4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

Dec. 15, Room A
Invited lecture: Neurofluid: a new concept of the CNS fluid dynamics

New mechanisms for the efflux of neurofluids andneurometabolites: key relationships between thefunctions of meningeal lymphatic vessels andextravascular fluid pathways
Masahiro Miura
Department of Anatomy, Faculty of Medicine, Oita University, Japan

Although produced through different mechanisms, both cerebrospinal fluid and cerebral interstitial
fluid have recently been called “neurofluids,” as they are both neurally related fluid components thatmove freely. These neurofluids are primarily produced in the intracerebral microvascular networkand the ventricular choroid plexus, but understanding the pathophysiology of cerebrospinal fluid(CSF) abnormalities, such as leaks and drainage issues, requires a detailed description of neurofluid
production and absorption mechanisms, which is still largely unknown. The brain region is an organsystem in which lymphatic vessels are not developed. As a result, neurofluids are considered
to compensate at the main drainage system of the upstream efflux pathways for the glymphatic
clearance system connecting perivascular spaces and intramural periarterial drainage, with the
exception of reabsorption through brain microvascular networks. For the downstream efflux pathwaysof both systems, the 2015 discovery of the meningeal lymphatic vessel as a new efflux pathway hascaused some reconsideration of efflux pathways to the deep cervical lymph nodes. However, thechanging mechanism by which the downstream efflux pathway drains extracranially into the generalsomatic lymphatic system is still unknown.
The classical absorption pathway from the cribriform plate through the lymphatic system of the nose
mucosae was thought to be an active CSF absorption pathway that is unique to rodents and inactive
in humans. On the one hand, the new absorption pathway of CSF draining into the ocular lymphatic
system via the optic nerve sheath is fascinating. On the other hand, in the spinal cord region, theabsorption system mediated by the epidural lymphatic network (EDLN) is considered to be in chargeof CSF pressure regulation. Its operation depends on the link that it forms with the pre-lymphatic
channel (PLC) on the most inner surface of the spinal nerve root sheath (Miura et al, 1998). As a leakinto the spinal root sheath through the PLC is generally a physiological phenomenon, that area isinterpreted to be a subarachnoid space in the broad sense of the word and a physiological reservoir[magnetic resonance imaging (MRI - teardrop sign)] for CSF. That being said, water balance in thecentral nervous system is also closely related to postnatal development and age-related regression of
the meningeal lymphatic network (MLN) and EDLN, which are linked to the meningeal related PLC.
In this presentation, we will reconsider the latest neurofluid discharge pathways (nine varieties)
based on our experimental findings and describe the histochemical characteristics of meningeal
lymphatic networks, a key component in the lymphatic absorption pathway for neurofluids (CSF tracer
injection experiments, MRI analysis, etc.). Furthermore, we will describe the structural features of themeningeal PLC, a physiological guidance pathway to the MLN, in humans.
This study was approved by the Ethics Committees of the Faculty of medicine, Oita University(approval No.2014-716 and 2020-1979). (COI:NO)
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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

