Objective Assessment of Arterial Steal Phenomenon in Direct Carotid Cavernous Fistula Using 2D Parametric Parenchymal Blood Flow Analysis

The aim of the study is to evaluate the hemodynamic changes and the parenchymal perfusion associated with carotid cavernous fistulas before and after embolization using two-dimensional (2D) parenchymal blood flow analysis. A 15-year-old boy presented with 2-month history of progressive right eye proptosis, chemosis, and diplopia after a motor vehicle accident. Intracranial liquid embolization using Onyx-18 through the inferior petrosal approach was done with balloon protection at the opening of the fistula in the internal carotid artery, resulting in complete occlusion of the fistula. Parenchymal blood flow analysis was done before and immediately after embolization. 2D parametric parenchymal blood flow analysis is newly introduced software that can provide data cannot be conveyed by conventional digital subtraction angiography alone. The software allows for objective assessment of the arterial steal and the parenchymal perfusion both pre, and post-embolization. Pre-embolization assessment may influence the therapeutic decision, while post-embolization assessment can evaluate the treatment efficacy.