Neuroendoscopic Transventricular Approach for Prepontine Biopsy in a Child: A Minimally Invasive Route to Skull Base Pathology. Technical Note

Neuroendoscopic Transventricular Approach for Prepontine Biopsy in a Child: A Minimally Invasive Route to Skull Base Pathology. Technical Note | 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 Case Report Neuroendoscopic Transventricular Approach for Prepontine Biopsy in a Child: A Minimally Invasive Route to Skull Base Pathology. Technical Note Jose Javier Guil-Ibañez, Mario Gomar-Alba, Fernando García-Pérez, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7255232/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract We present the case of an 8-year-old female patient with a large skull base lesion presenting clinically with signs of increased intracranial pressure and obstructive hydrocephalus. Due to the lesion’s location and associated hydrocephalus, a minimally invasive neuronavigated intraventricular biopsy was performed via the prepontine cistern. Institutional review board approval was obtained. Legal guardians provided consent for the procedure and use of the patient's image. The operating surgeon also consented to the use of their image in the video. This approach allowed for safe tissue sampling while simultaneously addressing cerebrospinal fluid circulation impairment through endoscopic third ventriculostomy. The case highlights the feasibility and efficacy of combining intraventricular neuroendoscopy with neuronavigation for managing complex skull base lesions in pediatric patients. Minimally invasive intraventricular biopsy techniques guided by neuronavigation have been reported in the literature as valuable tools for obtaining diagnostic tissue in challenging anatomical locations while minimizing morbidity. Moreover, endoscopic third ventriculostomy remains a standard intervention for obstructive hydrocephalus, especially when performed concomitantly with lesion biopsy to optimize patient outcomes. Our report adds to this growing body of evidence by demonstrating successful application in a pediatric skull base tumor with significant mass effect. This case underscores the importance of a tailored, multidisciplinary approach combining advanced neuroendoscopic techniques and neuronavigation to improve diagnostic accuracy and therapeutic safety in complex neurosurgical cases. Skull Base Endoscopic Third Ventriculostomy Hydrocephalus Paediatric Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction Tumors involving the skull base and posterior fossa in the pediatric population are uncommon and can pose significant diagnostic and surgical challenges, especially when deeply located or extending across compartments. In these cases, timely tissue diagnosis is essential for treatment planning. When such lesions obstruct cerebrospinal fluid (CSF) pathways, as in cases with prepontine extension, they can cause life-threatening hydrocephalus requiring urgent intervention. Minimally invasive neuroendoscopic procedures allow direct access to deep midline structures with reduced brain retraction and morbidity 1-2 . When combined with neuronavigation, these approaches offer precise targeting for biopsy and the opportunity to manage associated hydrocephalus 3,4 . We report a case of a pediatric patient who underwent neuronavigation-guided endoscopic biopsy of a large skull base lesion through a transventricular-translaminar terminalis approach, with resolution of hydrocephalus and histopathological diagnosis of a clear cell meningioma. Case Example An 8-year-old girl was admitted to the emergency department with a several-week history of progressive headache and daytime somnolence. There was no prior history of neurological disease or trauma. Ophthalmological examination revealed bilateral papilledema. Brain MRI revealed a large extra-axial lesion centered in the right cerebellopontine angle with extension into the sellar and parasellar regions, causing anterior brainstem compression and obstructive triventricular hydrocephalus (Figure 1) . Due to the diagnostic uncertainty and symptomatic hydrocephalus, a decision was made to perform a neuronavigation-assisted endoscopic biopsy. The goal was both to obtain a histopathological diagnosis and relieve hydrocephalus via CSF flow restoration. Surgical Technique (Video 