Venous Imaging for Reflux Using Duplex Ultrasonography

Chronic venous disease is very prevalent and has significant socioeconomic impact in the society. After physical examination is performed duplex ultrasound (DU) has become the method of choice for evaluating venous disease. This is because it is noninvasive, portable, easily repeatable, has great resolution, evaluates anatomy and function, offers very good differential diagnosis, and has relatively low cost. DU examination should be performed with the patient in the standing position to increase its diagnostic yield. Cutoff values for venous reflux have been established and generally accepted with a retrograde flow of >500 ms for superficial, deep calf veins, deep femoral, and perforator veins and >1,000 ms for common femoral, femoral, and popliteal veins. Anatomic variations in both the superficial and deep venous systems are very common (i.e., duplication of the popliteal or femoral vein, hypoplasia of the great saphenous vein); hence, careful examination is mandatory. Segmental reflux has a mild to moderate clinical presentation, while extensive involvement is associated with skin changes. Around 80% of patients with chronic venous disease have reflux alone, 17% have reflux and obstruction, while obstruction alone is uncommon. The combination of reflux and obstruction has usually the worst prognosis. Site-specific DU examination is important in tailoring therapeutic interventions according to pertinent findings. DU is important for obtaining venous access, performing endovenous ablation, foam sclerotherapy, while it can also be useful for vein angioplasty and stenting, insertion of inferior vena cava filters, and guide thrombolysis. The introduction of intravascular ultrasound has facilitated the development of strategies to overcome limitations of ultrasound technology. Examination of lower extremities can be challenging especially in obese patients, in the presence of edema, while inability of the patient to cooperate during the examination can impact the quality of testing. Despite these limitations, DU remains the standard of care in detecting vein disease.