In vitro evaluation of a retrievable low-profile nitinol vena cava filter.
OBJECTIVE
To evaluate the clot-trapping ability, stability, and migration of a new low-profile, retrievable inferior vena cava (IVC) filter in an in-vitro model.


METHODS
The SafeFlo IVC filter consists of two superelastic nitinol wires that form a double-ring platform and spiral filter. The filter is collapsed into a 5-6-F catheter and delivered into the IVC model. The in-vitro model closely simulates the physical parameters of flow in the human IVC. Human blood clots of 2-mm and 4-mm diameters and 3-cm lengths were injected into the flow system in sets of five clots. Filter delivery and retrieval were performed in every series. Filtration was evaluated in IVC models of 20-mm and 24-mm lumen diameter in vertical and horizontal positions. Stability and migration of the filter were evaluated by direct vision of maintenance of position and shape before and after clot trapping.


RESULTS
Filter delivery and retrieval were straightforward and repeatable in a total of 20 procedures. The filters maintained shape and position throughout the study. A total of 248 clots were injected and 225 (90.7%) were trapped. The individual tests in horizontal and vertical positions with either clot size demonstrated trapping rates of 85.7%-97.1%.


CONCLUSIONS
The SafeFlo IVC filter is a stable and effective filter in an in-vitro model. The filter design is amenable to simple delivery and retrieval.
Bruckheimer
Elchanan
E
Section of Pediatric Cardiology, Schneider Children's Medical Center Israel, Kaplan 14, Petach Tikva, Israel. elchananb@bezeqint.net
Judelman
Alon G
AG
Bruckheimer
Simon D
SD
Tavori
Isaac
I
Naor
Gil
G
Katzen
Barry T
BT
D000497:Alloys / Q000627:therapeutic use*; D001777:Blood Coagulation / Q000187:drug effects; D020099:Coated Materials, Biocompatible / Q000627:therapeutic use*; D020878:Device Removal; D004867:Equipment Design; D017743:Equipment Reuse; D004869:Equipment Safety; D005548:Foreign-Body Migration; D006801:Humans; D008955:Models, Cardiovascular; D011655:Pulmonary Embolism / Q000097:blood / Q000628:therapy; D016306:Vena Cava Filters
D000497:Alloys; D020099:Coated Materials, Biocompatible; C013616:nitinol