BackgroundThe optimal management of ipsilateral extracranial internal carotid artery (ICA) stenosis during endovascular treatment (EVT) is unclear. We compared the outcomes of two different strategies: EVT with vs without carotid artery stenting (CAS).MethodsIn this observational study, we included patients who had an acute ischaemic stroke undergoing EVT and a concomitant ipsilateral extracranial ICA stenosis of ≥50% or occlusion of presumed atherosclerotic origin, from the Dutch Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands (MR CLEAN) Registry (2014–2017). The primary endpoint was a good functional outcome at 90 days, defined as a modified Rankin Scale score ≤2. Secondary endpoints were successful intracranial reperfusion, new clot in a different vascular territory, symptomatic intracranial haemorrhage, recurrent ischaemic stroke and any serious adverse event.ResultsOf the 433 included patients, 169 (39%) underwent EVT with CAS. In 123/168 (73%) patients, CAS was performed before intracranial thrombectomy. In 42/224 (19%) patients who underwent EVT without CAS, a deferred carotid endarterectomy or CAS was performed. EVT with and without CAS were associated with similar proportions of good functional outcome (47% vs 42%, respectively; adjusted OR (aOR), 0.90; 95% CI, 0.50 to 1.62). There were no major differences between the groups in any of the secondary endpoints, except for the increased odds of a new clot in a different vascular territory in the EVT with CAS group (aOR, 2.96; 95% CI, 1.07 to 8.21).ConclusionsFunctional outcomes were comparable after EVT with and without CAS. CAS during EVT might be a feasible option to treat the extracranial ICA stenosis but randomised studies are warranted to prove non-inferiority or superiority.