Avaliação da terceiro ventriculostomia endoscópica em lactentes: uma revisão sistemática da literatura e metanálise / Evaluation of endoscopic third ventriculostomy in infants: a systematic literature review and meta-analysis

Introdução: A hidrocefalia é um distúrbio da fisiologia do líquido cefalorraquidiano (LCR), usualmente associada ao aumento a pressão intracraniana (PIC) e expansão dos ventrículos cerebrais. Representa uma das condições mais comuns em neurocirurgia pediátrica. A terceiro ventriculostomia endoscópica (TVE) é uma opção de tratamento à hidrocefalia que visa eliminar a dependência do paciente às derivações ventrículo peritoneais. Embora a baixa idade seja associada à falha da TVE, ainda não existe consenso sobre a realização da TVE em crianças abaixo de 24 meses. Objetivos: Mensurar a taxa de falha da TVE em crianças até 24 meses; medir a associação entre menor idade, diferentes etiologias da hidrocefalia e a falha da TVE. Metodologia: Seguindo a metodologia do PRISMA-P foram identificados estudos nas bases com os descritores relacionados à TVE, falha e lactentes, sem limite de data. Várias etapas foram realizadas por dois pesquisadores de forma cega e independente. Nas leituras de resumo e texto completo aplicou-se um formulário de elegibilidade com critérios elaborados para esta RSL. Dois instrumentos - Escala de Newcastle-Ottawa e Formulário de análise de qualidade - viabilizaram a análise qualitativa que permitiu a inclusão e a extração de dados. Os testes Q e I2 avaliaram a heterogeneidade e o modelo de efeito randômico foi utilizado para o cálculo das estimativas metanalíticas. Os programas OpenMeta [Analyst] e Review Mananger versão 5.4 foram utilizados. Resultados: Foram identificados 440 estudos nas bases Pubmed, Embase e Lilacs e 1 por referência de artigo. Foram retirados 134 títulos duplicados, por não serem elegíveis 118 na leitura de resumos e 155 na leitura de textos completos. Dos 34 estudos analisados 8 foram excluídos pela análise de qualidade e após a retirada de uma coorte repetida foram incluídos 25 artigos. A taxa de falha da TVE variou de 14,6 a 77,8%. Não foi possível calcular uma estimativa sumária da taxa de falha dos estudos em função da alta heterogeneidade (I²: 82,2). Optou-se então pela metanálise em subgrupos. Não foi detectada heterogeneidade (I²=0, p=0,56) portanto, a medida metanalítica para a falha de acordo com a idade, comparando lactentes menores de 6 meses com lactentes de 6 a 24 meses foi RR=1,73 IC95%[1,22-2,45]. Ao considerar estenose de aqueduto a categoria de base para análise de outros subgrupos o RR metanalítico com significância estatística foi obtido para infecção 2,07 IC95%[1,13-3,79], para hemorragia intraventricular: 2,27 IC95%[1,40-3,68], para mielomeningocele : 2,13, IC95%[1,01-4,48]. Apesar da ausência de heterogeneidade, o RR para lesão de fossa posterior foi de 1,31 IC95%:[0,69-2,40] incluiu o valor nulo e não foi significativo (p= 0,41). A taxa de falha da repetição de TVE variou de 0-90%, as etiologias foram estenose de aqueduto, infecção, hemorragia e outros. Os principais achados na repetição do procedimento foram membrana adicional e estoma fechado. Discussão e Conclusões: A medida metanalítica sumária para taxa de falha não foi obtida devido à grande heterogeneidade dos estudos. Foram feitas tentativas de agrupamento por tamanho da casuística e por data de realização que poderiam sugerir maior domínio da técnica mas a heterogeneidade se manteve. As principais complicações relatadas foram fístula liquórica e hemorragia intraoperatória, relacionando-se com a falha da cirurgia. Não foi possível avaliar os lactentes que foram submetidos à TVE em associação com reservatório de LCR. Os resultados desta RSL e metanálise confirmam que a idade menor de 6 meses é um fator prognóstico para a falha da TVE e demonstram o valor prognóstico de outras etiologias da hidrocefalia como a infecção, a hemorragia intraventricular e a mielomeningocele onde o risco para a falha da TVE foi 2 vezes maior.

