May-Thurner Syndrome in Pregnancy [7K

Abstract

INTRODUCTION: Thromboembolic disease is responsible for approximately 11% of maternal deaths in the United States. May-Thurner syndrome occurs when compression by the right common iliac artery against the fifth lumbar vertebra causes left common iliac vein obstruction and thrombosis. The incidence is 22-24%. It increases the risk for deep vein thrombosis. Pregnancy and oral contraceptives are risk factors. Diagnosis is by CT, MRI and venography. If anticoagulation therapy is not effective, angioplasty and endovascular stenting are needed. If undiagnosed and untreated, the patient can develop post-thrombotic syndrome with chronic edema, pain, hyperpigmentation, varicosities and skin ulcerations. METHODS: A 34 year old female G3 P0020 at 27 weeks gestation presented with left thigh, groin and gluteal region swelling and pain. Doppler studies were negative. Symptoms persisted and MRI/MRV diagnosed thrombosis of the left common and external iliac veins. The only antecedent precipitating event was a 2.5 hour plane flight 10 days prior. Screening for hypercoagulable disorders was negative. The patient was placed on Lovenox antepartum, anti Xa levels followed and continued postpartum for 6 weeks. MRV 2 months postdelivery revealed partial recanalization of vessels. In her second uneventful pregnancy, the patient initiated early care, was started on Lovenox, and delivered vaginally. CONCLUSION: May-Thurner syndrome is a rare condition with significant morbidity and mortality. Apart from pregnancy, this patient had no risk factors. The continuing symptoms prompted an appropriate diagnosis by MRV. Immediate anticoagulant treatment helped to prevent post-thrombotic syndrome. A high index of suspicion is needed to avoid misdiagnosis.