September-October 2016

Introduction

Collateral Circulation in Acute Ischemic Stroke: A Too-Long-Neglected Treasure That Was Always Before Our Eyes

Francois Nicoli

Prof. François Nicoli

The story of the cerebral collateral circulation began a very long time ago, more than a century.1

As early as 1987, an angiographic study performed in patients with a subacute proximal MCA occlusion provided evidence of the clinical impact of the velocity of the retrograde collateral filling. Authors of this study found that if the conduction time of contrast medium, from … more »

Brain

Prediction of Infarction and Reperfusion in Stroke by Flow- and Volume-Weighted Collateral Signal in MR Angiography

André Kemmling

André Kemmling

Recent randomized trials have shown the efficacy of imaging-based patient selection in predicting benefit from thrombectomy after acute proximal occlusion in the anterior circulation. The underlying concept of imaging-based criteria rests on the assumption that a small irreversible infarct (core lesion) in relation to a large area of potentially treatable hypoperfused critical ischemia identifies a patient with the optimal constellation for … more »

ADULT BRAIN

Degree of Collaterals and Not Time Is the Determining Factor of Core Infarct Volume within 6 Hours of Stroke Onset

André Kemmling

Ken Uchino

Treatment of acute ischemic stroke has focused on patient selection over the past 2 decades. After time from onset to treatment was shown to be the important outcome predictor in intravenous thrombolysis, other predictors of success in reperfusion therapy were investigated, in order improve patient selection beyond the standard timeframe (initially 3 hours for thrombolysis and 6 hours for endovascular therapy). … more »

ADULT BRAIN

Dynamic Magnetic Resonance Angiography Provides Collateral Circulation and Hemodynamic Information in Acute Ischemic Stroke

María Hernández Pérez

María Hernández Pérez

Until recently, conventional angiography has been the only technique able to give information about the dynamic status of the intracranial vessels. Despite different CT and MR techniques that have been developed to assess the grade of collateral circulation after a cerebral arterial occlusion, we found that the great majority of these methods lacked information about changes in the blood … more »

Brain

Perfusion-Weighted Imaging–Derived Collateral Flow Index is a Predictor of MCA M1 Recanalization after IV Thrombolysis

Francois Nicoli

Prof. François Nicoli

“There are three principal cranial collateral pathways…. (including) pial anastomoses between and among the three major cerebral arteries. These collateral pathways exist awaiting demand, and enlarge as demand for flow rate and volume increases. It is our impression that (stroke) prognosis is related to the richness of demonstrable pathways.”

These sentences are quite topical, but were formulated in 1966 by Love … more »

ADULT BRAIN

Effect of Collaterals on Clinical Presentation, Baseline Imaging, Complications, and Outcome in Acute Stroke

Richard Aviv

Richard Aviv

Collateral status is recognized as fundamentally important in patient selection and outcome determination in acute stroke. Yet, there were until recently a paucity of larger studies examining its effect in the presence of recanalization and common complications in stroke therapy such as hemorrhagic transformation. We wanted to tease out these elements with the intent of quantifying the contribution of collaterals to … more »