1) Under general anesthesia, the patient was placed supine with the head in a neutral position. Electromagnetic neuronavigation was used to plan the optimal trajectory to the third ventricle and tuber cinereum (Figure 2) . A left frontal burr hole was placed anterior to Kocher’s point to allow a trajectory toward the floor of the third ventricle and prepontine cistern. A rigid neuroendoscope was advanced into the lateral ventricle, through the foramen of Monro into the third ventricle. The tuber cinereum was identified and gently perforated using blunt dissection to access the prepontine cistern. A sample of the lesion was obtained using endoscopic biopsy forceps under direct visualization (Figure 3) . CSF flow from the third ventricle to the prepontine cistern was confirmed intraoperatively, resulting in immediate decompression of the ventricles. Hemostasis was achieved with irrigation, and the endoscope was removed. No intraoperative complications occurred. An external ventricular drain was placed as a safety measure. It always remained closed, with continuous intracranial pressure monitoring, and was removed the day after surgery. The postoperative course was uneventful, imaging studies revealed no complications and confirmed ostomy patency (Figure 4) and the patient was discharged pending histopathological results to determine the need for adjuvant treatment. Histopathological Findings Histological analysis revealed a clear cell meningioma (WHO grade II). Immunohistochemistry was positive for EMA and vimentin, consistent with meningothelial origin. Ki-67 proliferation index was low. Given the histological diagnosis and imaging characteristics, a second-stage microsurgical resection was scheduled. Discussion This case illustrates the utility of a neuronavigation-assisted endoscopic transventricular approach for the management of deep-seated skull base lesions in pediatric patients. The approach allowed for both effective treatment of obstructive hydrocephalus and minimally invasive acquisition of tissue for histological diagnosis. The transventricular trans-tuber cinereum route provides safe access to the prepontine and interpeduncular cisterns, particularly useful when lesions extend to these regions. In this case, early biopsy was essential due to the broad differential diagnosis of skull base lesions in children, which includes atypical meningiomas, chordomas, chondrosarcomas, and germ cell tumors. Clear cell meningioma is a rare histologic subtype, more common in pediatric populations and associated with a higher recurrence rate, underscoring the importance of early and accurate diagnosis. Endoscopic biopsy not only allowed for histological confirmation but also addressed CSF flow obstruction, avoiding the need for temporary or permanent CSF diversion. Conclusion Neuronavigation-assisted endoscopic transventricular biopsy via the tuber cinereus is a safe and effective technique in pediatric patients with deep parasellar extra-axial lesionsand associated obstructive hydrocephalus. It allows for accurate histological diagnosis and restores physiological CSF pathways, reducing the need for shunt placement. This approach should be considered in complex skull base tumors where minimal invasiveness and early diagnosis are essential for therapeutic decision-making. Abbreviations CSF: cerebrospinal fluid Declarations COMPLIANCE WITH ETHICAL STANDARDS: Details of previous presentation(s): The authors declare that this manuscript has not been previously published in whole or in part or submitted elsewhere for review. Disclosure of funding: No funding was received to assist with the preparation of the manuscript. Disclosure of financial support, and industry affiliations: Authors declare that they have no personal or institutional financial interest in drugs, materials, or devices described in their submissions. Conflict of interest/Competing interests: The authors declare that they have no conflict of interest to declare that are relevant to the content of this article. Ethics approval: All procedures performed in the studies involving human participants were in accordance with ethical standards of the institutional and national research committee and with the 1964 Helsinki Declaration and its later amendments. Consent to participate and consent for publication: Informed