Faculty Profiles - NAGATA Yuichi

Sellar arachnoid cystに対する経鼻内視鏡手術

内視鏡下経鼻頭蓋底手術後の再建戦略

竹内和人, 永田雄一, 山本太樹, 原田英幸, 齋藤竜太

日本内分泌学会雑誌 Vol. 97 ( S.HPT ) page： 16 - 18 2021.9

永田雄一, 竹内和人, 山本太樹, 水野晃宏, 永谷哲也, 齋藤竜太

日本内分泌学会雑誌 Vol. 97 ( S.HPT ) page： 49 - 51 2021.9

A new primate model of hypophyseal dysfunction

Kawabata Teppei, Suga Hidetaka, Takeuchi Kazuhito, Nagata Yuichi, Sakakibara Mayu, Ushida Kaori, Ozone Chikafumi, Enomoto Atsushi, Kawamoto Ikuo, Itagaki Iori, Tsuchiya Hideaki, Arima Hiroshi, Wakabayashi Toshihiko

SCIENTIFIC REPORTS Vol. 11 ( 1 ) page： 10729 2021.5

Language：Japanese Publisher：Scientific Reports

For pituitary regenerative medicine, the creation of a hypophyseal model in monkeys is necessary to conduct future preclinical studies; however, previous studies reported that hypophysectomy in monkeys is not always safe or satisfactory. This study aimed to create a hypophyseal dysfunction model in a cynomolgus monkey using a safer surgical technique and establish the protocol of pituitary hormone replacement therapy for this model. Surgical resection of the pituitary gland of a 7.8-year-old healthy adult cynomolgus male monkey weighing 5.45 kg was performed to create a hypophyseal dysfunction model for future regenerative studies. Endoscopic transoral transsphenoidal surgery was used to perform hypophysectomy under navigation support. These procedures were useful for confirming total removal of the pituitary gland without additional bone removal and preventing complications such as cerebrospinal fluid leakage. Total removal was confirmed by pathological examination and computed tomography. Hypopituitarism was verified with endocrinological examinations including stimulation tests. Postoperatively, the monkey’s general condition of hypopituitarism was treated with hormone replacement therapy, resulting in long-term survival. The success of a minimally invasive and safe surgical method and long-term survival indicate the creation of a hypophyseal dysfunction model in a cynomolgus monkey; hence, this protocol can be employed in the future.

DOI： 10.1038/s41598-021-90209-3

Importance of Hydrostatic Pressure and Irrigation for Hemostasis in Neuroendoscopic Surgery

ISHIKAWA Takayuki, TAKEUCHI Kazuhito, YAMAMOTO Taiki, NAGATA Yuichi, NATSUME Atsushi

Neurologia medico-chirurgica Vol. 61 ( 2 ) page： 117 - 123 2021.2

Language：English Publisher：The Japan Neurosurgical Society

Recently neurosurgical operations have been carried out with water irrigation such as endoscopic third ventriculostomy and tumor resections in ventricles. Water irrigation is one of several published methods that promote hemostasis; however, not enough experimental evidence exists on its efficacy. In this study, we investigate whether hydrostatic pressure and persistent irrigation promote hemostasis in neuroendoscopic surgery. We dissected tails of 12–16-week-old C57BL/6 male mice at 5 mm proximal from the tip and checked for bleeding times under dry and wet conditions at pressures of 0 cmH2O, 10 cmH2O, 15 H2O, and 20 cmH2O without persistent irrigation to bleeding point and 10 cmH2O with persistent irrigation. We then examined the dissected edge with hematoxylin–eosin staining and measured the size of vessels. The average bleeding time of each group is as follows: dry: 203.4 sec, wet: 164.4 sec, 5 cmH2O: 138.6 sec, 10 cmH2O: 104.6 sec (P <0.001), 20 cmH2O: 56 sec (P <0.001), and 10 cmH2O with persistent irrigation: 72.8 sec (P <0.01 compared to 10 cmH2O without persistent irrigation). The maximum caliber of mice’s tail artery was 50–60 μm. Hydrostatic pressure and irrigation are important factors contributing to hemostasis.