ACADEMIC EDUCATION:
1980-1984
B.S. Health science, University of Tsukuba, Faculty of Health science and Physical education(Neurophysiology), Tsukuba, Japan
1984-1986
M.S. Neurophysiology, University of Tsukuba, Graduate school of Comprehensive Human Sciences, Master's
Program in Health Science and Sports Medicine, Tsukuba, Japan
National Institute of Advanced Industrial Science and Technology (AIST), Health and Medical ResearchInstitute (graduate student)
1994
Ph.D Neuroanatomy, Oita Medical University. Faculty of Medicine: No.64
2003
MHLW-accredited cadaveric autopsy qualifications (License): No.7719
PROFESSIONAL ACTIVITIES:1986 1989
Assistant professor in the Department of Anatomy and Life Structure, University of Juntendo, Faculty of
Medicine, Tokyo
1989-1996
Assistant professor in the Department of Anatomy (I)Faculty of Medicine, Oita Medical University, Oita
1996-2005
Lecturer in the Department of Anatomy (I),
Faculty of Medicine, Oita Medical University, Oita
2005-present Senior Lecturer in the Division of Morphological Analysis, Department of Anatomy, Biology and Medicine,
Faculty of Medicine, Oita University, Oita
(1997-1998)
Institut für Anatomie und Zellbiologie, Medizinische Fakultät
Julius-Maximilians-Universität Würzburg, Würzburg, Germany(Visiting scientist) (Head: Prof. Dr. M.v. Lüdinghausen)(2001)
Division of Anatomy and Histology, Department of Basic Sciences, Faculty of Dental Sciences University of
Peradeniya, Peradeniya, Sri Lanka (JAICA educational support)
MEMBERSHIP OF MAIN ACADEMIC SOCIETIES:Japanese Society of iNPH
Japanese Association of Anatomists (Board member)
Japanese Society of Lymphology
Japanese Cancer Association
American Association of Clinical Anatomists (AACA)
Japanese Society for Lymphedema Therapy
HONRS AND AWARDS:
1. Young Investigator Award of the British Association of Clinical Anatomists 1997 (Glasgow, England)
2. Academic NISHI Award of the Japanese Society of Lymphology 2009 (Osaka)
3. Japanese Traveling fellowship (Japanese Association of Anatomists) 2010, 2019 (Iwate & Niigata)
4. Best Research & Presentation Award of the Japanese Society of Anesthesiologists 2013 (Sapporo)
5. Best Poster Award of the Japanese Society for Lymphedema Therapy 2019 (Tokushima)
6. Best Presentation Award of the Japanese Society of regional Anesthesia 2018, 2019 (Kochi & Matsumoto)
7. Best Paper Award of the Kyushu・Yamaguchi Society of Sports Medicine 2019 (Fukuoka)

94th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

Dec. 15, Room A
Invited lecture: Neurofluid: a new concept of the CNS fluid dynamics

Neurofluid (clinical): pediatric posttraumatic low ICP syndrome
Koichi Takahashi
Department of Neurosurgery, Sannou Hospital10

4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

Dec. 15, Room A
Special session: Controversies in surgical management of pediatric brain tumors

2: Convection Enhanced Delivery in Diffuse Intrinsic Pontine Glioma(DIPG): does it the way to go?
AnswerRyuta Saito
Department of Neurosurgery, Nagoya University

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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

Dec. 15, Room C
Educational session 4: From basic to advanced management—surgery
for syndromic, complex craniosynostosis

How to surgically treat complex craniosynostosis?
Ikkei Tamada, MD, PhD
Department of Plastic and Reconstructive Surgery, Tokyo Metropolitan Children’s
Medical CenterIn the comprehensive treatment of craniosynostosis, a multidisciplinary team approach grounded inprotocol is mandatory. On the other hand, the protocol of each institution can be influenced by new
concepts. In the past two decades, posterior cranial vault distraction, suturectomy with postoperative
helmet therapy, and spring-assisted cranioplasty have changed global trends in craniosynostosis
management.
Tokyo Metropolitan Children's Medical Center’s craniofacial team began their operations in 2010. Aftersome changes were made to the institutional protocol, 52 patients with complex craniosynostosis
comprising 17 cases of major craniosynostosis syndrome (Crouzon, Apert, and Pfeiffer syndrome),
seven of miscellaneous syndromes, eight of bicoronal synostosis of unknown etiology, 14 ofbilambdoid and sagittal synostosis, and six of other forms of multiple synostosis were surgicallytreated between January 2011 and September 2023.
As above mentioned, each craniosynostosis case is treated in accordance with the institutional
protocol, using an algorithm for practical decision making. In particular, the type of cranioplasty forsyndromic craniosynostosis is determined by taking into consideration age at surgery, degree of
proptosis, occipital region shape, suture condition, and skull thickness. The institutional protocol
involves three, basic, surgical techniques i.e., fronto-orbital advancement, posterior cranial vault
distraction, and strip craniectomy with postoperative helmet therapy. If the patient presents severe
proptosis, early fronto-orbital advancement with or without distraction osteogenesis is considered.
Then, if the patient is aged <6 months the strip craniectomy with postoperative helmet therapy is
considered. This procedure helps to achieve the natural, round shape of the head and adequate
cranial bone thickness, enabling subsequent treatments to be performed on a more secure footing.
Usually, posterior cranial vault distraction is considered after confirming that the bone status of theposterior region can withstand the distraction. At present, fronto-facial monobloc advancement is notconsidered as a routine technique in the institutional protocol.
Sometimes patients present with a severe deformity requiring more individualized treatment. In suchcases, other treatment strategies and techniques may be adopted to ensure safe and successful
surgery.

