The Experts below are selected from a list of 165 Experts worldwide ranked by ideXlab platform

Kazunori Tanaka - One of the best experts on this subject based on the ideXlab platform.

  • greater superficial petrosal nerve neurinoma case report
    Journal of Neurosurgery, 1999
    Co-Authors: Yoshiaki Kumon, Saburo Sakaki, Shinsuke Ohta, Shiro Ohue, Koh Nakagawa, Kazunori Tanaka
    Abstract:

    The authors report a case of middle cranial fossa neurinoma arising from the left greater superficial petrosal nerve in a 21-year-old woman who presented with a left-sided otitis media that chronically recurred over a period of 5 years. On examination, the patient had a left-sided mild conductive hearing impairment and a slight disturbance in tear secretion on the left side, with sensory disturbance in the left palate. Three-dimensional computerized tomography scans clearly demonstrated the enlargement of the Foramen Lacerum and Foramen ovale, and heavily T2-weighted magnetic resonance images revealed the tumor's location along with the course of the greater superficial petrosal nerve and its extension into the tympanic cavity. Following complete surgical excision of the tumor and tympanoplasty via a middle cranial fossa approach, the patient retained useful hearing without facial palsy.

Eric W Wang - One of the best experts on this subject based on the ideXlab platform.

  • endoscopic endonasal transclival transcondylar approach for Foramen magnum meningiomas surgical anatomy and technical note
    Neurosurgery, 2015
    Co-Authors: Eric W Wang, Paul A Gardner, Carl H Snyderman, Weihsin Wang, Kumar Abhinav, Juan C Fernandezmiranda
    Abstract:

    BACKGROUND: The endoscopic endonasal approach provides a direct route to ventral Foramen magnum (FM) lesions like meningiomas, which are difficult to access. Endonasal access at the FM is limited laterally by the occipital condyles and inferiorly by the C1 anterior arch and the odontoid process, which may need partial resection. OBJECTIVE: We investigated the surgical anatomy and technical nuances for endonasally increasing the surgical corridor at the FM region both laterally and inferiorly. Unique to our report, we quantified the amount of required medial condyle resection to obtain exposure of the lateral aspects of the FM. METHODS: Five fresh human head silicone-injected specimens underwent endonasal inferior transclival, transcondylar approaches. The lateral limit of medial condyle resection was defined using a vertical line extending inferiorly from Foramen Lacerum and its intersection with the occipital condyle. The condylectomy was limited posteriorly by the cortical bone surrounding the hypoglossal canal. The volume of the resected condyle (cubic centimeters) for 10 sides was measured using the pre- and postdissection computed tomography-volumetric analysis. RESULTS: The mean percentage condylar volume resected during a unilateral medial condylectomy was 18% (9.7%-28.3%). The surgical corridor was extended inferiorly in all specimens without violating the transverse ligament by drilling the superior aspects of C1 anterior arch and the exposed odontoid tip. These operative nuances were successfully applied in the operating room. CONCLUSION: Anatomical landmarks can reliably guide an endonasal anteromedial condyle resection. Minimal condyle resection is required to widen lateral access at the FM, which minimizes the risk of craniocervical instability.

  • eustachian tube and internal carotid artery in skull base surgery an anatomical study
    Laryngoscope, 2014
    Co-Authors: Paul A Gardner, Carl H Snyderman, Carlos D Pinheironeto, Juan C Fernandezmiranda, Jianfeng Liu, Barry E Hirsch, Eric W Wang
    Abstract:

    Objectives/Hypothesis The eustachian tube (ET) is an important landmark in skull base surgery, which has a close relationship with the petrous segment of the internal carotid artery (ICA). The goal of the current study was to establish the detailed anatomic relationship of the ET and petrous segment of the ICA. Study Design Anatomical study. Methods Six silicon-injected adult cadaveric heads (12 sides) were dissected using a lateral infratemporal fossa approach (type C) and endoscopic endonasal approach. The ET and ICA were exposed; their detailed relationships were demonstrated. High-quality pictures were obtained. Results In the anterior genu/Foramen Lacerum segment of the ICA, the vidian nerve was an important landmark. The cartilaginous ET was divided into four segments, from anterior to posterior: nasopharyngeal, pterygoid, Lacerum, and petrosal segment. The anterior and inferior wall of the carotid canal was consistently between the horizontal ICA and petrous segment of the cartilaginous ET. In the posterior genu of the ICA, the bony part of the ET, and the tendon of the tensor tympani muscle were paramount landmarks. The posterior genu of the ICA was imbedded in the carotid canal. The landmarks of the junction of the cartilaginous ET and bony ET were the sphenoid spine and Foramen spinosum. Conclusions The anatomical segmentation of the ET provides the basis for safe and effective transection of the ET in skull base surgery. An understanding of the complex relationships of the ET and petrous segment of the ICA is paramount for surgically dealing with disease located within the region of the ET and petrous segment of the ICA. Level of Evidence NA Laryngoscope, 124:2655–2664, 2014