Introduction: Hydrocephalus is a disorder of the cerebrospinal fluid (CSF) physiology, usually associated with increased intracranial pressure (ICP) and expansion of the cerebral ventricles. It represents one of the most common conditions treated in pediatric neurosurgery. Third endoscopic ventriculostomy (ETV) is a treatment option for hydrocephalus that aims to eliminate the patient's dependence on shunt. Young age is associated with surgery failure, and it is not clear whether or not ETV should be performed in children under 24 months old. Objectives: Measure the failure rate of TVE in children under 24 months old; measure is a relation between failure and younger age and hydrocephalus etiology. Methodology: This review was developed observing the parameters of the PRISMA-P guidelines. Systematic search using PubMed Embase and Lilacs using respective entry terms for each mesh terms ETV, failure and infants was carried out. the articles were chosen by reading abstracts, full text, applying the eligibility form and quality analysis - newcastle scale and quality form. The data were analyzed in OpenMeta[Analyst] and Review Mananger version 5.4, The Q and I² tests and random effect model were used to derive the meta-analytic estimates. Results: 440 studies were identified in Pubmed, Embase and Lilacs databases and 1 by article reference. 134 duplicates were removed, as 118 were not eligible when reading abstracts and 155 when reading full text. Of the 34 studies analyzed, 8 were excluded by the quality analysis and, after the removal of a repeated cohort e cohort, 25 articles were included. The failure rate of TVE ranged from 14.6 to 77.8%. It was not possible to calculate a summary estimate of the failure rate of the studies due to the high heterogeneity (I²: 82.2). Subgroup analysis was chosen The RR for age 1.73 CI95%:[1.22-2.45]; the RR for etiology, comparing each onde with aqueduct stenosis, were: infection 2.07 CI95%[1.13-3.79], intraventricular hemorrhage RR: 2.27 CI95%[1.40-3.68], RR for spinal dysraphism: 2.13 CI95%[1.01-4.48]. The RR for posterior fossa-space occupying lesions was 1.31 IC95%:[0.69-2.40], and not statistically significant. The failure rate for re-do ETV ranged from 0- to 90%, the re-do ETV etiologies were aqueduct stenosis, intraventricular infection, hemorrhage and others. The main intraoperative findings were extra membrane and closed stoma. Discussion and Conclusions: Due to the great heterogeneity of the sample, it was not possible to calculate the failure rate of infants. The most reported complications were CSF fistula and hemorrhage, related to the failure of the surgery. It was not possible to evaluate infants who underwent ETV in association with a CSF reservoir. The results of this systematic review and meta-analysis confirm that the age untill 6 months old is a prognostic factor for the failure of ETV and demonstrate the prognostic value of other aetiologies of hydrocephalus such as infection, intraventricular hemorrhage and myelomeningocele, in which the risk for ETV failure was 2 times higher.

Migration of Oxidized Cellulose to the Ventricle as a Complication of Endoscopic Third Ventriculostomy: A Case Report

Endoscopic third ventriculostomy (ETV) is an increasingly common neurosurgical procedure. Hemostatic agentes (porcine gelatin and oxidized cellulose) are normally placed to plug the cortical hole after ETV to avoid cerebral spinal fluid leakage, subdural hygroma, and hemorrhage. Here we report the case of a 6-year-old boy with hydrocephalus who underwent ETV and which oxidized cellulose was placed to plug the cortical hole.Magnetic resonance imaging of the head performed 3 months after the procedure showed the presence of oxidized cellulose in the ventricle. After an unsuccessful attempt to remove the cellulose, it was decided that the patient should be kept under observation. Twoyears later, the child is in good health and without any complaints. Hemostatic agents (especially oxidized cellulose) used on the cortical hole after ETV can migrate to the ventricle and compromise the procedure. Follow-up should be performedfor such patients, and the main focus should be on not causing further injury.

