Extrinsic compression of left iliac vein does not predict the development of post thrombotic syndrome in left side deep venous thrombosis

Purpose: Left side deep venous thrombosis (DVT) is associated with May-Thurner's anatomical variation and is often instigated by invasive treatment. The aim of this study is to analyze the influence of left iliac vein narrowness on incidence of post thrombotic syndrome (PTS) that developed after left side DVT. Methods: Forty-one left side DVT cases that were followed up for more than 1 year were enrolled. The iliac vein narrowness was measured by the shortest distance from the right iliac artery to the 5th lumbar vertebra overlying left iliac vein in computed tomography (CT) scan. The incidence of PTS was measured by phone-call history taking for specific symptoms of PTS. The means of the shortest distance were compared by independent t-test. Results: The number of PTS cases was eleven (26.8%). The level of thrombus, demographic data and other risk factors were similar in both PTS and non-PTS groups except the mean risk factor score. The mean of the shortest distance of PTS group and non-PTS group were 5.56 mm and 5.89 mm, respectively. Conclusion: The degree of left iliac vein narrowness measured by the shortest distance from the right iliac artery and the 5th lumbar vertebral body was not a predictive factor for PTS.