Identifying Iliac Vein Stenosis with Duplex Ultrasonography

Abstract

Introduction. —Deep vein thrombosis should be considered as one of the differential causes of unilateral lower-extremity swelling. When the lower-extremity venous duplex ultrasound is negative for a deep vein thrombosis and a proximal occlusion is suspected, investigation should be completed with interrogation of the pelvic veins. Case Report. —We describe a 66-year-old man with a history of rectal carcinoma treated with chemotherapy, radiation, and proctosigmoidectomy who presented to the vascular laboratory with left lower-extremity swelling and erythema. A lower-extremity venous duplex was performed with a Phillips iU22 9–3 MHZ linear transducer, which revealed monophasic flow in the distal left external iliac vein with normal compression images. Further evaluation with a 5–1 MHZ curved array probe revealed a velocity shift within the external iliac vein consistent with iliac vein stenosis. A venogram confirmed a critical stenosis in the mid left external iliac vein with associated thrombus. The patient underwent mechanical thrombectomy and placement of 10 by 40 mm Smart stent. Post-interventional venogram demonstrated excellent antegrade flow and no evidence of residual thrombus. Discussion. —If left untreated, venous stenosis may predispose the patient to persistent lower extremity swelling, venous thrombosis, and venous stasis ulcers. Because of the underlying anatomic defect, symptoms may not improve with conservative management, including anticoagulation. Several diagnostic modalities can be considered for diagnosis of the venous stenosis, including venous duplex ultrasound, magnetic resonance venography, computed tomography with venous phase, venography, and intravascular ultrasound. Conclusion. —Cost considerations makes venous duplex a valuable, noninvasive, first-line method to investigate suspected venous stenosis.