May-Thurner Syndrome Complicated by Acute Iliofemoral Vein Thrombosis: Helical CT Venography for Evaluation of Long-Term Stent Patency and Changes in the Iliac Vein

OBJECTIVE. The purpose of this study was to use CT venography to evaluate long-term patency and changes in the iliac veins after stent placement for acute iliofemoral vein thrombosis due to May-Thurner syndrome. MATERIALS AND METHODS. From December 1999 to July 2007, 30 patients (22 women, eight men; age range, 30-78 years; mean, 56.7 years) with acute iliofemoral vein thrombosis due to May-Thurner syndrome diagnosed with CT venography were treated with catheter-directed thrombolysis and stent placement. The patients underwent follow-up CT venography at variable intervals according to clinician discretion. The primary objective was to determine the primary patency of the stented segment. The secondary objective was to investigate the potential role of CT venography by analyzing the morphologic features and interval changes in stented iliac veins. Cumulative primary and secondary stent patency rates were calculated by Kaplan-Meier estimation. RESULTS. Four stent occlusions and one stent collapse were found at the first follow-up CT venographic examination within 1 year (mean duration, 129.3 days) after treatment. One stent occlusion and one stent collapse were managed successfully. The primary and secondary patency rates were 83.3% and 90% 1 and 5 years after treatment. The morphologic features of the common iliac vein did not affect stent patency or expanded stent diameter. During sequential CT venographic follow-up, no new in-stent stenosis or occlusion was found. CONCLUSION. Iliac stents placed for May-Thurner syndrome with acute thrombosis had excellent long-term patency. Restenosis or occlusion occurred early, and initial luminal patency was well maintained during long-term follow-up.