MAY-THURNER SYNDROME: UNCOMMONLY COMMON

Abstract

SESSION TITLE: Thrombosis Jamboree: Rare and Unique Cases SESSION TYPE: Rapid Fire Case Reports PRESENTED ON: 10/19/2022 12:45 pm - 1:45 pm INTRODUCTION: May-Thurner syndrome is a venous compression syndrome characterized by common iliac vein compression between the left lumbar spine and the common iliac artery. The most common pattern is left common iliac vein compression by the right common iliac artery. Clinical presentation can vary from asymptomatic to signs and symptoms of venous stasis. This can include lower extremity swelling, edema, pain, and ulceration. More advanced stenosis results in deep vein thrombosis (DVT). The exact incidence and prevalence of MTS are unknown; however, it is felt to be underdiagnosed. MTS can be attributed to 2-5% of all venous thromboembolism (VTE). We present a case of DVT and pulmonary embolism (PE) in a patient who was found to have MTS. CASE PRESENTATION: The patient was an 83-year-old male with diabetes mellitus and hypertension who presented to the emergency department (ED) for evaluation of dyspnea on exertion. In the ED he was noted to be in respiratory distress, but otherwise hemodynamically stable. He was hypoxic, requiring supplemental oxygen via nasal cannula. Serum studies and chest radiographs were unremarkable. Computed tomography angiography of the chest revealed saddle pulmonary embolism extending into bilateral upper lobar arteries. After a thorough history, it was felt the VTE was unprovoked. The patient was admitted to the ICU and underwent emergent catheter-directed pulmonary artery thrombectomy. Anticoagulation was initiated with unfractionated heparin infusion. An echocardiogram revealed normal left ventricular function and a moderately dilated right ventricle. Lower extremity ultrasound revealed extensive clot burden in the left femoral, popliteal, and tibial veins. Lower extremity angiography revealed compression of the left common iliac vein. He subsequently underwent venous thrombectomy and common iliac vein stenting. He tolerated the procedures and hospitalization well and was ultimately discharged in stable condition DISCUSSION: MTS is characterized by compression of the left common iliac vein by the right common iliac artery, with resultant stenosis and venous stasis. It is estimated to cause 2-5% of all VTE although the prevalence may be higher (1). Diagnosis requires a high clinical suspicion, as MTS does not present specific findings in the setting of VTE. Initial presentation could range from lower extremity swelling to pain, venous stasis, or ulcerations – all of which could be attributed to the DVT (2). Making the diagnosis is important, however, as it presents a chance for therapeutic endovascular intervention. CONCLUSIONS: Our case highlights first that MTS may be very underdiagnosed. Secondly, it is a cause of provoked venous thromboembolism. It may therefore present a therapeutic endovascular option and may alter the duration of anticoagulation. For these reasons, the clinician should consider MTS in the differential for all VTE, and especially for recurrent VTE Reference #1: 1. Sigua-Arce P, Mando R, Spencer L, Halalau A. Treatment of May–Thurner's syndrome and associated complications: A multicenter experience. Int J Gen Med. 2021;14:4705–10. Reference #2: 2. Knuttinen MG, Naidu S, Oklu R, Kriegshauser S, Eversman W, Rotellini L, et al. May-Thurner: Diagnosis and endovascular management. Cardiovasc Diagn Ther. 2017;7(Suppl 3):S159–64. DISCLOSURES: No relevant relationships by Wajahat Khan No relevant relationships by Nelson Okoh