IVC Filters

IVC Filters

Key recommendations

§   IVC filters should be considered:

1.      to prevent PEs in patients with DVT who have a contraindication to anticoagulation.

2.      PEs despite therapeutic anticoagulation but high dose warfarin INR 3.5 or LMW heparin should be considered first particularly in those with thrombophilia (APS or cancer).

3.      Pregnant women who have contraindications to anticoagulation or develop VTE shortly before delivery.

4.      Pre op patients with recent VTE (<1 month) in whom anticoagulation must be interrupted

5.      chronic thromboembolic pulmonary hypertension undergoing pulmonary endarterectomy

§   IVC filters are not indicated:

§        Unselected patients who will receive conventional anticoagulation

§        In thrombolysis for DVT

§        Free floating thrombus is not an indication for insertion

§   Anticoagulation should be considered in patients with an IVC filter when the temporary contraindication is no longer present.

§   There is insufficient evidence to support a recommendation that all filter recipients should be treated with indefinite anticoagulation.

§        Removable filters should be used for patients with a short term contraindication to anticoagulation.

§   Should be removed within 10-14 days

VC filters used instead of anticoagulation

§   Only one trial of IVC filters Decousus et al., NEJM 1998 - all patients received either LMW or unfractionated heparin.

§   1.1 v 4.8% with filters v no filter had PEs at day 12

§   21 v 12% had recurrent DVTs at 2 years

§   At 8 years follow up recurrent PEs were 6 v 15% but DVTs were 37 v 27%

§   <50% were anticoagulated for over a year

§   Evidence from case series conflicting – some suggesting that filters and anticoagulation have similar efficacy / others showing anticoagulation to be more effective

Complications of filter placement

§   Normally can be put in with an INR of 1.5

Immediate

§   Misplacement (1.3%)

§   Pneumothorax (0.02%)

§   Haematoma (0.6%)

§   Air embolism (0.2%)

§   Carotid artery puncture (0.04%)

§   Arteriovenous fistula (0.02%)

Early complications

§   Insertion site thombosis

§   Infection

Late complications

§   Recurrent DVT (21%)

§   IVC thrombosis (2 to 10%); 22% at 5 years; 33% at 9 years (50% had leg swelling)

§   Post-thrombotic syndrome (15-40%)

§   IVC penetration (0.3%)

§   Filter migration (0.3%)

§   Filter tilting and fracture

§   Entrapment of guidewires