consent to participate and for publication was obtained from all individual participants included in the study. Written informed consent was obtained from the parents as legal guardians. References Lee, H. J., & Park, J. S. (2020). Neuronavigation-assisted intraventricular biopsy for deep-seated brain lesions: Outcomes and technical considerations. Neurosurgical Review, 43(1), 147–154. Smith, R. A., Thompson, E. B., & Davis, K. M. (2018). Endoscopic biopsy of skull base lesions using neuronavigation guidance: A case series. Operative Neurosurgery, 14(3), 221–227. Johnson, M. L., Roberts, D. T., & Evans, P. R. (2017). Endoscopic third ventriculostomy combined with tumor biopsy in pediatric hydrocephalus: A clinical series. Journal of Neurosurgery: Pediatrics, 20(4), 365–372. Kumar, S., & Gupta, N. (2019). Minimally invasive neuroendoscopic techniques for skull base tumors: A review. World Neurosurgery, 129, 12–20. Additional Declarations No competing interests reported. Supplementary Files FinalVideoBlinded.mp4 Video 1. 2D Operative Video Cite Share Download PDF Status: Posted Version 1 posted 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-7255232","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":520244293,"identity":"ed0dd1ea-3632-4179-8276-7bf7037feb3d","order_by":0,"name":"Jose Javier Guil-Ibañez","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA/ElEQVRIiWNgGAWjYBACxgYgIcHAwMPG3nzA4AOQw8ZOrBY+nmMJhTNAWpiJtU5OIsfgMw+IRUgLc3v7wwcWNYdl2CRyDDfb/Nomz8fMwPjhYw4eh/WcMTaQOHaYh43nWbFxbt9twzZmBmbJmdvwaJmRwyYhwZYG9H7yNuPcntuMQC1szLx4taQ//yHxD6iFIcH8t2XPbXsitCSYMUi22fCwcaQYGDP8uJ1IWAvQLxKSfUAtwEA27G24ndzGzNiM1y+GwBD7LPFNwl6+HRiVP/7ctp3f3nzww0d8WhqAAS0Bt7MNTDbgVg8E8iAlH+DcP3gVj4JRMApGwQgFABE1TESITo6HAAAAAElFTkSuQmCC","orcid":"","institution":"Complejo Hospitalario Torrecárdenas","correspondingAuthor":true,"prefix":"","firstName":"Jose","middleName":"Javier","lastName":"Guil-Ibañez","suffix":""},{"id":520244294,"identity":"ab35f798-2bd4-4d36-8132-7cfd2df072f7","order_by":1,"name":"Mario Gomar-Alba","email":"","orcid":"","institution":"Complejo Hospitalario Torrecárdenas","correspondingAuthor":false,"prefix":"","firstName":"Mario","middleName":"","lastName":"Gomar-Alba","suffix":""},{"id":520244295,"identity":"dea5e292-1da1-4fe9-8331-e2a84b4e6eca","order_by":2,"name":"Fernando García-Pérez","email":"","orcid":"","institution":"Complejo Hospitalario Torrecárdenas","correspondingAuthor":false,"prefix":"","firstName":"Fernando","middleName":"","lastName":"García-Pérez","suffix":""},{"id":520244297,"identity":"829aefc5-be17-41d4-a990-8193014cd5ae","order_by":3,"name":"Antonio Huete-Allut","email":"","orcid":"","institution":"Complejo Hospitalario Torrecárdenas","correspondingAuthor":false,"prefix":"","firstName":"Antonio","middleName":"","lastName":"Huete-Allut","suffix":""}],"badges":[],"createdAt":"2025-07-30 17:08:22","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7255232/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7255232/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":92280331,"identity":"cc86298f-c3ef-442e-941a-0d4c4ca114e4","added_by":"auto","created_at":"2025-09-26 16:09:36","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":107702,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003ePreoperative imaging studies. A-B\u003c/strong\u003e: Preoperative CT scan. \u003cstrong\u003eC-D\u003c/strong\u003e: Preoperative MRI\u003c/p\u003e","description":"","filename":"Figure1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7255232/v1/8ec5857995105d1616ab996b.jpg"},{"id":92280332,"identity":"d4aa2fbd-035c-4b9e-86f8-c9a0a3befbc4","added_by":"auto","created_at":"2025-09-26 16:09:36","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":108794,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003ePlanning and Neuronavigation. A\u003c/strong\u003e: Trajectory planning using a neuronavigation system. \u003cstrong\u003eB\u003c/strong\u003e: Neuronavigated entry into the ventricular system using a trocar\u003c/p\u003e","description":"","filename":"Figure2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7255232/v1/b0483f54590aab196d56404a.jpg"},{"id":92280818,"identity":"0be1955a-0a66-440b-b2fe-89a0d0aeadb7","added_by":"auto","created_at":"2025-09-26 16:17:36","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":110233,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eImages