An 80-year-old male with severe constipation experienced a sudden headache during defecation. Shortly after, he visited local clinic for medication and abrupt left hemiplegia occurred. He was in a drowsy state and had dysarthria. The NIHSS score was 12. The brain MRI revealed a pontine infarction (). The T1-weighted image demonstrated a mural thickening with hyperintensity at the right anterior wall of the basilar artery (). On the vertebral angiogram, a contrast filling defect was found on the right anterior wall of the mid-basilar artery which was responsible for the luminal stenosis. Based on these radiological findings, a right anterior wall dissection of the basilar artery with mural hematoma was suspected. Similar to those angiographic findings on Case 1, the postero-superior border of the defect where the intimalflap might exist had a smooth and clear margin, and the inferior border where the mural hematoma and false lumen might be exposed had an irregular and unclear margin ().\nDuring the angiographic evaluation, his motor power dramatically improved to grade III. He had full recovery after conservative treatments including administration of low-molecular heparin and antiplatelet agent. Follow-up vertebral angiogram after two weeks demonstrated a fusiform aneurysmal dilatation with clearly visible intimal flap (). Since such aneurysmal formation caused by the enlargement of the false lumen has an extremely fragile wall and its rupture seemed to have a high mortality rate, an endovascular treatment was performed. Double stents were inserted into the true lumen fully covering the diseased segment. After the stenting, the false lumen was somewhat collapsed, but some residual false lumen was still visible (). Follow-up angiogram at two months after the initial ischemic onset demonstrated a complete healing of the dissection (). He remained in a symptom free state.
A 56-year-old male presented with deep stuporous consciousness with a Hunt and Hess grade of IV. Initial brain CT showed a thick SAH at the basal cistern, sylvian fissures, and anterior interhemispheric fissure (). Conventional cerebral angiography showed an azygous ACA, chronic total occlusion of the left proximal internal carotid artery (ICA), and a fusiform aneurysm on the right side wall of the A2 segment (). An arterial fenestration was also observed at the cavernous ICA. The aneurysm measured 6.25×2.86 mm in size on the 3-dimensional rotational angiogram with a neck size of 6.25 mm and height of 2.02 mm. The distal ACA flow remained patent without stenosis or occlusion.\nStent-assisted coil embolization of the azygous A2 dissecting aneurysm was performed under general anesthesia. A tiny remnant was left at the proximal portion (), however, follow-up angiography after two weeks showed complete obliteration of the aneurysm with preservation of the parent artery (). He showed improvement to drowsy mentality, but remained in a wheelchair-bound state.