Paraneoplastic Left Subclavian Artery Thrombus with Embolic Stroke: Conservative Management with Thrombus Dissolution Without Recurrent Stroke Using Triple Medicinal Therapy

Known or occult malignancy is associated with both venous and arterial thromboembolic complications and is a risk factor for recurrent ischemic events, early deterioration, disability, and mortality after stroke. It is primarily attributed to paraneoplastic coagulopathy, characterized by the expression of procoagulant factors. The estimated incidence of malignancy in stroke patients is approximately 10% but may be as high as 20% in certain Asian populations. Recognizing this etiology and gaining a deeper understanding of the underlying paraneoplastic coagulation disorders, particularly in cryptogenic stroke, are critical for guiding secondary prevention and expediting the diagnosis of occult malignancies following ischemic stroke. A 62-year-old patient with left hemianopia and a diagnosed subocclusive thrombus in the left subclavian artery near the origin of the vertebral artery was transferred to our stroke unit from an outside hospital. Upon admission, MRI revealed multiple embolic ischemic lesions in both cerebellar hemispheres and the right occipital lobe. Due to the risk of thrombus dislodgement and mild neurological symptoms, endovascular treatment was not performed and conservative treatment with triple therapy was initiated. On the same day, a loading dose of acetylsalicylic acid and ticagrelor was administered and a continuous infusion of eptifibatide was started. After 3 days, the eptifibatide infusion was switched to a therapeutic dose of low-molecular-weight heparin and dual antiplatelet therapy was maintained. No pathologic findings regarding the cause of the thrombus were observed on further examination. At follow-up, the visual field had improved and a reduction in thrombus burden in the left subclavian artery was observed. The patient was discharged home on day 5 with no neurological deficits. Two months after discharge, he was diagnosed with rectal cancer and underwent appropriate treatment. At the 8-month MRI, the thrombus was completely resolved. No hemorrhagic or ischemic complications were observed during the follow-up period. We present a case of subocclusive thrombus in the left subclavian artery, probably of paraneoplastic nature with embolic ischemic lesions. Conservative management with triple medicinal therapy resulted in a complete dissolution of the thrombus without recurrent embolic ischemia or hemorrhagic events.