PITCH registry study design: Pediatric Infratentorial Tumors – Related Complications of Hydrocephalus. Observational, prospective, multicenter study evaluating mortality, infection rate, and number of surgeries associated with the treatment of hydrocephalus secondary to infratentorial tumors in childhood and adolescence

PITCH registry study design: Pediatric Infratentorial Tumors – Related Complications of Hydrocephalus. Observational, prospective, multicenter study evaluating mortality, infection rate, and number of surgeries associated with the treatment of hydrocephalus secondary to infratentorial tumors in childhood and adolescence | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Method Article PITCH registry study design: Pediatric Infratentorial Tumors – Related Complications of Hydrocephalus. Observational, prospective, multicenter study evaluating mortality, infection rate, and number of surgeries associated with the treatment of hydrocephalus secondary to infratentorial tumors in childhood and adolescence Marcos Devanir Silva Costa, Paloam Cardoso Nôvo, Thaís Neri Andrade Almeida Garcia, and 32 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8614229/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 5 You are reading this latest preprint version Abstract Introduction: Posterior fossa tumors are the main pediatric solid neoplasms, and more than 60% of these tumors are associated with the occurrence of hydrocephalus, which can be treated through different strategies, such as endoscopic third ventriculostomy (ETV), ventriculoperitoneal shunt (VPS), external ventricular drainage (EVD), or direct resection of the lesion without other diversion methods. The safest and most efficient drainage method remains controversial, and several studies are limited to a single center, with retrospective analysis, most of them compromised by the limited number of participants, so multicenter and prospective studies are necessary to understand what would be the best treatment strategy. Methods: This is a non-concurrent, prospective, multicenter cohort study conducted in more than twenty pediatric neurosurgery centers in Latin America, in which patients will be divided into 4 groups according to the chosen treatment for hydrocephalus (ETV, EVD, VPS, and resection), and mortality and infection rates, the number of surgeries related to hydrocephalus treatment, and its complications in the first year of hydrocephalus treatment will be analyzed. Patients will be followed prospectively for up to 12 months after the index surgery, which will be considered the surgery performed for the treatment of hydrocephalus, and each group will include at least 100 patients. Conclusion: The online REDCap platform will be used for the records of the PITCH study, which will allow the collection of prospective data in different centers in Latin America, aiming to compare the treatment modalities for obstructive hydrocephalus secondary to posterior fossa tumors (ETV, EVD, VPS, resection) and to evaluate the impact of these treatments in the first year after the diagnosis of hydrocephalus associated with posterior fossa tumor. Endoscopic third ventriculostomy Ventriculoperitoneal shunt External ventricular drainage Treatment outcomes Figures Figure 1 INTRODUCTION Among all childhood cancers, central nervous system (CNS) tumors account for 20.7%, second only to leukemias; however, among solid tumors, they are the most common, and of these, infratentorial tumors represent 60% of cases [ 1 ]. Posterior fossa tumors are associated with hydrocephalus [ 2 ], specifically non-communicating hydrocephalus, since most of these tumors cause direct or indirect obstruction of the fourth ventricle and/or its outflow pathways [ 3 , 4 , 5 ]. In a study of 117 children with posterior fossa tumors, Culey et al. [ 4 ] reported hydrocephalus in 83% of the patients. Dias MS et al. [ 5 ] concluded that one quarter to one third of infants with posterior fossa tumors were associated with hydrocephalus requiring diversion. Although it may be intuitive to think that obstructive hydrocephalus can be treated with tumor resection, several factors predispose to persistent hydrocephalus after tumor removal: young age, preoperative hydrocephalus, midline tumor location, metastases, subtotal resection, tumor pathology, use of external ventricular drains, and postoperative complications [ 6 ]. There are several clinical contexts related to the treatment of hydrocephalus secondary to posterior fossa tumors; therefore, various management strategies for hydrocephalus secondary to infratentorial tumors have been described, such as endoscopic third ventriculostomy (ETV), ventriculoperitoneal shunt (VPS), external ventricular drainage (EVD), or direct resection of the lesion without other diversion methods [ 7 – 10 ]. However, each of these strategies has risks and benefits associated with the therapeutic decision made for each patient, and part of the difficulty in choosing a safer treatment method is due to the multiple outcomes selected in studies with different methodologies, making comparison between studies and between hydrocephalus treatment methods very difficult. Thus, with the collaborative effort presented, we defined the need for a multicenter prospective study on the main types of treatment for hydrocephalus caused by posterior fossa tumors in children. The PITCH study aims to compare the different treatment modalities for obstructive hydrocephalus secondary to posterior fossa tumors (ETV, EVD, VPS, resection), considering mortality and infection rates, the number of surgeries related to hydrocephalus treatment, and its complications in the first year after the first surgery performed to treat hydrocephalus. In addition, to compare the different histological types and treatment modalities and their chances of failure, to compare the interval between the chosen treatment method and the initiation of adjuvant therapy, when performed, after tumor resection surgery, and to compare the length of hospitalization related to the treatment of hydrocephalus and its complications among the different treatment methods (ETV, EVD, VPS, tumor resection). METHODS A non-concurrent, prospective, multicenter, controlled cohort study will be conducted to evaluate the outcomes of the different treatment modalities for hydrocephalus secondary to posterior fossa tumors (ETV, EVD, VPS, tumor resection), considering: mortality rate, surgical site infection and device-associated infection, number of surgeries related to hydrocephalus, and its complications in the first year after the first surgery performed to treat hydrocephalus. The study is approved by the scientific committee of the Instituto de Oncologia Pediátrica IOP/GRAACC and by the ethics committee of the Federal University of São Paulo (UNIFESP), as well as by all ethics committees of the participating centers. Patients will be included in the study after obtaining the Free and Informed Consent Form (FICF) from their legal guardians and the Assent Form (AF) from patients under 18 years of age with a diagnosis of hydrocephalus secondary to posterior fossa tumor, confirmed through imaging exams (computed tomography (CT) and magnetic resonance imaging (MRI)) and who will undergo surgical resection of the posterior fossa lesion. CHARACTERISTICS OF THE INCLUSION AND EXCLUSION CRITERIA The patients included will be under 18 years old with a diagnosis of hydrocephalus secondary to a primary tumor of the central nervous system (CNS) located in the posterior fossa, characterized by clinical data and radiological imaging (CT or MRI). Hydrocephalus secondary to posterior fossa tumor will be characterized when the patient presents a tumor in the posterior fossa causing obstruction of cerebrospinal fluid circulation and enlargement of the lateral ventricles and third ventricle, with such enlargement documented by imaging exams such as cranial CT or MRI, which must identify, in addition to ventricular enlargement, the presence of enlargement of the temporal horns of the lateral ventricles (> 2 mm) and transependymal edema in the frontal and/or occipital horns of the lateral ventricles. In addition, the patient must present signs and symptoms related to increased intracranial pressure (ICP), such as headache, irritability, vomiting, strabismus and/or unilateral or bilateral sixth cranial nerve palsy, papilledema, bradycardia, arterial hypertension, and altered level of