Diagnostic value of the femoral vein flow pattern for the detection of an iliocaval venous obstruction.

OBJECTIVE

Identification of iliocaval obstructions has traditionally been difficult due to the lack of a reliable noninvasive screening technique. Although femoral vein flow patterns have been used to detect outflow obstructions, the diagnostic accuracy of indirect Doppler parameters has not yet been fully elucidated. The purpose of this study was to establish the diagnostic value of the femoral vein waveform in detecting chronic iliocaval venous lesions.

METHODS

Medical records of consecutive patients with chronic venous disease classified as Clinical, Etiologic, Anatomic, and Pathophysiologic (CEAP) C3-6 between March 2011 and December 2012 were assessed retrospectively. The results of common femoral vein duplex ultrasound examinations, based on the presence or absence of respiratory variation in the femoral flow as well as its response to the Valsalva maneuver, were compared with contrast venography and intravascular ultrasound imaging of the inferior vena cava and the bilateral common and external iliac veins. Three types of flow patterns in the common femoral vein were identified with duplex ultrasound examination: phasic flow correlated with respiration, minimally phasic flow (showing some phasicity but no cessation with respiration), and monophasic flow (continuous flattened flow). In addition, three types of responses to the Valsalva maneuver were recorded: complete cessation of flow, reversal of flow, and continuation of flow.

RESULTS

The study evaluated 86 patients (63 men, 23 women) with a mean age 40.3 ± 1.5 years. Contrast venography and intravascular ultrasound imaging were used to detect venous obstructions in the inferior vena cava and the right and left iliac veins in 16.3%, 32.6%, and 80.2% of patients, respectively. When various flow parameters were evaluated, the combination of common femoral vein monophasic flow at rest and continuous flow during the Valsalva maneuver had the highest diagnostic value for iliocaval venous obstructions. The sensitivity, specificity, positive predictive value, and negative predictive value of the combination of monophasic flow at rest and unceasing forward flow during the Valsalva maneuver for the diagnosis of any degree of iliac venous obstruction were 38.1%, 100%, 100%, and 55.8%, respectively. The sensitivity and negative predictive value of these diagnostic parameters increased as the degree of obstruction increased.

CONCLUSIONS

An iliocaval venous obstruction is a frequent feature of chronic venous disease. Doppler examination of the common femoral vein can be used as a screening test for iliocaval venous obstructions. The monophasic flow of the common femoral vein is a reliable diagnostic tool for the detection of possible iliac vein obstructions.