OBJECTIVE

Venous compression at the iliac confluence is a reported risk factor for deep vein thrombosis, with venous stenting as the standard management for relieving this compression. Kibbe et al demonstrated that left common iliac vein (LCIV) compression is present in 35.3% of asymptomatic patients. However, this study included only adults with an average age of 40 years. The iliac vein confluence in patients under 21 years with no symptoms attributable to venous disease was evaluated in this study. The study goal is to determine prevalence of LCIV narrowing in patients under age 21 years, and as such, assist in determining the appropriate treatment for iliac vein compression in this patient population.

METHODS

A retrospective review of patients aged 13-20 undergoing abdominal/pelvic computed tomography (CT) imaging for nonvascular indications was performed. This group was compared with patients aged 35 to 65 years undergoing CT imaging for similar reasons. Axial CT images were reviewed by two independent examiners to identify the diameter of the noncompressed left and right CIVs below the confluence and the diameter of the LCIV at the site of compression between the right common iliac artery and spine.

RESULTS

A total of 122 patients aged 13 to 20 years were identified with high-quality CT imaging and no venous symptoms for image review. Mean LCIV diameter was 12.7 ± 2.5 mm, and mean right CIV diameter was 13.1 ± 2.2 mm. The diameter of the LCIV at the confluence was 4.2 ± 1.8 mm, resulting in a mean diameter stenosis of the LCIV of 69.4% ± 12.6%. In this population, 55.7% of patients were found to have ≥70% stenosis of the LCIV on CT imaging compared with 1.7% of patients aged 35 to 65 years (P < .001). There was no statistical difference in the percentage of LCIV stenosis in young patients based on body mass index, gender, race, or ethnicity.

CONCLUSIONS

Severe compression of the LCIV at the iliac confluence was identified in over 50% of asymptomatic patients aged 13 to 20 years on CT imaging performed for nonvascular reasons. This suggests that narrowing of the LCIV is a normal anatomic finding in this age group. The incidence of severe compression is significantly lower in older asymptomatic persons. In young persons, the high incidence of iliac vein compression on CT imaging suggests that this finding may not be a significant risk factor for deep vein thrombosis or limb symptoms, questioning the need for routine intervention for compression correction in this patient population.