consciousness (drowsiness, stupor, or coma). Participating centers will be those that offer, through the public health system and/or supplementary health system, surgical treatment for patients under 18 years of age with posterior fossa tumor. Patients who were initially treated for hydrocephalus in an external center may be included, provided that all necessary information for inclusion in the study is available. Patients will be excluded from the study if they have lesions in sites other than the posterior fossa as the main focus, patients who have previously undergone surgical resection of posterior fossa tumors, patients without hydrocephalus associated with posterior fossa tumor, patients with posterior fossa tumors and hydrocephalus who will not undergo surgical resection of the lesion (for example, diffuse intrinsic pontine glioma), or cases in which only biopsy of the lesion is considered, patients who refuse to participate in the study, and patients whose data regarding hydrocephalus and its characterization cannot be recovered with the level of detail necessary for the study. RESULTS Participant recruitment will occur through spontaneous demand and may take place in the immediate postoperative period of the hydrocephalus surgery, but it must occur, without exception, in the preoperative period for the tumor surgery, requiring the signing of the Informed Consent Form. Data collection will occur according to the child’s routine clinical care. OUTCOME ASSESSMENT The primary outcome of this study will be the number of reintervention surgeries for the treatment of hydrocephalus after the index surgery for hydrocephalus treatment, which will be chosen at the discretion of each participating center and the attending physician responsible for the patient’s initial treatment. A) Login and password that each center receives to begin the data entry. B) Selection of the research arm. C) and D) an overview of the data used. A separate confidential record will be maintained with the identifying information — full name of the patient and legal guardian, date of birth, sex, ethnicity, identifying number of the participating center, local hospital record, and REDCap ID — to ensure that duplication of patients in the study does not occur. In the preoperative survey, the following information will be collected: (Table 1 ) Table 1 – Information on preoperative variables. Variable Definition / Categories Patient identification number Unique patient code Age In years Date of birth dd/mm/yyyy Date of diagnosis Date of the initial exam (CT, MRI, or transfontanellar ultrasound) documenting posterior fossa tumor + hydrocephalus Lesion topography Main location (> 50% of volume): • 4th ventricle • Cerebellar hemisphere • Cerebellar vermis • Cerebellopontine angle • Brainstem Tumor size Largest axial diameter (mm) Histological classification Preoperative diagnosis (if available) + pathological confirmation (e.g., Astrocytoma, Ependymoma, Medulloblastoma, ATRT) Malignancy grade WHO 2021 classification (adjusted after final pathology report) Clinical signs/symptoms E.g.: headache, vomiting, dizziness, gait disturbance, diplopia, facial palsy, choking, etc. Leptomeningeal spread Leptomeningeal thickening/enhancement on contrast-enhanced MRI Hydrocephalus on imaging Radiological criteria: • Increased Evans index • Temporal horn dilation (> 2 mm) • Ependymal transudation • Ballooning of the 3rd ventricle • “Beaten silver” appearance • Empty sella • Concavity of the 3rd ventricle floor Type of initial intervention ETV, EVD, VPS, or tumor resection + date of procedure For each procedure chosen as a management strategy for hydrocephalus, its particularities will be considered (Table 2 ): Table 2 – Information on the modalities chosen for the treatment of hydrocephalus secondary to posterior fossa tumor. Procedure Specific variables VPS • Location of proximal catheter (frontal/occipital) • Type of valve (fixed, adjustable, flow-regulated) • Brand (national/imported) • Antibiotic impregnation (yes/no) • Distal catheter trimming (yes/no) EVD • Use (pre- or intraoperative) • Location of proximal catheter (frontal/occipital) • Brand (national/imported) • Antibiotic impregnation (yes/no) • Initial height of the system ETV • Type of endoscope (rigid/flexible) • Satisfactory stoma (opening of the 3rd ventricle and Liliequist membrane, visualization of the basilar artery) • Opening instrument (Fogarty 3F/4F/5F, scissors, biopsy forceps) Tumor resection • Surgical approach: midline suboccipital, retrosigmoid, or far-lateral • Without pre/intraoperative implantation of drainage devices During postoperative follow-up, data will be collected regarding the occurrence of postoperative complications associated with the initial surgical procedure (if any), such as (Table 3 ): Table 3 – Postoperative information on complications associated with the surgical procedure. Outcome Definition / Criteria Classification CSF leak CSF leakage through the surgical wound (posterior fossa/ETV). • Simple : resolves spontaneously or with simple measures (pressure bandage, lumbar puncture, suture reinforcement). • Clinically important : continuous leakage, need for dural/skin re-approach or placement of EVD/VPS. Simple / Important Pseudomeningocele Palpable, clinical or radiological subdermal CSF collection. • Simple : improves with puncture/bandaging. • Clinically important : does not improve, causes significant discomfort, wound risk, or requires surgery/EVD/VPS. Simple / Important Surgical site infection ANVISA 2017 criteria. • Superficial incisional : up to 30 days, skin/subcutaneous tissue, criteria of purulent drainage, positive culture or clinical signs. • Deep incisional : up to 30–90 days (with implants), involves fascia/muscle, criteria of drainage, abscess, dehiscence, fever/local signs. Superficial / Deep Meningitis / Ventriculitis ANVISA 2017 criteria. Positive CSF culture OR clinical signs (fever, headache, neck stiffness, irritability) + laboratory/imaging/microbiology changes. Present / Absent Brain / subdural / epidural abscess / Encephalitis ANVISA 2017 criteria. Positive culture, surgical, histopathological or radiological finding; neurological symptoms and positive microbiology. Present / Absent Hyponatremia Na + 145 mg/dL or above laboratory reference, requiring intervention (DDAVP). Present / Absent Subdural hygroma CSF collection over the cerebral convexity, below the dura, on imaging. Present / Absent Intracranial hemorrhage Positive imaging finding. • Simple : no clinical repercussions, no surgery. • Clinically relevant : neurological symptoms + need for surgery. Simple / Relevant CSF hypotension Orthostatic headache, improvement when lying down + imaging findings (small ventricles, collections, venous engorgement). Present / Absent Histological classification WHO 2021 – Tumor malignancy grade. According to WHO Extent of resection • Total: no residual tumor. • Near-total: 1.5 cm³. Total / Near-total / Subtotal Adjuvant treatment Record of start date (CT and/or RT). Date Reinterventions / Additional exams Need for additional exams or subsequent surgeries, with documentation of type, date, reason, and hospitalization time. Details Death Date and relation to hydrocephalus or tumor. Date Tumor surgery date When different from initial hydrocephalus treatment. Date Time intervals Between initial treatment, tumor surgery, and start of adjuvant therapy. Days/months Failure of initial treatment Need for new surgeries for hydrocephalus or related death. Time to failure Ascending transtentorial herniation Imaging evidence or neurological worsening after EVD. Present / Absent New tumor hemorrhage New hemorrhagic focus after EVD/VPS/ETV (imaging or clinical). Present / Absent Qualitative assessment of the operative field 0–10 scale for two aspects: • Neural relaxation (0 = no relaxation, transdural herniation; 10 = complete relaxation, adequate space for manipulation). • Cerebellar quality (0 = extremely friable/bleeding; 10 = not friable, not bleeding). Score (0–10) Cerebellar mutism / Posterior fossa syndrome Diagnosis when criteria A and B1 (mutism) are present, or, in the absence of B1, when A + B2 + C or D are fulfilled. Criterion A: Acquired cerebellar lesion (e.g., postoperative or stroke) with symptoms in the following criteria, appearing up to 2 weeks after injury. Criterion B: Speech/language deficits: • B1 Mutism : total inability to speak. • B2 Impaired language : short phrases (single