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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

EDUCATION
2000 Graduate from Keio University School of Medicine
CAREER HISTRY[2010 March-present] Attending Surgeon, Director (July 2014-), Department of Plastic and Reconstructive Surgery, Tokyo
Metropolitan Children's Medical Center[2009-2010] Attending Surgeon, Department of Plastic and Reconstructive Surgery, Tokyo Metropolitan Kiyose Children's
Hospital[2008 December-] Visiting scholar, Craniofacial Center Chang Gung Memorial Hospital[2008 June] Visiting fellow and observer, Australian Craniofacial Unit
[2007-2008] Attending Surgeon, Department of Plastic and Reconstructive Surgery, Tokyo Metropolitan Kiyose Children's
Hospital[2006-2007] Instructor, Department of Plastic and Reconstructive Surgery,Keio University[2005-2006] Attending Surgeon, Department of Plastic and Reconstructive Surgery, National Tokyo Medical Center[2004-2005] Chief Resident, Department of Plastic and Reconstructive Surgery, Keio University[2003-2004] Department of Surgery, Tokyo Metropolitan Kiyose Children's Hospital[2002-2003] Department of Surgery, Mito Kyodo Hospital[2000-2002] Resident, Department of Plastic and Reconstructive Surgery, Keio University
LICENSURE
Active Member, Asian Pacific Craniofacial Association
Active Member, International Society of Craniofacial Surgery
Board Certification for Plastic and Reconstructive Surgery, Japan
Board Certification for Cranio-Maxillo-Facial Surgery, Japan
Board Certification for Pediatric Plastic Surgery, Japan7

4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

Dec. 15, Room A
Meet experts 3 (Luncheon seminar): Surgery for pediatric congenital
deformative craniovertebral
junction (CVJ) lesions

Management of complex Craniovertebral junction (CVJ)
surgery in children
Ryo Ando
Department of Neurosurgey, Chiba Children’s Hospital

CVJ region is one of the complex structures in terms of embryological development. Congenital
misstructure can easily occur in such region. CVJ takes several roles mechanically andphysiologically.
1) Stability and mobility2) Neural transformation from brain to cervical spinal cord3) CSF dynamics between posterior cranial fossa to spinal canalAnother factor we should take into consideration is that children’s spine is growing structure.
Sometimes, follow-up observation for natural course or minimum conservative approach is better way
rather than hasty surgical intervention. This presentation will discuss the management of complex
CVJ surgery in children especially focusing on complex Chiari malformations, spinal deformities withsegmentation failure, and skeletal dysplasia.
Complex Chiari is the pathological concept described by Brockmeyer group recently. According
to their description, the patients with brain stem herniation or Chiari malformation type 1.5, basilar
invagination, and Clivo-axial angle(CXA)<125°are at higher risk of Occipito-cervical(OC) fusion. Thismeans more complicated anatomical variance provokes refractory pathophysiological condition of
Chiari malformation. On our experience, the patients with CXA<125°and Klause index<25mm tend topresent syringomyelia and to become symptomatic which require surgical intervention in earlier stageof their life. The procedure is basically decompression, including additional tonsillectomy. No patients
underwent anterior decompression or OC fusion so far.
Segmentation failure in developing spine can cause complex spinal anomaly. Though the number islimited, three patients are described here. The patient with the fusion or separation failure of clivus
and apical segment of dens showed C1-2 instability, and posterior fixation was required. Second
patient with multiple complex segmentation failure who had the past surgical history of Foramen
magnum decompression (FMD) and C1 laminectomy, presented with acute transient episode ofupper and lower extremities weakness after trauma. The patient had another stenotic lesions at thelevel of C3-5 though, she remained stable with conservative management of mild exercise restriction
only. Third patient with facet hypoplasia of C4-6 demonstrates hyperlordosis resulting in retroflexedodontoid and basilar invagination causing anterior compression of brain stem. She underwent
transoral odontoidectomy followed by O-C2,3 fusion.
In Skeletal dysplasia, achondroplasia is the most common. Although anatomy of foramen magnum(FM) varies considerably from normal population, FMD including lateral aspects of FM is usually
the operative technique of choice. Stenosis is the predominant pathology in achondroplasia.
Chondrodysplasia punctata (CDP) is characterized by punctate calcification of the vertebral body15

