Case Presentation: 28F PMH of cholelithiasis s/p recent lap cholecystectomy presented with chest pain and lower extremity edema for 2 days. Chest pain was not associated with shortness of breath or diaphoresis. It was relieved by postoperative pain medications. The day of presentation, the patient reported edema of her left leg along with tenderness and erythema. She also reported a syncopal episode that morning associated with palpitations. Notably, the patient had been on bedrest for the past 4-5 days after recent surgery. Lower extremity duplex was positive for deep venous thrombus. CTA showed bilateral pulmonary embolism without evidence of right heart strain. Trans-thoracic echo showed a LVEF of 60% with normal LV and RV function and no valvular disease. Hypercoagulable workup resulted negative. Cardiology was consulted for catheter-directed thrombolysis due to large clot burden in her lower extremity. Successful mechanical thrombectomy was performed. Invasive venography confirmed the presence of extensive iliofemoral deep venous thrombosis and extrinsic compression of the proximal left common iliac vein by the right common iliac artery consistent with May-Thurner Syndrome. A non-drug-eluting stent was placed proximal to the common iliac vein. The patient was given aspirin and apixaban and discharged with follow up.
Discussion: This case report highlights syncope secondary to pulmonary embolism as an initial presentation of May-Thurner Syndrome. Pulmonary embolism as a presenting complaint of this condition is very rare and not well studied as a prognostic factor. May-Thurner Syndrome (MTS) is an anatomically variable condition of venous outflow obstruction caused by partial obstruction of the left common iliac vein by the overlying right common iliac artery. This causes entrapment of the left common iliac vein against a bony structure, predisposing patients to venous stasis. Symptomatic MTS is uncommon, clinical symptoms are present in approximately 25% of patients. A recent study from John Hopkins concluded that >70% compression of the iliac vein is needed to cause a deep venous thrombosis in patients with this anatomical abnormality. MTS presents in the second to third decade of life and is more common in women. Femoral stick venogram is the gold standard test for diagnosis as it can show the area of obstruction with the presence of collaterals. A lower extremity venous duplex is unable to make the diagnosis as it is unable to assess the integrity of the vasculature beyond the femoral veins. An international retrospective analyzed 399 patients with iliac vein compression syndrome, finding that only 7% of these patients had symptomatic pulmonary embolism. In this study, endovascular thrombolysis and collateral filling were associated with the presence of pulmonary embolism. Though the pathogenesis is not completely understood, it is accepted that anticoagulation alone is not enough to prevent a clinical recurrence of MTS. Early therapies using endovascular intervention to decompress the iliac vein are considered gold standard. Concurrent anticoagulation is also necessary, with variable lengths of time proposed.
Conclusions: Limited research exists regarding patient prognosis when the initial presenting symptoms of MTS include pulmonary embolism. Further research is needed to delineate patient prognosis and mortality with pulmonary embolism in the setting of May-Thurner syndrome.
To cite this abstract:Tariq, A; Robledo, I; Sidhu, R. Provoked DVT- Is It May Thurner Syndrome?. Abstract published at Hospital Medicine 2018; April 8-11; Orlando, Fla. Abstract 884. https://www.shmabstracts.com/abstract/provoked-dvt-is-it-may-thurner-syndrome/. Accessed January 22, 2020.