The Role of Ultrasound to Identify Non-thrombotic Lower Extremity Pathology

Accreditation in peripheral venous testing can be obtained based upon femoropopliteal duplex ultrasound evaluation, and many laboratories limit their examination to this segment only. This simplified protocol detects acute femoropopliteal deep venous thrombosis (DVT) but misses calf vein DVT, superficial venous thrombosis, chronic DVT, venous reflux, and other non-venous findings potentially responsible of the pateints' presenting conditions. A protocol limited to the femoropopliteal segment results in additional unnecessary testing and can create patient dissatisfaction. We evaluated the differences in the diagnosis between a limited femoropopliteal vs a complete approach to the venous ultrasound evaluation of the lower extremities in patients examined in an outpatient vascular laboratory. A data base with the complete ultrasound exams of the lower extremity including the common femoral, deep femoral, popliteal, tibial and peroneal veins, calf musclar veins, great and lesser saphenous veins performed in 167 consecutive patients from July 2009 was queried. Acute femoropopliteal DVT was found in 9% of the patients. Acute infrapopliteal DVT was found in 2%. Chronic femoropopliteal DVT was found in 7%. Acute infrapopliteal DVT was encountered in 2%. Acute superficial thrombophlebitis was encountered in 10% and chronic SVT in 4%. In addition, deep venous insufficiency (>500 milliseconds) was found in 44% and superficial venous insufficiency in 24 % (>500 milliseconds). A mass (cyst, hematoma, solid mass or aneurysm) was found in 9%. Limited femoropopliteal ultrasound examination for acute DVT would have only detected 7.8 % of the positive findings. These data suggest that the duplex exam can be used to further delineate the cause of outpatients' symptoms as compared to the limited protocol.