4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

and instability due to hypoplasia of the anterior element. Among five our patients, three of which hadparalysis from early on, were treated with C1 laminectomy only, with additional cervical collar wearing.
The other one requires posterior fusion. Metatropic dysplasia, so named because of the progressive
spinal deformity, was treated with FMD and C1 laminectomy in two of four our patients. In one case,restenosis due to hyperosteogenesis occurred, and O-C4 re-decompression was added.
To deal with complex CVJ lesions in children, appropriate choice of timing and surgical technique ismandatory. Sometimes staged treatment is preferable in selected patients according to developing
spine.
Education
1998-2004: School of Medicine, Tsukuba University (M.D.)
Certification and Licensure
2004: Japan Medical License
2010: Board Certification, Japan Neurosurgical Society
2015: Board Certification, Japanese Society of Spinal Surgery
Professional Training and Employment
2004-2006: Junior Residency, Asahi General Hospital (Chiba, Japan)
2006-2009: Senior Residency, Department of Neurosurgery, Asahi General Hospital
2009-2010: Medical staff, Department of Pediatric Neurosurgery, Chiba Children’s Hospital (Chiba, Japan)
2010-2011: Medical staff, Department of Spinal Surgery, Kameda Medical Center (Chiba, Japan)
2011-2012(Apr): Senior Surgeon, Department of Spinal Surgery, Kameda Medical Center (Chiba, Japan)
2012(May)-2014(Mar): Medical staff, Department of Pediatric Neurosurgery, Chiba Children’s Hospital (Chiba, Japan)
2014(Apr)-: Senior Surgeon, Department of Pediatric Neurosurgery, Chiba Children’s Hospital (Chiba, Japan)
2020(Apr)-preesnt: Chief Surgeon, Department of Pediatric Neurosurgery, Chiba Children’s Hospital (Chiba, Japan)
Academic Award
2015 Best Paper Award, Symptomatic Chiari type-2 malformation. To operate or not to operate? Consideration of its natural
history. 1st Congress of Asian-Australasian Society for Pediatric Neurosurgery and Inaugural Meeting2015 Best Presentation Award, Decompressive surgery for high cervical stenosis in metatropic dysplasia. The 27th Annual
Meeting of KSPN and 2015 JSPN-KSPN Joint Meeting16

4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

Dec. 15, Room C
Meet experts 4 (Luncheon seminar): How to start up intraoperative neurophysiologicalmonitoring in pediatric neurosurgery

Spinal surgery: motor, sensory & urinary function
Tsunenori Takatani
Department of Anesthesiology, Nara Medical University

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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

Dec. 15, Room A
Symposium 7: Tethered cord syndrome: how to diagnose, when andhow to operate?

