Lower extremity venous sonography in the high-risk cancer population: One leg or two?

OBJECTIVE. We correlated the diagnostic yield of unilateral and bilateral l ower extremity venous sonograms in a high-risk cancer population with the c linical indication for the examination. MATERIALS AND METHODS. Reports from 433 bilateral and 619 unilateral lower extremity Doppler sonograms obtained over an 18-month period in patients wi th cancer were retrospectively reviewed, and clinical indication and findin gs were determined. RESULTS, Overall, 228 (22%) of 1052 examinations revealed deep venous throm bosis (DVT): 83 (19%) of 433 bilateral and 145 (23%) of 619 unilateral. Amo ng studies performed for unilateral symptoms (pain, edema, or postorthopedi c procedure), 23% (135/581) of unilateral and 27% (44/162) of bilateral stu dies revealed DVT. Among these 44 bilateral studies with positive findings performed for unilateral symptoms, there were 30 DVT in the symptomatic sid e, 12 bilaterally, and two in the asymptomatic side alone. Ten percent (11/ 110) of the bilateral studies performed for bilateral symmetric symptoms re vealed DVT. Among studies performed for bilateral asymmetric symptoms, 13% (1/8) of the unilateral and 8% (2/25) of the bilateral studies revealed DVT : both bilateral studies showed positive findings in the more symptomatic s ide. Among studies performed for suspected or proven pulmonary embolus, 20% (23/113) of bilateral and 54% (7/13) of unilateral studies had positive fi ndings. CONCLUSION. In a high-risk cancer population, the incidence of DVT in patie nts with unilateral symptoms is more than twice that of patients with bilat eral symptoms. Because DVT isolated to an asymptomatic lower extremity is r are (1%), bilateral sonographic examination is generally unnecessary with u nilateral lower extremity symptoms.