Filter complications and their management.

Complications from the use of vena caval filters are rare but can occur at placement, during other procedures, or late in follow-up. Placement problems such as bleeding from the insertion site or embolism from thrombus manipulation are largely avoidable. Technical difficulties with introduction, positioning, or misplacement have been minimized by use of flexible carriers and guidewires. However, later insertion of guidewires without fluoroscopy for line changes can lead to problems of entrapment. Filter capture of emboli can result in further thrombus propagation at that site or in filter obstruction. Management of these events requires adequate visualization to determine whether to use lytic therapy or a second filter. Late complications include filter strut fracture in 0.05% of cases and filter penetration, of even rarer functional significance. Pain that can be attributed to the filter has been found only in a single case of pelvic misplacement. The limited consequences of mechanical changes in the filter argue strongly against unnecessary interventions, which frequently result in an increase in morbidity.