words or 2–3-word phrases), agrammatism, atypical rhythm (slow, scanning, ballistic) and/or anomia. Criterion C: Emotional/affective changes: irritability, emotional lability, or flat affect. Criterion D: Motor dysfunction: apraxia, ataxia, dysmetria, hypokinesia, or hemiparesis. Present / Absent SAMPLE SIZE CALCULATION Considering the difficulty in establishing what would be the precise number of patients to have statistical power to analyze the combined outcome of this study, we used as a basis the study by Dewan, M. et al. [ 18 ], which analyzed, in a multicenter retrospective study, a total of 241 patients over a period of 13 years, with the smallest patient group having 58 cases. Therefore, we considered a minimum sample of 100 patients for each intervention group, and while the smallest group has not reached this minimum number, we will continue including patients in the other groups. STATISTICAL ANALYSIS For the statistical analysis of categorical variables, we will use the Chi-square test or Fisher’s exact test, as appropriate. Quantitative variables will be compared using Student’s t test, Mann–Whitney test, or one-way ANOVA, as needed. We will opt for parametric tests when the samples prove to originate from a population with normal distribution according to the Kolmogorov–Smirnov test. We will consider α = 0.05 to characterize statistical significance. Data analysis and graph creation will be performed using GraphPad Prism version 10.1.1 for Mac, GraphPad Software, Boston, Massachusetts, USA. DISCUSSION The discussion regarding the safest and most efficient drainage method, and when to perform it (before, during, after tumor resection, or whether to simply monitor hydrocephalus after resection without the need for perioperative diversion), remains controversial in the literature [ 11 – 15 ], since each method presents characteristic advantages and disadvantages that also depend on hospital infrastructure [ 7 ]. Several studies reported in the literature are restricted to a single center [ 3 , 7 , 8 , 12 – 17 ], and most are limited by the small number of participants [ 18 ]. Thus, multicenter, prospective, and randomized studies in this area are necessary [ 9 , 11 , 18 ]. Described in 1923 by William Mixter [ 19 ], endoscopic third ventriculostomy provides the benefits of treating hydrocephalus at presentation and reducing its incidence after resection, in addition to avoiding the placement of drains and enabling tumor resection under low intracranial pressure conditions [ 3 , 6 ]. Moreover, the procedure reduces intraoperative and late complications associated with EVD and VPS placement and promotes the “physiological” restoration of cerebrospinal fluid circulation [ 17 ]. However, it is a procedure that may be associated with complications such as hemorrhage, bradycardia, hemiparesis, memory dysfunction, diabetes insipidus, epilepsy, infection, and fistula [ 17 ]. Tamburrini G et al. [ 20 ], in a study conducted with 30 children, reported that factors such as extent of tumor resection, degree of hydrocephalus, histology, and tumor location were not associated with ETV success. Srinivasan et al. [ 8 ] recommended the procedure only in cases of symptomatic hydrocephalus and reported a higher failure rate associated with ependymoma. VPS is one of the alternatives for the treatment of hydrocephalus [ 21 ]. However, it may present complications such as infection, ascites, visceral perforation, hemorrhage, and peritonitis [ 17 ], as well as other rarer complications such as device migration or extrusion [ 22 ]. Metastatic cell dissemination, such as in medulloblastoma, may occur through the VPS catheter [ 23 – 25 ]. In patients under 19 years of age with hydrocephalus secondary to posterior fossa tumor, ETV failure occurs earlier when compared to VPS, although cumulative failure is lower with ETV (21%) than with VPS (29%) [ 26 ]. In the study conducted by El-Gaidi et al. [ 12 ], after VPS placement, 121 (84.6%) of the 214 patients improved from symptoms related to increased ICP, 27 (12.6%) showed no changes after VPS, and 6 deteriorated neurologically. Among the 87 patients who underwent ETV, only 60 (67%) presented ICP improvement. Regarding EVD, we know that it instantly reduces ICP and enables its monitoring visually, without the uncertainty resulting from other temporizing procedures [ 7 ], and is used for rapid control of elevated ICP [ 23 ]. However, EVD use is considered a risk factor for permanent hydrocephalus [ 9 ] and is correlated with complications. Helmbold LJ et al. [ 25 ] correlated the procedure with the occurrence of wound dehiscence and CSF leakage, while Verhey LH et al. [ 11 ] reported a higher incidence of postoperative cranial nerve deficits and contraindicated the routine use of intraoperative adjunctive EVD in patients with stable hydrocephalus. Furthermore, in the study by Krause et al. [ 9 ], EVD use carried a threefold risk for subsequent ETV or VPS in children older than 2 years and was not shown to be more effective than surgery alone for controlling ventricular enlargement. Hedrich C et al. [ 7 ], when analyzing 114 patients retrospectively, found low rates of infection (lower than those reported in the literature), CSF leakage, and absence of wound dehiscence and pseudomeningocele, thus considering EVD a safe and effective procedure. Helmbold LJ et al. [ 25 ] did not find a significant correlation between the procedure and meningitis or pseudomeningocele. Patient selection for EVD placement remains challenging and must be clarified through prospective multicenter analyses [ 11 ]. Our hypothesis is that endoscopic third ventriculostomy may be one of the most effective strategies for the treatment of hydrocephalus secondary to posterior fossa tumors. The present study proposes to conduct a multicenter and prospective analysis of hydrocephalus treatment procedures in order to elucidate factors such as efficiency, mortality and infection rates, associated risk factors, and the timing of such methods (preoperative or postoperative), thereby contributing to addressing this controversy in the literature. Declarations FUNDING This study did not receive any specific financial support from public, commercial, or non-profit funding agencies. Author Contribution M.D.S.C. and P.C.N. were responsible for study conception and design, development of the research protocol, and drafting of the original manuscript.T.N.A.A.G., G.Á.G.C., B.Á.M., W.L.P., T.C.S.M., F.S., and P.A.D. contributed to study coordination, supervision of data collection, critical revision of the manuscript for important intellectual content, and correspondence with participating centers.P.R.J.R., C.E.B.J., B.O.L., T.P.C., G.M.F., P.T.H.F., M.V.S., G.S., I.V.F., M.S., R.R., E.F., S.M.R., V.Y., E.P., S.A., C.M., A.K.M., E.S., R.A.G., J.W.J.B., A.V.G., C.F., R.A.D., and G.M. served as local center investigators, contributing to patient recruitment, data acquisition, and implementation of the study protocol at their respective institutions.S.C. provided senior oversight of the study, contributed to protocol refinement, and critically reviewed the manuscript.All authors reviewed and approved the final version of the manuscript and agree to be accountable for all aspects of the work, ensuring its accuracy and integrity. 