Quantitative analysis of revascularization in ischemic moyamoya disease via whole-brain computed tomography perfusion: A retrospective single-center study

Ischemic moyamoya disease (MMD) can be treated with the revascularization of superficial temporal artery to middle cerebral artery (STA-MCA) bypass combined with encephalo-duro-arterio-myo-synangiosis (EDAMS) effectively. The purpose of the present study was to quantify the revascularization of STA-MCA bypass combined with EDAMS via whole-brain computed tomography perfusion (WB-CTP).Seventy-nine consecutive patients with ischemic MMD who admitted to our hospital from August 2012 to October 2018 were carried out STA-MCA bypass combined with EDAMS. WB-CTP was performed at 24hours prior to operation and 3 months following bypass with a follow-up WB-CTP, respectively. Both automatic analysis of WB-CTP (MIStar, Apollo Medical imaging Technology, Melbourne, Australia) for analyzing values of brain volume in delayed time (DT) >3seconds and DT>6seconds, relative cerebral blood flow (gamma CBF)<30% and its mismatch ratio or percentage and diffusion-weighted imaging of magnetic resonance imaging in the ischemic penumbra and the infarct core at the 2 time points were studied for verifying the effectiveness of the combined revascularization. Changes in DT values at MCA-terminal territory after revascularization had been investigated. The dynamic data were with reference to the individual cerebellar arteries.All patients with ischemic MMD underwent STA-MCA bypass combined with EDAMS successfully. The preoperative brain volume in DT>3seconds in MCA-terminal territory was significantly larger than that of postoperative one (P<.05) in the ischemic penumbra in ischemic MMD. The mismatch ratio in brain volume of 24hours prior to revascularization in MCA-terminal territory was significantly lower than that of 3 months (P<.05) following combined revascularization. The percentage of mismatch in brain volume of 24hours prior to revascularization vs that of 3 months and the value of gamma CBF<30% were similar to the above mismatch ratio (P<.05). The ratio of postoperative brain volume in DT>3seconds vs DT>6seconds indicated no significant differences compared with that of preoperative one (P>.05).The WB-CTP can be regarded as a choice for quantifying the combined revascularization in the ischemic penumbra and the infarct core in ischemic MMD. As proposed methods, brain volume in DT>3seconds, the value of gamma CBF<30% and mismatch ratio in brain volume in MCA-terminal territory should be paid more attention in assessing the validity of STA-MCA bypass combined with EDAMS in ischemic MMD.