Hiroyuki Morishima

Contralateral transcondylar approach for aneurysms of the posterior inferior cerebellar artery-vertebral artery complex.

We report a patient with an aneurysm of the left vertebral artery (VA)-posterior inferior cerebellar artery (PICA) complex that was treated successfully via a contralateral transcondylar approach. The aneurysm was small, pointed laterally to the right, and was located across the midline just above the level of the foramen magnum. This unusual location required special consideration during diagnostic evaluation and surgical planning. To simulate the operative view, the patients head was turned 45 degrees. This extreme oblique view offered useful information with respect to the choice of side from which the surgical approach should be made. Removal of the posteromedial part of the occipital condyle allowed us to clip the aneurysmal neck without difficulty although the surgical approach was made on the side contralateral to the parent artery. We conclude that the contralateral approach for VA-PICA aneurysms should be considered when aneurysms cross the midline, and that extradural removal of the basal bony structures, including the occipital condyle, can provide a wide wirking space without excessive retraction on the brain stem.

Neuroimaging characteristics and growth pattern on magnetic resonance imaging in a 52-year-old man presenting with pituicytoma: a case report

IntroductionPituicytoma is a rare neoplasm of the neurohypophysis. To the best of our knowledge there have been no reports of pituicytoma in which long-term magnetic resonance imaging observation was performed. We calculated the doubling time of the tumor volume and described the growth pattern of a pituicytoma.Case presentationA 52-year-old Japanese man with a history of decreased libido was found to have a sellar and suprasellar mass. He underwent transsphenoidal surgery, but only a small specimen was obtained because of intraoperative bleeding. The tentative histological diagnosis was schwannoma. He noticed bitemporal hemianopsia 7 years later. A follow-up magnetic resonance imaging disclosed a tumor volume doubling time of 3830 days. Transcranial gross-total tumor resection was performed. The lesion consisted of elongated and plump tumor cells that were arranged in a fascicular or storiform pattern and were positive for S-100 protein and focally positive for glial fibrillary acidic protein. The final histological diagnosis was pituicytoma.ConclusionPituicytoma is a slow-growing tumor, but the growth rate may change during follow-up.

A Patient with Sinking Skin Flap Syndrome who Underwent Perfusion MRI before and after Cranioplasty

Background:Sinking skin flap syndrome(SSFS)manifests as subjective symptoms, such as headache, dizziness, and undue fatigability, in addition to neurologic symptoms, such as hemiplegia, aphasia, and perceived failure, when the skin over a bone defect sinks in the weeks or months following a decompressive craniectomy. Indeed, these symptoms can improve after a cranioplasty. Case presentation:A 58-year-old woman presented with a disturbance of consciousness. She was found to have a subarachnoid hemorrhage due to a ruptured right middle cerebral artery aneurysm. She underwent a craniotomy with clipping of the affected artery and a decompressive craniectomy on the same day. Post-operatively, the disturbance of consciousness improved, but the left-sided paralysis persisted. She complained of intractable headaches, was disoriented, and a lack of spontaneity emerged as the skin over the bone defect sank. She underwent cranioplasty on the 43rd day after admission, and the symptoms resolved promptly after surgery. Rehabilitation was canceled at the onset of symptoms, but resumed after the symptoms improved. Based on perfusion MRI, the cerebral blood flow(CBF):cerebral blood volume(CBV)ratio of the affected side increased before and after surgery compared with the healthy side. A lumboperitoneal shunt was placed on the 52nd day after admission to manage the hydrocephalus. She was discharged from the hospital with higher brain dysfunction and a mild state of paralysis. Conclusion:The timing of cranioplasty in patients with SSFS has not yet been established, but surgery should be performed before symptoms appear because SSFS impairs rehabilitative efforts.

A case of organized arachnoid cyst with repeated hemorrhage

Hemorrhage sometimes occurs within arachnoid cysts, however, organized arachnoid cysts has not been reported. We speculate the previous invasive stress or some kind of infection may have triggered the formation of the organized membrane, which may have formed via a similar mechanism to that for organized chronic subdural hematomas.

Percutaneous transluminal angioplasty in a patient with internal carotid artery stenosis following gamma knife radiosurgery for recurrent pituitary adenoma.

Background: Intracranial vascular complications following radiosurgery are extremely rare. Case Description: We report a case of stenosis in the internal carotid artery 5 years after gamma knife radiosurgery for a recurrent pituitary adenoma. Percutaneous transluminal angioplasty was performed successfully with anatomical and functional improvement. Conclusion: These results suggested the importance of monitoring for arterial stenosis in the long-term follow-up. Moreover, this is the first case of endovascular treatment as an effective therapy for intracranial arterial stenosis due to radiotherapy.