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Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 15 Mar, 2026 Reviewers invited by journal 04 Mar, 2026 Editor assigned by journal 19 Jan, 2026 Submission checks completed at journal 19 Jan, 2026 First submitted to journal 15 Jan, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8614229","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Method Article","associatedPublications":[],"authors":[{"id":602225002,"identity":"56f8f5ce-e072-47bd-a80e-ef87c963e737","order_by":0,"name":"Marcos Devanir Silva Costa","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA/0lEQVRIiWNgGAWjYEgAfhCRUECMUjYoLdkA0mJAihaDA2ASt0Ld9rMPP3z4YycnP7/52YOPbffkjM+vTvzwwIBBnl/sAFYtZmfSjSVntiUbGxxjMzec2VZsbHbj7WYJoMMMZ85OwK7lQBobM2/DgcQNbAxm0rxtCYnbbpzdANKSYHAbh5bzz9iYef4cSJzfxv5N+i9Qy+YZZzf/wKvlBtAWHrYDiQ3HeMykGYFaNvD3bsNvy41nzFC/5JRJ9pxLMJa4wbvNIsFAArdfzqcxQkKs+fg2iR9lCXL8/Wc33/xRYSPPL41dCxYgAVYpQaxyEOA/QIrqUTAKRsEoGAEAAOG2Xi687yzxAAAAAElFTkSuQmCC","orcid":"","institution":"Federal University of São Paulo","correspondingAuthor":true,"prefix":"","firstName":"Marcos","middleName":"Devanir Silva","lastName":"Costa","suffix":""},{"id":602225004,"identity":"c069af13-2c33-44a9-9d44-fbaf7ca82b63","order_by":1,"name":"Paloam Cardoso Nôvo","email":"","orcid":"","institution":"Federal University of São Paulo","correspondingAuthor":false,"prefix":"","firstName":"Paloam","middleName":"Cardoso","lastName":"Nôvo","suffix":""},{"id":602225006,"identity":"afec3810-dcac-421f-9acf-8a5a366789b6","order_by":2,"name":"Thaís Neri Andrade Almeida Garcia","email":"","orcid":"","institution":"Federal University of São Paulo","correspondingAuthor":false,"prefix":"","firstName":"Thaís","middleName":"Neri Andrade Almeida","lastName":"Garcia","suffix":""},{"id":602225016,"identity":"1be4dbcf-df20-42b7-b65a-62cd98582dc6","order_by":3,"name":"Guilherme Ávila Girotto de Camargo","email":"","orcid":"","institution":"Federal University of São Paulo","correspondingAuthor":false,"prefix":"","firstName":"Guilherme","middleName":"Ávila Girotto","lastName":"de Camargo","suffix":""},{"id":602225018,"identity":"1c034e7e-c8d5-4e0e-9bcd-47e1d3a1fc78","order_by":4,"name":"Bruna de Ávila Medeiros","email":"","orcid":"","institution":"Federal University of São Paulo","correspondingAuthor":false,"prefix":"","firstName":"Bruna","middleName":"de Ávila","lastName":"Medeiros","suffix":""},{"id":602225024,"identity":"8499a3b7-1266-4dfd-be0b-624aad031da3","order_by":5,"name":"Paulo Ronaldo Jube Ribeiro","email":"","orcid":"","institution":"Hospital das Clínicas da Faculdade de Medicina da UFG","correspondingAuthor":false,"prefix":"","firstName":"Paulo","middleName":"Ronaldo Jube","lastName":"Ribeiro","suffix":""},{"id":602225028,"identity":"4a307cae-2028-45c5-aa7c-e56aa4446ef7","order_by":6,"name":"Carlos Eduardo Barros Juca","email":"","orcid":"","institution":"Hospital Infantil Albert Sabin","correspondingAuthor":false,"prefix":"","firstName":"Carlos","middleName":"Eduardo Barros","lastName":"Juca","suffix":""},{"id":602225034,"identity":"fdc5bef1-fce4-4f91-9e2c-c1b0bd4d0608","order_by":7,"name":"Benicio Oton de Lima","email":"","orcid":"","institution":"Hospital da Criança de Brasília","correspondingAuthor":false,"prefix":"","firstName":"Benicio","middleName":"Oton","lastName":"de Lima","suffix":""},{"id":602225035,"identity":"823a220f-8baf-4fab-8606-e69affa689fc","order_by":8,"name":"Tatiana Protzenko Cervante","email":"","orcid":"","institution":"Instituto Fernandes Figueira - 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Paulo","correspondingAuthor":false,"prefix":"","firstName":"Wagner","middleName":"Lazaretto","lastName":"Padua","suffix":""},{"id":602225082,"identity":"4615fa5b-e448-4d1e-915a-02a69dcaab6f","order_by":31,"name":"Thais Cristina Souza Melo","email":"","orcid":"","institution":"Federal University of São Paulo","correspondingAuthor":false,"prefix":"","firstName":"Thais","middleName":"Cristina Souza","lastName":"Melo","suffix":""},{"id":602225086,"identity":"3fe7299c-f85f-4376-9211-aeff2921dd86","order_by":32,"name":"Fernando Suzuki","email":"","orcid":"","institution":"Federal University of São Paulo","correspondingAuthor":false,"prefix":"","firstName":"Fernando","middleName":"","lastName":"Suzuki","suffix":""},{"id":602225092,"identity":"c11649aa-4034-45b0-9598-76150769fd7d","order_by":33,"name":"Patrícia Alessandra Dastoli","email":"","orcid":"","institution":"Federal University of São Paulo","correspondingAuthor":false,"prefix":"","firstName":"Patrícia","middleName":"Alessandra","lastName":"Dastoli","suffix":""},{"id":602225095,"identity":"b6fe2483-c5e9-4af8-b4c0-c7a1cbc56d98","order_by":34,"name":"Sergio Cavalheiro","email":"","orcid":"","institution":"Federal University of São Paulo","correspondingAuthor":false,"prefix":"","firstName":"Sergio","middleName":"","lastName":"Cavalheiro","suffix":""}],"badges":[],"createdAt":"2026-01-16 01:23:06","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8614229/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8614229/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":104374053,"identity":"cf6c20d8-3c29-4aab-a30b-357f1f1dccbf","added_by":"auto","created_at":"2026-03-11 06:05:14","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":183730,"visible":true,"origin":"","legend":"\u003cp\u003eRepresentative screenshot of the online registry (\u003ca href=\"https://redcap.unifesp.br/\" target=\"_new\"\u003ehttps://redcap.unifesp.br/\u003c/a\u003e), referring to the general data entry and the patient’s inclusion in the study.\u003cbr\u003e\nA) Login and password that each center receives to begin the data entry. B) Selection of the research arm. C) and D) an overview of the data used.\u003c/p\u003e","description":"","filename":"Picture1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8614229/v1/7d642c076db469b327165867.jpg"},{"id":104405376,"identity":"23780c14-f101-4bd0-b884-bf4a84dd1c3e","added_by":"auto","created_at":"2026-03-11 12:22:44","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1093997,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8614229/v1/cdd93843-2e80-4585-ba72-f7ab740f7d88.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"PITCH registry study design: Pediatric Infratentorial Tumors – Related Complications of Hydrocephalus. Observational, prospective, multicenter study evaluating mortality, infection rate, and number of surgeries associated with the treatment of hydrocephalus secondary to infratentorial tumors in childhood and adolescence","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eAmong all childhood cancers, central nervous system (CNS) tumors account for 20.7%, second only to leukemias; however, among solid tumors, they are the most common, and of these, infratentorial tumors represent 60% of cases [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Posterior fossa tumors are associated with hydrocephalus [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e], specifically non-communicating hydrocephalus, since most of these tumors cause direct or indirect obstruction of the fourth ventricle and/or its outflow pathways [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn a study of 117 children with posterior fossa tumors, Culey et al. [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e] reported hydrocephalus in 83% of the patients. Dias MS et al. [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e] concluded that one quarter to one third of infants with posterior fossa tumors were associated with hydrocephalus requiring diversion.\u003c/p\u003e \u003cp\u003eAlthough it may be intuitive to think that obstructive hydrocephalus can be treated with tumor resection, several factors predispose to persistent hydrocephalus after tumor removal: young age, preoperative hydrocephalus, midline tumor location, metastases, subtotal resection, tumor pathology, use of external ventricular drains, and postoperative complications [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThere are several clinical contexts related to the treatment of hydrocephalus secondary to posterior fossa tumors; therefore, various management strategies for hydrocephalus secondary to infratentorial tumors have been described, such as endoscopic third ventriculostomy (ETV), ventriculoperitoneal shunt (VPS), external ventricular drainage (EVD), or direct resection of the lesion without other diversion methods [\u003cspan additionalcitationids=\"CR8 CR9\" citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. However, each of these strategies has risks and benefits associated with the therapeutic decision made for each patient, and part of the difficulty in choosing a safer treatment method is due to the multiple outcomes selected in studies with different methodologies, making comparison between studies and between hydrocephalus treatment methods very difficult.\u003c/p\u003e \u003cp\u003eThus, with the collaborative effort presented, we defined the need for a multicenter prospective study on the main types of treatment for hydrocephalus caused by posterior fossa tumors in children. The PITCH study aims to compare the different treatment modalities for obstructive hydrocephalus secondary to posterior fossa tumors (ETV, EVD, VPS, resection), considering mortality and infection rates, the number of surgeries related to hydrocephalus treatment, and its complications in the first year after the first surgery performed to treat hydrocephalus. In addition, to compare the different histological types and treatment modalities and their chances of failure, to compare the interval between the chosen treatment method and the initiation of adjuvant therapy, when performed, after tumor resection surgery, and to compare the length of hospitalization related to the treatment of hydrocephalus and its complications among the different treatment methods (ETV, EVD, VPS, tumor resection).