of the neuroendoscopic procedure. A\u003c/strong\u003e: Left lateral ventricle entry. \u003cstrong\u003eB\u003c/strong\u003e: Left lateral ventricle. \u003cstrong\u003eC\u003c/strong\u003e: Third ventricle entry \u003cstrong\u003eD\u003c/strong\u003e: Opening of the tuber cinereum with visualization of the lesion in the parasellar región E: Vascular structures and subarachnoid membranes of the prepontine cistern F: Sampling of the lesión\u003c/p\u003e","description":"","filename":"Figure3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7255232/v1/81d64e46d302c07aef959e1a.jpg"},{"id":92280333,"identity":"1c0a6d70-152f-4b72-88b6-62033d205172","added_by":"auto","created_at":"2025-09-26 16:09:36","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":98729,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003ePostoperative imaging studies. A-B\u003c/strong\u003e: Pre- and postoperative CT scans showed no evidence of surgical complications. There was a reduction in ventricular size with the presence of an external ventricular drain as a safety measure. \u003cstrong\u003eC-D\u003c/strong\u003e: Pre- and postoperative MRI showed patency of the ostomy.\u003c/p\u003e","description":"","filename":"Figure4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7255232/v1/37939b186fcae4df53c87bb4.jpg"},{"id":92356707,"identity":"df992cda-5a85-47b4-a168-888dd7bf7c21","added_by":"auto","created_at":"2025-09-28 14:38:44","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":820111,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7255232/v1/1513a3c6-a6f4-4b62-aebe-c3d7a941526d.pdf"},{"id":92280527,"identity":"e9be80b8-e8f9-487e-b54c-7faed4d7c07a","added_by":"auto","created_at":"2025-09-26 16:10:01","extension":"mp4","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":539954061,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eVideo 1. 2D Operative Video\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"FinalVideoBlinded.mp4","url":"https://assets-eu.researchsquare.com/files/rs-7255232/v1/a9bd8b8924e8e74b075bf7b8.mp4"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eNeuroendoscopic Transventricular Approach for Prepontine Biopsy in a Child: A Minimally Invasive Route to Skull Base Pathology. Technical Note\u003c/p\u003e","fulltext":[{"header":"Introduction","content":"\u003cp\u003eTumors involving the skull base and posterior fossa in the pediatric population are uncommon and can pose significant diagnostic and surgical challenges, especially when deeply located or extending across compartments. In these cases, timely tissue diagnosis is essential for treatment planning. When such lesions obstruct cerebrospinal fluid (CSF) pathways, as in cases with prepontine extension, they can cause life-threatening hydrocephalus requiring urgent intervention.\u003c/p\u003e\n\u003cp\u003eMinimally invasive neuroendoscopic procedures allow direct access to deep midline structures with reduced brain retraction and morbidity\u003csup\u003e1-2\u003c/sup\u003e. When combined with neuronavigation, these approaches offer precise targeting for biopsy and the opportunity to manage associated hydrocephalus\u003csup\u003e3,4\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eWe report a case of a pediatric patient who underwent neuronavigation-guided endoscopic biopsy of a large skull base lesion through a transventricular-translaminar terminalis approach, with resolution of hydrocephalus and histopathological diagnosis of a clear cell meningioma.\u003c/p\u003e"},{"header":"Case Example","content":"\u003cp\u003eAn 8-year-old girl was admitted to the emergency department with a several-week history of progressive headache and daytime somnolence. There was no prior history of neurological disease or trauma. Ophthalmological examination revealed bilateral papilledema. Brain MRI revealed a large extra-axial lesion centered in the right cerebellopontine angle with extension into the sellar and parasellar regions, causing anterior brainstem compression and obstructive triventricular hydrocephalus \u003cstrong\u003e(Figure 1)\u003c/strong\u003e.\u003c/p\u003e\n\u003cp\u003eDue to the diagnostic uncertainty and symptomatic hydrocephalus, a decision was made to perform a neuronavigation-assisted endoscopic biopsy. The goal was both to obtain a histopathological diagnosis and relieve hydrocephalus via CSF flow restoration.