Hemodynamic Tandem Intracranial Lesions on Magnetic Resonance Angiography in Patients Undergoing Carotid Endarterectomy

Abstract

BackgroundHemodynamic tandem intracranial lesions (TILs) on intracranial magnetic resonance angiography, which develop flow dependently, have been overlooked clinically in patients undergoing carotid endarterectomy. As they represent severe baseline hemodynamic compromise at the segment, they may be associated with distinctive clinical outcomes.Methods and ResultsWe assessed 304 consecutive carotid endarterectomy cases treated over 3 years. Included cases had both preoperative and postoperative intracranial 3‐dimensional time‐of‐flight magnetic resonance angiography, of which signal intensities are flow dependent, and postoperative diffusion‐weighted imaging (≤3 days following carotid endarterectomy). Preoperative TILs in the ipsilateral intracranial arteries were evaluated by the presence of nonexclusive components: focal stenosis (>50%), diffuse stenosis (>50%), and decreased signal intensities (>50%). The components showing postoperative normalization were considered hemodynamic. TILs with hemodynamic components were defined as hemodynamic TILs, while others as consistent TILs. Baseline characteristics and postoperative outcomes were analyzed among 3 groups: no TILs, consistent TILs, and hemodynamic TILs. Preoperative TILs were identified in 104 (34.2%) cases; 54 (17.8%) had hemodynamic components. Diffuse stenosis and decreased signal intensities were usually reversed postoperatively. Patients with hemodynamic TILs tended to have severe proximal carotid stenosis and recent strokes (≤14 days). For the outcome, hemodynamic TILs were independently associated with the advent of postoperative ischemic lesions on diffusion‐weighted imaging (odds ratio: 2.50; 95% CI, 1.20–5.20).ConclusionsIn patients undergoing carotid endarterectomy, a significant number of preoperative TILs demonstrated hemodynamic components, which were reversed postoperatively. The presence of such components was distinctively associated with the postoperative incidence of new ischemic lesions.

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

“…Full publications were retrieved of 164 studies published up to 31 December 2016. Seventy-nine studies were excluded for the following reasons: MRI to detect cerebral ischaemia did not include DWI sequences, or DWI was not done in all patients (n = 15); 22–36 no DWI was performed before treatment (n = 11); 37–47 post-procedural DWI was performed more than seven days after treatment (n = 3); 48–50 the number of DWI+ patients or procedures could not be extracted (n = 6); 51–56 or information on procedural stroke was lacking or patients with procedural stroke were excluded from the analysis (n = 6). 49,57–68 One study was excluded because the analysis was restricted to patients with available six months’ follow-up who constituted less than half of the study population (n = 1).…”

The Impact of Cerebral Atherosclerosis According to Location on Prognosis after Coronary Artery Bypass Grafting

“…Carotid revascularization might have prevented the development of postoperative stroke because this procedure improves the perfusion of proximal vascular beds and subsequent intracranial arteries [27]. In our cohort, 30% (5/17) of patients with preoperative carotid stenting also had significant atherosclerosis in the intracranial arteries distal to the treated carotid artery.…”

Editor's Choice – Predictors of New Ischaemic Brain Lesions on Diffusion Weighted Imaging After Carotid Stenting and Endarterectomy: A Systematic Review

“…17 It is therefore not unexpected that a risk benefit for asymptomatic patients applies for development of DWI lesions as well. 18,19 CEA patients with impeded pre-procedural haemodynamics may be at risk during clamping of the carotid artery, since it may cause a critical reduction in cerebral perfusion. Only one of the included studies reporting cerebral haemodynamics used routine intraluminal shunting; 19 others stated that no shunt was used.…”

“…18,19 CEA patients with impeded pre-procedural haemodynamics may be at risk during clamping of the carotid artery, since it may cause a critical reduction in cerebral perfusion. Only one of the included studies reporting cerebral haemodynamics used routine intraluminal shunting; 19 others stated that no shunt was used. 20e22 It is unclear whether these studies used electrophysiological neuromonitoring to determine maintenance of sufficient cerebral perfusion after carotid artery cross clamping.…”

“…8 Studies finding a positive association between increased inflammatory markers and new lesions used CRP or hsCRP as an inflammatory marker. 19,23 These studies advocate that inflammation may be related to the presence of macrophages and T lymphocytes in the plaque, which is associated with plaque instability. This hypothesis is strengthened by studies finding differences in levels of inflammatory markers between symptomatic and asymptomatic patients.…”