA.
Darlene
D
Sanchez
Universidad CES, Medellin, Colombia.
Carolina
C
Maya
Department of Radiology, UT Health Science Center at San Antonio, San Antonio, TX, USA.
Ghazwan
G
Kroma
Department of Radiology, UT Health Science Center at San Antonio, San Antonio, TX, USA.
Andres
A
Garza-Berlanga
Department of Radiology, UT Health Science Center at San Antonio, San Antonio, TX, USA.
Rajeev
R
Suri
D062905:Central Venous Catheters; D020878:Device Removal / Q000379:methods*; D004867:Equipment Design; D005471:Fluoroscopy / Q000379:methods; D008954:Models, Biological; D008955:Models, Cardiovascular; D016306:Vena Cava Filters
Vena cava; catheters; embolism/thrombosis; filter insertions