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Featured researches published by Kazunari Yoshida.


Journal of Neurosurgery | 2016

Various patterns of the middle cerebral vein and preservation of venous drainage during the anterior transpetrosal approach

Shunsuke Shibao; Masahiro Toda; Maaya Orii; Hirokazu Fujiwara; Kazunari Yoshida

OBJECTIVEnThe drainage of the superficial middle cerebral vein (SMCV) has previously been classified into 4 subtypes. Extradural procedures and dural incisions during the anterior transpetrosal approach (ATPA) may interrupt the route of drainage from the SMCV. In this study, the authors examined the relationship between anatomical variations in the SMCV and the corresponding surgical modifications to the ATPA that are necessary for venous preservation.nnnMETHODSnThis study included 48 patients treated via the ATPA in whom the SMCV was examined using 3D CT venography. The drainage patterns of the SMCV were classified into 3 types: cavernous or absent (Type 1), sphenobasal (Type 2), and sphenopetrosal (Type 3). Type 2 was subdivided into medial (Type 2a) and lateral (Type 2b), and Type 3 was subdivided into vein (Type 3a), vein and sinus (Type 3b), and sinus (Type 3c). The authors performed 3 ATPA modifications to preserve the SMCV: epidural anterior petrosectomy with subdural visualization of the sphenobasal vein (SBV), modification of the dural incision, and subdural anterior petrosectomy. Standard ATPA can be performed with Type 1, Type 2a, and Type 3a drainage. With Type 2b drainage, an epidural anterior petrosectomy with subdural SBV visualization is appropriate. The dural incision should be modified in Type 3b. With Type 3c, a subdural anterior petrosectomy is required.nnnRESULTSnThe frequency of each type was 68.7% (33/48) in Type 1, 8.3% (4/48) in Type 2a, 4.2% (2/48) in Type 2b, 14.6% (7/48) in Type 3a, 2.1% (1/48) in Type 3b, and 2.1% (1/48) in Type 3c. No venous complications were found.nnnCONCLUSIONSnThe authors propose an SMCV modified classification based on ATPA modifications required for venous preservation.


Acta Neurochirurgica | 2014

Primary dural closure and anterior cranial base reconstruction using pericranial and nasoseptal multi-layered flaps in endoscopic-assisted skull base surgery

Ryosuke Tomio; Masahiro Toda; Toshiki Tomita; Masaki Yazawa; Maya Kono; Kaoru Ogawa; Kazunari Yoshida

IntroductionDural and anterior cranial base reconstruction is essential in the surgical resection of a craniofacial tumor that extends from the paranasal sinuses to the subdural space. Watertight reconstruction of vascularized tissue is essential to prevent postoperative liquorrhea, especially under conditions that prevent wound healing (e.g., postoperative irradiation therapy).MethodWe successfully treated two cases of olfactory neuroblastoma by endoscopic-assisted craniotomy with primary dural closure and anterior cranial base reconstruction using a multi-layered flap technique. Dural defects were closed using temporal fascia or fascia lata in a conventional fashion, immediately after detaching the subdural tumor, in order to isolate and prevent contamination of subdural components and cerebrospinal fluid (CSF) from the tumor and nasal sinuses. Tumor removal and anterior cranial base reconstruction were performed without any concern of CSF contamination after dural closure by craniotomy and endoscopic endonasal approach (EEA). Vascularized pericranial flaps (PCF) and nasoseptal flaps (NSF) were used simultaneously as doubled-over layers for reconstruction.ResultsThe tumor was completely removed macroscopically and the anterior cranial base was reconstructed in both cases. CSF leak and postoperative meningitis were absent. Postoperative and irradiation therapy courses were successful and uneventful.ConclusionsThis multi-layered anterior cranial base reconstruction consisted of three layers: a fascia for dural plasty and double-layered PCF and NSF. This surgical reconstruction technique is suitable to treat craniofacial tumors extending into the subdural space through the anterior cranial base dura mater.


Neurologia Medico-chirurgica | 2014

Transoral vs. endoscopic endonasal approach for clival/upper cervical chordoma

Satoka Shidoh; Masahiro Toda; Takeshi Kawase; Hideo Nakajima; Toshiki Tomita; Kaoru Ogawa; Kazunari Yoshida

The surgical results of 18 cases of clival/upper cervical chordoma treated in the last decade via the endoscopic endonasal approach (EEA, 9 cases) and the transoral-transpalatal approach (TO-TPA, 9 cases) were compared. Each group showed the same incidence of subdural invasion, with 5 cases each. The superior (frontal base) and lateral surgical fields were wider by EEA, but the inferior view lower than the cranio-vertebral junction (CVJ) was wider by TO-TPA. Gross total removal was achieved in 3 cases in the EEA group, but in only 1 case in the TO-TPA group. Differences in radicality might be due to the extent of the lateral and subdural overview. However for large tumors extending below the CVJ, TO-TPA was the only viable approach for surgical removal. Surgical complications were higher in the EEA (4 cases) than the TO-TPA group (1 case), and were mainly caused by aggressive management of subdural invasion in the EEA group. Post-operative oral intake was earlier and the operative time was shorter in the EEA group. The surgical results were more radical and less invasive in the EEA group than the TO-TPA group. However in tumors extending below the CVJ, the surgical field in EEA was limited, indicating the need to use the transoral route or a combination of routes. A higher complication rate following subdural management was a negative factor that requires improvement in the EEA group and two-staged EEA followed by a transcranial approach may be considered for the cases with subdural invasion.


