Trans-abdominal Ultrasonography Accurately Identifies a Significant Iliac Vein Area Reducing Lesion in Patients with Pelvic Venous Insufficiency

Introduction, Objectives, and/or Purpose:

Introduction: In patients with pelvic venous disorders (PeVD) secondary to pelvic venous insufficiency (PVI), the optimal imaging modality is ill defined. Trans-abdominal ultrasongraphy (TAU) is widely utilized to identify the presence of an iliac vein stenosis. The purpose of this investigation is to determine the accuracy of TAU for determining the presence of an iliac vein area reducing lesion.

Methods: From January to December 2020, a retrospective review of prospectively collected data in 96 patients treated for symptomatic PVI at the Center for Vascular Medicine was performed. All patients had complete history and physicals, demographics, CEAP, rVCSS, TAU, diagnostic venography and intra-vascular ultrasonograpy (IVUS) measurements recorded in our electronic medical record system. TAU was performed in the supine position and iliac vein diameters of the common femoral, external iliac, common iliac veins and the inferior vena cava were obtained. Differences in body habitus were normalized by dividing minimal diameter measurements to the ipsilateral common femoral vein, subtracting this number from 1 and multiplying by 100 (Stenosis=(Minimal diameter/common femoral diameter -1)x 100). The normalized stenoses were then compared to IVUS derived area reducing measurements. A receiver operator curve was created and a logistic regression analysis for the probability of predicting an area reducing lesion of greater than 50% and 60% with TAU was performed. Sensitivity, specificity, positive and negative predictive values were subsequently calculated.

Results: The average age of the entire cohort was 49.8±13.5 with 69 females and 27 males. CEAP distribution was the following: C0 (5%), C1 (5%), C2 (10%), C3 (40%), C4a,b (30%), C5 (7%), C6 (3%). Average rVCSS was 6.2±2.6. Indications for intervention were leg symptoms alone in 43%, pelvic symptoms alone in 3% and combined leg and pelvic symptoms in 54%. TAU identified a stenosis of 50% or greater in 92/96 (96%) of patients. For a 50% or greater stenosis, a normalized diameter of 3 millimeters or less demonstrated a sensitivity, specificity, positive and negative predictive value of 75%, 75%, 98% and 12%. The logistic regression analysis indicated that the probability of TAU to predict the presence of a 60% or greater area reducing lesion was statistically significant (OR=1.03, 95% CI (1.01, 1.05), and p-value=0.009). The area under the receiver operator curve (c-statistic) was 68.6%. The sensitivity, specificity, positive and negative predictive values were 67%, 67%, 81.5% and 47.6% for a normalized diameter of 4 millimeters or less.

Conclusion(s):

Conclusions: The ability of TAU to identify an iliac vein stenosis of 50% or greater is 96%. The positive predictive value of TAU for identifying a 60% or greater iliac vein area reducing lesion is high with moderate sensitivity and specificity. For patients with symptoms consistent with a PeVD secondary to PVI, TAU is a good pre-intervention screening modality in properly trained vascular imaging specialists that correlates well with IVUS measurements.