16-year follow-up study of Vena Cava Filters Group.

Aim: The prevalence of venous thromboembolic disease (VTED) is between 0.05% and 0.1% whereas its incidence is approximately 0.1%. Out of 100 patients with deep vein thrombosis (DVT), 5 will develop clinically serious pulmonary embolism (PE), one of which will be fatal. It is well known from the literature that surgical interventions carried out without antithrombotic prophylaxis have a 30% incidence of DVT, which can be halved with adequate prophylaxis. The aim of this study is to evaluate the immediate, middle- and long-term complications of caval filters by identifying any of the problems connected with or independent of the presence of the filter, also in relation to international literature data.
Methods: In view of the evolution of VTED surgical prevention methods, we have analyzed our case record composed of 821 patients (October 1984-October 2002), treated with different surgical solutions for VTED, with indications for the placement of 634 caval filters.
Results: The 30-day follow-up of all the 634 filters placed (100%) shows no mortality from the procedure and any of its immediate complications. The middle-term follow-up (from 1 month to 5 years) of 361 filters (57%) shows 0.55% mortality from PE while the long-term follow-up (5-16 years) of 105 filters (17%) shows a percentage decrease in all complications and no mortality from PE. The results also show a progressive annual decrease in the number of filters placed.
Conclusions: The lower incidence of complications, compared to that reported in the literature, can be attributed to both improved operator dexterity in the placement of the filter and correct management of the complications. The lower number of filters used can be explained by improved therapeutic possibilities with new low molecular weight heparins (LMWH) and by current diagnostic as well as instrumental and biochemical monitoring methodologies.