The effect of venous thrombus location and extent on the development of post-thrombotic signs and symptoms.

OBJECTIVE: This prospective study determined the incidence of signs and symptoms of chronic venous disease and recurrent venous thrombotic events (VTE) in relation to the location and extent of the initial venous thrombus.

METHODS: A first episode of acute deep vein thrombosis (DVT) occurred in 120 lower extremities of 105 patients (59 men; mean age, 54 years [range, 23-82 years]). Patients who presented with pain, swelling, or signs and symptoms of pulmonary embolism of <10 days were included. The DVT was diagnosed with duplex ultrasound (DUS) imaging. Patients were grouped by those having thrombosis in one venous segment (group A) or multiple levels (group B). Patients were treated with heparin and warfarin. Patients with at least 1-year of follow-up with clinical and DUS were included.

RESULTS: No difference was found in the duration of signs and symptoms at presentation. The median follow-up was 3.4 years (range, 1.2-7 years). More symptomatic limbs were seen in group B (71 of 79) compared with group A (21 of 41; P < .001). Post-thrombotic syndrome (PTS) was more advanced in group B vs group A, including the prevalence of skin damage and ulceration (61 of 79 vs 26 of 41, P < .001; 29 of 79 vs 6 of 41, P = .019, respectively). Limbs with calf DVT that had focal thrombosis were most often asymptomatic. Calf thrombosis in patients with proximal DVT produced the highest prevalence of PTS. Venous claudication was exclusively found in group B and was present only when iliac veins were involved. Recurrent thrombosis had a trend for a higher prevalence in group B (5 of 41 vs 16 of 79, P = .39). Reflux, obstruction, or a combination of the two were more common in group B (61 of 79) vs group A (15 of 41; P < .0001). Limbs with both reflux and obstruction were more likely to develop skin damage (group A, 5 of 6 vs 1 of 35, P < .0001; group B, 24 of 29 vs 5 of 50, P < .0001).

CONCLUSIONS: Recurrent thrombosis and skin damage is more likely to develop in patients with multiple sites of thrombosis than in those with thrombosis in a single vein segment. Patients with reflux and obstruction presented more skin damage than those with reflux or obstruction alone. Involvement of the calf veins in the presence of proximal vein thrombosis increased the likelihood for PTS.