Impact of leukoaraiosis severity on the association of outcomes of mechanical thrombectomy for acute ischemic stroke: a systematic review and a meta-analysis

Abstract

Background Leukoaraiosis (LA) severity is associated with poor outcome after mechanical thrombectomy (MT) for acute ischemic stroke (AIS) caused by large vessel occlusion. This meta-analysis aimed to assess the association of LA severity with AIS-related risk factors and outcomes of MT. Methods PubMed, Web of Science, EMBASE, and Cochrane Collaboration Database was searched for studies on MT for AIS with LA. We conducted a random-effects meta-analysis for the prevalence of stroke risk factors and the MT outcome in the absent to moderate LA and severe LA groups. Results We included seven cohort studies involving 1294 participants (1019 with absent to moderate LA and 275 with severe LA). The absent to moderate LA group had a significantly lower prevalence of coronary artery disease (odds ratio [OR] 0.43; 95% CI 0.29-0.66), atrial fibrillation (OR, 0.26; 95% CI 0.17-0.38), hypertension (OR, 0.39; 95% CI 0.24-0.61), and ischemic stroke (OR, 0.27; 95% CI 0.15-0.50) than the severe LA group. There were no significant between-group differences in symptom onset to recanalization time (364.4 versus 356.2 min, mean difference 19.4; 95% CI − 28.3 to 67.2), final recanalization rate (modified thrombolysis in cerebral infarction score of 2b/3; OR, 0.87; 95% CI 0.55-1.38), and symptomatic intracranial hemorrhage (OR, 0.62; 95% CI 0.34-1.11). The absent to moderate LA group had a higher good functional outcome (modified Rankin Scale score of 0-2 at 90 days; OR, 4.55; 95% CI 3.20-6.47) and a lower mortality rate (179/1019 vs 108/275; OR, 0.28; 95% CI 0.20-0.39). Conclusion There are unique differences in the characteristics of risk factors and clinical outcomes of ischemic stroke across patients with LA of different severity. Patients with severe LA are more likely to be associated with risk factors for cerebrovascular disease and have a poor post-MT outcome.

Emerging role of white matter lesions in cerebrovascular disease

“…In patients receiving IVT, Kongbunkiat et al's meta‐analysis (Kongbunkiat et al, 2017) and several retrospective studies (Curtze, Haapaniemi, et al, 2015; Neumann‐Haefelin et al, 2006; Palumbo et al, 2007) found moderate to severe leukoaraiosis to significantly increase the risk of sICH. Conversely, recent studies in patients undergoing EVT found no significant association between WML severity and sICH (Albo et al, 2021; Atchaneeyasakul et al, 2017; Boulouis et al, 2019; Guo et al, 2019; Huo, Chen, et al, 2020; Liu et al, 2019; Mistry et al, 2020; Mutzenbach et al, 2020). The findings in IVT cohorts may be confounded by the already increased risk of haemorrhage associated with IVT relative to EVT.…”

“…Early neurological improvement (ENI) is assessed 24 h after baseline and is defined according to change in National Institutes of Health Stroke Scale (NIHSS) score. Most contemporary studies demonstrated no association of leukoaraiosis with recanalisation rates (Albo et al, 2021; Atchaneeyasakul et al, 2017; Boulouis et al, 2019; Huo, Chen, et al, 2020; Mistry et al, 2020) or ENI (Albo et al, 2021; Mistry et al, 2020). However, a recent study by Guo et al reported reduced rates of ENI in patients with severe WMLs after EVT (Guo et al, 2020).…”

“…However, the benefits of reperfusion therapy may not be consistent for all patients. Recent studies have shown that the presence of severe leukoaraiosis on baseline imaging is associated with significantly worse outcomes in AIS patients after reperfusion therapy (Huo, Chen, et al, 2020). The severity of leukoaraiosis has been hypothesised to be associated with clinical outcomes post‐reperfusion therapy, including functional outcome, survival, procedural success, and post‐treatment complications.…”

“…Poor functional outcome is most defined as an mRS of 3–6. A recent meta‐analysis by Huo et al investigated the effects of leukoaraiosis on outcomes in 1294 AIS patients undergoing EVT (Huo, Chen, et al, 2020). Patients with severe leukoaraiosis were significantly associated with poorer functional outcomes at 90 days post‐stroke than those with absent to moderate leukoaraiosis.…”

Corneal Nerve Loss in Patients with Acute Ischemic Stroke: A Surrogate Marker for Poor Pial Collaterals

“…Animal studies have shown that "rarefaction of collaterals" is associated with multiple cardiovascular risk factors 13 . Additionally, MR imaging has also shown that the presence of white matter hyperintensities is associated with a poor pial collateral circulation 14 and their severity is associated with poor outcomes after stroke 15 .…”