\u003c/p\u003e"},{"header":"METHODS","content":"\u003cp\u003eA non-concurrent, prospective, multicenter, controlled cohort study will be conducted to evaluate the outcomes of the different treatment modalities for hydrocephalus secondary to posterior fossa tumors (ETV, EVD, VPS, tumor resection), considering: mortality rate, surgical site infection and device-associated infection, number of surgeries related to hydrocephalus, and its complications in the first year after the first surgery performed to treat hydrocephalus. The study is approved by the scientific committee of the Instituto de Oncologia Pedi\u0026aacute;trica IOP/GRAACC and by the ethics committee of the Federal University of S\u0026atilde;o Paulo (UNIFESP), as well as by all ethics committees of the participating centers. Patients will be included in the study after obtaining the Free and Informed Consent Form (FICF) from their legal guardians and the Assent Form (AF) from patients under 18 years of age with a diagnosis of hydrocephalus secondary to posterior fossa tumor, confirmed through imaging exams (computed tomography (CT) and magnetic resonance imaging (MRI)) and who will undergo surgical resection of the posterior fossa lesion.\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eCHARACTERISTICS OF THE INCLUSION AND EXCLUSION CRITERIA\u003c/h2\u003e \u003cp\u003eThe patients included will be under 18 years old with a diagnosis of hydrocephalus secondary to a primary tumor of the central nervous system (CNS) located in the posterior fossa, characterized by clinical data and radiological imaging (CT or MRI).\u003c/p\u003e \u003cp\u003eHydrocephalus secondary to posterior fossa tumor will be characterized when the patient presents a tumor in the posterior fossa causing obstruction of cerebrospinal fluid circulation and enlargement of the lateral ventricles and third ventricle, with such enlargement documented by imaging exams such as cranial CT or MRI, which must identify, in addition to ventricular enlargement, the presence of enlargement of the temporal horns of the lateral ventricles (\u0026gt;\u0026thinsp;2 mm) and transependymal edema in the frontal and/or occipital horns of the lateral ventricles. In addition, the patient must present signs and symptoms related to increased intracranial pressure (ICP), such as headache, irritability, vomiting, strabismus and/or unilateral or bilateral sixth cranial nerve palsy, papilledema, bradycardia, arterial hypertension, and altered level of consciousness (drowsiness, stupor, or coma).\u003c/p\u003e \u003cp\u003eParticipating centers will be those that offer, through the public health system and/or supplementary health system, surgical treatment for patients under 18 years of age with posterior fossa tumor. Patients who were initially treated for hydrocephalus in an external center may be included, provided that all necessary information for inclusion in the study is available.\u003c/p\u003e \u003cp\u003ePatients will be excluded from the study if they have lesions in sites other than the posterior fossa as the main focus, patients who have previously undergone surgical resection of posterior fossa tumors, patients without hydrocephalus associated with posterior fossa tumor, patients with posterior fossa tumors and hydrocephalus who will not undergo surgical resection of the lesion (for example, diffuse intrinsic pontine glioma), or cases in which only biopsy of the lesion is considered, patients who refuse to participate in the study, and patients whose data regarding hydrocephalus and its characterization cannot be recovered with the level of detail necessary for the study.\u003c/p\u003e \u003c/div\u003e"},{"header":"RESULTS","content":"\u003cp\u003eParticipant recruitment will occur through spontaneous demand and may take place in the immediate postoperative period of the hydrocephalus surgery, but it must occur, without exception, in the preoperative period for the tumor surgery, requiring the signing of the Informed Consent Form. Data collection will occur according to the child\u0026rsquo;s routine clinical care.\u003c/p\u003e\n\u003ch3\u003eOUTCOME ASSESSMENT\u003c/h3\u003e\n\u003cp\u003eThe primary outcome of this study will be the number of reintervention surgeries for the treatment of hydrocephalus after the index surgery for hydrocephalus treatment, which will be chosen at the discretion of each participating center and the attending physician responsible for the patient\u0026rsquo;s initial treatment.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eA) Login and password that each center receives to begin the data entry. B) Selection of the research arm. C) and D) an overview of the data used.\u003c/p\u003e \u003cp\u003eA separate confidential record will be maintained with the identifying information \u0026mdash; full name of the patient and legal guardian, date of birth, sex, ethnicity, identifying number of the participating center, local hospital record, and REDCap ID \u0026mdash; to ensure that duplication of patients in the study does not occur.\u003c/p\u003e \u003cp\u003eIn the preoperative survey, the following information will be collected: (Table \u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e)\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003e\u0026ndash; Information on preoperative variables.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDefinition / Categories\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePatient identification number\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eUnique patient code\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eIn years\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDate of birth\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003edd/mm/yyyy\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDate of diagnosis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDate of the initial exam (CT, MRI, or transfontanellar ultrasound) documenting posterior fossa tumor\u0026thinsp;+\u0026thinsp;hydrocephalus\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLesion topography\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMain location (\u0026gt;\u0026thinsp;50% of volume):\u003c/p\u003e \u003cp\u003e\u0026bull; 4th ventricle\u003c/p\u003e \u003cp\u003e\u0026bull; Cerebellar hemisphere\u003c/p\u003e \u003cp\u003e\u0026bull; Cerebellar vermis\u003c/p\u003e \u003cp\u003e\u0026bull; Cerebellopontine angle\u003c/p\u003e \u003cp\u003e\u0026bull; Brainstem\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTumor size\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLargest axial diameter (mm)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHistological classification\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePreoperative diagnosis (if available)\u0026thinsp;+\u0026thinsp;pathological confirmation (e.g., Astrocytoma, Ependymoma, Medulloblastoma, ATRT)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMalignancy grade\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eWHO 2021 classification (adjusted after final pathology report)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eClinical signs/symptoms\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eE.g.: headache, vomiting, dizziness, gait disturbance, diplopia, facial palsy, choking, etc.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLeptomeningeal spread\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLeptomeningeal thickening/enhancement on contrast-enhanced MRI\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHydrocephalus on imaging\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRadiological criteria:\u003c/p\u003e \u003cp\u003e\u0026bull; Increased Evans index\u003c/p\u003e \u003cp\u003e\u0026bull; Temporal horn dilation (\u0026gt;\u0026thinsp;2 mm)\u003c/p\u003e \u003cp\u003e\u0026bull; Ependymal transudation\u003c/p\u003e \u003cp\u003e\u0026bull; Ballooning of the 3rd ventricle\u003c/p\u003e \u003cp\u003e\u0026bull; \u0026ldquo;Beaten silver\u0026rdquo; appearance\u003c/p\u003e \u003cp\u003e\u0026bull; Empty sella\u003c/p\u003e \u003cp\u003e\u0026bull; Concavity of the 3rd ventricle floor\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eType of initial intervention\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eETV, EVD, VPS, or tumor resection\u0026thinsp;+\u0026thinsp;date of procedure\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eFor each procedure chosen as a management strategy for hydrocephalus, its particularities will be considered (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e):\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003e\u0026ndash; Information on the modalities chosen for the treatment of hydrocephalus secondary to posterior fossa tumor.