| Postphlebitic (postthrombotic) Syndrom (PPS) The Incidence and severity of the PPS are correlated to the initial site of thrombosis and its extent. Following DVT, the incidence of PPS after 5 years is about 24%, and after 20 years about 90%. The development of PPS is more likely to occur after recurrent episodes of DVT. Postthrombotic alternations of the deep veins are the main cause, including obstruction and stenosis of the venous outflow of the leg into the abdominal veins and destruction of the venous valves. The latter direct the blood flow produced by the muscle pump. Both entities lead to venous hypertension resulting in the clincal symptoms: leg pain and swelling, and, in severe cases, venous ulceration. Complications include localized eczema, reduction of mobility in the ankle joint due to painful fixation, and very rarely subcutaneous bone metaplasia.
During development of PPS four phases can usually be distinguished: - Disturbance of the venous drainage (first 2 month)
- Development of collateral veins and recanalization of the occluded vessel (between month 3 and 12);
- Stabilized phase (2nd year);
- From the 3rd year on the situation usually worsens due to valve-incompetence and insufficiency.
Two approaches are possible to prevent and to treat PPS: compression therapy and thrombolytic therapy. The first one, performed with compression stockings, is considered the basic therapy. Together with general measures like avoidance of longer periods of sitting or standing, raised leg position at night, and movement therapy, it is the intention to lower the venous hypertension. The purpose of the thrombolytic therapy is to reduce the damage to venous valves. However, results from clinical trials have not clearly shown beneficial effects with either method.
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