Silent brain infarcts on diffusion-weighted imaging after carotid revascularisation: A surrogate outcome measure for procedural stroke? A systematic review and meta-analysis

Abstract

Aim: To investigate whether lesions on diffusion-weighted imaging (DWIþ) after carotid artery stenting (CAS) or endarterectomy (CEA) might provide a surrogate outcome measure for procedural stroke. Materials and Methods: Systematic MedLine V R database search with selection of all studies published up to the end of 2016 in which DWI scans were obtained before and within seven days after CAS or CEA. The correlation between the underlying log odds of stroke and of DWIþ across all treatment groups (i.e. CAS or CEA groups) from included studies was estimated using a bivariate random effects logistic regression model. Relative risks of DWIþ and stroke in studies comparing CAS vs. CEA were estimated using fixed-effect Mantel-Haenszel models. Results: We included data of 4871 CAS and 2099 CEA procedures (85 studies). Across all treatment groups (CAS and CEA), the log odds for DWIþ was significantly associated with the log odds for clinically manifest stroke (correlation coefficient 0.61 (95% CI 0.27 to 0.87), p ¼ 0.0012). Across all carotid artery stenting groups, the correlation coefficient was 0.19 (p ¼ 0.074). There were too few CEA groups to reliably estimate a correlation coefficient in this subset alone. In 19 studies comparing CAS vs. CEA, the relative risks (95% confidence intervals) of DWIþ and stroke were 3.83 (3.17-4.63, p < 0.00001) and 2.38 (1.44-3.94, p ¼ 0.0007), respectively. Discussion: This systematic meta-analysis demonstrates a correlation between the occurrence of silent brain infarcts on diffusion-weighted imaging and the risk of clinically manifest stroke in carotid revascularisation procedures. Conclusion: Our findings strengthen the evidence base for the use of DWI as a surrogate outcome measure for procedural stroke in carotid revascularisation procedures. Further randomised studies comparing treatment effects on DWI lesions and clinical stroke are needed to fully establish surrogacy.

Combination of Single- and Paired-Pulse Somatosensory Evoked Potentials in Ischemic Monitoring: Preliminary Investigation in Carotid Endarterectomy

“…Postoperative DWI abnormalities in the present study were seen in 11.8% (4/34) of the patients, which were roughly in agreement with a meta-analysis study done in CEA patients that demonstrated prevalence of postoperative abnormalities in 10.6% [ 24 ]. Whereas this fact potentially indicates a high clinical demand for intraoperative evaluation of DWI abnormalities, the conventional SEPs in the present study indicated low sensitivity.…”

The&nbsp;biochemical markers associated with TCD to evaluate the curative effect after Carotid Artery Stenting

“…Meanwhile, the MRI which performed on the post-operation patients contemporaneously revealed the emerging hyperintense signals in DWI sequences. So the DWI (+) shown in the operative patients maybe ascribe to the particulate embolism after CAS [11] . Because astrocytes are very sensitive to cerebral ischemia and hypoxia, the embolism could cause the astrocytes damaged and produced excessive GFAP and S100B into CSF.…”

“…Some researchers pointed out that the ischemic brain lesion after CAS could increase the risk of recurrent cerebrovascular events [10] . So they recommended the application of Diffusion Weighted Imaging (DWI) as a surrogate outcome measure for procedural stroke in carotid revascularisation procedure [11] . But the two above imaging tools in some extent have the disadvantages of poor repeatability, high costs and susceptible to the operators.…”

Surrogate Markers and Reporting Standards for Outcome After Carotid Intervention

“…2 DWI lesions qualify as a strong surrogate measure as they meet three conditions: (i) a plausible biological relationship with stroke; 3 (ii) an association with increased risk of post-procedural stroke/transient ischaemic attack); 4 and (iii) the treatment effect on DWI lesions correlates with that on stroke. 5 According to these three qualifications, DWI lesions quantified as number and/ or volume are an excellent surrogate endpoint for studies evaluating treatment modifications.…”

“…A 2019 meta-analysis established that for an underlying 3% absolute difference in procedural stroke risk among revascularisation techniques, a 90% sample size reduction could be achieved when using DWI lesions rather than classic endpoints. 5 Of note, little is known about the optimal timing of the post-procedural scan as both ongoing haemodynamic disturbance and thrombo-embolic events days after the procedure are common. Also, magnetic resonance (MR) field strength may influence the number of DWI lesions, 2 and thus timing and image acquisition protocols should be harmonised in future research.…”