DOI： 10.2176/nmc.oa.2020-0278

Novel Endoscopic Technique for Inserting a Sheath into a Slit Ventricle: The Water-Slide Technique

Yamamoto Taiki, Takeuchi Kazuhito, Nagata Yuichi, Mizuno Akihiro, Wakabayashi Toshihiko

WORLD NEUROSURGERY Vol. 145 page： 1 - 4 2021.1

Language：Japanese Publisher：World Neurosurgery

Background: The efficacy and safety of endoscopic procedures for slit ventricle syndrome (SVS) have been presented in recent studies. However, inserting a sheath into a target ventricle is essential in the beginning of endoscopic procedures for SVS, and this maneuver is challenging owing to the quite narrow ventricular space. We report a novel flexible endoscopic technique, the water-slide technique, that can effectively guide a sheath into a slit ventricle without the use of other adjunctive devices, such as a neuronavigation system and an ultrasound machine. Methods: Ten endoscopic procedures using the water-slide technique were performed in 9 patients with SVS. All patients had undergone ventriculoperitoneal shunt placement. Using the technique, the sheath was first placed on the flexible endoscope. The endoscope was then inserted into the lateral ventricle along the tract around the pre-existing ventricular catheter with irrigation of artificial cerebrospinal fluid via the working channel of the endoscope. After the endoscope reached the ventricle, the sheath was inserted into the ventricle along the endoscope. The endoscope was then used as a stylet. The endoscopic procedure was performed afterward. Continuous irrigation of artificial cerebrospinal fluid via the working channel is important when using this technique. Results: In all cases, the sheath was successfully introduced to the slit ventricle without the use of adjunctive devices. There were no postoperative complications correlated with the maneuver. Conclusions: This novel endoscopic technique is effective and safe for inserting a sheath into a target ventricle in the management of SVS.

DOI： 10.1016/j.wneu.2020.08.206

Fully Endoscopic Transcylinder Trans-Magendie Foraminal Approach for Fourth Ventricular Cavernoma: A Technical Case Report

Nagata Yuichi, Takeuchi Kazuhito, Yamamoto Taiki, Mizuno Akihiro, Wakabayashi Toshihiko

WORLD NEUROSURGERY Vol. 142 page： 104 - 107 2020.10

Language：Japanese Publisher：World Neurosurgery

Background: Neuroendoscopy offers wide and close surgical views with fine illumination, even in deep surgical sites. Furthermore, transcylinder surgery has the advantage that a tubular retractor can protect critical neurovascular structures in the surgical corridor. These advantages of neuroendoscopy and transcylinder surgery can contribute to safer and less invasive surgical approaches for deep-seated fourth ventricular lesions, for which various critical neurovascular structures exist along the surgical route. Case Description: A 54-year-old man with a fourth ventricular cavernoma underwent tumor resection via the endoscopic transcylinder trans-Magendie foraminal approach. A 6.8-mm transparent sheath (cylinder) was introduced into the fourth ventricle via the foramen of Magendie without incisions in the inferior medullary velum or the tela choroidea, resulting in the minimal retraction of and trauma to critical neurovascular structures in the surgical corridor. Under the view of a 2.7-mm rigid neuroendoscope, the lesion was completely removed with preservation of a venous anomaly on the ventral side of the aqueduct of Sylvius. Neuroendoscopy could offer a fine surgical view even under continuous irrigation with artificial cerebrospinal fluid; it prevented collapse of the fourth ventricle and facilitated anatomic understanding by the surgeons. The postoperative course was uneventful. Conclusions: Our novel approach can be an effective surgical option for fourth ventricular lesions with minimal cerebellar retraction and injury.

