Proposal of a champagne bottle neck sign grading system reflecting advanced Suzuki stage and hemodynamic compromise in patients with Moyamoya disease.

PURPOSE: The champagne bottle neck sign (CBNS) is regarded as a characteristic finding of the cervical internal carotid artery in patients with moyamoya disease (MMD). However, there is no universal definition, and its clinical significance remains unclear. Here, we aimed to propose a novel CBNS grading system using catheter angiography. METHODS: First, we proposed a novel grading system for CBNS using the lateral view of common carotid artery angiograms. Three grades were defined (grades 0,1, and 2). CBNS grade was defined as a ratio of the internal carotid artery diameter to the common carotid artery diameter of < 0.5 on the lateral view of the common carotid artery angiogram. CBNS grade 2 additionally required plump enlargement of the bulbous portion of the cervical internal carotid artery. We then conducted a retrospective case-control study including 134 patients (247 sides) with MMD and 94 patients (98 sides) with non-MMD intracranial large artery stenosis/occlusion. Finally, we analyzed the association between CBNS grade and clinical features, including Suzuki stage and hemodynamic impairment. RESULTS: CBNS grade 2 demonstrated a strong association with MMD, although grade 2 CBNS was infrequently observed among patients with non-MMD intracranial large-artery stenosis/occlusion (p < 0.001). Additionally, multivariate analysis demonstrated a significant association between CBNS grade 2 and hemodynamic impairment, which was present in 32.5% (13/40) and 55.9% (19/34) of MMD sides at CBNS grades 1 and 2, respectively (p < 0.001). CONCLUSION: We propose a CBNS grading system for MMD patients. CBNS grade 2, characterized by pronounced enlargement of the bulbous portion of the cervical internal carotid artery, may serve as an imaging marker of advanced Suzuki stage and hemodynamic impairment in MMD.