Endovascular treatment effects onrecovery of hemodynamics and cognitionin asymptomatic carotid artery stenosis

Background:Internal carotid-artery stenosis (ICAS)accounts for approximately 10–20% of all strokes.1While effective endovascular treatment is available bycarotid artery stenting (CAS) or carotid endarterectomy(CEA), they come with substantial risks.2Those compet-ing risks complicate treatment decisions especially inasymptomatic ICAS and create the need for improvedpostoperative outcome evaluations. Moreover, revascular-ization effects on cognitive impairments are widelyunknown.3Aim:This MRI-study evaluated endovascular treatmentefficacy in asymptomatic ICAS by clinically applicablehemodynamic imaging. We evaluated capillarytransit-time heterogeneity (CTH) and relative cerebralblood volume (rCBV) with additional visual attentiontesting.Method:16 asymptomatic unilateral high-grade ICAS-patients (age 71.4>5.8y) and 17 age-matched healthycontrols (HC,age 70.8>5.3y) underwent MRI on a 3TPhilips Ingenia twice (10.5 months mean follow-up time).White matter lesions (WML) were derived from FLAIR,4CTH and rCBV from dynamic susceptibility contrast5andtheir lateralization compared within grey matter of themiddle cerebral arterial circulation.6Cognitive testingwith inter-hemispheric sensitivity was based on thetheory of visual attention.7Results/Conclusions:Ipsilateral increases of CTH byþ21.4% (p<0.01, Figure 1(a)) and rCBV byþ4.3%(p<0.03, Figure 1(a)) indicate microvascular impair-ments5 and chronic vasodilation8in ICAS at baseline.After endovascular treatment, hemodynamics recoveredby reduced lateralization of 80% (p<0.04, Figure 1(a)) inline with known short-term effects.9,10However, visualattention deficits persisted (Figure 1(b)).10Here, improvedCTH11might counteract with cognitive decline by microemboli,12as postoperative WML increased slightly butnon-significantly (Figure 1(c)). In conclusion, hemodynam-ics recovered after asymptomatic ICAS revascularization,whereas cognitive impairments seem irreversible