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Dive into the research topics where Kimihiko Orito is active.

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Featured researches published by Kimihiko Orito.


Stroke | 2016

Leakage Sign for Primary Intracerebral Hemorrhage A Novel Predictor of Hematoma Growth

Kimihiko Orito; Masaru Hirohata; Yukihiko Nakamura; Nobuyuki Takeshige; Takachika Aoki; Gousuke Hattori; Kiyohiko Sakata; Toshi Abe; Yuusuke Uchiyama; Teruo Sakamoto; Motohiro Morioka

Background and Purpose— Recent studies of intracerebral hemorrhage treatments have highlighted the need to identify reliable predictors of hematoma expansion. Several studies have suggested that the spot sign on computed tomographic angiography (CTA) is a sensitive radiological predictor of hematoma expansion in the acute phase. However, the spot sign has low sensitivity for hematoma expansion. In this study, we evaluated the usefulness of a novel predictive method, called the leakage sign. Methods— We performed CTA for 80 consecutive patients presenting with spontaneous intracerebral hemorrhage. Two scans were completed: CTA phase and delayed phase (5 minutes after the CTA phase). By comparing the CTA phase images, we set a region of interest with a 10-mm diameter and calculated the Hounsfield units. We defined a positive leakage sign as a >10% increase in Hounsfield units in the region of interest. Additionally, hematoma expansion was determined on plain computed tomography at 24 hours in patients who did not undergo emergent surgery. Results— Positive spot signs and leakage signs were present in 18 (22%) patients and 35 (43%) patients, respectively. The leakage sign had higher sensitivity (93.3%) and specificity (88.9%) for hematoma expansion than the spot sign. The leakage sign, but not the spot sign, was significantly related with poor outcomes (severely disabled, vegetative state, and death) in all of the patients (P=0.03) and in patients with a hemorrhage in the putamen (P=0.0016). Conclusions— The results indicate that the leakage sign is a useful and sensitive method to predict hematoma expansion.


Surgical Neurology International | 2015

Sequential pathological changes during malignant transformation of a craniopharyngioma: A case report and review of the literature

Tetsuya Negoto; Kiyohiko Sakata; Takachika Aoki; Kimihiko Orito; Shinji Nakashima; Masaru Hirohata; Yasuo Sugita; Motohiro Morioka

Background: Malignant transformation of craniopharyngiomas is quite rare, and the etiology of transformation remains unclear. The prognosis of malignantly transformed craniopharyngiomas is very poor. Case Description: A 36-year-old male had five craniotomies, five transsphenoidal surgeries, and two radiation treatments until 31 years of age after diagnosis of craniopharyngioma at 12 years of age. All serial pathological findings indicated adamantinomatous craniopharyngioma including those of a surgery performed for tumor regrowth at 31 years of age. However, when the tumor recurred approximately 5 years later, the pathological findings showed squamous metaplasia. The patient received CyberKnife surgery, but the tumor rapidly regrew within 4 months. The tumor was resected with the cavernous sinus via a dual approach: Transcranial and transsphenoidal surgery with an extracranial-intracranial bypass using the radial artery. Pathologic examination of a surgical specimen showed that it consisted primarily of squamous cells; the lamina propria was collapsed, and the tumor cells had enlarged nuclei and clarification of the nucleolus. The tumor was ultimately diagnosed as malignant transformation of craniopharyngioma. After surgery, he received combination chemotherapy (docetaxel, cisplatin, and fluorouracil). The tumor has been well controlled for more than 12 months. Conclusion: Serial pathological changes of the craniopharyngioma and a review of the 20 cases reported in the literature suggest that radiation of the squamous epithelial cell component of the craniopharyngioma led to malignant transformation via squamous metaplasia. We recommend aggressive surgical removal of craniopharyngiomas and avoidance of radiotherapy if possible.


Surgical Neurology International | 2016

Comparative outcome analysis of anterior choroidal artery aneurysms treated with endovascular coiling or surgical clipping

Takachika Aoki; Masaru Hirohata; Kei Noguchi; Satoru Komaki; Kimihiko Orito; Motohiro Morioka

Background: Treatment of anterior choroidal artery (AChA) aneurysms with endovascular coiling or surgical clipping may increase the risk of ischemic complications owing to the critical territory supplied by the AChA. We analyzed the surgical results of endovascular coiling and surgical clipping for AChA aneurysms performed in a single institution, as well as the role of indocyanine green-videoangiography (ICG-VAG) and motor-evoked potential (MEP). Methods: We analyzed 50 patients (51 aneurysms; 21 men, 29 women; mean age: 58 years) including 25 with subarachnoid hemorrhage treated with endovascular coiling or surgical clipping between April 1990 and October 2013. The complication rates and clinical outcomes of the coil group (mean follow-up: 61 months) and the clip group (mean follow-up: 121 months) were analyzed with a modified Rankin scale. Results: The overall clinical outcome of the coil group (95%) was better than that of the clip group (85%). Especially, the outcomes in the coil group were better in the first investigated period (1990–2007) (P < 0.05). However, after the introduction of ICG-VAG and MEP, the outcomes in the clip group improved significantly (P = 0.005), and treatment-related complications decreased from 20 to 4.7%. Eleven aneurysms (coil group: 8, clip group: 3) showed small neck remnants but no remarkable regrowth, except for 1 case during the mean follow-up period of 91 months. Conclusions: Surgical clipping of AChA aneurysms has become safer because of ICG-VAG and MEP monitoring. Coiling and clipping of AChA aneurysms showed good and comparable outcomes with these monitoring methods.


