Insufficient Recanalization of Thrombotic Venous Occlusion - Risk for Postthrombotic Syndrome

Purpose: To investigate the relationship between recanalization rate of occluded veins after deep venous thrombosis (DVT) and development of postthrombotic syndrome (PTS). Materials and Methods: Patients treated for DVT of the lower limbs were evaluated 12-36 months after acute DVT. Of 100 patients, 34 developed PTS, defined as Villalta score of >= 5. Symptoms and signs of PTS were assessed, and ultrasound examination of the veins was performed, checking for residual thrombus and presence of reflux. Results: Patients with PTS were older (64.0 y vs 55.5 y; P = .007) and more frequently experienced recurrent DVT (15% vs 3%; P = .030). Patients with PTS had a lower rate of recanalization. Patients with residual thrombus appeared to be at increased risk for PTS development compared with patients with total recanalization (odds ratio 6.0; 95% confidence interval, 1.7-21.9; P = .006). No difference in the presence of reflux was observed. Conclusions: Incomplete or absent recanalization is associated with a higher incidence of PTS, probably as a consequence of deteriorated blood flow and increased venous pressure. This suggests early recanalization could improve the outcome of DVT treatment in selected patients.