Rapid Formation of Cerebral Microbleeds after Carotid Artery Stenting

Abstract

Background: Recent studies reported that cerebral microbleeds (CMBs), i.e. small areas of signal loss on T₂*-weighted gradient-echo (GE) imaging, could develop rapidly after acute ischemic stroke. We hypothesized that CMBs rapidly emerge after carotid artery stenting (CAS). Objective: We investigated the frequency of and predisposing factors for CMBs after CAS. Methods: We retrospectively examined MRI before and after CAS in 88 consecutive patients (average age: 71.7 ± 7.2 years, average rates of carotid stenosis: 72.6 ± 12.8%) who underwent CAS for carotid artery stenosis between March 1, 2009, and September 30, 2010. We defined new CMBs as signal losses that newly appeared on the follow-up GE. We examined the association of new CMBs with demographics, risk factors, and baseline MBs. Results: Among 88 patients, 18 (20.5%) had CMBs initially, and 7 (8.0%) developed new CMBs right after CAS. New CMBs appeared on the same side of CAS in all of the 7 patients. New CMBs appeared significantly more frequently in the CMB-positive group than in the CMB-negative one (22% vs. 4%, p = 0.03) on the pre-CAS MRI. Multivariate analysis also revealed that the presence of CMBs before CAS was an independent predictor of new development of CMBs after CAS (odds ratio: 8.09, 95% confidence interval: 1.39–47.1). Conclusion: CMBs can develop rapidly after CAS, especially in patients with pre-existing CMBs. Since the existence of CMBs prior to CAS suggests a latent vascular damage which is vulnerable to hemodynamic stress following CAS, particular attention should be paid to the prevention of intracerebral hemorrhage due to hyperperfusion after CAS.

Volumetric Analysis of Carotid Plaque Components and Cerebral Microbleeds: A Correlative Study

“…16,17 This condition has gained particular consideration in the last years because studies have demonstrated that it is associated with the presence and outcome of cerebral strokes and with neurodegenerative disorders. [18][19][20] Some recent papers have indicated an association between the atherosclerotic disease of the carotid artery and the presence of CMBs, 7,21,22 and Saba et al 7 found that the presence and the degree of severity of CMBs are associated with the presence of some specific plaque subcomponents, namely the fatty components. The purpose of our study was to explore the potential association between the carotid artery plaque volume (and the volume of its subcomponents) and the CMBs.…”

“…The prevalence of CMBs we found was 23.5% (16 of 68), and it is similar to other previously published papers. 16,[21][22][23][24] However, some recent papers have reported a very high prevalence of CMBs. 25,26 This difference can be explained by the fact that the detection of CMBs is reliant on the paramagnetic property of hemosiderin which disrupts the local magnetic field (the so-called "susceptibility effect") on T2*-weighted GRE.…”

A Case of Suspected Metallic Embolism after Carotid Artery Stenting

“…We believe that the abnormal signal spot represented some metal because the MRI findings of the lesion included no MRI signals resulting in a signal void, a susceptibility artifact resulting in the high-intense halo and the "blooming" appearance, and no signal changes over time, and these characteristics completely consisted with those of cases that we previously reported as suspected metallic embolisms after endovascular coil embolization for cerebral aneurysms. 3) Besides embolism, hemosiderin deposition might be considered because microbleeds were reported to occur after CAS in approximately 10% of the cases 6,7) and the abnormal spot was low intensity in all the images. However, this was unlikely because the surrounding halo on T2 and DWIs and the "blooming" effect on SWI were inconsistent with hemosiderin.…”

New Cerebral Microbleeds After Mechanical Thrombectomy for Large-Vessel Occlusion Strokes

“… 14 , 15 New CMBs could also occur shortly in 8% of patients after carotid artery stenting. 18 The development of CMBs was attributable to blood–brain barrier (BBB) disruption and small arteries or arteriole rupture. 4 , 5 Sudden reperfusion and hemodynamic changes after mechanical thrombectomy could aggravate the BBB disruption.…”

“… 14 – 16 New CMBs have also been reported to occur shortly after carotid artery stenting or cardiac valve surgery. 17 , 18 …”