Subcutaneously tethered temporary filter: pathologic effects in swine.
OBJECTIVE
To evaluate the histopathologic effects of the Tempo-filter, a temporary caval filter, on the caval wall and determine the feasibility of deployment and removal of the device in swine.


METHODS
Filters were placed in the infrarenal inferior vena cava of 11 swine. The tethering catheter was sutured in a subcutaneous pocket near the puncture site. The original tethering catheter used in humans and a stiffer catheter designed to prevent migration in swine were evaluated. Postplacement, mid-study, and preexplant vena cavography procedures were performed. Four swine underwent in situ dissection at 3-10 weeks. Filters were removed from seven animals just before they were killed at 1-6 weeks.


RESULTS
All filters were successfully placed. All seven filters were successfully removed at up to 6 weeks after placement. Cephalic migration of more than 1 cm was observed in 10 of 11 swine (100% of original catheters, 83% of stiff catheters). Other complications were more common with stiffer tethering catheters, including caval stenosis in 40% of original catheters and 100% of stiff catheters, filter cone thrombus in 0% and 67%, tethering catheter thrombus in 20% and 83%, pulmonary embolism in 0% and 50%, and death in 0% and 17%, respectively. There was mild vessel wall damage in the vena cava.


CONCLUSIONS
Placement of the Tempofilter and removal at up to 6 weeks after placement is feasible.
Kuszyk
B S
BS
Department of Cardiovascular and Interventional Radiology, Johns Hopkins Hospital, Baltimore, MD 21287, USA.
Venbrux
A C
AC
Samphilipo
M A
MA
Magee
C A
CA
Olson
J L
JL
Osterman
F A
FA
D000818:Animals; D003251:Constriction, Pathologic / Q000209:etiology; D062109:Dermatologic Surgical Procedures; D004210:Dissection; D004867:Equipment Design; D005069:Evaluation Studies as Topic; D005240:Feasibility Studies; D005548:Foreign-Body Migration / Q000209:etiology / Q000517:prevention & control; D011655:Pulmonary Embolism / Q000209:etiology; D011677:Punctures; D011859:Radiography; D013499:Surface Properties; D015996:Survival Rate; D013536:Suture Techniques; D013552:Swine; D013927:Thrombosis / Q000209:etiology; D016306:Vena Cava Filters / Q000009:adverse effects; D014682:Vena Cava, Inferior / Q000000981:diagnostic imaging / Q000473:pathology*