DOI： 10.1016/j.wneu.2020.06.171

Endoscopic Treatment Strategy for a Disproportionately Large Communicating Fourth Ventricle: Case Series and Literature Review

KAWABATA Teppei, TAKEUCHI Kazuhito, NAGATA Yuichi, ISHIKAWA Takayuki, CHOO Jungsu, WAKABAYASHI Toshihiko

Neurologia medico-chirurgica Vol. 60 ( 7 ) page： 351 - 359 2020.7

Language：English Publisher：The Japan Neurosurgical Society

An isolated fourth ventricle (IFV) is characterized by fourth ventricular dilation due to obstruction of its inlet and outlet. A disproportionately large communicating fourth ventricle (DLCFV) is a rare subtype of IFV, characterized by dilation of the fourth ventricle, regardless of the size of the lateral ventricles, with no apparent obstruction of the cerebral aqueduct. To our knowledge, this is the first case series describing endoscopic diagnosis and treatment strategy for DLCFV. We retrospectively reviewed six cases of DLCFV in which endoscopic surgery was performed at our institution and affiliated facilities between June 2013 and March 2017. DLCFV was diagnosed using radiographic imaging and intraoperative endoscopy. We also conducted a PubMed search and included only original studies related to DLCFV treatment written in English in our review of the literature. Endoscopic third ventriculostomy (ETV) was performed in all patients. Additional endoscope-assisted placement of a fourth ventriculoperitoneal (VP) shunt was performed in two patients who could not be managed with ETV alone because of severe adhesion of the interpeduncular cistern due to subarachnoid hemorrhage (SAH). The patients’ symptoms and the size of the fourth ventricle improved with surgical treatment, without complications. Endoscopic surgery for DLCFV appears to be a safe and effective treatment. Based on our treatment strategy, ETV is the first-line treatment for DLCFV. Endoscope-assisted placement of the fourth VP shunt can be treatment for severe adhesion of the interpeduncular cistern.

DOI： 10.2176/nmc.oa.2019-0299

Preservation of Olfactory Function Following Endoscopic Single-Nostril Transseptal Transsphenoidal Surgery

Kawabata Teppei, Takeuchi Kazuhito, Nagata Yuichi, Ishikawa Takayuki, Choo Jungsu, Sato Yusuke, Tambara Masao, Teranishi Masaaki, Wakabayashi Toshihiko

WORLD NEUROSURGERY Vol. 132 page： E665 - E669 2019.12

Language：Japanese Publisher：World Neurosurgery

Objective: Olfactory dysfunction is a significant postoperative complication related to endoscopic transsphenoidal surgery (TSS). This study aimed to determine the impact of endoscopic TSS on olfactory function. Methods: We conducted a prospective study of 32 patients with sellar or parasellar tumors who were treated with endoscopic TSS between December 2013 and October 2016. TSS was performed via a right transseptal approach. We performed the Toyota and Takagi olfactometer test and the venous olfaction test for the evaluation of olfactory function preoperatively and at 1 and 3 months postoperatively. Results: The results of the Toyota and Takagi test showed that olfactory function deteriorated in 4 of 32 (12.5%) patients 1 month postoperatively and improved to preoperative baseline levels in all patients 3 months after the procedure. Olfactory function deteriorated in 1 of 31 (3.2%) patients 3 months after the procedure. The venous olfaction test revealed no response in 1 of 31 (3.2%) patients 1 month postoperatively, with no improvement 3 months after the procedure. Conclusions: Endoscopic single-nostril transseptal TSS for sellar or parasellar tumor resection has minimal impact on olfactory function.

DOI： 10.1016/j.wneu.2019.08.051

Three types of dural suturing for closure of CSF leak after endoscopic transsphenoidal surgery.

