Summary
Diagnosis of recurrent deep-vein thrombosis (DVT) is difficult because of limitations
in distinguishing acute from old thrombi. In the past, an ultrasound method for diagnosis
of recurrent ipsilateral DVT was developed, which relies on repeated measurements
of the diameters of the common femoral and popliteal veins. To assess the safety of
withholding anticoagulation from patients with improved or stable compression vein
diameters, 205 consecutive patients presenting with suspected recurrent ipsilateral
DVT were evaluated. The vein diameter was measured under compression with the transducer
and compared with earlier ultrasound results. Patients with stable or improved ultrasound
findings had repeat ultrasound assessments after 2 (± 1) and 7 (± 1) days. Patients
with repeatedly normal ultrasound results were followed-up for six months to determine
the incidence of symptomatic recurrent venous thromboembolism.
Of the 205 patients, 153 had stable or improved ultrasound findings. Repeat ultrasound
assessment became abnormal in 3, and recurrence was confirmed by venography in all.
A six months follow-up was done in the remaining 150 patients with repeatedly normal
ultrasound tests and showed 2 (1.3%; 95% CI, 0.02 to 4.7%) confirmed non-fatal venous
thromboembolic complications. The positive predictive value of a stable or improved
ultrasound was 90% (95% CI, 77 to 97%).
In conclusion, it is safe to withhold anticoagulant treatment from patients with suspected
recurrent ipsilateral DVT in whom compression ultrasonography showed improved or stable
vein diameters.
Keywords
DVT - thrombi - ultrasonography