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProcedure\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSpecific variables\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVPS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026bull; Location of proximal catheter (frontal/occipital)\u003c/p\u003e \u003cp\u003e\u0026bull; Type of valve (fixed, adjustable, flow-regulated)\u003c/p\u003e \u003cp\u003e\u0026bull; Brand (national/imported)\u003c/p\u003e \u003cp\u003e\u0026bull; Antibiotic impregnation (yes/no)\u003c/p\u003e \u003cp\u003e\u0026bull; Distal catheter trimming (yes/no)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEVD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026bull; Use (pre- or intraoperative)\u003c/p\u003e \u003cp\u003e\u0026bull; Location of proximal catheter (frontal/occipital)\u003c/p\u003e \u003cp\u003e\u0026bull; Brand (national/imported)\u003c/p\u003e \u003cp\u003e\u0026bull; Antibiotic impregnation (yes/no)\u003c/p\u003e \u003cp\u003e\u0026bull; Initial height of the system\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eETV\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026bull; Type of endoscope (rigid/flexible)\u003c/p\u003e \u003cp\u003e\u0026bull; Satisfactory stoma (opening of the 3rd ventricle and Liliequist membrane, visualization of the basilar artery)\u003c/p\u003e \u003cp\u003e\u0026bull; Opening instrument (Fogarty 3F/4F/5F, scissors, biopsy forceps)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTumor resection\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026bull; Surgical approach: midline suboccipital, retrosigmoid, or far-lateral\u003c/p\u003e \u003cp\u003e\u0026bull; Without pre/intraoperative implantation of drainage devices\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eDuring postoperative follow-up, data will be collected regarding the occurrence of postoperative complications associated with the initial surgical procedure (if any), such as (Table \u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e):\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003e\u0026ndash; Postoperative information on complications associated with the surgical procedure.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOutcome\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDefinition / Criteria\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eClassification\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCSF leak\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCSF leakage through the surgical wound (posterior fossa/ETV).\u003c/p\u003e \u003cp\u003e\u0026bull; \u003cem\u003eSimple\u003c/em\u003e: resolves spontaneously or with simple measures (pressure bandage, lumbar puncture, suture reinforcement).\u003c/p\u003e \u003cp\u003e\u0026bull; \u003cem\u003eClinically important\u003c/em\u003e: continuous leakage, need for dural/skin re-approach or placement of EVD/VPS.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSimple / Important\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePseudomeningocele\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePalpable, clinical or radiological subdermal CSF collection.\u003c/p\u003e \u003cp\u003e\u0026bull; \u003cem\u003eSimple\u003c/em\u003e: improves with puncture/bandaging. \u0026bull; \u003cem\u003eClinically important\u003c/em\u003e: does not improve, causes significant discomfort, wound risk, or requires surgery/EVD/VPS.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSimple / Important\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSurgical site infection\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eANVISA 2017 criteria.\u003c/p\u003e \u003cp\u003e\u0026bull; \u003cem\u003eSuperficial incisional\u003c/em\u003e: up to 30 days, skin/subcutaneous tissue, criteria of purulent drainage, positive culture or clinical signs.\u003c/p\u003e \u003cp\u003e\u0026bull; \u003cem\u003eDeep incisional\u003c/em\u003e: up to 30\u0026ndash;90 days (with implants), involves fascia/muscle, criteria of drainage, abscess, dehiscence, fever/local signs.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSuperficial / Deep\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMeningitis / Ventriculitis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eANVISA 2017 criteria. Positive CSF culture OR clinical signs (fever, headache, neck stiffness, irritability)\u0026thinsp;+\u0026thinsp;laboratory/imaging/microbiology changes.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePresent / Absent\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBrain / subdural / epidural abscess / Encephalitis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eANVISA 2017 criteria. Positive culture, surgical, histopathological or radiological finding; neurological symptoms and positive microbiology.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePresent / Absent\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHyponatremia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNa\u0026thinsp;+\u0026thinsp;\u0026lt;\u0026thinsp;135 mg/dL or below laboratory reference, requiring intervention (fluid restriction/NaCl).\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePresent / Absent\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHypernatremia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNa\u0026thinsp;+\u0026thinsp;\u0026gt;\u0026thinsp;145 mg/dL or above laboratory reference, requiring intervention (DDAVP).\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePresent / Absent\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSubdural hygroma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCSF collection over the cerebral convexity, below the dura, on imaging.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePresent / Absent\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIntracranial hemorrhage\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePositive imaging finding.\u003c/p\u003e \u003cp\u003e\u0026bull; \u003cem\u003eSimple\u003c/em\u003e: no clinical repercussions, no surgery. \u0026bull; \u003cem\u003eClinically relevant\u003c/em\u003e: neurological symptoms\u0026thinsp;+\u0026thinsp;need for surgery.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSimple / Relevant\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCSF hypotension\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOrthostatic headache, improvement when lying down +\u0026thinsp;imaging findings (small ventricles, collections, venous engorgement).\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePresent / Absent\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHistological classification\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eWHO 2021 \u0026ndash; Tumor malignancy grade.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAccording to WHO\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eExtent of resection\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026bull; Total: no residual tumor.\u003c/p\u003e \u003cp\u003e\u0026bull; Near-total: \u0026lt; 1.5 cm\u0026sup3;.\u003c/p\u003e \u003cp\u003e\u0026bull; Subtotal: \u0026gt; 1.5 cm\u0026sup3;.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eTotal / Near-total / Subtotal\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAdjuvant treatment\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRecord of start date (CT and/or RT).\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDate\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eReinterventions / Additional exams\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNeed for additional exams or subsequent surgeries, with documentation of type, date, reason, and hospitalization time.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDetails\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDeath\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDate and relation to hydrocephalus or tumor.