Objective: Several studies have evaluated the natural history of deep vein thrombosis (DVT), but few have correlated the clinical progression using duplex ultrasound (DU) imaging during the first year. This study was designed to determine the relationship of changes in the venous system and correlate them with long-term progression of disease.
Methods: Consecutive patients with a first episode of proximal DVT documented by DU imaging were included prospectively. Clinic examinations were performed at 3, 6, and 12 months, and yearly thereafter. The CEAP system was used to grade disease severity. DU imaging was performed at least once, 1 year after the diagnosis, and repeated at 5 years. The proximal veins were divided the common femoral vein, femoral vein, and popliteal vein segments for analysis. Thrombosed veins were subsequently graded as completely, partially, and fully recanalized. Recurrent DVT cases were also recorded.
Results: The study included 64 patients with 73 involved limbs; of which, skin damage was documented in three (4%) at 1 year and in 18 (25%) at 5 years (P = 0.0006; relative risk [RR], 3.92; 95% confidence interval [CI], 1.36-11.3). Overall from 1 to 5 years, 50 limbs remained the same. A change in clinical class occurred in 23 limbs (31.5%), including five limbs that progressed from class 0 to 3, 15 limbs from class 3 to 4 and 6, and three from class 4 to 5 and 6. DU imaging of these 23 limbs progression showed that the most important predictor for class progression was ipsilateral recurrent DVT (RR, 4.4; 95% CI, 1.4-13.3). Recurrent DVT at 1 year occurred in 21.9%, including ipsilateral in 15.6% and contralateral in 6.3%. Total recurrence at 5 years was 31.3%, including ipsilateral in 23.4% and contralateral in 7.8%. Limbs with ipsilateral recurrence were more likely to have partial recanalization, reflux, and more vein segments involved compared with those with contralateral recurrence or no recurrence (11 of 15 vs 16 of 58; RR, 4.7; 95% CI, 1.7-13.3).
Conclusion: Clinical class progression from year 1 to 5 occurs in 30% of post-thrombotic limbs. The most important predictor for progression in clinical class was ipsilateral recurrent DVT.