A 20 year-old G1P1 female with no significant history presents with acute left lower abdominal and thigh pain. She has had no recent surgeries or immobility and has never been on oral contraceptives. Her pregnancy was complicated by pre-eclampsia and she delivered at 37 weeks. Physical exam demonstrated tenderness and induration of her left medial thigh with calf pain on active dorsiflexion of the ankle. Lower extremity venous ultrasound revealed a large occlusive deep venous thrombosis (DVT) extending from the left popliteal vein to the inferior vena cava at the renal level. Venography was performed by interventional radiology (IR) and noted that the right common iliac artery crosses the left common iliac vein, consistent with May-Thurner syndrome (MTS). The patient underwent intravascular thrombolysis and left common iliac vein stent placement which she tolerated well. Hypercoagulable workup was initiated and showed positive lupus anticoagulant and anti-cardiolipin IgM antibodies suggestive of anti-phospholipid antibody syndrome (APLAS). The patient was discharged on warfarin therapy, however, returned two weeks later with a recurrent DVT and she underwent IR guided thrombolysis and angioplasty. She was discharged with enoxaparin. One week later, she was re-admitted for recurrent DVT. During this admission, she developed heparin-induced thrombocytopenia necessitating a change in anti-coagulation to fondaparinux. She subsequently presented two weeks later with shortness of breath and chest pain and was found to have a pulmonary embolus requiring a bivalirudin infusion. Anti-coagulation was eventually changed to apixaban and she has had clinical improvement. Repeat ultrasound and computed tomography of the chest have demonstrated decreased clot burden.
Discussion:
Unprovoked DVT necessitates further evaluation which revealed two causes in this patient, anatomic compression of the left iliac vein from MTS and hypercoagulability from APLAS. MTS is often unrecognized but is thought to represent 2-5% of lower extremity venous disorders and is more common in women. Anatomic causes should especially be considered in patients with few co-morbidities and no predisposing risk factors as patients could be a candidate for IR intervention. Hypercoagulable patients are at high risk of recurrence and hospital re-admission, and compliance to anti-coagulants should be emphasized at discharge.
Conclusions:
Venous thrombosis is a common diagnosis among admitted adult patients. It is important to consider May-Thurner syndrome in patients who present with left lower extremity thrombosis and no other reason for hypercoagulability. This case represents a few interesting etiologies of venous thrombosis in one patient and the occasional necessity for trialing different anticoagulants to find the one that is successful in treatment.