Tratamiento endoscópico de quistes coloideos del tercer ventrículo / Third ventricle colloid cysts endoscopic approach

Introducción: los quistes coloideos (QC) son tumores benignos de crecimiento lento, que comprenden menos del 1% de los tumores intracraneales. Se presentan en adultos jóvenes y se ubican más frecuentemente en el techo del tercer ventrículo. El objetivo de este trabajo es presentar una serie de pacientes con QC del tercer ventrículo operados por vía endoscópica, analizar la técnica quirúrgica, ventajas y desventajas. Desarrollo: se realizó una búsqueda retrospectiva de pacientes operados por vía endoscópica, en el Servicio de Neurocirugía del Hospital Italiano de Buenos Aires, de tumores del tercer ventrículo en un período de 2 años (2013-2015), con diagnóstico de QC confirmado por anatomía patológica . Se identificaron cinco pacientes, tres mujeres y dos hombres, cuyo promedio de edad fue de 50 años. No hubo complicaciones perioperatorias y ninguno mostró recidiva en el lapso de observación. Conclusión: la vía endoscópica es una vía técnicamente simple y con muy baja morbilidad. Si bien no siempre puede realizarse una exéresis completa, los trabajos prospectivos permitirán definir si esto resulta suficiente para el control de la enfermedad. (AU)

Colloid cysts are benign, slow-growing tumors, comprising less than 1% of intracranial tumors. They occur in young adults and are more frequently located on the roof of the third ventricle. The objective of this study is to present a series of patients with Colloid cysts operated endoscopically and analyze advantages and disadvantages of this surgical technique. We performed a retrospective review of Colloid Cysts operated on endoscopically, at the Neurosurgical Department of Hospital Italiano de Buenos Aires in a period of 2 years (2013-2015). Five patients were identified, three women and two men whose average age was 50 years. No perioperative complications were observed, with no recurrences during the follow up period. Conclusion: the endoscopic approach is technically simple and has very low morbidity. Although a complete excision can not always be performed, prospective studies will allow us to define whether if is sufficient to control the disease. (AU)

Embriología del sistema ventricular cerebral / Cerebral ventricular system embryology

El Sistema Ventricular Cerebral se desarrolla de forma paralela al resto del Sistema Nervioso Central, facilitando la circulación del Líquido Cefalorraquídeo, desde su separación del líquido amniótico a nivel embrionario. Este desarrollo es necesario para entender correctamente la anatomía ventricular y facilitar el abordaje para patologías intraventriculares. El objetivo de esta revisión es reconocer los puntos más importantes en la embriología ventricular para facilitar el aprendizaje de la anatomía quirúrgica ventricular.

The cerebral ventricular system is developed in parallel with the rest of the central nervous system, facilitating the circulation of cerebrospinal fluid, from the amniotic fluid separation in the embryonic phases. This development is necessary to correctly understand the ventricular anatomy and facilitate approach to intraventricular pathologies. The objective of this review is to recognize the most important points in the ventricular embryology and in the intraventricular endoscopic vision to facilitate learning of the ventricular surgical anatomy.

Choroid plexus coagulation for pediatric hydrocephalus: review of historical aspects and rebirth

This study aims to review historical aspects and rebirth of the endoscopic choroid plexus coagulation (CPC) for pediatric hydrocephalus. The first CPC procedure goes back to early 1930s. After the development of other treatment methods and the understanding of CSF dynamics, the application of CPC dramatically decreased by 1970s. In 2000s, there was a rebirth of CPC in combination with endoscopic third ventriculostomy (ETV), and remains one of the options for the treatment of pediatric hydrocephalus in selected cases. CPC might provide a temporary reduction in CSF production to allow the further development of CSF absorption in infant, and adding to ETV for infants with communicating hydrocephalus may increase the shunt independent rate thus avoiding the consequence of late complication related to the shunt device. This is important for patients who are difficult to be followed up, due to geographical and/or socioeconomic difficulties. And also adding CPC to ETV for obstructive hydrocephalus in infants younger than 1 year of age may also increase the successful rate. Furthermore, CPC may be an option for cases with high chance of shunt complication such as multiloculated hydrocephalus, extreme hydrocephalus and hydranencephaly. In comparison with the traditional treatment of CSF shunting, the role of CPC needs to be further evaluated in particular concerning the neurocognitive development.

Evidences in the treatment of idiopathic normal pressure hydrocephalus / Evidências no tratamento da hidrocefalia de pressão normal idiopática.

Summary Introduction: idiopathic normal pressure hydrocephalus (INPH) is characterized by gait apraxia, cognitive dysfunction and urinary incontinence. There are two main treatment options: ventriculoperitoneal shunt (VPS) and endoscopic third ventriculostomy (ETV). However, there are doubts about which modality is superior and what type of valve should be applied. We are summarizing the current evidence in INPH treatment. Methods: an electronic search of the literature was conducted on the Medline, Embase, Scielo and Lilacs databases from 1966 to the present to obtain data published about INPH treatment. Results: the treatment is based on three pillars: conservative, ETV and VPS. The conservative option has fallen into disuse after various studies showing good results after surgical intervention. ETV is an acceptable mode of treatment, but the superiority of VPS has made the latter the gold standard. Conclusion: well-designed studies with a high level of appropriate evidence are still scarce, but the current gold standard for treatment of INPH is conducted using VPS. .

