Faculty Profiles - NAGATA Yuichi

Endoscopic Cystoventricular Stenting in Awake Patients with Electrical Stimulation Mapping for Convexity Cysts: Three Case Reports and a Systematic Review Open Access

Okumura, E; Takeuchi, K; Nagata, Y; Iwami, K; Motomura, K; Ohka, F; Sato, Y; Hirose, T; Saito, R

WORLD NEUROSURGERY Vol. 193 page： 108 - 118 2025.1

Language：English Publisher：World Neurosurgery

Surgical interventions for arachnoid cysts and glioependymal cysts primarily focus on cyst decompression and establishing communication with cerebrospinal fluid spaces. However, a standardized surgical strategy for symptomatic convexity cysts lacking surrounding cerebrospinal fluid space is still lacking due to the limited number of cases. This systematic review aims to evaluate surgical interventions for symptomatic convexity cysts and proposes a safe and effective treatment approach we have developed. A systematic review of the literature was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Surgical techniques were categorized into cystoperitoneal shunt, cyst excision, cyst fenestration, cyst ventriculostomy, and several uniquely modified methods. Using a method different from these previous reports, we performed endoscopic cystoventricular stenting via burr hole in 3 cases of convexity cysts. While traditional methods have proven effective, cystoperitoneal shunt may lead to malfunction, infection, and subdural hematoma; wall excision is invasive and increases morbidity risks. Fenestration and cystoventriculostomy have also reported cases of recurrence. Other methods also pose issues, including off-label use of instruments and inadequate consideration for removal. The method we performed for placing the stent catheter with multiple side holes demonstrated long-term effectiveness. Furthermore, the surgery was conducted with the patient fully awake, and the use of electrical stimulation mapping enabled preservation of higher neurocognitive functions, including language, working memory, and spatial cognition, at the puncture site. This novel approach offers advantages such as minimally invasive procedure, preservation of safe brain function, and long-term patency. Further studies are warranted to validate these findings and improve surgical strategies for convexity cysts.

DOI： 10.1016/j.wneu.2024.10.031

Isolation of ependymal cilia from mouse brain( vol 409, 110198, 2024) Open Access

Mizuno, A; Takeuchi, K; Nagata, Y; Harada, H; Yamamoto, T; Ishikawa, T; Maeda, S; Ohka, F; Ueno, H; Saito, R

JOURNAL OF NEUROSCIENCE METHODS Vol. 412 page： 110293 2024.12

Language：English Publisher：Journal of Neuroscience Methods

The authors regret that the affiliation information was incomplete in the original article. The correct and complete affiliation information should be as follows: Akihiro Mizunoa,b a Department of Neurosurgery, Komaki City Hospital, Aichi, Japan b Department of Neurosurgery, Nagoya University, Nagoya, Japan This research was conducted while the author was affiliated with Nagoya University. The addition of this affiliation is important for accurately reflecting the research context. The authors would like to apologize for any inconvenience caused.

DOI： 10.1016/j.jneumeth.2024.110293

INTRA-OPERATIVE GENETIC ANALYSES FOR DECISION-MAKING DURING TUMOR REMOVAL OF ADULT-TYPE DIFFUSE GLIOMA USING RAPID QUANTITATIVE PCR DEVICE Open Access

Ohka, F; Maeda, S; Shimizu, H; Motomura, K; Takeuchi, K; Nagata, Y; Deguchi, S; Shiba, Y; Yamaguchi, J; Takido, Y; Nakamura, A; Ito, S; Saito, R

NEURO-ONCOLOGY Vol. 26 2024.11

DISTANT PARENCHYMAL RECURRENCE DURING LONG-TERM USE OF TTFIELDS TREATMENT FOR GLIOBLASTOMA Open Access

Takido, Y; Ohka, F; Deguchi, S; Motomura, K; Mitsuya, K; Shiba, Y; Takeuchi, K; Nagata, Y; Yamaguchi, J; Kibe, Y; Fuse, Y; Maeda, S; Shimizu, H; Nohira, S; Yamamoto, R; Ito, S; Nakamura, A; Saito, R

NEURO-ONCOLOGY Vol. 26 2024.11

ESTABLISHMENT OF PITUITARY NEUROENDOCRINE TUMOR (PITNET) ORGANOID MODELS Open Access

Maeda, S; Ohka, F; Kanamori, F; Okumura, Y; Takeuchi, K; Nagata, Y; Yamaguchi, J; Harada, H; Shimizu, H; Takido, Y; Saito, R

