Page 343 - Libro 2

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The Inferior Vena Cava and Iliac Veins
Michael Costanza
OBJECTIVES
Describe the anatomy and physiology of the inferior vena cava and iliac veins
Identify the most useful positions for the patient and sonographer for conducting an ultrasound exam of the inferior vena cava and iliac veins
Recognize useful maneuvers to improve the ergonomics and imaging quality of an ultrasound exam of the inferior vena cava and iliac veins
List the required images for an ultrasound exam of the inferior vena cava and iliac veins
Understand the most common pathologic conditions and anatomic variants of the inferior vena cava and iliac veins
Describe how color, spectral, and power Doppler evaluations are complementary to each other and grayscale images
List the grayscale, color, and spectral Doppler characteristics of the most common pathologic conditions and anatomic variants of the inferior vena cava and iliac veins
KEY TERMS
confluence | inferior vena cava | pulmonary embolus | retroperitoneum | thrombosis
GLOSSARY
confluence the union of two or more veins to form a larger vein; the equivalent of a bifurcation in the arterial system
inferior vena cava filter a typically cone-shaped medical device designed to prevent pulmonary embolism; an inferior vena cava filter is placed into the inferior vena cava so that it can trap venous thromboemboli from the lower extremities before they travel to the heart and lungs
pulmonary embolus the obstruction of the pulmonary arteries usually from detached
The retroperitoneal location of the inferior vena cava (IVC) and iliac veins make them challenging to ex- amine sonographically. Successful imaging of the IVC and iliac veins requires knowledge of their anatomy and physiology as well as appropriate preparation
fragments of a blood clot that travels from the lower extremity veins
retroperitoneum the space between the abdominal cavity and the muscles and bones of the posterior abdominal wall; vascular structures in the retroperitoneum include the inferior vena cava, the iliac veins, and the abdominal aorta
thrombosis partial or complete occlusion of a blood vessel due to clot
and patient positioning. Because these vessels can be the source of a pulmonary embolus, careful evalua- tion is essential. In addition to detecting a thrombus, ultrasound has proven to be a useful tool to aid in the placement of IVC filters and their follow-up.
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