Resumo Introdução: a hidrocefalia de pressão normal idiopática (HPNI) é caracterizada por apraxia da marcha, disfunção cognitiva e incontinência urinária. Existem duas principais opções terapêuticas: derivação ventriculoperitoneal (DVP) e terceiro ventriculostomia endoscópica (TVE). No entanto, há dúvidas sobre qual modalidade é superior e que tipo de válvula deve ser aplicada. Este artigo resume as evidências atuais no tratamento de HPNI. Métodos: uma busca eletrônica da literatura foi realizada nas bases de dados Medline, Embase, SciELO e Lilacs, de 1966 até o momento presente para revelar os dados publicados sobre o tratamento da HPNI. Resultados: o tratamento é baseado em três pilares: conservador isolado, TVE e DVP. A opção conservadora caiu em desuso depois de vários estudos revelarem bons resultados após a intervenção cirúrgica. A TVE é uma modalidade de tratamento aceitável, mas a superioridade da DVP torna-a o padrão-ouro. Conclusão: estudos com evidência de alto nível, adequados e bem desenhados, ainda são escassos. O tratamento padrão-ouro atual de HPNI é realizado com DVP. .

Endoscopic third ventriculostomy has no higher costs than ventriculoperitoneal shunt / Terceiro ventriculostomia endoscópica não apresenta custos mais elevados do que a derivação ventrículo peritoneal

Objective: To evaluate the cost of endoscopic third ventriculostomy (ETV) compared to ventriculoperitoneal shunt (VPS) in the treatment of hydrocephalus in children. Method: We studied 103 children with hydrocephalus, 52 of which were treated with ETV and 51 with VPS in a prospective cohort. Treatment costs were compared within the first year after surgery, including subsequent surgery or hospitalization. Results: Twenty (38.4%) of the 52 children treated with VPS needed another procedure due to shunt failure, compared to 11 (21.5%) of 51 children in the ETV group. The average costs per patient in the group treated with ETV was USD$ 2,177,66±517.73 compared to USD$ 2,890.68±2,835.02 for the VPS group. Conclusions: In this series there was no significant difference in costs between the ETV and VPS groups. .

Objetivo: Avaliar os custos da terceiro ventriculostomia endoscópica (TVE) comparada à derivação ventrículo peritoneal (DVP) no tratamento da hidrocefalia em crianças. Método: Foram estudadas 103 crianças com hidrocefalia, 52 das quais tratadas com TVE e 51 com DVP numa coorte prospectiva. Foram comparados os custos do tratamento no primeiro ano após a cirurgia, incluindo cirurgias ou internações subsequentes. Resultados: Vinte (38,4%) das 52 crianças tratadas com DVP necessitaram de outro procedimento por disfunção da válvula, em comparação a 11 (21,5%) das 51 crianças do grupo tratado com TVE. Os custos médios por paciente no grupo tratado com TVE foram de USD$ 2,177.66±517.73 comparados a USD$ 2.890,68±2.835,02 para o grupo DVP. Conclusões: Nesta série não houve diferença significativa de custos entre o grupo TVE e DVP. .

Endoscopic third ventriculostomy is a safe and effective procedure for the treatment of Blake's pouch cyst / Terceiroventriculostomia endoscopica e um procedimento efetivo e seguro para o tratamento dos cistos da bolsa de Blake

OBJECTIVE: Blake's pouch cyst (BPC) is a midline cystic malformation of the posterior fossa, within Dandy-Walker's complex (DWC), often associated with hydrocephalus. Endoscopic third ventriculostomy (ETV) has been an alternative to conventional methods for BPC treatment. This study aimed at reporting our experience with ETV in a series of patients with BPC. METHODS: Of 33 patients diagnosed with midline posterior fossa cyst, 26 met the protocol criteria for DWC, and eight subjects with BPC were selected (aged one month to two years old). All cases were treated with ETV. RESULTS: Five patients were male; and three were prenatally diagnosed. They had hydrocephalus and motor deficiencies. Motor assessment at a five-year follow-up yielded normal findings. All patients improved, and only one had residual cognitive dysfunction, despite overall neurological improvement. There were no complications. CONCLUSIONS: ETV was a safe and effective procedure, reducing risks and morbidity associated with open surgery and shunt-related problems. .