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDate\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTumor surgery date\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eWhen different from initial hydrocephalus treatment.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDate\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTime intervals\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBetween initial treatment, tumor surgery, and start of adjuvant therapy.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDays/months\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFailure of initial treatment\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNeed for new surgeries for hydrocephalus or related death.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eTime to failure\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAscending transtentorial herniation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eImaging evidence or neurological worsening after EVD.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePresent / Absent\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNew tumor hemorrhage\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNew hemorrhagic focus after EVD/VPS/ETV (imaging or clinical).\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePresent / Absent\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eQualitative assessment of the operative field\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u0026ndash;10 scale for two aspects:\u003c/p\u003e \u003cp\u003e\u0026bull; Neural relaxation (0\u0026thinsp;=\u0026thinsp;no relaxation, transdural herniation; 10\u0026thinsp;=\u0026thinsp;complete relaxation, adequate space for manipulation).\u003c/p\u003e \u003cp\u003e\u0026bull; Cerebellar quality (0\u0026thinsp;=\u0026thinsp;extremely friable/bleeding; 10\u0026thinsp;=\u0026thinsp;not friable, not bleeding).\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eScore (0\u0026ndash;10)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCerebellar mutism / Posterior fossa syndrome\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDiagnosis when criteria A and B1 (mutism) are present, or, in the absence of B1, when A\u0026thinsp;+\u0026thinsp;B2\u0026thinsp;+\u0026thinsp;C or D are fulfilled.\u003c/p\u003e \u003cp\u003eCriterion A: Acquired cerebellar lesion (e.g., postoperative or stroke) with symptoms in the following criteria, appearing up to 2 weeks after injury.\u003c/p\u003e \u003cp\u003eCriterion B: Speech/language deficits:\u003c/p\u003e \u003cp\u003e\u0026bull;\u003cem\u003eB1 Mutism\u003c/em\u003e: total inability to speak.\u003c/p\u003e \u003cp\u003e\u0026bull;\u003cem\u003eB2 Impaired language\u003c/em\u003e: short phrases (single words or 2\u0026ndash;3-word phrases), agrammatism, atypical rhythm (slow, scanning, ballistic) and/or anomia. Criterion C: Emotional/affective changes: irritability, emotional lability, or flat affect. Criterion D: Motor dysfunction: apraxia, ataxia, dysmetria, hypokinesia, or hemiparesis.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePresent / Absent\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e\n\u003ch3\u003eSAMPLE SIZE CALCULATION\u003c/h3\u003e\n\u003cp\u003eConsidering the difficulty in establishing what would be the precise number of patients to have statistical power to analyze the combined outcome of this study, we used as a basis the study by Dewan, M. et al. [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e], which analyzed, in a multicenter retrospective study, a total of 241 patients over a period of 13 years, with the smallest patient group having 58 cases. Therefore, we considered a minimum sample of 100 patients for each intervention group, and while the smallest group has not reached this minimum number, we will continue including patients in the other groups.\u003c/p\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eSTATISTICAL ANALYSIS\u003c/h2\u003e \u003cp\u003eFor the statistical analysis of categorical variables, we will use the Chi-square test or Fisher\u0026rsquo;s exact test, as appropriate. Quantitative variables will be compared using Student\u0026rsquo;s t test, Mann\u0026ndash;Whitney test, or one-way ANOVA, as needed. We will opt for parametric tests when the samples prove to originate from a population with normal distribution according to the Kolmogorov\u0026ndash;Smirnov test. We will consider α\u0026thinsp;=\u0026thinsp;0.05 to characterize statistical significance. Data analysis and graph creation will be performed using GraphPad Prism version 10.1.1 for Mac, GraphPad Software, Boston, Massachusetts, USA.\u003c/p\u003e \u003c/div\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eThe discussion regarding the safest and most efficient drainage method, and when to perform it (before, during, after tumor resection, or whether to simply monitor hydrocephalus after resection without the need for perioperative diversion), remains controversial in the literature [\u003cspan additionalcitationids=\"CR12 CR13 CR14\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e], since each method presents characteristic advantages and disadvantages that also depend on hospital infrastructure [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eSeveral studies reported in the literature are restricted to a single center [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan additionalcitationids=\"CR13 CR14 CR15 CR16\" citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e], and most are limited by the small number of participants [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Thus, multicenter, prospective, and randomized studies in this area are necessary [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eDescribed in 1923 by William Mixter [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e], endoscopic third ventriculostomy provides the benefits of treating hydrocephalus at presentation and reducing its incidence after resection, in addition to avoiding the placement of drains and enabling tumor resection under low intracranial pressure conditions [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eMoreover, the procedure reduces intraoperative and late complications associated with EVD and VPS placement and promotes the \u0026ldquo;physiological\u0026rdquo; restoration of cerebrospinal fluid circulation [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. However, it is a procedure that may be associated with complications such as hemorrhage, bradycardia, hemiparesis, memory dysfunction, diabetes insipidus, epilepsy, infection, and fistula [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eTamburrini G et al. [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e], in a study conducted with 30 children, reported that factors such as extent of tumor resection, degree of hydrocephalus, histology, and tumor location were not associated with ETV success. Srinivasan et al. [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e] recommended the procedure only in cases of symptomatic hydrocephalus and reported a higher failure rate associated with ependymoma.\u003c/p\u003e \u003cp\u003eVPS is one of the alternatives for the treatment of hydrocephalus [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. However, it may present complications such as infection, ascites, visceral perforation, hemorrhage, and peritonitis [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e], as well as other rarer complications such as device migration or extrusion [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eMetastatic cell dissemination, such as in medulloblastoma, may occur through the VPS catheter [\u003cspan additionalcitationids=\"CR24\" citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. In patients under 19 years of age with hydrocephalus secondary to posterior fossa tumor, ETV failure occurs earlier when compared to VPS, although cumulative failure is lower with ETV (21%) than with VPS (29%) [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn the study conducted by El-Gaidi et al. [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e], after VPS placement, 121 (84.6%) of the 214 patients improved from symptoms related to increased ICP, 27 (12.6%) showed no changes after VPS, and 6 deteriorated neurologically. Among the 87 patients who underwent ETV, only 60 (67%) presented ICP improvement.