Preoperative Magnetic Resonance Imaging Findings Associated with Preexisting Basilar Artery Stenosis in Endovascular
Hirofumi Asano1, Tatsuya Shimizu1, Kazuki Wakabayashi2
1Department of Neurosurgery, Gunma University Graduate School of Medicine.
Insights
Pontine hyperintensity on diffusion-weighted imaging may indicate basilar artery stenosis in acute basilar artery occlusion. This finding can help guide endovascular revascularization decisions for stroke patients.
Area of Science:
- Neurology
- Vascular Neurology
- Neuroradiology
Background:
- Atherosclerotic stenosis is common in acute basilar artery occlusion (ABAO).
- Preoperative identification of stenosis is crucial for endovascular revascularization but reliable imaging indicators are lacking.
- Stenosis often requires additional procedures beyond mechanical thrombectomy.
Purpose of the Study:
- To identify preoperative magnetic resonance imaging (MRI) findings associated with underlying basilar artery stenosis in patients undergoing acute endovascular revascularization.
- To improve preoperative assessment and treatment planning for ABAO.
Main Methods:
- Retrospective analysis of 13 patients with stenosis and 35 without, identified via post-recanalization angiography.
- Evaluation of preoperative MRI findings, including diffusion-weighted imaging (DWI) and magnetic resonance angiography (MRA).
- Statistical analysis adjusting for National Institutes of Health Stroke Scale (NIHSS) score.
Main Results:
- Pontine hyperintensity on DWI was independently associated with basilar artery stenosis (p<0.05).
- Non-visualization of the proximal basilar artery on MRA was more frequent in the stenosis group but not independently associated after adjustment.
- The stenosis group required more additional endovascular procedures; the non-stenosis group achieved recanalization with thrombectomy alone.
Conclusions:
- Pontine hyperintensity on DWI is an independent predictor of underlying basilar artery stenosis in ABAO.
- Absence of pontine hyperintensity may help exclude stenosis.
- Concordant pontine hyperintensity and proximal basilar artery non-visualization on MRA may suggest stenosis before treatment.
Abstract:
Underlying atherosclerotic stenosis is more common in acute basilar artery occlusion than in anterior circulation, and often necessitates additional procedures such as balloon angioplasty or stent placement during endovascular revascularization. Preoperative recognition of underlying basilar artery stenosis may be clinically relevant, but reliable imaging indicators remain unclear. This study aimed to identify preoperative magnetic resonance imaging findings associated with underlying basilar artery stenosis in patients undergoing acute endovascular revascularization. We retrospectively analyzed patients at three institutions between 2018 and 2023. Patients were divided into stenosis and non-stenosis groups based on post-recanalization angiographic findings. Stenosis was identified in 13 patients and was found to be absent in 35 patients. Pontine hyperintensity on diffusion-weighted imaging was more frequent in the stenosis group and remained independently associated with preexisting basilar artery stenosis after adjustment for preoperative National Institutes of Health Stroke Scale score. Non-visualization of the proximal basilar artery on magnetic resonance angiography was also more frequent in the stenosis group, but did not remain independently associated after adjustment. Additional endovascular procedures were more frequently required in the stenosis group, whereas recanalization was achieved with mechanical thrombectomy alone in the non-stenosis group. Functional outcomes at discharge were comparable between the groups. In acute basilar artery occlusion, pontine hyperintensity on diffusion-weighted imaging was independently associated with preexisting basilar artery stenosis. Its absence may help exclude underlying stenosis, whereas concordant positivity of pontine hyperintensity and proximal basilar artery non-visualization may support suspicion of stenosis before treatment.
