Venous obstructions and thrombosis can present diagnostic challenges due to their varied presentations and potential for significant complications if untreated. Pulse wave doppler ultrasound via identification of damping or loss of cardiac pulsatility and/ or respiratory phasicity of venous waveforms serves as a practical, noninvasive, fast, and efficient diagnostic tool for identifying venous obstructions in the presence of compressible veins beyond the point of evaluation.We present two cases demonstrating the effectiveness of pulse wave doppler ultrasound in identifying significant and life-threatening venous obstructions. The first case involves a 68-year-old male with an incidental finding of a compressible left subclavian vein showing a monophasic waveform. Further investigation revealed significant compression of the left brachiocephalic vein by an aortic arch aneurysm. The second case describes a 65-year-old male with a compressible right femoral vein but a monophasic waveform, leading to the discovery of extensive thrombosis from the iliac veins to the inferior vena cava. This series proposes to always assess cardiac pulsatility and respiratory phasicity during doppler ultrasound procedure such as thyroid ultrasounds, deep vein thrombosis (DVT) evaluations, and pre-central vein catheterizations for identifying any venous obstructions, whether they are intrinsic or extrinsic, and for reducing the risk of thromboembolic complications.
Keywords: aortic arch aneurysm; cardiac pulsatility; central venous catherization; color doppler; deep venous thrombosis; monophasic waveform; multiphasic waveform; respiratory phasicity; spectral doppler; ultrasound.