\u003c/p\u003e \u003cp\u003eRegarding EVD, we know that it instantly reduces ICP and enables its monitoring visually, without the uncertainty resulting from other temporizing procedures [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], and is used for rapid control of elevated ICP [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. However, EVD use is considered a risk factor for permanent hydrocephalus [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] and is correlated with complications.\u003c/p\u003e \u003cp\u003eHelmbold LJ et al. [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e] correlated the procedure with the occurrence of wound dehiscence and CSF leakage, while Verhey LH et al. [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e] reported a higher incidence of postoperative cranial nerve deficits and contraindicated the routine use of intraoperative adjunctive EVD in patients with stable hydrocephalus. Furthermore, in the study by Krause et al. [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], EVD use carried a threefold risk for subsequent ETV or VPS in children older than 2 years and was not shown to be more effective than surgery alone for controlling ventricular enlargement.\u003c/p\u003e \u003cp\u003eHedrich C et al. [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], when analyzing 114 patients retrospectively, found low rates of infection (lower than those reported in the literature), CSF leakage, and absence of wound dehiscence and pseudomeningocele, thus considering EVD a safe and effective procedure. Helmbold LJ et al. [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e] did not find a significant correlation between the procedure and meningitis or pseudomeningocele. Patient selection for EVD placement remains challenging and must be clarified through prospective multicenter analyses [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eOur hypothesis is that endoscopic third ventriculostomy may be one of the most effective strategies for the treatment of hydrocephalus secondary to posterior fossa tumors. The present study proposes to conduct a multicenter and prospective analysis of hydrocephalus treatment procedures in order to elucidate factors such as efficiency, mortality and infection rates, associated risk factors, and the timing of such methods (preoperative or postoperative), thereby contributing to addressing this controversy in the literature.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eFUNDING\u003c/h2\u003e \u003cp\u003eThis study did not receive any specific financial support from public, commercial, or non-profit funding agencies.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eM.D.S.C. and P.C.N. were responsible for study conception and design, development of the research protocol, and drafting of the original manuscript.T.N.A.A.G., G.\u0026Aacute;.G.C., B.\u0026Aacute;.M., W.L.P., T.C.S.M., F.S., and P.A.D. contributed to study coordination, supervision of data collection, critical revision of the manuscript for important intellectual content, and correspondence with participating centers.P.R.J.R., C.E.B.J., B.O.L., T.P.C., G.M.F., P.T.H.F., M.V.S., G.S., I.V.F., M.S., R.R., E.F., S.M.R., V.Y., E.P., S.A., C.M., A.K.M., E.S., R.A.G., J.W.J.B., A.V.G., C.F., R.A.D., and G.M. served as local center investigators, contributing to patient recruitment, data acquisition, and implementation of the study protocol at their respective institutions.S.C. provided senior oversight of the study, contributed to protocol refinement, and critically reviewed the manuscript.All authors reviewed and approved the final version of the manuscript and agree to be accountable for all aspects of the work, ensuring its accuracy and integrity.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003e-Gurney JG, Severson RK, Davis S, Robison LL (1995) Incidence of cancer in children in the United States: sex-, race-, and 1-year age-specific rates by histologic type. 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Basic Clin Neurosci. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.32598/BCN.9.10.285\u003c/span\u003e\u003cspan address=\"10.32598/BCN.9.10.285\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"childs-nervous-system","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"cnsy","sideBox":"Learn more about [Child's Nervous System](http://link.springer.com/journal/381)","snPcode":"381","submissionUrl":"https://submission.nature.com/new-submission/381/3","title":"Child's Nervous System","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Endoscopic third ventriculostomy, Ventriculoperitoneal shunt, External ventricular drainage, Treatment outcomes","lastPublishedDoi":"10.21203/rs.3.rs-8614229/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8614229/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eIntroduction: Posterior fossa tumors are the main pediatric solid neoplasms, and more than 60% of these tumors are associated with the occurrence of hydrocephalus, which can be treated through different strategies, such as endoscopic third ventriculostomy (ETV), ventriculoperitoneal shunt (VPS), external ventricular drainage (EVD), or direct resection of the lesion without other diversion methods. The safest and most efficient drainage method remains controversial, and several studies are limited to a single center, with retrospective analysis, most of them compromised by the limited number of participants, so multicenter and prospective studies are necessary to understand what would be the best treatment strategy.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eMethods: This is a non-concurrent, prospective, multicenter cohort study conducted in more than twenty pediatric neurosurgery centers in Latin America, in which patients will be divided into 4 groups according to the chosen treatment for hydrocephalus (ETV, EVD, VPS, and resection), and mortality and infection rates, the number of surgeries related to hydrocephalus treatment, and its complications in the first year of hydrocephalus treatment will be analyzed. Patients will be followed prospectively for up to 12 months after the index surgery, which will be considered the surgery performed for the treatment of hydrocephalus, and each group will include at least 100 patients.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eConclusion: The online REDCap platform will be used for the records of the PITCH study, which will allow the collection of prospective data in different centers in Latin America, aiming to compare the treatment modalities for obstructive hydrocephalus secondary to posterior fossa tumors (ETV, EVD, VPS, resection) and to evaluate the impact of these treatments in the first year after the diagnosis of hydrocephalus associated with posterior fossa tumor.\u003c/p\u003e","manuscriptTitle":"PITCH registry study design: Pediatric Infratentorial Tumors – Related Complications of Hydrocephalus. Observational, prospective, multicenter study evaluating mortality, infection rate, and number of surgeries associated with the treatment of hydrocephalus secondary to infratentorial tumors in childhood and adolescence","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-03-11 06:05:05","doi":"10.21203/rs.3.rs-8614229/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-03-16T02:23:55+00:00","index":"","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-03-05T03:47:33+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-01-20T04:01:58+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-01-20T04:01:02+00:00","index":"","fulltext":""},{"type":"submitted","content":"Child's Nervous System","date":"2026-01-16T01:05:41+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"childs-nervous-system","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"cnsy","sideBox":"Learn more about [Child's Nervous System](http://link.springer.com/journal/381)","snPcode":"381","submissionUrl":"https://submission.nature.com/new-submission/381/3","title":"Child's Nervous System","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"8eb9f786-b790-4664-bb44-7d0c0c6721b5","owner":[],"postedDate":"March 11th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-04-19T15:24:07+00:00","versionOfRecord":[],"versionCreatedAt":"2026-03-11 06:05:05","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8614229","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8614229","identity":"rs-8614229","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}