BASELINE COLLATERAL CIRCULATION IS ASSOCIATED WITH EARLY OUTCOMES IN PATIENTS WITH LARGE-VESSEL OCCLUSION ACUTE ISCHEMIC STROKE TREATED WITH MECHANICAL THROMBECTOMY

Abstract

Introduction: Mechanical thrombectomy (MT) is an established treatment of acute ischemic stroke (AIS) due to large-vessel occlusion (LVO). Adequacy of brain collateral vessels has been shown to affect early outcoes of AIS patients treated with endovascular reperfusion therapies.
Aim: We sought to prospectively evaluate the impact of collaterals on the outcomes of AIS patients due to LVO treated MT in two tertiary stroke centers in Greece.
Methods: Consecutive LVO patients treated with MT in two SITS (Safe Implementation of Thrombolysis in Stroke) Registry centers in Greece were evaluated during a three-year period (January 2015-December 2017). Collateral status was assessed on digital subtraction angiography (DSA) using ASITN/SIR classification. Baseline characteristics, admission stroke severity (quantified by NIHSS-score) and three-month functional outcome (determined by modified Rankin Scale) were recorded.
Results: Patients with poor collaterals on DSA were more likely to harbor tandem (extracranial internal carotid artery & middle cerebral artery) occlusions and present with higher admission median NIHSS-scores (20 vs. 15 points; p = 0.038). Patients with poor collaterals had higher (p < 0.05) median mRS-scores at discharge and at three-months. The three-month mortality and functional independence rates were higher (50% vs. 10%; p = 0.015) and lower (20% vs. 70%; p = 0.010) respectively in LVO patients with poor collaterals.
Conclusions: Poor baseline collateral status is more common in LVO patients with tandem occlusions and is associated with higher baseline stroke severity and three-month mortality rates. Patients with good baseline collateral circulation are more likely to be functional independent at three-months following stroke onset.