Source: Ann Urol  |  Posted 9 years ago

A combination of clinical probability, ultrasonography and D-dimer measurements is a practical and safe way of ruling out deep vein thrombosis in patients with clinically suspected thrombosis.

This practical approach also reduces the need for repeat ultrasonography, report Dr L W Tick and colleagues from the Meander Medical Center, Amersfoort, The Netherlands.

To evaluate the new non-invasive approach to these patients, the investigators examined 811 patients with clinically suspected deep vein thrombosis.

Primary endpoint was venous thromboembolism occurring in a three-month follow-up period.

Of 280 patients (35%) with a low clinical probability, 30 (11%) had an abnormal initial ultrasonography and were treated. Of the other 250 untreated patients with low clinical probability and a normal ultrasonography, five (2%; 95% confidence interval [CI]: 1 to 5%) developed a nonfatal venous thromboembolism during follow-up.

Among the 531 patients (65%) with a moderate-to-high clinical probability, 300 (56%) had an abnormal ultrasonography. Of the remaining 231 patients with normal ultrasonography, 148 had a normal D-dimer test; none of these patients developed deep vein thrombosis during follow-up.

Seventy-seven of the 83 patients with an abnormal D-dimer test underwent repeat ultrasonography about one week later; none of the 64 patients with a second normal ultrasound developed symptomatic deep vein thrombosis in follow-up.