Venous function and clinical outcome following deep vein thrombosis.

The severity of post-thrombotic symptoms in 111 limbs (107 patients) with previous phlebographically proven deep vein thrombosis (DVT) was correlated with superficial and deep venous function as determined by foot volumetry (n = 90) and duplex ultrasonography (n = 62). The median delay between DVT and assessment was 8 (range 1-34) years. Symptoms were mild (group 1) in 31 limbs (28 per cent), moderate (group 2) in 41 (37 per cent) and severe (group 3) in 39 (35 per cent). There was no significant relationship between the site of DVT, or the time since DVT, and the severity of symptoms. Without tourniquet occlusion of superficial veins, limbs in group 3 had a significantly shorter half-refilling time than those in groups 1 and 2 (P = 0.01). Although a similar trend was observed after tourniquet occlusion of superficial veins, this was not statistically significant. There was no significant difference in the expelled volumes between the three clinical groups. On duplex scanning, deep and superficial venous reflux was detected in just over half of the limbs in each group. Eight patients had entirely normal scans and none of them had severe symptoms (P = 0.04). This study identifies a strong association between severe postphlebitic syndrome and venous reflux, such that it may be considered that venous reflux is necessary for the development of severe post-thrombotic symptoms. However, many patients with severe reflux have only mild symptoms and additional factors must therefore contribute to the development of severe postphlebitic syndrome.