Three-dimensional computed tomography venography reconstruction facilitates the identification of atypical radiological features of the May-Thurner syndrome.

Abstract Objective May-Thurner syndrome (MTS) is typically characterized by compression of the left common iliac vein by the overlying right common iliac artery. This study aimed to evaluate the occurrence of atypical imaging features of MTS with three-dimensional computed tomography venography reconstruction (3D-CTV) and analyze their correlation with clinical features. Methods We analyzed 268 patients with left lower extremity chronic venous disease (CVD) using 3D-CTV in a single institution from January to June 2019. An area stenosis percentage >50% was defined as significant venous compression. Of them, 92 patients had at least one significant iliac and/ or vena cava compression, which was confirmed using 3D-CTV. Eighty-nine patients underwent digital subtraction venography via the left common femoral vein and were compared with their 3D-CTV characters. Different types of venous compression were evaluated using 3D-CTV. The relationship between compression type, sex, age, and CVD symptoms was further evaluated. Results One hundred six venous compression sites were found in 92 patients. Atypical compression included inferior vena cava (IVC) compression and partial IVC compression (8.5% and 55.7%, respectively). Multiple compressions accounted for 14.1% (n=13) of cases. The compression sites were significantly correlated with the clinical symptoms (p=0.017) and were related to sex (p=0.001). The number of patients with IVC and partial IVC compression in the false-negative group of venography was four (33.3%) and six (50%), respectively. Conclusions 3D-CTV facilitates the detection of atypical venous compression in patients with MTS with notable chronic symptoms. Patients with multiple compressions have more severe clinical symptoms and higher false-negative rates of venography. IVC compression is more likely to occur in female patients with MTS.