Angiographic Predictors of Outcomes After Balloon Test Occlusion

Area of Science:

• Neurology
• Vascular Surgery
• Radiology

Background:

• Balloon test occlusion (BTO) with single-photon emission computed tomography (SPECT) predicts tolerance for internal carotid artery occlusion.
• Cerebral circulation's anatomic features may predict BTO outcomes and identify patients prone to test failure.

Purpose of the Study:

• To investigate if angiographic characteristics of the circle of Willis can predict the outcome of balloon test occlusion.
• To identify specific vessel diameter thresholds predictive of BTO failure.

Main Methods:

• Retrospective analysis of 57 patients undergoing internal carotid artery BTO.
• SPECT imaging performed after 15-30 minutes of occlusion with induced hypotension.
• Angiographic measurement of circle of Willis vessel diameters and correlation with BTO failure.

Main Results:

• Twelve patients (21.1%) failed BTO.
• Smaller anterior communicating artery (ACom) diameter was most predictive of BTO failure (AUC 0.907).
• An ACom diameter threshold of 1.1 mm predicted BTO failure with 91.7% sensitivity and 77.8% specificity.

Conclusions:

• Angiographic findings, particularly ACom diameter, can predict BTO results.
• A small ACom (<1.1 mm) identifies patients likely to fail BTO, informing clinical decisions.