In patients with proximal middle cerebral artery occlusion undergoing endovascular stroke treatment, collateral vessels are a pivotal factor in determining reperfusion success, final infarct size, and clinical outcome.
To determine the impact of collateral vessel status on clinical and imaging outcomes in patients undergoing endovascular therapy (EVT) for proximal middle cerebral artery (MCA) occlusion.
Materials and Methods
There were 160 patients with proximal MCA occlusion at six centers in this institutional review board–approved multicenter EVT registry. Angiograms were analyzed at a blinded core laboratory, and collateral vessel status was assessed by using the American Society of Interventional and Therapeutic Neuroradiology (ASITN)/Society of Interventional Radiology (SIR) collateral vessel grading system, while reperfusion was assessed by using the Thrombolysis in Cerebral Infarction (TICI) scale. Good outcome was defined as a modified Rankin Scale score of 0–2 at follow-up. Binary logistic regression analysis was performed by using parameters with P < .2 in univariate analysis.
Good clinical outcome was attained in 62 (39%) of the 160 patients, and TICI 2b–3 reperfusion was achieved in 94 (59%) patients. Nineteen patients had ASITN/SIR collateral vessel grades of 0 or 1, 63 patients had a grade of 2, and 78 patients had grades of 3 or 4. Better collateral vessels were associated with higher reperfusion rates (21%, 48%, and 77% for ASITN/SIR grades of 0 or 1, 2, and 3 or 4, respectively; P < .001), a higher proportion of infarcts smaller than one-third of the MCA territory (32%, 48%, and 69% for ASITN/SIR grades of 0 or 1, 2, and 3 or 4, respectively; P < .001), and a higher proportion of good clinical outcome (11%, 35%, and 49% for ASITN/SIR grades of 0 or 1, 2, and 3 or 4, respectively; P = .007). At multivariable analysis, collateral vessel status independently predicted reperfusion, final infarct size, and clinical outcome. Within an onset-to-treatment time (OTT) of 0–3 hours, collateral vessel status predicted final infarct size and reperfusion. Within an OTT of 3–6 hours, it additionally predicted clinical outcome, with 53% of patients with ASITN/SIR grades of 3 or 4 having a good outcome, as compared with 0% of patients with grades of 0 or 1 and 27% of patients with a grade of 2 (P = .008).
In this patient population, collateral vessel status independently predicted the pivotal outcome parameters of reperfusion, infarct size, and clinical outcome. These data underscore the utility of patient selection for EVT on the basis of collateral vessel status.
© RSNA, 2015
- 1. . Collateral flow predicts response to endovascular therapy for acute ischemic stroke. Stroke 2011;42(3):693–699. Crossref, Medline, Google Scholar
- 2. . Effect of collateral blood flow on patients undergoing endovascular therapy for acute ischemic stroke. Stroke 2014;45(4):1035–1039. Crossref, Medline, Google Scholar
- 3. . Collaterals at angiography and outcomes in the Interventional Management of Stroke (IMS) III trial. Stroke 2014;45(3):759–764. Crossref, Medline, Google Scholar
- 4. . Factors that determine penumbral tissue loss in acute ischaemic stroke. Brain 2013;136(Pt 12):3554–3560. Crossref, Medline, Google Scholar
- 5. . Endovascular therapy of 623 patients with anterior circulation stroke. Stroke 2012;43(4):1052–1057. Crossref, Medline, Google Scholar
- 6. . Age dependency of successful recanalization in anterior circulation stroke: the ENDOSTROKE study. Cerebrovasc Dis 2013;36(5-6):437–445. Crossref, Medline, Google Scholar
- 7. . Periprocedural aspects in mechanical recanalization for acute stroke: data from the ENDOSTROKE registry. Neuroradiology 2013;55(9):1143–1151. Crossref, Medline, Google Scholar
- 8. . Recommendations on angiographic revascularization grading standards for acute ischemic stroke: a consensus statement. Stroke 2013;44(9):2650–2663. Crossref, Medline, Google Scholar
- 9. . Trial design and reporting standards for intra-arterial cerebral thrombolysis for acute ischemic stroke. Stroke 2003;34(8):e109–e137. Crossref, Medline, Google Scholar
- 10. . Randomised double-blind placebo-controlled trial of thrombolytic therapy with intravenous alteplase in acute ischaemic stroke (ECASS II). Second European-Australasian Acute Stroke Study Investigators. Lancet 1998;352(9136):1245–1251. Crossref, Medline, Google Scholar
- 11. . Endovascular therapy after intravenous t-PA versus t-PA alone for stroke. N Engl J Med 2013;368(10):893–903. Crossref, Medline, Google Scholar
- 12. . Solitaire flow restoration device versus the Merci retriever in patients with acute ischaemic stroke (SWIFT): a randomised, parallel-group, non-inferiority trial. Lancet 2012;380(9849):1241–1249. Crossref, Medline, Google Scholar
- 13. . Trevo versus Merci retrievers for thrombectomy revascularisation of large vessel occlusions in acute ischaemic stroke (TREVO 2): a randomised trial. Lancet 2012;380(9849):1231–1240. Crossref, Medline, Google Scholar
- 14. . Collateral flow averts hemorrhagic transformation after endovascular therapy for acute ischemic stroke. Stroke 2011;42(8):2235–2239. Crossref, Medline, Google Scholar
- 15. . Impact of collateral flow on tissue fate in acute ischaemic stroke. J Neurol Neurosurg Psychiatry 2008;79(6):625–629. Crossref, Medline, Google Scholar
Article HistoryReceived April 22, 2014; revision requested June 6; revision received August 15; accepted September 10; final version accepted September 19.
Published online: Dec 29 2014
Published in print: Mar 2015