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSurgical Technique (Video 1)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eUnder general anesthesia, the patient was placed supine with the head in a neutral position. Electromagnetic neuronavigation was used to plan the optimal trajectory to the third ventricle and tuber cinereum \u003cstrong\u003e(Figure 2)\u003c/strong\u003e. A left frontal burr hole was placed anterior to Kocher\u0026rsquo;s point to allow a trajectory toward the floor of the third ventricle and prepontine cistern.\u003c/p\u003e\n\u003cp\u003eA rigid neuroendoscope was advanced into the lateral ventricle, through the foramen of Monro into the third ventricle. The tuber cinereum was identified and gently perforated using blunt dissection to access the prepontine cistern. A sample of the lesion was obtained using endoscopic biopsy forceps under direct visualization \u003cstrong\u003e(Figure 3)\u003c/strong\u003e.\u003c/p\u003e\n\u003cp\u003eCSF flow from the third ventricle to the prepontine cistern was confirmed intraoperatively, resulting in immediate decompression of the ventricles. Hemostasis was achieved with irrigation, and the endoscope was removed. No intraoperative complications occurred. An external ventricular drain was placed as a safety measure. It always remained closed, with continuous intracranial pressure monitoring, and was removed the day after surgery. The postoperative course was uneventful, imaging studies revealed no complications and confirmed ostomy patency \u003cstrong\u003e(Figure 4)\u003c/strong\u003e and the patient was discharged pending histopathological results to determine the need for adjuvant treatment.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eHistopathological Findings\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eHistological analysis revealed a clear cell meningioma (WHO grade II). Immunohistochemistry was positive for EMA and vimentin, consistent with meningothelial origin. Ki-67 proliferation index was low. Given the histological diagnosis and imaging characteristics, a second-stage microsurgical resection was scheduled.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis case illustrates the utility of a neuronavigation-assisted endoscopic transventricular approach for the management of deep-seated skull base lesions in pediatric patients. The approach allowed for both effective treatment of obstructive hydrocephalus and minimally invasive acquisition of tissue for histological diagnosis.\u003c/p\u003e\n\u003cp\u003eThe transventricular trans-tuber cinereum route provides safe access to the prepontine and interpeduncular cisterns, particularly useful when lesions extend to these regions. In this case, early biopsy was essential due to the broad differential diagnosis of skull base lesions in children, which includes atypical meningiomas, chordomas, chondrosarcomas, and germ cell tumors.\u003c/p\u003e\n\u003cp\u003eClear cell meningioma is a rare histologic subtype, more common in pediatric populations and associated with a higher recurrence rate, underscoring the importance of early and accurate diagnosis. Endoscopic biopsy not only allowed for histological confirmation but also addressed CSF flow obstruction, avoiding the need for temporary or permanent CSF diversion.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eNeuronavigation-assisted endoscopic transventricular biopsy via the tuber cinereus is a safe and effective technique in pediatric patients with deep parasellar extra-axial lesionsand associated obstructive hydrocephalus. It allows for accurate histological diagnosis and restores physiological CSF pathways, reducing the need for shunt placement. This approach should be considered in complex skull base tumors where minimal invasiveness and early diagnosis are essential for therapeutic decision-making.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eCSF: cerebrospinal fluid\u0026nbsp;\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eCOMPLIANCE WITH ETHICAL STANDARDS:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eDetails of previous presentation(s): The authors declare that this manuscript has not been previously published in whole or in part or submitted elsewhere for review.