Acute phase endovascular intervention on a pseudoaneurysm formed due to rupture of an anterior communicating artery aneurysm

A 79-year-old woman presented with a subarachnoid hemorrhage. Angiography revealed pseudoaneurysm formation due to rupture of a true saccular anterior communicating artery aneurysm. Coil embolization, limited to the true aneurysm, was performed successfully with a favorable clinical outcome. This procedure can be considered as an alternative treatment option for similar aneurysms in cases where surgical clipping is contraindicated.

Risk Factors of Contralateral Microembolic Infarctions Related to Carotid Artery Stenting

This study sought to analyze the incidence of contralateral microembolic infarctions (MIs) on diffusion-weighted imaging (DWI) following protected carotid artery stenting (CAS) and compared the difference of risk factors between ipsilateral and contralateral lesions. From April 2010 to March 2017, 147 CASs in 140 patients were performed. All the patients underwent DWI within 1 week before and 24 hrs after the procedures. CAS was successfully completed in 145 (98.6%) of the 147 procedures. Forty-nine (33.8%) patients with new MIs revealed on postprocedural DWI were enrolled. They were divided into ipsilateral and contralateral groups based on the side of the CAS and MIs. The ipsilateral group indicates patients with MIs exclusively on the side of CAS. The contralateral group includes patients with MIs on the opposite side of the CAS or both sides. Patients with MIs at vertebrobasilar territory were excluded. Patient characteristics, morphology of the carotid artery and aortic arch, and procedural data were retrospectively assessed and compared between the two groups. Twenty-two (15.2%) and 14 (9.7%) patients were assigned to the ipsilateral and contralateral groups, respectively. Advanced age, left-sided stenosis, severe aortic arch calcification (AAC) on chest X-ray and contralateral carotid occlusion significantly increased the occurrence of contralateral MIs. On multivariable logistic regression analysis, severe AAC was statistically more frequent in the contralateral group. In the present study, the incidences of contralateral MIs after CAS is relatively not low. Advanced aortic atherosclerosis is statistically predictive for contralateral MIs. AAC on chest X-ray is a useful finding for estimating aortic atherosclerosis in candidates for CAS.

Unexpected complications immediately after cranioplasty

An 84‐year‐old man with subarachnoid hemorrhage underwent craniotomy and clipping with external decompression. Perfusion magnetic resonance imaging showed subclinical sinking skin flap syndrome, and he underwent cranioplasty on postoperative day 58. No problems occurred during the operation, but cerebral edema and hemorrhage were recognized on immediate postoperative computed tomography. Edema continued to progress, but edema and bleeding eventually improved without additional surgery.

Management of Adverse Event in Neurosurgery Issues Concerning HAP

The high disease rate and high mortality rate, suggest the necessity of the appropriate education to treat Hospital Acquired Pneumonia (HAP) even in neurosurgical field. For rapidly progressed aging society, in Japan, appropriate measures to prevent in-hospital complications including HAP, will be focused much more in the future.

Impact of Aneurysmal Neck Position in Endovascular Therapy for Anterior Communicating Artery Aneurysms

Anterior communicating artery (ACoA) aneurysms have a complex architecture and many variations, making endovascular therapy more difficult in some cases. The aim of this study was to investigate whether the neck position of an aneurysm was identifiable for determining the immediate angiographic success and procedural complications in the coiling of the ACoA aneurysms. We conducted a retrospective case review of 40 patients with ACoA aneurysms treated by endovascular therapy from 2008 to 2015. The mean age was 66.8 years. Thirty-five aneurysms were ruptured; five were unruptured. For the analysis, the patients were divided into two groups according to the neck position of aneurysms: the true ACoA group, 9 patients with the neck located on the ACoA itself; and the other ACoA group, 31 patients with the neck at the junction of the A1 and A2 portions of an anterior cerebral artery. Morphological characteristics (dome size, dome direction, rate of wide neck, and angulation of aneurysms in relation to the parent artery) were analyzed along with immediate angiographic results, volume embolization ratio (VER), and procedural complications. Small aneurysms with superior dome projection and acute angulation of the aneurysm direction occurred more often in the true ACoA group. The rates of complete obliteration, VER, and procedural complications were 33.3%, 32.3%, and 22.2% in the true ACoA group and 54.8%, 36.3%, and 6.5% in the other ACoA group, respectively. True ACoA aneurysms could present an anatomical difficulty in endovascular coiling. Aneurysmal neck position should be accurately assessed to achieve successful embolization of the ACoA aneurysms.