Diagnosis, surgical procedure, and prevention of retethering
Toshiaki Hayashi
Miyagi Children’s HospitalPreference: Spinal lipomas can be classified into two major types, lipoma of the filum terminale andlipoma of the conus medullaris(LCM). LCM often causes neurological symptoms known as tethered
cord syndrome (TCS). The symptoms can be seen at diagnosis and during long-term follow-up. In
this report, we present the long-term results of surgical treatment of pediatric LCM in our department
and discuss the treatment strategy for CL in the literature. Possible risk factors for retethered cord
syndrome (ReTCS) were evaluated in the long-term follow-up period.
Methods: Consecutive pediatric patients with LCM who underwent first untethering surgery andwere followed for more than 100 months were retrospectively analyzed. Pre- and postoperative
clinical and radiological data were reviewed to analyze the outcomes of surgery and identify
potential risk factors for ReTCS. The surgery was performed with a partial removal technique undercontinuous intraoperative electrophysiological monitoring, including monitoring of anal sphincter
and calf muscles. Briefly, after exposure of the lipoma, detethering of the spinal cord was performedby cutting the lipoma or tethering bands. Subpial removal of the lipoma was performed using an
ultrasonic aspiration system. The aim of lipoma removal was to release the spinal cord from the dura
and allow CSF to surround the spinal cord and lipoma complex without injuring the spinal cord androots. Lipomas were not removed aggressively. Aberrant roots were cut under electrophysiologicalmonitoring. If the roots were involved in the lipoma, the lipoma was either minimally removed or not
removed to protect the roots and the surrounding pial surface. The pia that was seen around thestump of the removed lipoma was approximated to reconstruct the pial surface. If the dural defectdid not allow primary dural closure, such as surgery for lipomyelomeningocele, the dural defect was
repaired using a fascia patch
Results: During follow-up, the overall 10-year and 15-year progression-free survival rates were about
80% and 75% respectively. On Univariate analysis, lipoma type of Lipomyelomeningocele, age atsurgery, and mean growth rate after surgery were significant factors associated with ReTCS. Cox
proportional hazard models showed that lipoma type of lipomyelomeningocele and mean growth rate
after surgery were significantly associated with the occurrence of ReTCS.
Discussion: The more complex lesions and high growth rate after surgery seem to increase the riskof ReTCS. Considering that the highest growth rate is seen in infancy, to perform prophylactic surgery
in infancy for LCM with a high risk of adhesion, such as lipomyelomeningocele and transitional LCM
may not be a good option. However, the dilemma is that TCS symptoms in infancy are not always
easy to diagnose. Larger prospective studies and registries are need to define the risk of ReTCS
more adequately.

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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

Education and Academic Qualifications:
1994
Graduated from Tohoku University School of Medicine
1994
Medical Doctor, Japan Ministry of Health
2001
Ph.D (Medical Science) Tohoku University Graduate School of Medicine, Sendai, Japan
2001
Board Certified Neurosurgeon, Japan Neurosurgical society
Employment:
2003-2012
Chief, Department of Neurosurgery, Miyagi Children’s Hospital, Sendai, Japan
2012-2018
Chief, Department of Neurosurgery, Sendai City Hospital, Sendai, Japan
2018-2020
Associate Professor, Department of Neurosurgery, Tohoku Medical and Pharmaceutical University, Sendai,Japan
2020-present Director, Department of Neurosurgery, Miyagi Children’s Hospital, Sendai, Japan
2021
Professor, Department of Pediatric Neurosurgery, Tohoku University, Graduate School of Medicine
Award:
2001 Tohoku Cerebrovascular Disorders Research Association Award
2010, 2020 Jiro Suzuki Award, Department of Neurosurgery, Tohoku University
2013 Kawabuchi Award, Japanese Society of Pediatric Neurosurgery

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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

Dec. 15, Room A
Symposium 8: Surgery for pediatric hypertonia

ITB in Asia-Australasia
Shiro Horisawa
Tokyo Women’s Medical University

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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

Dec. 15, Room A
Symposium 9: Management of neonatal intraventricular hemorrhage(IVH) & subsequent hydrocephalus

Management of neonatal IVH in Japan
Young-Soo Park
Department of Neurosurgery and Children’s Medical Center, Nara Medical University

