Ultrasound-Guided Cava Filter Placement

Abstract

Pulmonary embolism from deep venous thrombosis reduces the cross-sectional area of the pulmonary vascular bed, resulting in an incremental increase in pulmonary vascular resistance and subsequent increased right ventricular afterload. Thus, large or recurrent pulmonary emboli can be fatal. Anticoagulation alone can decrease the mortality rate to less than 5%, but cannot be used universally in all patient populations. The advent of the inferior vena cava filter has drastically changed the management of patients with lower extremity deep venous thrombosis and a contraindication to anticoagulation. Developed in the 1940s, this device has evolved into a modality that has proven effective at preventing life-threatening pulmonary emboli. Mechanical caval interruption devices have since improved as well, including a significant decrease in delivery sheath size, which aids in achieving post-procedural hemostasis. Because of these improvements, IVC filter placement has changed from a procedure performed exclusively in the operating room with venotomy to a bedside percutaneous procedure using ultrasound guidance. Successful use of transabdominal duplex ultrasound and IVUS eliminate the need for radiocontrast dye administration thus avoiding the known risk of renal failure and anaphylaxis. Other advantages include decreased radiation exposure to the patient and hospital personnel, reduced need for patient transport, and decreased cost compared to traditional placement in the operating room suite. In a cost containment era, it is feasible to think that future mechanical caval interruption will occur more commonly at the bedside than in the traditional operating theater.