Intracranial endovascular balloon test occlusion: indications, methods, and predictive value.

Abrupt interruption of the internal carotid artery without a balloon test occlusion (BTO) carries a 26% risk of cerebral infarction. BTO is a test used to decrease this risk by evaluating the efficacy of the collateral circulation. Clinical tolerance of parent vessel occlusion can be assessed by a BTO with several variables, including the clinical examination, angiographic assessment, stump pressure, induced hypotension, perfusion scanning, transcranial Doppler ultrasonography, and neurophysiologic monitoring. This review discusses the indications, methods, predictive value, and complications of BTO.