058 - Not a Clot! Mimickers of Iliofemoral Venous Thrombosis and Treatment Strategies
Purpose: 1. Identify differential diagnoses of iliofemoral venous thrombosis 2. Review imaging modalities and physical examination findings that may help distinguish between thrombus and other mimickers 3. Discuss potential treatment strategies by case examples, including: venous compression by paralabral or ganglion cysts, arterial pseudoaneurysm, perivascular tumor, perivascular post-radiation changes, inguinal ligament compression, and others.
Material and Methods: Iliofemoral deep venous thrombosis (DVT) is a common diagnosis that has typical imaging features on ultrasound and cross-sectional imaging. In unusual circumstances, pathologies extrinsic to the vein may abut, compress, or even invade the vein lumen, resulting in signs and symptoms that mimic venous obstruction. In addition, the imaging characteristics of the mimickers may also overlap with DVT, further muddying their proper diagnosis. A meticulous evaluation of available imaging and understanding of the potential differential diagnoses of iliofemoral DVT may allow prospective diagnosis and avoid unnecessary treatments.
Results: In review of sonographic imaging, typical features of iliofemoral thrombus should be identified: a vein lumen that is noncompressible and contains nonmobile internal echoes. Cross-sectional imaging with contrast-enhanced CT or MRI can better show perivascular pathology and should be given consideration when ultrasound is ambiguous (e.g., ganglion cyst compressing the vein). Internal color Doppler evaluation and spectral waveform analysis may provide further information as to the cause of venous obstruction (e.g., extrinsic compression by arterial pseudoaneurysm). Conventional venography may be misleading as only intraluminal filling defects or venous stenosis may be visualized, although useful adjunctive techniques such as intravascular ultrasound or biopsy may be performed at the time to elucidate the “external” cause of venous obstruction. If an extrinsic pathology is discovered affecting the vein and resulting in venous obstruction, treatment may then be of the extrinsic pathology and/or of the vein, typically with stenting.
Conclusions: In rare circumstances, pathologies extrinsic to the vein that have imaging characteristics similar to thrombus may contribute to venous obstructive symptoms. Awareness of the differential diagnoses and their treatment may allow prospective diagnosis and avoid unnecessary interventions for DVT.