The Incidence and Significance of Iliac Vein Stenosis in Patients with Deep Vein Thrombosis

Background

The role of iliac vein stenosis (IVS) in the development of deep vein thrombosis (DVT) is poorly understood. This study determines the incidence of IVS in patients diagnosed with DVT and assesses its impact on presentation and outcomes. Our hypothesis is that the presence of IVS increases the risk of long-term ipsilateral DVT recurrence.

Methods

A retrospective study of the electronic medical records of consecutive adult patients treated for lower extremity DVT was performed. Only patients with cross-sectional imaging (computed tomography or magnetic resonance with intravenous contrast) were included. Patient and DVT characteristics were recorded. Cross-sectional imaging was reviewed for the presence or absence of ipsilateral IVS (≥50%). Patients were divided into 2 groups based on the presence or absence of IVS to compare characteristics and outcomes. Subgroup analyses on patients with provoked DVT, cancer-related DVT, and unprovoked DVT were performed.

Results

There were 548 patients with DVT and 32% had evidence of ipsilateral IVS on cross-sectional imaging. There were no significant differences in baseline characteristics or treatment methods between the 2 groups. There was a trend toward patients with IVS having less incidence of pulmonary embolism on presentation (22.9% vs. 29.7%, P = 0.1) but that difference did not reach statistical significance in the overall comparison. Subgroup analysis in patients with cancer-related DVT (n = 227) showed that patients with IVS were significantly more likely to develop ipsilateral recurrent DVT compared to patients with no IVS (12.9% vs. 4.5%, P = 0.045). Patients with unprovoked DVT with IVS had significantly lower pulmonary embolism on presentation than patients with unprovoked DVT without IVS (24.2% vs. 39.8%, P < 0.03).

Conclusions

Ipsilateral ≥50% IVS is present in approximately a third of patients presenting with DVT. The presence of IVS seems to play a differential role in ipsilateral DVT recurrence and prevention of pulmonary embolization in different groups of patients presenting with DVT.