Cook Inferior Vena Cava Filter (CIVC) Study Findings

WHAT IS PE?

The annual incidence of pulmonary embolism (PE) worldwide is estimated at approximately 1 case per 1,000 people, although exact figures are challenging due to underdiagnosis and variability in reporting.¹ PE is a serious and potentially life-threatening condition that can result from blood clot formation in the legs, known as deep vein thrombosis (DVT). These clots can travel to the lungs and can lead to serious health consequences. Inferior vena cava (IVC) filters may be indicated for the prevention of recurrent PE when anticoagulant therapy is contraindicated; anticoagulant therapy has failed in thromboembolic diseases; emergency treatment following massive PE where anticipated benefits of conventional therapy are reduced; and chronic, recurrent PE where anticoagulant therapy has failed or is contraindicated.

Backed by clinical data: the CIVC study

The findings from the Cook Inferior Vena Cava Filter (CIVC) study demonstrate technical success in placement and retrieval while maintaining safety and effectiveness outcomes.²

The study, which evaluated Cook vena cava filters, found that freedom from new symptomatic PE remained high, with low rates of major adverse events (MAEs) such as filter migration, fracture, and embolization.² Notably, retrieval was attempted in over 70% of patients, with a 94.9% success rate for the overall patient cohort,² demonstrating the utility of IVC filters in clinical practice when placed and retrieved according to the Instructions for Use and the Society for Interventional Radiology guidelines.³

Products referred to in this study are not available in all markets.

Study background

The CIVC study was a 2-year, prospective, multicentre, single-arm, investigational-device-exemption (IDE) study.²

The CIVC study was a 2-year, prospective,
multicentre, single-arm, IDE study.

Study demographics	Patient demographics	Indications for placement (94.9% of filters placed as temporary devices)
• 473 patients enrolled	• Mean age 61.1 ± 16.1 years	Patients receiving a filter had:
• 28 sites (US, UK, AUS)	• 57.3% male, 42.7% female	• Current DVT (48.4%) and/or current PE (20.7%)
• Celect and Celect Platinum filters (324 patients)		• A contraindication to anticoagulation (40.4%) or no contraindication but an added risk (21.4%)
• Günther Tulip® filter (149 patients)		• No VTE; considered at risk (30.9%)

From 2014 to 2017, investigators studied clinical results in patients who received a Cook vena cava filter.² The study’s primary endpoints were technical placement success and 1-year freedom from new symptomatic PE while a filter was indwelling, as well as 1-year freedom from MAEs.² Follow-up was conducted for 2 years or for 30 days after filter retrieval.²

Primary effectiveness endpoint:

Rate of technical placement success and 12-month freedom from new symptomatic PE while a filter was indwelling²

Primary safety endpoint:
Rate of 12-month freedom from MAEs (clinical perforation, clinical migration, clinical fracture, embolization of the filter or filter fragments to the heart or lungs, IVC thrombotic occlusion, new symptomatic DVT while the filter was indwelling, access site complications with clinical sequelae, procedure- or device-related death)²

Secondary endpoints:
Rate of technical placement success and 12-month freedom from new symptomatic PE while a filter was indwelling; rate of 12-month freedom from MAEs; rate of 12-month freedom from grade 2 or grade 3 filter leg interaction with the IVC; filter migration; filter fracture; and filter embolization (assessed for the overall cohort and for each stratum)²

Grade 2 indicates a filter leg outside the IVC, within the retroperitoneum; grade 3 indicates a filter leg in contact with another organ (see glossary).

Secondary measures:
PE, DVT (symptomatic and total), IVC thrombotic occlusion, and postplacement filter outcomes including fracture, embolization, significant migration, filter leg interaction with the IVC wall, clinical perforation, filter retrieval measures, access site adverse events with clinical sequelae, and procedure- or device-related death (assessed for the overall cohort and for each stratum)²

The study showed Cook filters are
effective at preventing PE while also being highly retrievable.²

Freedom from new symptomatic
PE while a filter is indwelling

Kaplan-Meier estimate (no. of patients at risk, no. of events)

Successful filter retrieval

Filter retrieval information	Reported
	Celect stratum²*
Successful filter retrieval attempts	95.2% (219/230)
Days to successful filter retrieval: mean ± SD (N, min-max)	134.0 ± 111.4 (219, 0–603)

Celect Vena Cava filter endpoints data²

Celect stratum endpoints*	12 months	24 months
Kaplan-Meier estimates (number of patients at risk, number of events)
Freedom from clinical perforation	89.2% (66, 16)	47.1% (11, 38)
Freedom from symptomatic filter leg integration with the IVC	98.5% (71, 2)	98.5% (17, 2)
Freedom from filter embolization	100% (71, 0)	100% (17, 0)
Freedom from new symptomatic deep vein thrombosis	92.6% (63, 17)	89.5% (13, 19)
Freedom from filter fracture	100% (71, 0)	100% (17, 0)
Freedom from filter migration >20 mm	100% (71, 0)	98.6% (15, 1)

*Celect stratum consisted of Celect and Celect Platinum vena cava filters.

