Venous duplex scanning for unilateral symptoms: When do we need a contralateral evaluation?

Objectives:Determine the need for bilateral duplex scanning (DS) in patients with unilateral symptoms of acute DVT of the leg.Design:Prospective study.Materials:One thousand, one hundred and sixty-one consecutive patients with recent unilateral symptoms of pain or swelling.Methods:Bilateral DS were performed and demographic data including risk factors for DVT were entered into a computerised database.Results:Of the 250 cases (22%) of acute DVT, thrombus was confined to the symptomatic limb in 80% (200/250) and to the asymptomatic limb (AL) in 5% (12/250), while bilateral DVT was found in 15% (38/250). The management was not altered by the contralateral DS findings in any patient with bilateral thrombus. Ten of the 12 cases of DVT confined to the AL were localised to the infrapopliteal level; advanced malignancy, recent joint surgery or hypercoagulability were noted in nine patients, including all those requiring treatment.Conclusions:In the presence of unilateral symptoms of DVT, we recommend DS of the symptomatic extremity only; bilateral examination should be confined to patients with normal duplex findings in the symptomatic limb following recent joint surgery, or in the presence of advanced malignancy or hypercoagulability. Bilateral DS would therefore be required in approximately 11% of cases with unilateral symptoms of DVT