[Impedance plethysmography, Doppler echography and phlebography in deep venous thromboses of the lower limbs]

Computerized impedance plethysmography (CIP) and phlebography were performed on 165 consecutive outpatients with clinical suspicion of deep venous thrombosis (DVT) and on 220 consecutive asymptomatic patients hospitalized for hip fracture. Ninety-two asymptomatic patients were examined also with real-time B-mode US. In orthopedic patients CIP sensitivity, specificity, accuracy, positive and negative predictive values were 19.4%, 90.5%, 64.4%, 53.8% and 66.3%, respectively, for proximal and distal DVT, versus 19.7%, 88%, 77.5%, 77% and 86% for proximal DVT. In symptomatic patients CIP sensitivity, specificity, accuracy, positive and negative predictive values were 83%, 87%, 85%, 87% and 82%, respectively, for proximal and distal DVT, versus 91%, 88%, 89%, 82% and 94% for proximal DVT. CIP had great diagnostic utility in symptomatic DVT, whereas its diagnostic efficacy was low in asymptomatic patients. In orthopedic patients US sensitivity, specificity positive and negative predictive values were 44%, 99.2%, 95.7% and 81.6%, respectively. US diagnostic value was relatively high, but further investigation is needed. To date, phlebography seems to be the only effective method in the diagnosis of DVT in asymptomatic high risk patients.