OBJETIVO: O cisto da bolsa de Blake (CBB) é uma malformação cística mediana da fossa posterior, dentro do complexo de Dandy-Walker (CDW), frequentemente associada à hidrocefalia. A terceiroventriculostomia endoscópica (TVE) tem sido considerada uma alternativa aos métodos convencionais de tratamento do CBB. Este estudo teve como objetivo relatar nossa experiência com TVE em uma série de pacientes com CBB. MÉTODOS: Dos 33 pacientes diagnosticados com cisto mediano da fossa posterior, 26 preencheram os critérios do protocolo para CDW, dos quais oito foram selecionados com CBB (idades variando entre um mês a dois anos). Todos os casos foram tratados com TVE. RESULTADOS: Cinco pacientes eram do sexo masculino, três tiveram diagnóstico no pré-natal; e todos apresentavam hidrocefalia e alterações motoras. A avaliação motora após cinco anos apresentou resultados normais. Todos os pacientes melhoraram, e apenas um apresentou um leve déficit cognitivo, apesar da melhora neurológica geral. Não houve complicações. CONCLUSÕES: A TVE foi um procedimento seguro e eficaz, reduzindo riscos e morbidade associados à cirurgia aberta e a problemas relacionados aos shunts.

Neuroendoscopia pediátrica: análisis preliminar de los primeros 32 casos / Pediatric neuroendoscopy: preliminary analysis of the first 32 cases

INTRODUCCIÓN. Las técnicas endoscópicas han sido utilizadas con mayor frecuencia en los últimos años, lo cual está asociado al desarrollo de nuevos lentes y cámaras. En neurocirugía las usamos para el tratamiento de la hidrocefalia no comunicante, la biopsia de tumores intraventriculares y la fenestración de quistes intracraneales, entre otras múltiples indicaciones. MÉTODOS. Se realizó este procedimiento en el Hospital Pediátrico Docente «Juan Manuel Márquez¼, entre agosto de 2003 y agosto de 2005. Los pacientes fueron 32 niños con edades entre los 6 días y los 15 años. La técnica quirúrgica básica fue realizada a través de un agujero de trépano frontal, que permitió el acceso al sistema ventricular y la realización del procedimiento en dependencia del diagnóstico. Los pacientes fueron seguidos y evaluados mediante tomografía axial computarizada a los 3, 6 y 12 meses posoperatorios. RESULTADOS. Los pacientes tratados padecían hidrocefalia, tumores y quistes intracraneales, principalmente. Predominó el grupo de edad de 10 a 15 años (13 niños; 40 por ciento). Los menores de 1 año fueron 8 pacientes y constituyeron el 28 por ciento del total. La etiología más común fue la hidrocefalia no comunicante, la cual en 15 pacientes fue secundaria a una estenosis acueductal. El proceder endoscópico más frecuente fue la ventriculostomía premamilar del tercer ventrículo. En los 32 operados se practicó un total de 51 procedimientos neuroendoscópicos. Se logró realizar el procedimiento de comunicación y cedió la sintomatología de los pacientes. La evolución posoperatoria fue exitosa en 27 pacientes (84 por ciento) y solo en 5 pacientes (16 por ciento) no fue resolutiva. El método no produjo complicaciones graves. CONCLUSIONES. La neuroendoscopia probó ser una alternativa a las derivaciones en determinados pacientes, especialmente en niños con hidrocefalia no comunicante. Permitió una disminución significativa de los gastos en sistemas derivativos y disminuyó el rango de complicaciones, con lo cual la estadía hospitalaria fue considerablemente más corta(AU)

