The role of intravascular ultrasound in venous thromboembolism.

Venous thromboembolism (VTE) remains a serious problem, and treatments surrounding this potentially life-threatening disease continue to evolve. Evidence-based guidelines purport the need for minimally invasive catheter-based procedures as part of the armamentarium to prevent and treat VTE. When the appropriate clinical scenarios arise, intravascular ultrasound (IVUS) becomes a necessary part of those procedures to provide alternative imaging that complements traditional venography. IVUS of the major axial veins provides a 360-degree two-dimensional gray scale ultrasound image of lumen and vessel wall structures. IVUS remains the criterion standard for venous imaging when contemplating catheter-based procedures from the common femoral vein to the inferior vena cava. Not only can precise location and size of these veins be determined by the IVUS probe from key landmarks and venous branches, but other important abnormalities can be visualized. These include external compression, acute and chronic thrombus, fibrosis, mural wall thickening, spurs, and trabeculations. Specific procedures that use IVUS include the treatment of venous obstruction and the placement of vena cava filters at the bedside. IVUS remains a vital part of accurately imaging the major axial veins when contemplating catheter-based procedures to prevent or treat VTE-related disorders.