Extensive inferior vena cava thrombosis extending to the right atrium: a case report

Abstract

BACKGROUND: Inferior vena cava (IVC) thrombosis is an uncommon manifestation of venous thromboembolism, occurring in 2.6% to 4.0% of patients with lower- extremity deep vein thrombosis. Hyperhomocysteinemia has been proposed as a risk factor for venous thromboembolism, though its independent contribution remains controversial.

CASE REPORT: We report the case of a 24- year- old male with a history of vitiligo and Graves' disease who developed extensive IVC thrombosis extending into the right atrium during hospitalization for community- acquired pneumonia. The initial presentation included new- onset left lower- extremity edema on hospital day 7. Imaging revealed bilateral iliac and femoral deep vein thrombosis, complete occlusion of the left lower- extremity deep venous system, partially occlusive IVC thrombosis extending to the right atrium, and an acute pulmonary embolism. Transthoracic echocardiography confirmed a floating right atrial thrombus. A thrombophilia workup identified elevated plasma homocysteine (40 μmol/L upper limit of normal 18.5μmol/L) with normal vitamin B12 and folate levels. Testing for hereditary thrombophilias, malignancy, and autoimmune conditions was negative. The patient was treated conservatively with therapeutic anticoagulation (unfractionated heparin followed by low- molecular- weight heparin for 3 months, then acenocoumarol) and elastic compression stockings. After 5 years of follow- up, he remains asymptomatic without residual edema. Serial imaging demonstrated resolution of thrombus in the suprahepatic IVC and right atrium, with persistent residual thrombosis and endoluminal synechiae in IVC segments, and progressive development of venous collateral circulation.

CONCLUSION: This case demonstrates that extensive IVC thrombosis with right atrial extension can be successfully managed with anticoagulation alone in hemodynamically stable patients. Moderate hyperhomocysteinemia was the only identified risk factor, underscoring the importance of comprehensive thromboembilia evaluation in young patients with extensive venous thromboembolism. Although the role of hyperhomocysteinemia as an independent risk factor remains debated, it may contribute to thrombotic risk in young patients without other identifiable causes.