Learn more about our filters and retrieval devices: Schedule time with your Cook representative.

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Glossary

Deep vein thrombosis (DVT):

thrombus in the deep veins, usually of the lower extremities or pelvis; documented by contrast venography, duplex ultrasound CT, or MR venography

Filter embolization:

postplacement movement of the filter or its components to a distant anatomical site completely out of the target zone (e.g., heart or lungs); documented by imaging or at autopsy

Filter fracture:

any loss of structural integrity (breakage or separation) of the filter; documented by imaging or at autopsy

Filter leg interaction with the IVC:

Grade 0: normal; filter strut confined entirely within the IVC
Grade 1: filter strut immediately adjacent to the external aspect of the IVC wall (likely reflecting tenting of the IVC wall)
Grade 2: filter strut entirely outside of the IVC lumen and within the retroperitoneum as evidenced by a ‘halo’ of retroperitoneal fat around axially viewed strut
Grade 3: filter strut touching, impressing, or perforating another organ (e.g., liver, bowel, aorta, psoas muscle, vertebral body, or lymph nodes)

Filter migration:

change in filter position compared with its deployed position (cranial or caudal); classified as significant (>20 mm) or insignificant (<20 mm); documented by plain radiography, CT, or venography

Major adverse events (MAEs):

Access site adverse events with clinical sequelae: arteriovenous fistula, haematoma, or bleeding requiring transfusion (≥2 units), hospitalisation (either admission or extended stay), or further treatment
Clinical fracture: loss of structural integrity (breakage or separation) of a filter identified by imaging and associated with clinical sequelae and/or requiring intervention; confirmed by core laboratory
Clinical migration: caudal or cranial movement of a filter resulting in surgical or endovascular intervention; confirmed by core laboratory
Clinical perforation: protrusion of filter legs through the wall of the IVC causing haemorrhage or heamatoma or touching, impressing, or perforating another organ (e.g., liver, bowel, aorta, psoas muscle, vertebral body, or lymph nodes); documented using CT and confirmed by core laboratory
Embolization of a filter or filter fragments to the heart or lungs: postplacement movement of the filter or its components to the heart or lungs; documented by imaging or at autopsy and confirmed by core laboratory
IVC thrombotic occlusion: presence of an occluding thrombus in the IVC occurring after filter placement (may be symptomatic or asymptomatic); documented by appropriate imaging or at autopsy and confirmed by core laboratory
New symptomatic DVT while a filter is indwelling: documented by appropriate imaging and confirmed by core laboratory
Procedure- or device-related death: death directly attributable to a filter or filter placement or the retrieval procedure itself; documented by clinical findings, imaging, or at autopsy, or as adjudicated by a clinical events committee (CEC)

Pulmonary embolism (PE):

Emboli to lungs via the pulmonary artery, which can arise from DVT in the lower extremities or pelvis; documented using pulmonary arteriography, cross-sectional imaging, significant change in ventilation or perfusion lung scan, or at autopsy

Technical placement success:

deployment of a filter in a location suitable to provide sufficient mechanical protection against PE with no filter deformation, fracture, premature release, or clinical migration

Learn more about our filters and retrieval devices: Schedule time with your Cook representative.

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Kahn SR, de Wit K. Pulmonary embolism. N Engl J Med. 2022;387(1):45–57.
Van Allan RJ, Smouse HB, McWilliams RG, et al. Two-year outcomes from the Cook Inferior Vena Cava Filter (CIVC) study. J Vasc Interv Radiol. 2025;36(4):583–593.e3.
Kaufman JA, Barnes GD, Chaer RA, et al. Society of Interventional Radiology clinical practice guideline for inferior vena cava filters in the treatment of patients with venous thromboembolic disease. J Vasc Interv Radiol. 2020;31(10):1529–1544.

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The CIVC study was a 2-year, prospective,
multicentre, single-arm, IDE study.

Successful filter retrieval

Celect Vena Cava filter endpoints data²

Learn more about our filters and retrieval devices: Schedule time with your Cook representative.

Glossary

Learn more about our filters and retrieval devices: Schedule time with your Cook representative.

Thank You for Your Interest in Cook Medical's Products

The CIVC study was a 2-year, prospective,multicentre, single-arm, IDE study.

Successful filter retrieval

Celect Vena Cava filter endpoints data2

Learn more about our filters and retrieval devices: Schedule time with your Cook representative.

Glossary

Learn more about our filters and retrieval devices: Schedule time with your Cook representative.

Thank You for Your Interest in Cook Medical's Products

The CIVC study was a 2-year, prospective,
multicentre, single-arm, IDE study.

Celect Vena Cava filter endpoints data²