Evaluation of the Crux IVC Filter in an animal model.
OBJECTIVE
To determine the safety and performance of a new inferior vena cava (IVC) filter in an ovine model and evaluate the retrievability at 5 weeks.


METHODS
The Crux Vena Cava Filter (VCF) is composed of 2 nitinol spiral supports with a polymeric filter suspended between them. Retrieval tails on each end facilitate retrieval. Twelve filters were placed in the infrarenal IVCs of 12 sheep. The vessels were imaged pre and post deployment to assess acute device performance. At 5 weeks, the vessels were re-imaged to evaluate continued device performance and vessel integrity. Nine of 12 filters were retrieved, and the animals were returned to their housing. The other 3 animals were sacrificed, and the filters and vessels were processed for gross and histological examination. At 9 weeks, 4 weeks after filter retrieval, vessel integrity of the remaining 9 animals was again assessed under fluoroscopy. The animals were sacrificed, and the IVCs were explanted for study.


RESULTS
All 12 filters were implanted without complications at the intended deployment site and remained fixed over the implantation period. At 5 weeks, the filters intended for recovery were successfully retrieved, with a mean capture time of 9.6+/-13.7 minutes. There were no complications during the 4-week follow-up after filter retrieval. Post-retrieval imaging at 5 and 9 weeks showed no visible signs of vessel wall damage. Histological study of 3 explanted vessels and filters revealed slight neointima encapsulation of the filter elements and minimal incorporation. Gross examination of the post-retrieval vessel walls after the 4-week healing period showed minimal superficial vessel damage; histology showed minimal residual signs of hemorrhage, with little to no inflammatory reaction.


CONCLUSIONS
The Crux VCF was deployed and safely retrieved without incident at 5 weeks in an animal model. There was no significant damage seen to the IVCs 1 month after filter retrieval.
Division of Vascular & Endovascular Surgery, UT Southwestern Medical Center, Dallas, TX 75390-9157, USA.
Erin H
EH
Murphy
Rodney A
RA
White
David
D
Rosenthal
Eric D
ED
Johnson
Christopher K
CK
Zarins
Thomas J
TJ
Fogarty
Frank R
FR
Arko
D000497:Alloys; D000818:Animals; D002404:Catheterization / Q000295:instrumentation*; D020878:Device Removal; D004724:Endoscopy; D008422:Materials Testing; D023421:Models, Animal; D010690:Phlebography; D011474:Prosthesis Design; D019919:Prosthesis Implantation; D012756:Sheep; D013997:Time Factors; D016306:Vena Cava Filters; D014682:Vena Cava, Inferior / Q000473:pathology
D000497:Alloys; C013616:nitinol