Rapidly growing distal choroidal artery aneurysm re-rupture following revascularization for hemorrhagic Moyamoya disease: A case report.

Intracranial hemorrhage is the leading cause of neurological deficits and poor prognosis in adult patients with Moyamoya disease (MMD). Intracranial hemorrhage is occasionally accompanied by MMD-associated aneurysm and requires additional treatment. To date, direct or indirect bypass surgery or endovascular treatment, such as coil embolization, has been adopted and has achieved successful outcomes. The rapid growth of MMD-associated aneurysms and rebleeding after direct bypass surgery via superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis has rarely been reported. We report a case of a rapidly growing fragile arterial pseudoaneurysm in a patient with MMD. A 45-year-old female was admitted with a headache and decreased mental status. Radiological evaluation, including distal subtraction angiography, revealed intraventricular hemorrhage with a left posterior choroidal artery pseudoaneurysm. Within 4 days after revascularization surgery via STA-MCA direct bypass, the size of the pseudoaneurysm rapidly increased and rebleeding occurred, requiring coil embolization. After endovascular therapy and a second STA-MCA bypass surgery, the patient recovered well and was discharged 8 days later. Follow-up radiological imaging revealed an obliterated pseudoaneurysm without rebleeding or complications. In this case, the rapid growth of an MMD-associated pseudoaneurysm was observed after revascularization surgery because of temporary hemodynamic instability. This report raises questions regarding the causes and management of unstable postbypass hemodynamics.

Morphologic differences between ruptured and unruptured choroidal anastomosis in adult moyamoya disease: a high-resolution vessel wall imaging study.

OBJECTIVE: Choroidal anastomosis (ChA) has been implicated as the main indicator of an increased hemorrhagic risk in adult moyamoya disease. In this retrospective study, the authors aimed to identify the potential risk factors that can influence the rupture of ChA. METHODS: The authors evaluated the clinical and radiological data on brain hemispheres positive for ChA from September 2019 to March 2023. The rupture status of the ChA was determined using previously described methods. Two independent raters quantitatively investigated the lumen diameter (LD) and lumen area (LA) of the ChA using high-resolution vessel wall imaging (VWI). Multivariate logistic regression analysis was conducted to identify the risk factors for ruptured ChA. RESULTS: Ruptured and unruptured ChAs were identified in 16 and 60 hemispheres, respectively. Univariate analysis showed that the mean values of the LD (1.251 ± 0.241 vs 0.967 ± 0.214 mm, p < 0.001) and LA (1.607 ± 0.445 vs 0.945 ± 0.372 mm2, p < 0.001) of ChAs were significantly greater in the ruptured group than in the unruptured group. A periventricular anastomosis (PA) score of 1, indicating the angiographic presence of ChA alone, was more prevalent in the ruptured group than in the unruptured group (43.8% vs 11.7%, p = 0.003). Multivariate analysis demonstrated that a larger LA of the ChA (OR 37.01, 95% CI 5.787-236.7, p < 0.001) and PA score 1 (OR 6.661, 95% CI 1.260-35.21, p = 0.026) were independently associated with ruptured ChA hemispheres. Receiver operating characteristic curve analysis revealed that the optimal cutoff point for the LA was 1.285 mm2 (sensitivity 81.3%, specificity 86.7%). CONCLUSIONS: A larger LA (> 1.285 mm2) of the ChA and the angiographic presence of ChA alone are independent risk factors for a ruptured ChA. Revascularization surgery for the prevention of future hemorrhage may be indicated for hemispheres with a high-risk unruptured ChA. These characteristics may help to determine treatment strategies for patients with an unruptured ChA.

Massive Hyperostotic Meningioma En Plaque Mimicking Fibrous Dysplasia.

The authors report an extremely rare case of a massive hyperostotic meningioma en plaque, which had characteristics of unique bony growth. A 34-year-old man presented with a palpable solid mass in the left cranial region that had gradually grown in size with a broad base on the calvarium for 8 years. Radiologically, the area involved by the mass ranged from the sphenoid bone to the frontal, parietal, temporal, and occipital bones. Three-dimensional CT revealed multiple growing spiculate features on the inner and outer cranial surface. Even though the radiologic features resembled fibrous dysplasia, it was histologically found to be a type of meningioma.

High resolution vessel-wall imaging for peripheral aneurysms in adult moyamoya disease: a report of three cases.

Peripheral aneurysms in patients with moyamoya disease have been reported to be hazardous owing to their rupture-prone nature. High-resolution vessel wall imaging has recently emerged as a useful modality for evaluating intracranial aneurysmal status. We present the vessel-wall imaging of peripheral aneurysms in three patients with moyamoya disease. Strong circumferential wall enhancement was observed in ruptured peripheral aneurysms. Peripheral aneurysms were located at the connection point between the single main stem and the multiple medullary tributaries of the choroidal anastomosis. Using high-resolution vessel-wall imaging, we identified the characteristics of peripheral aneurysms in patients with moyamoya disease.