Ishikawa T, Takeuchi K, Nagata Y, Choo J, Kawabata T, Ishizaki T, Wakabayashi T

Journal of neurosurgery Vol. 131 ( 5 ) page： 1625 - 1631 2019.11

Peel-off resection of the pituitary gland for functional pituitary adenomas: pathological significance and impact on pituitary function

Nagata Yuichi, Takeuchi Kazuhito, Yamamoto Taiki, Ishikawa Takayuki, Kawabata Teppei, Shimoyama Yoshie, Inoshita Naoko, Wakabayashi Toshihiko

PITUITARY Vol. 22 ( 5 ) page： 507 - 513 2019.10

Language：Japanese Publisher：Pituitary

Purpose: Functional pituitary adenomas (FPAs) lacking a well-defined pseudocapsule can invade the adjacent pituitary gland. In such situations, peel-off resection of the adjacent pituitary gland after selective adenomectomy might lead to complete tumor removal, resulting in optimal endocrinological outcomes. Here, we present the significance of peel-off resection of the pituitary gland in patients with FPA in whom complete extracapsular tumor removal cannot be achieved. Methods: We performed a retrospective review of 21 patients with FPA who underwent transsphenoidal surgery (TSS). After selective adenomectomy, peel-off resection of the adjacent pituitary gland was performed in 13 patients because complete extracapsular resection could not be achieved, while peel-off resection was not performed in the remaining 8 patients because complete extracapsular resection was accomplished. The clinical outcomes of these groups were compared. The pituitary tissues obtained by peel-off resection were pathologically examined for tumor cells. Results: Early postoperative biochemical remission was achieved in 20 patients (95.2%). Anterior pituitary functions were not aggravated postoperatively in any patient: however, transient diabetes insipidus (DI) occurred in 2 patients. There were no statistically significant differences in the clinical outcomes of the two groups. A pseudocapsule was pathologically detected in the adjacent anterior pituitary even in patients in whom no pseudocapsule was intraoperatively detected. Tumor cells were pathologically detected in 7 (58.3%) of 12 pituitary tissues examined. Conclusions: Peel-off resection of the pituitary gland, which can remove a small tumor cell remnant in the adjacent pituitary, might maximize the effectiveness of TSS with minimal impact on postoperative pituitary function.

DOI： 10.1007/s11102-019-00980-w

Removal of the Medial Wall of the Cavernous Sinus for Functional Pituitary Adenomas: A Technical Report and Pathologic Significance

Nagata Yuichi, Takeuchi Kazuhito, Yamamoto Taiki, Ishikawa Takayuki, Kawabata Teppei, Shimoyama Yoshie, Wakabayashi Toshihiko

WORLD NEUROSURGERY Vol. 126 page： 53 - 58 2019.6

Language：Japanese Publisher：World Neurosurgery

Background: Removal of the medial wall of the cavernous sinus (MW) is challenging for neurosurgeons. We describe a practical method of endoscopic MW removal via endonasal transsphenoidal approach to minimalize intraoperative blood loss and postoperative morbidities. We also present the pathologic significance of this technique for functional pituitary adenomas (FPAs). Methods: We performed MW removal in patients with FPA with no well-defined pseudocapsule and a tumor in direct contact with the MW. The MW was judged to have tumor invasion based on the intraoperative appearance, and it was removed regardless of the appearance of MW involvement. Intraoperative findings and postoperative clinical, endocrinologic, and pathologic outcomes were retrospectively reviewed. Results: Fourteen patients underwent MW removal for FPA, including 12 patients with acromegaly and 2 with Cushing disease. Mean intraoperative blood loss was 170 mL (range, 32–400 mL), and none of the patients required blood transfusion. Among the 7 patients without intraoperative apparent MW involvement, 4 (57.1%) had pathologically confirmed tumor invasion into the MW (occult invasion). Biochemical remission by surgery alone was achieved in 13 patients (92.9%). Transient oculomotor palsy occurred in 1 patient (7.1%). Conclusions: Occult tumor invasion into the MW was often detected in patients with FPA without a well-defined pseudocapsule but in direct contact with the MW. Our technique can enhance the effectiveness of surgery with minimal postoperative morbidities.

DOI： 10.1016/j.wneu.2019.02.134