NEURO-ONCOLOGY Vol. 26 2024.11

Isolation of ependymal cilia from mouse brain Open Access

Mizuno, A; Takeuchi, K; Nagata, Y; Harada, H; Yamamoto, T; Ishikawa, T; Maeda, S; Ohka, F; Ueno, H; Saito, R

JOURNAL OF NEUROSCIENCE METHODS Vol. 409 page： 110198 2024.9

Language：English Publisher：Journal of Neuroscience Methods

Background: Ependymal cilia play a major role in the circulation of cerebrospinal fluid. Although isolation of cilia is an essential technique for investigating ciliary structure, to the best of our knowledge, no report on the isolation and structural analysis of ependymal cilia from mouse brain is available. New method: We developed a novel method for isolating ependymal cilia from mouse brain ventricles. We isolated ependymal cilia by partially opening the lateral ventricles and gently applying shear stress, followed by pipetting and ultracentrifugation. Results: Using this new method, we were able to observe cilia separately. The results demonstrated that our method successfully isolated intact ependymal cilia with preserved morphology and ultrastructure. In this procedure, the ventricular ependymal cell layer was partially detached. Comparison with existing methods: Compared to existing methods for isolating cilia from other tissues, our method is meticulously tailored for extracting ependymal cilia from the mouse brain. Designed with a keen understanding of the fragility of the ventricular ependyma, our method prioritizes minimizing tissue damage during the isolation procedure. Conclusions: We isolated ependymal cilia from mouse brain by applying shear stress selectively to the ventricles. Our method can be used to conduct more detailed studies on the structure of ependymal cilia.

DOI： 10.1016/j.jneumeth.2024.110198

神経内視鏡画像における機能性下垂体腫瘍を含めた手術支援AIシステムの構築 Open Access

布施佑太郎, 竹内和人, 橋本典明, 永田雄一, 永谷哲也, 竹内一郎, 齋藤竜太

日本内分泌学会雑誌 Vol. 100 ( S.HPT ) page： 19 - 21 2024.8

The Potential Role of Preoperative Posterior Cerebral Artery Involvement in Predicting Postoperative Transient Neurological Deficits and Ischemic Stroke After Indirect Revascularization in Patients With Moyamoya Disease

Araki, Y; Yokoyama, K; Uda, K; Kanamori, F; Takayanagi, K; Ishii, K; Nishihori, M; Goto, S; Tsukada, T; Takeuchi, K; Tanahashi, K; Nagata, Y; Nishimura, Y; Tanei, T; Nagashima, Y; Muraoka, S; Izumi, T; Seki, Y; Saito, R

WORLD NEUROSURGERY Vol. 187 page： E610 - E619 2024.7

Language：English Publisher：World Neurosurgery

Objective: Transient neurological deficits (TNDs) are known to develop after direct bypass for Moyamoya disease and may be risk factors for subsequent stroke. However, the factors involved in the development of TNDs and stroke after indirect revascularization alone, including their association with subsequent stroke, remain unclear. The purpose of this study was to investigate this issue. Methods: The subjects of the study were 30 patients with Moyamoya disease who underwent a total of 40 indirect revascularization procedures at our institution. Clinical and radiological data were collected retrospectively. To examine factors associated with the development of postoperative TND/stroke/asymptomatic disease, the clinical characteristics of each group were statistically compared. Results: The mean age at surgery was 7 years (range 1–63). TNDs developed after surgery in 9 out of 40 patients (22.5%). Stroke in the acute postoperative period occurred in 3 patients (7.5%), all of whom experienced cerebral infarctions. Demographic data and preoperative clinical information were not different between the groups. However, posterior cerebral artery involvement on preoperative imaging was significantly associated with the development of TNDs and stroke (P = 0.006). Furthermore, postoperative stroke was associated with unfavorable outcomes (P = 0.025). Conclusions: Posterior cerebral artery involvement is significantly associated with the occurrence of TNDs. In contrast, TNDs after indirect revascularization have little relationship with the subsequent development of stroke. TNDs usually resolve without new strokes, and a better understanding of this particular pathology could help establish an optimal treatment regimen.

