Do Waveforms Matter? Yes They Do! A Case in Point

Abstract

A 38-year-old G1P0 presented to the Vascular Lab at 32 weeks gestation for evaluation of persistent left lower extremity edema. The patient reported a 1-month history of left leg pain and swelling after a long car trip. Of note, she had 3 negative lower extremity ultrasounds at outside imaging facilities over the previous 6 weeks. Left lower extremity venous duplex was performed with B-mode, color, power, and spectral Doppler using a linear 12-3 MHz transducer and curvilinear 5-1 MHz transducer. Images were documented using Intersocietal Accreditation Commission Vascular Testing (IAC VT) protocol. Left lower extremity duplex revealed continuous flow in the bilateral common femoral veins. Right common iliac and external iliac vein Doppler waveforms demonstrated spontaneous and phasic flow. Left proximal common iliac and external iliac veins revealed continuous flow. Acute, occlusive deep venous thrombosis (DVT) was identified in the left distal common iliac vein. The left common iliac vein was enlarged, measuring 2.2 cm compared with the contralateral common iliac vein measuring 1.4 cm. Ultrasonographic infrainguinal demonstration of acute DVT is straightforward and usually achievable with standard ICA VT protocol. However, imaging of the proximal pelvic venous circulation can be more elusive, particularly in the pregnant patient. Therefore, it is imperative to assess the spectral Doppler waveforms and to investigate pelvic venous flow. Because of the sonographer’s attention to the common femoral waveforms, additional focused pelvic imaging was performed and located acute, occlusive iliac DVT as the cause of significant edema.