Remarkable advances in neonatal care have significantly improved the survival of extremely low birthweight infants (ELBWIs) in recent years. However, intraventricular hemorrhage (IVH) and subsequentpost-hemorrhagic hydrocephalus (PHH) remain to be major complications in ELBWIs, leading toa high incidence of cerebral palsy and cognitive impairment. Fragile infants are targeted and theirtreatment requires special attention and various difficulties. Although no standard management
has been established, a common treatment strategy is to provide temporary treatment such as
ventricular drainage, ventricular reservoir, or ventriculosubgaleal shunt, followed by permanent
ventriculoperitoneal shunt (VPS) after the infant grows. However, VPS for PHH in premature infants
leads to a variety of troublesome shunt-related complications, including infection and ventricularcatheter obstruction at a non-negligible incidence, further worsening functional outcomes.
In recent years, it has been elucidated that poor neurological functional prognosis is also due tolong-term brain exposure to the hematoma itself and its dissolution products. Challenging treatment
strategies are being attempted to improve neurodevelopmental function, including cognitive function,with the key concept of aggressively removing the hematoma and avoiding VPS.
Two challenging treatment strategies are being tried, one is neuroendoscopic ventricular lavage (NEL)
and the other is fibrinolytic therapy. These two treatment strategies are undoubtedly aggressive andpromising treatments for PHH in ELBWIs. Based on the results of studies reported since 2000, clinicaloutcomes, including VPS requirement rates, complication rates such as infection and secondary
bleeding, and cognitive function, were similar between the two treatment groups. However, advanced
surgical techniques are essential to perform NEL, and there are limitations in its application topatients with extremely small brains and without highly enlarged ventricles.
Considering various factors, the ideal treatment strategy for PHH in ELBWIs is currently considered
as follows. Step 1) EVD management with fibrinolytic therapy using urokinase (not tPA), Step 2) NEL
if possible, Step 3) intermittent CSF drainage with ventricular reservoirs, or ventriculosubgaleal shunt,
which has long been the standard of care. When progressed PHH cannot be controlled with these
therapies, VPS is the final treatment option.
This lecture will outline the fibrinolytic therapy using urokinase that is being tried in Japan. Our
fibrinolytic treatment consists of the following approaches. 1) continuous intracranial pressure control
from the early PHH stage; 2) morphological recovery of the brain mantle volume as soon as possible; 3)
rapid hematoma dissolution and wash out; 4) reduction of free radicals and inflammatory cytokines; 5)
restoration of physiological cerebrospinal fluid (CSF) dynamics; and 6) avoidance of permanent VPS
placement.
Until recently, the main goal of IVH and subsequent PHH treatment was to reduce mortality, since thetreated infants were vulnerable premature infants. And only how to safely perform permanent VPS
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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

surgery has been considered as an objective. However, the troublesome shunt-related complications
should prompt consideration of treatment guidelines that avoid VPS placement. Pediatricneurosurgeons should be proactive in reducing the risk of periventricular white matter injury andimproving neurodevelopmental outcomes.
Education and Professional Career
1990
M.D., Faculty of Medicine, Nara Medical University, Nara, JAPAN2006
Ph.D., Graduate School of Medicine, Nara Medical University, Nara, JAPAN
1990-2002 Resident in Department of Neurosurgery, Nara Medical University Hospital and the affiliated hospitals
2003
Assistant Professor, Department of Neurosurgery, School of Medicine, Nara Medical University, Nara, JAPAN
2006-2007 Post-doctoral clinical fellow, Department of Pediatric Neurosurgery, Rome Catholic University, A Gemelli Hospital,
Rome, ITALY (Professor C. Di Rocco)
2008
Lecturer, Department of Neurosurgery, School of Medicine, Nara Medical University, Nara, JAPAN2012~
Associate professor, Department of Neurosurgery, School of Medicine, Nara Medical University, Nara, JAPAN2016~
Clinical professor, Division of Children’s Medical Center, Nara Medical University Hospital, Nara, JAPANMain field of Interest
Pediatric Neurosurgery, Neuroendoscopy, Neurotrauma, Spinal Surgery

304th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

Dec. 15, Room A
Symposium 10: Moyamoya disease: what is the best practice?

Japanese Guideline of Moyamoya disease
Satoshi Kuroda
Department of Neurosurgery, University of Toyama

31