Neuro-oncology | 2014

Functional analysis of a novel glioma antigen, EFTUD1

Katsuya Saito; Yukihiko Iizuka; Shigeki Ohta; Satoshi Takahashi; Kenta Nakamura; Hideyuki Saya; Kazunari Yoshida; Yutaka Kawakami; Masahiro Toda

BACKGROUNDnA cDNA library made from 2 glioma cell lines, U87MG and T98G, was screened by serological identification of antigens by recombinant cDNA expression (SEREX) using serum from a glioblastoma patient. Elongation factor Tu GTP binding domain containing protein 1 (EFTUD1), which is required for ribosome biogenesis, was identified. A cancer microarray database showed overexpression of EFTUD1 in gliomas, suggesting that EFTUD1 is a candidate molecular target for gliomas.nnnMETHODSnEFTUD1 expression in glioma cell lines and glioma tissue was assessed by Western blot, quantitative PCR, and immunohistochemistry. The effect on ribosome biogenesis, cell growth, cell cycle, and induction of apoptosis and autophagy in glioma cells during the downregulation of EFTUD1 was investigated. To reveal the role of autophagy, the autophagy-blocker, chloroquine (CQ), was used in glioma cells downregulating EFTUD1. The effect of combining CQ with EFTUD1 inhibition in glioma cells was analyzed.nnnRESULTSnEFTUD1 expression in glioma cell lines and tissue was higher than in normal brain tissue. Downregulating EFTUD1 induced G1 cell-cycle arrest and apoptosis, leading to reduced glioma cell proliferation. The mechanism underlying this antitumor effect was impaired ribosome biogenesis via EFTUD1 inhibition. Additionally, protective autophagy was induced by glioma cells as an adaptive response to EFTUD1 inhibition. The antitumor effect induced by the combined treatment was significantly higher than that of either EFTUD1 inhibition or CQ alone.nnnCONCLUSIONnThese results suggest that EFTUD1 represents a novel therapeutic target and that the combination of EFTUD1 inhibition with autophagy blockade may be effective in the treatment of gliomas.


Neurologia Medico-chirurgica | 2015

Petrous apex cholesterol granuloma: importance of pedicled nasoseptal flap in addition to silicone T-tube for prevention of occlusion of drainage route in transsphenoidal approach--a technical note.

Shunsuke Shibao; Masahiro Toda; Toshiki Tomita; Katsuya Saito; Kaoru Ogawa; Takeshi Kawase; Kazunari Yoshida

Recently, petrous apex cholesterol granulomas (CGs) have been treated via the endoscopic endonasal transsphenoidal approach (EEA) using a silicone tube, to prevent drainage route occlusion. Occlusion of the drainage route has led to problems with recurrence. The aim of this report is to describe the use of a surgical technique to prevent drainage route occlusion. In surgical technique, the posterolateral wall of the sphenoid sinus was opened by EEA. After cyst debridement, a vascularized nasoseptal flap with a width of approximately 4 cm was inserted into the lumen with a silicone T-tube with a diameter of 7 mm. This technique was used in two patients: the first patient during the second operation after recurrence following occlusion of the drainage route, and the second patient during the first operation. Opening of the cyst wall was confirmed endoscopically in both patients 12–24 months after surgery, even after removal of the T-tube. In conclusion, the use of a pedicled nasoseptal flap with a silicone tube is useful to prevent CG recurrence, by paranasal cavitization of the cystic cavity.


Childs Nervous System | 2015

Pilocytic astrocytoma with anaplastic features presenting good long-term clinical course after surgery alone: a case report

Katsuya Saito; Masahiro Toda; Kazunari Yoshida

PurposePilocytic astrocytomas (PAs) are the most common brain tumor in children and typically have an excellent prognosis. However, some PAs show histologically anaplastic features. It is reported that PAs with anaplastic features often need the postoperative radiation and chemotherapy due to aggressiveness such as early local recurrence and dissemination. We describe an interesting case of primary anaplastic PA with good clinical course in the long-term.MethodsA 10-year-old man presented with worsening headache and vomiting. Magnetic resonance imaging (MRI) showed a large cystic tumor with contrast-enhanced solid component in a right occipital lobe. Magnetic resonance spectroscopy (MRS) showed the decrease of N-acetylaspartate (NAA) and the increase of choline and lipids, which suggested the malignancy.ResultsThe patient was operated with an occipital lobectomy. The tumor was incompletely resected due to the deep invasion to the inner wall of lateral ventricle. Pathological diagnosis was a pilocystic astrocytoma with anaplastic features. Although aggressive features were suspected from magnetic resonance spectroscopy and pathological findings, the remnant tumor showed no recurrence for 8xa0years without any postoperative treatments.ConclusionPAs could exhibit variable behavior, and careful managements including wait-and-scan should be considered, because adjuvant therapies may cause child’s growth disorder and malignant transformation.


