Diagnosis and surgical management of free-floating thrombus within the carotid artery.

Objective: Free-floating thrombus (FFT) of the carotid artery is a rare condition of currently unknown etiology. Less than 150 cases have been described in the published world literature to date.
Design and Setting: We present 6 consecutive cases of carotid FFT, identified prospectively from 5000 carotid duplex scans over a 34-month period in a single tertiary center for vascular surgery.
Results: All 6 cases involved the left carotid bifurcation in neurologically symptomatic individuals. In 5 of the 6 cases, FFT occurred in the absence of a significantly stenosing atheromatous plaque and was not associated with an elevation in velocity on duplex. The patients were all treated with surgical thromboendarterectomy, with good result.
Conclusions: Duplex imaging can underestimate the degree of stenosis. Free-floating thrombus presents a challenge in diagnosis due to its rapidly evolving nature. The management of FFT by acute thromboendarterectomy appears to be safe and effective in limiting further focal neurological sequelae.