Is the May-Thurner Syndrome a Major Risk Factor for Deep Vein Thrombosis in Total Hip Arthroplasty?

Background: May-Thurner syndrome (MTS) is iliac vein compression syndrome associated with postoperative deep vein thrombosis (DVT) resulting from chronic compression of the left iliac vein against lumbar vertebrae by the overlying right or left common iliac artery. MTS is not well known as a risk factor for DVT after total hip arthroplasty (THA). We evaluated the incidence of DVT after THA and analyzed if the MTS is a risk factor for DVT after THA. We hypothesized that MTS would be associated with an increased risk of developing DVT after THA. Methods: All patients > 65 years of age who underwent THA between January 1, 2009, and January 12, 2017, were identified. Among them, the patients who presented for postoperative DVT of the lower extremity were reviewed with medical record data. MTS was diagnosed with computed tomography (CT) angiography of the lower extremity. We analyzed the demographic data, symptoms, diagnoses, and treatment of MTS patients. Results: A total of 492 consecutive patients aged > 65 years who underwent operation for THA were enrolled. Among them, 5 patients (1.0%) presented for postoperative DVT of the lower extremity. After reviewing the CT angiography of the lower extremity, 4 out of 5 DVT patients (80%) were identified as having MTS. All MTS patients were female and presented with pain and swelling of the left leg. All MTS patients were treated with systemic anticoagulation, aspiration thrombectomy, and percutaneous transluminal angioplasty. Complete resolution of thrombus was observed in all patients. Conclusions: If the diagnosis of MTS is delayed, the morbidity and mortality rates are significantly increased. Orthopedic surgeons should be aware of MTS as a risk factor for DVT after THA. Moreover, preoperative evaluation with duplex sonography or CT angiography to confirm MTS should be considered. In this regard, this study is considered to have sufficient clinical value for early diagnosis and appropriate treatment of MTS after THA.