Background: There is no consensus regarding the management of carotid free-floating thrombi in patients with acute ischemic stroke and transient ischemic attack.
Aims: This systematic review aims to (1) describe the current imaging methods for diagnosis of carotid free-floating thrombi and its associated risk factors, (2) estimate the proportion of carotid free-floating thrombi diagnosed in stroke patients, (3) estimate the proportion of carotid free-floating thrombi patients treated medically and surgically, and (4) evaluate 30-day outcomes.
Methods: We searched MEDLINE, EMBASE, and manually for references reporting carotid free-floating thrombi from 1960 until June 2017. We estimated the frequency of carotid free-floating thrombi and evaluated 30-day outcomes using Cox regression. We defined the timing of surgical intervention as early (less than 72 h) and delayed (more or equal to 72 h).
Summary of review: We retrieved 525 carotid free-floating thrombi cases from 58 case series and 83 case reports. Carotid free-floating thrombi were present in 1.53% of stroke patients. Carotid free-floating thrombi diagnosis was made by digital subtraction angiography (38.1%), carotid duplex ultrasound (29.5%), and computed tomography angiography (29.5%). The 30-day risk of transient ischemic attack, silent brain ischemia, any stroke or death was 17.1%. In multivariate analyses, there were no differences in outcome for any anticoagulation regime or timing of revascularization procedure.
Conclusions: The diagnosis of carotid free-floating thrombi is more common due to the increased use of early noninvasive vascular imaging in transient ischemic attack and stroke. It poses a high short-term risk of stroke and death, but there is as yet no established treatment. The low quality of evidence in the carotid free-floating thrombi literature limits the interpretation of our results and warrants a large-scale prospective cohort study in carotid free-floating thrombi.
Keywords: Arterial disease; anticoagulants; carotid endarterectomy; carotid stenting; carotid thrombosis; computed tomography angiography; systematic review.