Case reports in neurological medicine | 2015

GH-Producing Pituitary Adenoma and Concomitant Rathke’s Cleft Cyst: A Case Report and Short Review

Ryota Tamura; Satoshi Takahashi; Katsura Emoto; Hideaki Nagashima; Masahiro Toda; Kazunari Yoshida

Concomitant pituitary adenoma (PA) and Rathkes cleft cyst (RCC) are rare. In some cases, such PA is known to produce pituitary hormones. A 53-year-old man was admitted to our hospital with a diagnosis of lacunar infarction in the left basal ganglia. Magnetic resonance imaging (MRI) incidentally showed a suprasellar mass with radiographic features of RCC. When he consulted with a neurosurgical outpatient clinic, acromegaly was suspected based on his appearance. A diagnosis of growth hormone- (GH-) producing PA was confirmed from hormonal examinations and additional MRI. Retrospectively, initial MR images also showed intrasellar mass that is compatible with the diagnosis of PA other than suprasellar RCC. The patient underwent endonasal-endoscopic removal of the PA. Since we judged that the RCC of the patient was asymptomatic, only the PA was completely removed. The postoperative course of the patient was uneventful and GH levels gradually normalized. Only 40 cases of PA with concomitant RCC have been reported to date, including 13 cases of GH-producing PA. In those 13 cases, RCC tended to be located in the sella turcica, and suprasellar RCC like this case appears rare. In a few cases, concomitant RCCs were fenestrated, but GH levels normalized postoperatively as in the cases without RCC fenestration. If radiographic imaging shows typical RCC, and PA is not obvious at first glance, the possibility of concomitant PA still needs to be considered. In terms of treatment, removal of the RCC is not needed to achieve hormone normalization.


The Keio Journal of Medicine | 2015

Steroid psychosis caused by perioperative steroid replacement for pituitary adenoma: A case report

Katsuhiro Mizutani; Masahiro Toda; Ryogo Kikuchi; Hiroyuki Uchida; Kazunari Yoshida

Steroid psychosis is a frequent complication of steroid treatment. Although perioperative steroid replacement therapy is generally administered in patients undergoing pituitary surgery, there are no previous reports concerning the development of steroid psychosis after perioperative steroid replacement therapy following pituitary surgery. We herein report a case of steroid psychosis induced by perioperative steroid replacement therapy for pituitary surgery. A 35-year-old man presented with a visual disturbance that had persisted for 1 year. A magnetic resonance imaging scan showed a large pituitary tumor, and a laboratory study revealed slight dysfunction of the hypothalamo-pituitary-adrenal axis. The patient was diagnosed with a non-functioning pituitary tumor and underwent tumor resection via the endoscopic endonasal approach. The initial dose of perioperative steroid replacement therapy was 200u2005mg of hydrocortisone administered immediately before the operation. The replacement dose was gradually tapered and discontinued over a 7-day period. On postoperative day 4, the patient exhibited an elated mood, grandiose delusions, anxiety, and agitation. We diagnosed these psychiatric symptoms as steroid psychosis induced by steroid replacement and we prescribed risperidone as a treatment. The symptoms gradually improved and did not recur. This case highlights the risk of steroid psychosis following treatment with perioperative steroid replacement therapy for pituitary adenoma and raises questions regarding the appropriateness of perioperative steroid replacement for pituitary adenoma.


NMC Case Report Journal | 2014

Isolated Pituitary Tuberculoma

Katsuya Saito; Masahiro Toda; Satoka Shido; Toshiki Tomita; Kaoru Ogawa; Kazunari Yoshida

Pituitary tuberculomas are extremely rare, even in the developing countries where tuberculosis is endemic. We report a rare case of isolated pituitary tuberculoma mimicking a pituitary adenoma or a Rathke’s cleft cyst in Japan, a developed country. The patient was a 69-year-old woman presented with visual disturbance. Head magnetic resonance imaging (MRI) with contrast enhancement revealed an isolated intrasellar mass showing central hypointensity with an irregularly enhancing rim. She was operated on via an endoscopic transsphenoidal approach. Histopathological findings and an interferon-gamma release assay were highly suspicious of an isolated tuberculous granuloma. After proper infection control management, she was treated with four-drug antituberculous therapy (ATT). Follow-up MRI showed no recurrence 3 years after the discontinuation of ATT. An isolated pituitary tuberculoma has rarely been reported, especially in developed countries. In conclusion, neurosurgeons should consider an isolated pituitary tuberculoma as one of the differential diagnoses for pituitary tumors, because special management for infection control is required for tuberculosis. An interferon-gamma release assay is helpful for the difficult diagnosis of an isolated pituitary tuberculoma with inactive tuberculosis.


Journal of Neurosurgery | 2014

Anterior petrosal approach.

Ryosuke Tomio; Masahiro Toda; Kazunari Yoshida; Hamid Borghei-Razavi

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