Subclavian and internal jugular veins at Doppler US: Abnormal cardiac pulsatility and respiratory phasicity as a predictor of complete central occlusion

In 21 consecutive patients, the authors analyzed changes in venous Doppler waveforms of damped or diminished cardiac pulsatility and respiratory phasi city. Each patient was suspected of having upper limb venous thrombosis, bu t thrombus was not visible at gray-scale ultrasonography (US) in the subcla vian and brachiocephalic veins. US findings were compared with phlebographi c findings. The results show that US can be used to establish the presence or absence of thrombosis in the distal portion of the brachiocephalic or su bclavian veins, which are inaccessible to direct insonation.