Incidence and risk factors of the post-thrombotic syndrome.

Annually 1-2 in every 1000 adults will develop a deep venous thrombosis of the lower extremity. A third to half of these patients will develop the post-thrombotic syndrome (PTS). However, predicting which patients will develop the PTS remains elusive. Ipsilateral thrombosis recurrence seems to be the most important risk factor. Moreover, residual venous occlusion and valvular reflux seem to predict PTS incidence to some degree. Laboratory parameters, including d-dimers and inflammatory markers, have shown promise in predicting development of the PTS in patients and are currently under investigation. Creating a model based on all combined risk factors and patient characteristics might aid in risk stratification in individual patients.