Proximal lower extremity chronic venous outflow obstruction: recognition and treatment

As postthrombotic disease becomes better understood, the importance of venous outflow obstruction is recognized increasingly. It appears that obstruction of the iliac vein is particularly important and results in more severe symptoms than more distal segmental blockages. Unfortunately, no accurate invasive or noninvasive test for the evaluation of obstruction is available. In fact, it is not known what degree of venous stenosis should be considered hemodynamically "critical." Thus, currently it is impossible to detect borderline obstructions of potential hemodynamic significance. A high index of suspicion must be maintained. The diagnosis relies on clinical signs and symptoms, and treatment must be based on results of morphologic investigations such as transfemoral phlebography or, preferably, intravascular ultrasonography. Percutaneous iliac venous balloon dilation and insertion of a stent offers a safe and efficient method to correct pelvic venous obstruction. It is less invasive and relatively safer than open surgery and can, therefore, be offered to a larger group of patients. Furthermore, initial percutaneous management does not preclude subsequent bypass or reflux surgery. Although the technique is recent and follow-up relatively short, there is cautious optimism that this treatment will be useful and replace bypass surgery for iliac venous obstruction.