[Ruptured Aneurysms on the Cortical Segment of the Distal Posterior Inferior Cerebellar Artery:A Report of Two Cases and a Literature Review].

Two unusual cases of ruptured distal posterior inferior cerebellar artery(PICA)aneurysm on the cortical segment were successfully treated with open surgery. A 76-year-old woman presented with a Hunt and Kosnik(H&K)grade II Subarachnoid hemorrhage(SAH). CT showed a slight SAH in the cisterna magna and around the vermis, and fourth intraventricular hematoma. Cerebral angiography revealed an aneurysm on the cortical segment of the distal PICA. Intraoperative findings identified the aneurysm as fusiform. Trapping of the aneurysm was performed, and the indocyanine green angiography fiuding confirmed aneurysmal flow disappearance and good circulation in the cerebellar cortex. An 89-year-old woman presented with H&K grade II SAH. CT revealed a thick SAH in the posterior cranial fossa, and third to fourth intraventricular hematoma with hydrocephalus. Cerebral angiography revealed an aneurysm on the cortical segment of the distal PICA. Intraoperative findings showed that the aneurysm was fusiform. Trapping and resection of the aneurysm were performed. Thirteen previous cases of aneurysms on the cortical segment of the distal PICA have been reported. Distal PICA aneurysms apparently show rebleeding more frequently than do aneurysms at other locations, so immediate direct surgery is necessary to avoid rebleeding. After proximal ligation or trapping of the aneurysm, indocyanine green angiography is useful to determine the need for revascularization.

[Frontal Base Penetrating Brain Injury by a Gardening Scissors:A Case Report].

A 43-year-old woman accidentally fell from a 1.5-m height with gardening scissors, and the cutting edge of the scissors pierced into her skull base through the left nasal cavity. After she pulled the scissors out by herself, her consciousness immediately deteriorated. She was transferred to Juntendo University Shizuoka Hospital by an ambulance helicopter. Intracerebral hematoma in the right frontal lobe caused by the middle cerebral artery injury was detected using brain computed tomography. Emergent hematoma evacuation with decompressive craniectomy was performed. In this procedure, cerebrospinal fluid(CSF)leakage was repaired using a multi-layered flap technique, which placed both the free autologous dura mater and pedicled temporalis muscle flaps into the damaged skull base space. After the surgery, CSF drainage was managed to control both intracranial pressure and CSF leakage. Upon discussion, several clinical issues can be highlighted. First, the gardening scissors were pulled out by the patient herself. Second, the foreign material penetrating the intracranial space might have conferred a high infection risk. Finally, it might be difficult to repair the severe damage inflicted upon the skull base by the large gardening scissors. In conclusion, it was considered that favorable results were obtained by the emergent surgical intervention and by repairing the skull base through forming a multi-layered flap with a combination of free and pedicled tissues.

A Case of Vertebral Artery Dissecting Aneurysm with Double Origin of the Posterior Inferior Cerebellar Artery Causing Subarachnoid Hemorrhage.

Double origin of the posterior inferior cerebellar artery (DOPICA) is rare but is associated with intracranial aneurysm formation. A 46-year-old man was brought to our hospital with severe subarachnoid hemorrhage (SAH). Digital subtraction angiography revealed right vertebral artery dissecting aneurysm (VADA) and DOPICA. The aneurysm involved the distal component of the posterior inferior cerebellar artery. The proximal component covered the original flow angiographically. Endovascular internal trapping and parent artery occlusion were performed for the aneurysm and the right vertebral artery (VA). Flow of the posterior inferior cerebellar artery was preserved by the proximal component of the posterior inferior cerebellar artery after trapping. The patient unfortunately died and autopsy revealed ischemic change in the right medulla oblongata. The ischemic change was considered to occur at the treatment according to the pathological findings. Sacrifice of one component of DOPICA to treat VADA with the expectation of preserved flow via the other component should be considered cautiously in terms of the neurovascular anatomy.