DOI： 10.1016/j.wneu.2024.04.135

Obstructive Hydrocephalus Due to Aggressive Posterior Fossa Tumor Exhibiting Histological Characteristics of Pilocytic Astrocytoma in Two Adult Neurofibromatosis Type 1 (NF1) Cases Open Access

Nawa, S; Ohka, F; Motomura, K; Takeuchi, K; Nagata, Y; Yamaguchi, J; Saito, R

CUREUS JOURNAL OF MEDICAL SCIENCE Vol. 16 ( 4 ) page： e58697 2024.4

Pediatric-type high-grade gliomas with <i>PDGFRA</i> amplification in adult patients with Li-Fraumeni syndrome: clinical and molecular characterization of three cases Open Access

Kibe, Y; Ohka, F; Aoki, K; Yamaguchi, J; Motomura, K; Ito, E; Takeuchi, K; Nagata, Y; Ito, S; Mizutani, N; Shiba, Y; Maeda, S; Nishikawa, T; Shimizu, H; Saito, R

ACTA NEUROPATHOLOGICA COMMUNICATIONS Vol. 12 ( 1 ) page： 57 2024.4

Language：English Publisher：Acta Neuropathologica Communications

Li-Fraumeni syndrome (LFS) is an autosomal dominant tumor predisposition syndrome caused by heterozygous germline mutations or deletions in the TP53 tumor suppressor gene. Central nervous system tumors, such as choroid plexus tumors, medulloblastomas, and diffuse gliomas, are frequently found in patients with LFS. Although molecular profiles of diffuse gliomas that develop in pediatric patients with LFS have been elucidated, those in adults are limited. Recently, diffuse gliomas have been divided into pediatric- and adult-type gliomas, based on their distinct molecular profiles. In the present study, we investigated the molecular profiles of high-grade gliomas in three adults with LFS. These tumors revealed characteristic histopathological findings of high-grade glioma or glioblastoma and harbored wild-type IDH1/2 according to whole exome sequencing (WES). However, these tumors did not exhibit the key molecular alterations of glioblastoma, IDH-wildtype such as TERT promoter mutation, EGFR amplification, or chromosome 7 gain and 10 loss. Although WES revealed no other characteristic gene mutations or copy number alterations in high-grade gliomas, such as those in histone H3 genes, PDGFRA amplification was found in all three cases together with uniparental disomy of chromosome 17p, where the TP53 gene is located. DNA methylation analyses revealed that all tumors exhibited DNA methylation profiles similar to those of pediatric-type high-grade glioma H3-wildtype and IDH-wildtype (pHGG H3-/IDH-wt), RTK1 subtype. These data suggest that high-grade gliomas developed in adult patients with LFS may be involved in pHGG H3-/IDH-wt. PDGFRA and homozygous alterations in TP53 may play pivotal roles in the development of this type of glioma in adult patients with LFS.

DOI： 10.1186/s40478-024-01762-7

Safety and efficacy of the endoscopic transsphenoidal transclival approach performed using direct cortical stimulation for pontine cavernous malformations.

Takeuchi K, Nagata Y, Sasagawa Y, Ito E, Yamamoto T, Mizuno A, Sasaki H, Kondo T, Araki Y, Nakada M, Saito R

Journal of neurosurgery Vol. 140 ( 2 ) page： 469 - 477 2024.2

Language：English Publisher：Journal of Neurosurgery

OBJECTIVE Surgical treatment of brainstem cavernous malformations (CMs) is challenging. Surgery using the endoscopic transsphenoidal transclival approach (eTSTCA) is reported as a useful alternative for ventral brainstem CMs. However, CMs located in the ventral midline of the brainstem are rare, and only a small number of case reports on these CMs treated with the eTSTCA exist. The efficacy and safety of the eTSTCA have not yet been fully examined. METHODS A retrospective analysis was performed for 5 consecutive patients who underwent surgery via the eTSTCA for treating ventral pontine CMs. RESULTS The average maximum CM diameter was 26.0 mm (18–38 mm). All patients underwent MR–diffusion tensor imaging, which confirmed that the corticospinal tract (CST) deviated posteriorly or laterally to the CM. Direct brainstem cortical stimulation was performed to localize the CST before making the cortical incision. After the excision of the CM, the cavity was filled with artificial CSF to make an aqueous surgical field (wet-field technique) for observing the tumor cavity and confirming complete hemostasis and resection. Total removal was achieved in all patients. The preoperative modified Rankin Scale score was 3 in 3 patients and 4 in 2 patients, whereas it was 1 in 2 patients and 0 in 3 patients 3 months after surgery. Postoperative CSF leakage was observed in 1 patient, and transient abducens nerve palsy was observed in 1 patient. No other intra- or postoperative complications were observed. CONCLUSIONS MR–diffusion tensor imaging and direct brainstem cortical stimulation were useful to ascertain the proximity of the CST to the CM. The endoscope provides a clear view even underwater, and it was safe and effective to observe the entire CM cavity and confirm complete hemostasis without additional retraction of the brainstem parenchyma, including the CST. The eTSTCA provides a direct access point to the lesion and may be a safer alternative treatment for patients whose CST deviates laterally or posteriorly to the CM.

