Free-floating thrombus in the internal carotid artery: diagnosis and treatment of 16 cases in a single center

Abstract

Background: Free-floating thrombus in the internal carotid artery (FFT-ICA) is a rare condition and its real incidence is unknown. The most common etiology is a complication of an atherosclerotic plaque, but several medical conditions can be responsible. The purpose of this study was to retrospectively analyze our experience with carotid endarterectomy in the management of FFT-ICA and also to analyze the patient outcome.

Methods: A retrospective review was performed of all patients admitted during the past 9 years with a diagnosis of FFT-ICA. Patient demographics, clinical manifestations, diagnostic modalities, surgical indications, operative details, postoperative courses, and follow-up information were recorded from the hospital database.

Results: Between January 2000 and December 2008, in our Unit, 2,572 carotid endarterectomies were performed for carotid artery disease. A total of 16 patients (16 of 2,572; 0.62%) were treated for an FFT-ICA. In all, 87.5% (14 of 16) of patients had neurological symptoms. All patients underwent a duplex scan. In 75% (12 of 16) of cases, additional diagnostic tests were performed: digital subtraction angiography (DSA), magnetic resonance angiography, or computed tomographic scan. Duplex scan and DSA detected the FFT-ICA in 62.5% and 100% of cases, respectively. Computed tomographic scan and magnetic resonance angiography failed to provide a diagnosis in majority of the patients (33.4% and 66.7%, respectively). The presence of FFT-ICA was confirmed intraoperatively in all cases. The cumulative stroke rate after surgery was 6.3% (one of 16). Of the total number of patients discharged, 68.75% showed an improvement of neurological symptoms, 12.5% were asymptomatic, 12.5% had no changes in symptoms, and 6.25% of cases worsened. At 30-day follow-up, the survival rate was 93.7% and 75% of patients showed an improvement of neurological symptoms, 12.5% were asymptomatic, and 6.25% died. In all, 6.25% of patients were lost to follow-up.

Conclusion: Patients with FFT-ICA are usually symptomatic and present with an acute emergency. DSA remains the gold standard diagnostic test in FFT-ICA detection. We cannot assert that early surgery is superior to temporary anticoagulation and/or delayed intervention because of the absence of a comparison group. However, our retrospective results suggest that prompt intervention seems to be a safe alternative in FFT-ICA treatment.