\u003c/p\u003e\n\u003cp\u003eDisclosure of funding: No funding was received to assist with the preparation of the manuscript.\u003c/p\u003e\n\u003cp\u003eDisclosure of financial support, and industry affiliations: Authors declare that they have no personal or institutional financial interest in drugs, materials, or devices described in their submissions.\u003c/p\u003e\n\u003cp\u003eConflict of interest/Competing interests: The authors declare that they have no conflict of interest to declare that are relevant to the content of this article.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eEthics approval: All procedures performed in the studies involving human participants were in accordance with ethical standards of the institutional and national research committee and with the 1964 Helsinki Declaration and its later amendments.\u003c/p\u003e\n\u003cp\u003eConsent to participate and consent for publication: Informed consent to participate and for publication was obtained from all individual participants included in the study. Written informed consent was obtained from the parents as legal guardians.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eLee, H. J., \u0026amp; Park, J. S. (2020). Neuronavigation-assisted intraventricular biopsy for deep-seated brain lesions: Outcomes and technical considerations. Neurosurgical Review, 43(1), 147\u0026ndash;154. \u003c/li\u003e\n\u003cli\u003eSmith, R. A., Thompson, E. B., \u0026amp; Davis, K. M. (2018). Endoscopic biopsy of skull base lesions using neuronavigation guidance: A case series. Operative Neurosurgery, 14(3), 221\u0026ndash;227. \u003c/li\u003e\n\u003cli\u003eJohnson, M. L., Roberts, D. T., \u0026amp; Evans, P. R. (2017). Endoscopic third ventriculostomy combined with tumor biopsy in pediatric hydrocephalus: A clinical series. Journal of Neurosurgery: Pediatrics, 20(4), 365\u0026ndash;372. \u003c/li\u003e\n\u003cli\u003eKumar, S., \u0026amp; Gupta, N. (2019). Minimally invasive neuroendoscopic techniques for skull base tumors: A review. World Neurosurgery, 129, 12\u0026ndash;20. \u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Skull Base, Endoscopic Third Ventriculostomy, Hydrocephalus, Paediatric ","lastPublishedDoi":"10.21203/rs.3.rs-7255232/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7255232/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eWe present the case of an 8-year-old female patient with a large skull base lesion presenting clinically with signs of increased intracranial pressure and obstructive hydrocephalus. Due to the lesion’s location and associated hydrocephalus, a minimally invasive neuronavigated intraventricular biopsy was performed via the prepontine cistern. Institutional review board approval was obtained. Legal guardians provided consent for the procedure and use of the patient's image. The operating surgeon also consented to the use of their image in the video. This approach allowed for safe tissue sampling while simultaneously addressing cerebrospinal fluid circulation impairment through endoscopic third ventriculostomy. The case highlights the feasibility and efficacy of combining intraventricular neuroendoscopy with neuronavigation for managing complex skull base lesions in pediatric patients.\u003c/p\u003e\n\u003cp\u003eMinimally invasive intraventricular biopsy techniques guided by neuronavigation have been reported in the literature as valuable tools for obtaining diagnostic tissue in challenging anatomical locations while minimizing morbidity. Moreover, endoscopic third ventriculostomy remains a standard intervention for obstructive hydrocephalus, especially when performed concomitantly with lesion biopsy to optimize patient outcomes. Our report adds to this growing body of evidence by demonstrating successful application in a pediatric skull base tumor with significant mass effect.\u003c/p\u003e\n\u003cp\u003eThis case underscores the importance of a tailored, multidisciplinary approach combining advanced neuroendoscopic techniques and neuronavigation to improve diagnostic accuracy and therapeutic safety in complex neurosurgical cases.\u003c/p\u003e","manuscriptTitle":"Neuroendoscopic Transventricular Approach for Prepontine Biopsy in a Child: A Minimally Invasive Route to Skull Base Pathology. 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