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Three Part Question

In [patients with proximal lower limb DVT] are [inferior vena cava filters better than standard anticoagulantion therapy] at [reducing pulmonary embolisation and minimising recurrence of DVT]?

Clinical Scenario

A 40 year old man attends the emergency department with a one week history of a painful, swollen right leg. An illeo-femoral deep vein thrombosis is diagnosed. He has no previous history of venous thromboembolism, however, his father has a history of PE. You decide to start him on standard anticoagulation therapy. A passing physician states that the patient is at high-risk for developing a PE, and suggests referral for insertion of an inferior vena cava filter. You wonder if there is any evidence to support this assertion.

Search Strategy

Medline 1966-01/04 using the Ovid interface.
[exp deep vein thrombosis OR exp venous thrombosis/ OR deep vein thromb$.mp OR deep venous thromb$.mp OR DVT.mp] AND [exp vena cava filters/ OR inferior vena cava filters.mp OR IVC$.mp] LIMIT to human AND English language.

Search Outcome

Altogether 463 papers were found of which 1 was a PRCT relevant to the question.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Decousus H et al, 1998, France	400 patients with proximal vein thrombosis 200 randomised to receive an IVCF and 200 to receive no IVCF Patients also randomised to receive LMWH or unfractionated heparin Follow-up data recorded day 12 and two years	PRCT (two-by-two factorial design) Multi-centre (44 sites)	Rate of recurrent VTE at 12 days: Filter group/no filter group	2 (1.1%) had had symptomatic or asymptomatic PE /9 (4.8%) had had symptomatic or asymptomatic PE /6 (3.4%) had symptomatic PE /12 (6.3%) had symptomatic PE	Overall 6 patients died of PE, no breakdown in the paper of filter verses no filter The study was powered for 400 patients per group (800), however a steering committee interrupted the study due to slow recruitment rate
			Recurrent VTE at 2 years: Filter group/no filter group	37 (20.8%) at 2y had had recurrent DVT (95% CI, P= 0.03). (16 had thrombosis at the filter site) /21 (11.6%) at 2y had had recurrent DVT
			Death at 12 days: Filter group/ No filter group	5 (2.5%), no PE/5 (2.5%), 4 PE
			Death at 2 years: Filter group/No filter group	43 (21.6%)/40 (20.1%)
			Major bleeding: Filter group/ no filter group/LMWH/UFH	17 (8.8%) /22 (11.8%) /16 (8.5%)/23 (12%)

Comment(s)

The authors conclude that any initial beneficial effects of the filter group were counter balanced by the increased rate of recurrent DVT, without any significant difference in mortality. There is only one RCT to be found in the literature addressing this question, while there is an abundance of literature supporting the use of anticoagulants as effective treatment for proximal DVT.

Clinical Bottom Line

Standard anticoagulants are the first treatment of choice for someone with a proximal DVT who has no contraindications to the treatment.

References

1. Decousus H, Leizorovicz A, Parent F, et al. A clinical trial of vena caval filters in the prevention of pulmonary embolism in patients with proximal deep-vein thrombosis. Prevention du Risque d'Embolie Pulmonaire par Interruption Cave Study Grp N Eng J Med 1998;338(7):409-15.