THE SITE OF RESIDUAL ABNORMALITIES IN THE LEG VEINS IN LONG-TERM FOLLOW-UP AFTER DEEP-VEIN THROMBOSIS AND THEIR RELATIONSHIP TO THE DEVELOPMENT OF THE POSTTHROMBOTIC SYNDROME

Two major sequelae of deep vein thrombosis (DVT), obstruction to outfl ow due to the presence of residual thrombus and reflux due to valvular damage, may contribute to the development of the post-thrombotic synd rome (PTS). We studied the nature and site of residual abnormality, no n-invasively with duplex ultrasound, in the veins of 69 limbs in 66 pa tients, 1 to 6 years after primary acute DVT. There were clinical feat ures of the PTS in 27 limbs and 42 legs were asymptomatic. The pattern of duplex abnormalities was complex and varied for both the PTS and a symptomatic groups. The proportion of abnormal common and external ili ac veins and abnormal common, deep and superficial femoral veins was s imilar for limbs with the PTS and asymptomatic limbs. Twenty-six per c ent of legs with the PTS had reflux at the saphenofemoral junction com pared with 19% asymptomatic legs (difference not significant). The PTS was associated with proportionally more abnormal popliteal veins (81% vs 55%) and posterior tibial veins (PTV), PTV#1 (41% vs 21%) and PTV# 2 (41% vs 14%) when compared with asymptomatic limbs. THe odds ratio f or a popliteal vein abnormality being associated with the PTS was 3.63 (95% CI 1.16 to 11.43). The odds ratios for PTV#1 and PTV#2 abnormali ties in association with the PTS compared to asymptomatic limbs were 2 .52 (95% CI 0.87 to 7.31) and 4.13 (95% CI 1.30 to 13.11). In conclusi on, residual venous abnormalities after DVT are common and when presen t in the popliteal and tibial veins are associated with an increased l ikelihood of PTS expression.