DOI： 10.3171/2023.6.JNS23324

Extended Endoscopic Endonasal Transplanum and Transdorsum Sellar Approach for the Resection of Retroinfundibular Craniopharyngioma With Two-Piece Dural Opening: A Technical Case Report

Matmusayev, M; Kariev, GM; Asadullaev, U; Takeuchi, K; Nagata, Y; Harada, H; Saito, R

CUREUS JOURNAL OF MEDICAL SCIENCE Vol. 16 ( 1 ) page： e51850 2024.1

A Case of Papillary Craniopharyngioma Mimicking Rathke's Cleft Cyst Open Access

HARADA Hideyuki, TAKEUCHI Kazuhito, NAGATA Yuichi, INOSHITA Naoko, ITO Eiji, OKUMURA Eriko, KONDO Tatsuma, SATO Yoshiki, SAITO Ryuta

NMC Case Report Journal Vol. 11 ( 0 ) page： 191 - 194 2024

Language：English Publisher：The Japan Neurosurgical Society

<p>Craniopharyngioma (CP) and Rathke's cleft cyst (RCC) are both suprasellar lesions. They are sometimes difficult to distinguish due to their similar findings. We report a case of papillary craniopharyngioma (pCP) with the clinical findings suggesting RCC. A 42-year-old female with intellectual disability presented to our hospital with severe visual dysfunction. Preoperative images revealed a suprasellar cystic lesion without calcification. We performed transsphenoidal surgery. Since the cyst had condensed-milk-like content suggesting RCC, we performed cyst fenestration and wash without removal of the cyst wall. Thereafter, we found fish-egg-like structures on the cyst wall. The histopathological analysis revealed that they had papillary structures surrounded by hyperplastic squamous epithelium with parakeratosis. Immunostaining for BRAF V600E was positive, leading to the diagnosis of pCP. After the surgery, her visual function improved and follow-up Magnetic resonance imaging at 18 months postoperatively showed no apparent recurrence. The presence of condensed-milk-like content suggests a likelihood of RCC indicating that aggressive resection may not be necessary. In contrast, the existence of fish-egg-like structures suggests pCP and requires careful follow-up.</p>

DOI： 10.2176/jns-nmc.2024-0057

Open Access

Endoscopic debulking canalization for optic pathway glioma with obstructive hydrocephalus

CiNii Research

Takeuchi, K; Ohka, F; Nagata, Y; Ito, E; Harada, H; Saito, R

CHILDS NERVOUS SYSTEM Vol. 39 ( 12 ) page： 3421 - 3425 2023.12

Language：English Publisher：Child's Nervous System

Optic pathway gliomas (OPGs) are benign tumors that can stop growing or even shrink. In recent years, surgical resection has not been considered the first-line treatment because of its high risk of complications. Chemotherapy is the mainstay of treatment for growing OPGs. Surgical treatment for OPGs with obstructive hydrocephalus is required. Ventriculoperitoneal shunting is effective for all types of hydrocephalus. However, long-term management is required, especially in pediatric cases, and there is a risk of shunt-related complications over a long lifespan. Debulking surgery for OPGs allows us to avoid shunt placement by creating a waterway and releasing the hydrocephalus. To reduce the surgical risk and invasiveness, we used an endoscopic canalization technique with a small-diameter cylinder. In this article, we present a case of endoscopic canalization of an obstructive hydrocephalus caused by OPGs in a 14-year-old female to illustrate our surgical technique. (Trial registration Registry name and number: Efficacy and safety of the neuro-endoscopic treatment for brain tumors (2019–0254)).