INTRODUCTION. The endoscopic techniques have been used more frequently in the last years, which is associated with the development of new lens and cameras. In neurosurgery, they are used for the treatment of non-communicating hydrocephaly, biopsy of the intraventricular tumors and the fenestration of intracranial cysts, among other multiple indications. METHODS. This procedure was carried out in "Juan Manuel Márquez" Pediatric Teaching Hospital from August 2003 to August 2005. The patients were 32 children between 6 days and 15 years old. The basic surgical technique was applied through a hole made by frontal trephination that allowed the access to the ventricular system and the performance of the procedure depending on the diagnosis. The patients were followed up and evaluated by computerized axial tomography at 3, 6 and 12 postoperative months. RESULTS. The patients treated mainly suffered from hydrocephaly and intracranial tumors and cysts. The age group 10-15 (13 children, 40 percent) predominated. 8 patients were under 1, accounting for 28 percent of the total. The most common aetiology was the non-communicating hydrocephaly, which in 15 patients was secondary to an aqueductal stenosis. The most frequent endoscopic procedure was the premammillary ventriculostomy of the third ventricle. It was possible to carry out the communication procedure and the patients's symptoms decreased. The postoperative evolution was successful in 27 patients (84 percent) and only 5 patients (16 percent) did not resolve. The method did not produce severe complications. CONCLUSIONS. The neuroendoscopy proved to be an alternative to the derivations in certain patients, specially in children with non-communicating hydrocephaly. It allowed a significant reduction of the expenses in derivative systems and diminished the range of complications, with which the length of hospital stay was considerably shorter(AU)

Infección relacionada con el drenaje ventricular externo: tratamiento intravenoso versus intratecal, revisión de la literatura / External ventricular drainage infection: intravenous vs intrathecal treatment, Review

Ante la emergencia de infecciones relacionadas al drenaje ventricular externo por gérmenes multirresistentes y la necesidad de utilizar antibióticos cuya acción en el sistema nervioso central es controvertida, surge la necesidad de emplear terapéuticas para la administración de fármacos cuyos beneficios merecen ser evaluados. Se realizó una búsqueda de la literatura en PUBMED y los datos fueron extraídos de estudios publicados entre 1987-2005. En esta revisión de la literatura se analizaron los resultados obtenidos, comparando: el tratamiento endovenoso con el tratamiento intratecal en pacientes con infección asociada a la ventriculostomía, los antibióticos utilizados y su penetración al líquido cefalorraquídeo (LCR) con cada vía. Finalmente, se propuso qué pacientes podrían beneficiarse con cada terapéutica, a pesar de la falta de evidencias claras, sugiriendo la necesidad de realizar un trabajo randomizado prospectivo comparando sus beneficios. Palabras clave: infección, tratamiento, ventriculitis.

Due to the emergency of external ventricular drainage infections, cause by multiresistant bacterial strains, and the need to treat them with antibiotics, whose action in the central nervous system is controversial, arises the terapeutic necessity to administer antibiotics whose benefits should be evaluated. We search the Pubmed library. The data were extracted from published studies between 1987-2005. In this reivision the results were analyzed, comparing envovenous versus intrathecal treatment in patients with a ventriculostomy associated infection, the antibiotics that were used and their cerebrospinal fluid (CSF) levels according to each route. Finally, even though there is a lack of clear evidence, we proposed which patients could benefit with each treatment. We conclude that a randomized prospective study, comparing the benefits of each treatment is needed.

Endoscopic third ventriculostomy in obstructed hydrocephalus.

Forty-three ETV were performed in 46 patients of obstructive hydrocephalus. Study was divided into two groups. Group 1 was with 29 children of less than two years age. Group 2 had seventeen patients of more than 2 years, adolescent and adults. Group 1 had 70% clinical and 63% radiological improvement whereas Group 2 showed 100% clinical and 73% radiological improvement. ETV failed in relieving the symptoms of hydrocephalus in eight patients. They were eventually benefited with VP Shunt. There was one postoperative death, which was not related to the procedure. ETV is an important alternative to VP Shunt in relieving hydrocephalus due to obstruction in CSF pathway.

Endoscopic third ventriculostomy.

We prospectively studied 8 patients who had an endoscopic third ventriculostomy performed between 1996 and 1997 in Songkhlanagarind Hospital. The surgical technique was described. Seven operations were successful and one operation failed. Success was found in cases of pure aqueductal stenosis, aqueductal stenosis with Dandy Walker malformation, and posterior fossa tumor. In a patient where an endoscopic third ventriculostomy failed, aqueductal stenosis with marked hydrocephalus was found. Marked dilation of the third ventricle could compress the aqueduct of Sylvius. Although there was communicating hydrocephalus, it looked like non-communicating hydrocephalus. To avoid a valvular shunting complication, we suggest performance of an endoscopic third ventriculostomy in selected non-communicating hydrocephalus patients.