Delay between clinical presentation and treatment of deep venous thrombosis in the lower limbs and regression of thrombosis.

Introduction: The objective was to investigate the delay between the onset of DVT symptoms and start of anticoagulation in common practice, assess whether this has any impact on the recanalization of venous thrombosis over one year follow up.

Methods: A prospective observational study on 76 consecutive patients (39 men, 51.3%) with DVT diagnosed using compression ultrasound (CUS). Timing was classified as very early treatment ≤72 hours, early treatment ˂7 days and late treatment ≥7 days from onset of symptoms. Further development of the disease was monitored by CUS in scheduled visits 1, 3, 6 and 12 months after the start of treatment.

Results: Mean delay from symptom onset to the start of anticoagulation was 11.1 days (median 7 days, range 1-42 days) with significant difference (p˂0.05) between proximal (12.9 days, median 30 days) and distal DVT (6.5 days, median 2 days). In less than 25% of all patients, with both proximal and distal DVT, treatment was started very early (≤72 hours), 40 patients (52.6%) received late treatment ≥7 days. There was a positive correlation between delay, average time of complete recanalization (≤72 hours 4.2 months, ≥7 days 5.3 months, p˂0.05) and rate of incomplete recanalization (≤72 hours 7.3%, ≥7 days 30.9%, p˂0.01) in proximal DVT, not in distal DVT.

Conclusions: There was a delay of ≥7 days in treating in more than half of our patients. The mean interval between clinical onset and start of treatment was significantly shorter and a delay ≥7 days significantly less frequent in patients with distal DVT compared to patients with proximal DVT. A very significant positive correlation between delay in treatment and rate of incomplete recanalization of proximal and distal thrombosis indicates that delayed anticoagulation could be a signal risk factor for the incomplete recanalization and development of PTS.