Stroke | 2016

Response by Orito and Morioka to Letter Regarding Article, “Leakage Sign for Primary Intracerebral Hemorrhage: A Novel Predictor of Hematoma Growth”

Kimihiko Orito; Motohiro Morioka

Thank you very much for your excellent suggestions for and comments on our study of the leakage sign. Several studies have used contrast media to predict hematoma expansion in patients with cerebral hemorrhage. Because many neurosurgeons are aware, the spot sign on computed tomography (CT) and similar methods have recently become very useful to predict hematoma growth. However, in some cases, large arteries …


World Neurosurgery | 2018

Novel Indirect Revascularization Technique with Preservation of Temporal Muscle Function for Moyamoya Disease Encephalo-Duro-Fascio-Arterio-Pericranial-Synangiosis: A Case Series and Technical Note

Kei Noguchi; Takachika Aoki; Kimihiko Orito; Soushou Kajiwara; Kana Fujimori; Motohiro Morioka

BACKGROUND Direct and/or indirect bypass surgery is the established approach for preventing stroke in patients with moyamoya disease. However, conventional indirect revascularization, including encephalo-myo-synangiosis, has some disadvantages associated with the mass effect of the temporal muscle under the bone flap and postsurgical depression in the temporal region. We devised a novel indirect revascularization method, using only the temporal fascia, to address the aforementioned disadvantages. METHODS A skin incision was performed along the superficial temporal artery. The temporal fascia was cut such that the base of the fascia flap was on the posterior side. The fascia and temporal muscles were dissected separately. After turning over the fascia, the muscle was cut such that the base of the muscle flap was on the anterior side. Craniotomy, direct bypass, and encephalo-duro-synangiosis were performed conventionally. Only the temporal fascia was used for indirect revascularization and duraplasty. The muscle was replaced in the anatomically correct position after replacing the bone flap. RESULTS We performed the aforementioned surgery on 18 (13 women and 5 men) consecutive patients (21 cerebral hemispheres) enrolled between 2012 and 2016. The average age was 28.7 years. The mean follow-up period was 31.6 months. In 17 patients (94%), the symptoms and cerebral blood flow improved. Digital subtraction angiography showed satisfactory angiogenesis from the temporal fascia. Depression in the temporal region and atrophy of the temporal muscle were negligible. CONCLUSIONS This surgical technique provides good clinical and cosmetic outcomes. It may also be one of the good surgical treatments available for symptomatic moyamoya disease.


Neurologia Medico-chirurgica | 2017

Management of Spontaneous Intracerebral Hematoma

Motohiro Morioka; Kimihiko Orito

The incidence of spontaneous intracerebral hematoma (SICH) is even now high worldwide, especially higher in Japan than in Western countries, despite the development of advances in blood pressure (BP) management and food/alcohol intake education. Although mortality and morbidity for SICH are high, some controversies remain regarding the appropriate acute phase of treatment. Recent studies have revealed that BP lowering treatment than 140 mmHg resulted in better outcomes. However the efficacy of surgical treatment for SICH has not been well established, with the exception of that for cerebellar SICH over 3 cm in diameter and life-saving procedures, although many randomized control studies and systematic reviews focused on surgical treatment have been reported. In this review, we summarize some issues and discuss strategies in development for the treatment of SICH.


The Kurume Medical Journal | 2010

Cerebrospinal Fluid following Cerebral Ischemia Accelerates the Proliferation of Bone Marrow Stromal Cells in vitro

Kimihiko Orito; Hideki Harada; Masato Hara; Shine Yamashita; Kiyoshi Kikuchi; Minoru Shigemori


Neurosurgical Review | 2018

Novel method of intraoperative ocular movement monitoring using a piezoelectric device: experimental study of ocular motor nerve activating piezoelectric potentials (OMNAPP) and clinical application for skull base surgeries

Kiyohiko Sakata; Keiko Suematsu; Nobuyuki Takeshige; Yui Nagata; Kimihiko Orito; Naohisa Miyagi; Naoki Sakai; Tsunekazu Koseki; Motohiro Morioka


Journal of Stroke & Cerebrovascular Diseases | 2017

Bilateral Internal Carotid Artery Aneurysms at the Subpetrosal Portion with Unilateral Lower Cranial Nerve Palsies: Review and Consideration of Surgical Strategy

Kei Noguchi; Takachika Aoki; Rokudai Sakamoto; Kimihiko Orito; Yasuharu Takeuchi; Masaru Hirohata; Motohiro Morioka


Surgery for Cerebral Stroke | 2015

Clinical Outcome of Surgical Clipping for Anterior Choroidal Artery Aneurysm

Takachika Aoki; Kei Noguchi; Satoshi Komaki; Kimihiko Orito; Gosuke Hattori; Masaru Hirohata; Motohiro Morioka

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