DOI： 10.1007/s00381-023-06053-5

Deep learning based identification of pituitary adenoma on surgical endoscopic images: a pilot study

Fuse, Y; Takeuchi, K; Hashimoto, N; Nagata, Y; Takagi, Y; Nagatani, T; Takeuchi, I; Saito, R

NEUROSURGICAL REVIEW Vol. 46 ( 1 ) page： 291 2023.11

Language：English Publisher：Neurosurgical Review

Accurate tumor identification during surgical excision is necessary for neurosurgeons to determine the extent of resection without damaging the surrounding tissues. No conventional technologies have achieved reliable performance for pituitary adenomas. This study proposes a deep learning approach using intraoperative endoscopic images to discriminate pituitary adenomas from non-tumorous tissue inside the sella turcica. Static images were extracted from 50 intraoperative videos of patients with pituitary adenomas. All patients underwent endoscopic transsphenoidal surgery with a 4 K ultrahigh-definition endoscope. The tumor and non-tumorous tissue within the sella turcica were delineated on static images. Using intraoperative images, we developed and validated deep learning models to identify tumorous tissue. Model performance was evaluated using a fivefold per-patient methodology. As a proof-of-concept, the model’s predictions were pathologically cross-referenced with a medical professional’s diagnosis using the intraoperative images of a prospectively enrolled patient. In total, 605 static images were obtained. Among the cropped 117,223 patches, 58,088 were labeled as tumors, while the remaining 59,135 were labeled as non-tumorous tissues. The evaluation of the image dataset revealed that the wide-ResNet model had the highest accuracy of 0.768, with an F1 score of 0.766. A preliminary evaluation on one patient indicated alignment between the ground truth set by neurosurgeons, the model’s predictions, and histopathological findings. Our deep learning algorithm has a positive tumor discrimination performance in intraoperative 4-K endoscopic images in patients with pituitary adenomas.

DOI： 10.1007/s10143-023-02196-w

ESTABLISHMENT OF ORGANOID MODELS OF PATIENT-DERIVED GH-PRODUCING PITUITARY ADENOMA

Maeda, S; Ohka, F; Kanamori, F; Okumura, Y; Takeuchi, K; Nagata, Y; Motomura, K; Yamaguchi, J; Kibe, Y; Harada, H; Shimizu, H; Takido, Y; Saito, R

NEURO-ONCOLOGY Vol. 25 2023.11

INTRA-OPERATIVE ANALYSES OF GENETIC ALTERATIONS IN THE CENTRAL NERVOUS SYSTEM TUMORS USING RAPID QUANTITATIVE PCR DEVICE

Ohka, F; Maeda, S; Yamaguchi, J; Shimizu, H; Motomura, K; Takeuchi, K; Nagata, Y; Nishikawa, T; Kibe, Y; Takido, Y; Saito, R

NEURO-ONCOLOGY Vol. 25 2023.11

Higher abundance of Campylobacter in the oral microbiome of Japanese patients with moyamoya disease

Takayanagi, K; Kanamori, F; Ishii, K; Yokoyama, K; Araki, Y; Sumitomo, M; Maeda, S; Goto, S; Ota, S; Nagata, Y; Nishihori, M; Maesawa, S; Izumi, T; Takasu, S; Saito, R

SCIENTIFIC REPORTS Vol. 13 ( 1 ) page： 18545 2023.10

Language：English Publisher：Scientific Reports

Genetic factors alone cannot explain the pathophysiology of moyamoya disease (MMD), and environmental factors such as an immune response are thought to be involved. Oral and gut microbiomes have attracted attention as environmental factors in the pathophysiology of some vascular and autoimmune diseases. However, the relationship between MMD and these microbiomes is yet to be thoroughly investigated. This prospective case–control study aimed to compare the microbiomes of Japanese patients with MMD with those of healthy individuals to identify the specific bacteria involved in MMD. Saliva and fecal samples were collected from 16 patients with MMD who had not undergone revascularization surgery. Fifteen healthy individuals were matched for age, sex, and body mass index. The microbiomes were determined using 16S rRNA sequencing and analyzed using QIIME2. Differentially abundant microbes were identified using LEfSE and ANCOM-BC. In the oral microbiome, the two analytical methods showed that Campylobacter was more abundant in patients with MMD than in healthy individuals. Differences in the gut microbiome were smaller than those in the oral microbiome. In conclusion, the oral microbiome profiles of patients with MMD significantly differ from those of healthy individuals. Campylobacter spp. could be a substantial environmental factor in the pathophysiology of MMD.

DOI： 10.1038/s41598-023-45755-3