Guideline for the prophylactic insertion of inferior vena cava filters in trauma patients

• Rationale
• Indications
• Timing
• Removal
• Conventional indications for IVC filter insertion
• Anticoagulation
• Contraindications to filter insertion
• Contraindications to filter retrieval

Rationale

The incidence of symptomatic deep venous thrombosis [DVT] in the population of patients with polytrauma is approximately 5-12%. The incidence of pulmonary embolism [PE] in this population is 1%.
IVC filters reduce the risk of large PE in patients with known DVT. Their use in patients considered at high risk of PE who cannot be anticoagulated (eg. Polytrauma patients) is unproven.

Indications

Consider Inferior Vena Cava [IVC] Filter insertion in polytrauma patients where the risks of DVT / PE are considered to be high and mechanical or pharmacological interventions to prevent DVT are contraindicated or impossible.

ie:

AND

AND

AND

AND

THEN

Timing

A request for filter insertion should be made as soon as the above described conditions are identified.

The referral should be consultant trauma-, neuro- or vascular- surgeon to consultant vascular interventional radiologist

The filter should be then inserted as soon as practically possible: on admission (consider at time of pelvic angiography or embolization) if possible, but within 72 hrs if not practical before that.

Patients undergoing procedures in angio suite as part of their trauma care (usually for haemorrhage control or aortic injury) should ideally be assessed for indications for IVC filter insertion at the same time, though IVC filter insertion should not delay other priorities in their care.

Removal

The vascular radiology department will make an appointment for IVC filter retrieval at the time of insertion. This will usually be six weeks from the date of insertion, or sooner where the patient can be anticoagulated sooner (see below)

Referring consultant (trauma, neurosurgery or spinal surgery) to ensure, if the patient is to be discharged or repatriated before 6 weeks, that they make arrangements with the vascular radiology department (23311) for earlier retrieval prior to the patient leaving the MTC.

Removal may occur anytime prior to six weeks if anticoagulation can be started (prophylactic or therapeutic).

A pre-removal Doppler Ultrasounf [dUS] of IVC, iliac and femoral veins should be requested at the same time as request to remove the filter to ensure there is no DVT (in which case formal anticoagulation will be required, or if contraindicated, the filter should remain in situ until anticoagulation can be undertaken).

Conventional indications for IVC filter insertion

The above recommendations apply to patients in whom there is considered to be a high risk of DVT / PE but in whom no DVT / PE has been identified. The conventional indications for IVC filter placement should not be overlooked….

• Known (proven) DVT / PE with contraindication to therapeutic anticoagulation.
• Proven PE despite therapeutic anticoagulation
• Proven DVT / PE with minimal physiological reserve
• Proven DVT / PE with likely poor compliance with anticoagulation (discuss)

Anticoagulation

There is no need for anticoagulation to be commenced solely because of the presence of an IVC filter.

Indications for anticoagulation (therapeutic or prophylactic) should be made based on the patients other comorbidity, bleeding risk and / or the development of DVT / PE. If the risks of anticoagulation have reduced sufficiently to allow this therapy, administration of LMWH should commence immediately and should not be delayed pending filter retrieval.

Prophylactic dose LMWH need not be stopped for an IVC filter retrieval. If a patient is on treatment dose LMWH the dose the evening before the procedure should be omitted. For patients at high risk of recurrent DVT in whom omitting a dose is considered too high risk (usually on the advice of a haematologist), the filter can be retrieved at nadir LMWH levels (just before the next dose). This may need adjustment of dosing times to coordinate with angio suite logistics. Please liaise with angio suite to arrange (23311).

Contraindications to filter insertion

• Allergy to nitinol.
• IVC diameter > 30 mm or < 15 mm
• Lack of suitable access vessel.
• Known infected thrombus or sepsis.

Contraindications to filter retrieval

• Lack of adequate venous access in neck (relative, please discuss)
• Progressive thrombus formation on anticoagulation.
• Remaining high risk of pulmonary embolus and ongoing contraindication to anticoagulation
• Thrombus in filter on imaging.