CONTRALATERAL DUPLEX SCANNING FOR DEEP VENOUS THROMBOSIS IS UNNECESSARY IN PATIENTS WITH SYMPTOMS

Purpose: Bilateral lower extremity venous duplex scanning for acute de ep venous thrombosis (DVT) has been advocated because of the high inci dence of occult contralateral leg involvement. We investigated the cli nical necessity of such a policy. Methods: The results from 2996 venou s duplex studies performed during the past 2 years were retrospectivel y reviewed. A total of 1694 of these scans were performed on patients with symptoms, of whom 248 (15%) were found to have an acute DVT. Symp toms were limited to one side in 198 patients, whereas bilateral compl aints were noted in 50 patients. Results: Among the patients with symp toms of acute DVT, 72 (29%) had bilateral involvement. Bilaterality wa s more Likely in patients with bilateral symptoms than in those with o nly unilateral symptoms (56% vs 22%; p < 0.005). Of the patients with unilateral symptoms and bilateral DVT, all of them had either acute (8 0%) or acute and chronic (20%) thrombosis in the symptomatic leg. The contralateral asymptomatic limb had fewer acute and more chronic DVT ( 41% and 55%, respectively). No patient from the entire group admitted with symptoms had an acute DVT in the asymptomatic limb without a conc omitant acute DVT in the symptomatic leg. Unilateral scanning would de crease the examination time by 21% and potentially increase total reim bursement for symptomatic venous scans by 9% compared with routine bil ateral duplex scanning. Conclusions: Although bilateral involvement is frequent in patients with symptoms of acute DVT, treatment in these p atients is not altered by this finding. We conclude that contralateral venous scanning in patients with unilateral symptoms is not clinicall y indicated and that unilateral scanning would result in improved cost -efficiency for vascular laboratories.