Role of Intravascular Ultrasound(IVUS) in Management of Acute and Chronic Iliocaval Obstruction

Acute and chronic venous disorders of the lower extremities affect millions of people and cause substantial disability. Surgeons and pathologists identified the presence of 'spur-like' abnormalities of the left common iliac vein, these abnormalities were hypothesized to result from compression and/or irritation from the adjacent crossing right common iliac artery. In the 1990s, physicians, starting to perform catheter-directed thrombolysis to treat extensive deep vein thrombosis (DVT), observed that about 50% of patients had an iliac vein stenosis.Treatment is aimed at ameliorating the symptoms and, whenever possible, at correcting the underlying abnormality. Graduated compression is the cornerstone of modern therapy. Deep system disease is often refractory to treatment, but superficial system disease can usually be treated by ablating the refluxing vessels. Effective venous return from the lower extremities requires the interaction of the heart, a pressure gradient, the peripheral muscle pumps of the leg, and competent venous valves. In the absence of pathology, this system functions to reduce venous pressure from approximately 100 mm Hg to a mean of 22 mm Hg within a few steps.

Nonthrombotic venous compression patients with left common iliac vein compression can present in the 2nd or 3rd decade of life and are more common in women. Patients can have limb pain, limb swelling, ipsilateral chronic venous insufficiency, lipodermatosclerosis, recurrent superficial venous thrombophlebitis, and venous claudication.

Thrombotic iliofemoral venous compression with a predisposing anatomic configuration with a prothrombotic physiological state can present with acute pain and swelling of the left lower extremity consistent with an acute iliofemoral DVT mostly phlegmasia cerulea dolens . In the acute phase, patients with a patent foramen ovale can also present with a pulmonary embolism, cryptogenic stroke, with or without pulmonary embolism, or systemic arterial embolism.

The abnormalities in venous physiology associated with chronic venous disease, and their quantification by diagnostic tests, are also considerably more complex than for PAD. With CVD one must gauge the effects of obstruction and/or reflux in a vascular bed uniquely designed to return venous blood to the heart against gravity with the aid of a peripheral muscle pump and in phase with respiratory mechanics.

Duplex ultrasound (DUS) is initial diagnostic test. The criteria include: poststenotic turbulence, as indicated by a mosaic velocity profile, abnormal Doppler signal at the area of stenosis, continuous flow with the Valsalva maneuver, and sluggish with no spontaneous flow and poor augmentation and no respiratory phasicity. But there is limitations as obesity ,casts, dressings, open wounds, Patients with severe edema/swelling and limited patient mobility.