Amin B Kassam - One of the best experts on this subject based on the ideXlab platform.

  • a road map to the internal carotid artery in expanded endoscopic endonasal approaches to the ventral cranial base
    Neurosurgery, 2014
    Co-Authors: Mohamed A Labib, Ricardo L. Carrau, Daniel M Prevedello, Edward E Kerr, Cristian Naudy, Hussam Abou Alshaar, Martin Corsten, Amin B Kassam
    Abstract:

    BACKGROUND: Injuring the internal carotid artery (ICA) is a feared complication of endoscopic endonasal approaches. OBJECTIVE: To introduce a comprehensive ICA classification scheme pertinent to safe endoscopic endonasal cranial base surgery. METHODS: Anatomic dissections were performed in 33 cadaveric specimens (bilateral). Anatomic correlations were analyzed. RESULTS: Based on anatomic correlations, the ICA may be described as 6 distinct segments: (1) parapharyngeal (common carotid bifurcation to ICA Foramen); (2) petrous (carotid canal to posterolateral aspect of Foramen Lacerum); (3) paraclival (posterolateral Foramen Lacerum to the superomedial aspect of the petrous apex); (4) parasellar (superomedial petrous apex to the proximal dural ring); (5) paraclinoid (from the proximal to the distal dural rings); and (6) intradural (distal ring to ICA bifurcation). Corresponding surgical landmarks included the Eustachian tube, the fossa of Rosenmuller, and levator veli palatini for the parapharyngeal segment; the vidian canal and V3 for the petrous segment; the fibrocartilage of Foramen Lacerum, Foramen rotundum, maxillary strut, lingular process of the sphenoid bone, and paraclival protuberance for the paraclival segment; the sellar floor and petrous apex for the parasellar segment; and the medial and lateral opticocarotid and lateral tubercular recesses, as well as the distal osseous arch of the carotid sulcus for the paraclinoid segment. CONCLUSION: The proposed endoscopic classification outlines key anatomic reference points independent of the vessel's geometry or the sinonasal pneumatization, thus serving as (1) a practical guide to navigate the ventral cranial base while avoiding injury to the ICA and (2) further foundation for a modular access system.

Jianfeng Liu - One of the best experts on this subject based on the ideXlab platform.

  • eustachian tube and internal carotid artery in skull base surgery an anatomical study
    Laryngoscope, 2014
    Co-Authors: Paul A Gardner, Carl H Snyderman, Carlos D Pinheironeto, Juan C Fernandezmiranda, Jianfeng Liu, Barry E Hirsch, Eric W Wang
    Abstract:

    Objectives/Hypothesis The eustachian tube (ET) is an important landmark in skull base surgery, which has a close relationship with the petrous segment of the internal carotid artery (ICA). The goal of the current study was to establish the detailed anatomic relationship of the ET and petrous segment of the ICA. Study Design Anatomical study. Methods Six silicon-injected adult cadaveric heads (12 sides) were dissected using a lateral infratemporal fossa approach (type C) and endoscopic endonasal approach. The ET and ICA were exposed; their detailed relationships were demonstrated. High-quality pictures were obtained. Results In the anterior genu/Foramen Lacerum segment of the ICA, the vidian nerve was an important landmark. The cartilaginous ET was divided into four segments, from anterior to posterior: nasopharyngeal, pterygoid, Lacerum, and petrosal segment. The anterior and inferior wall of the carotid canal was consistently between the horizontal ICA and petrous segment of the cartilaginous ET. In the posterior genu of the ICA, the bony part of the ET, and the tendon of the tensor tympani muscle were paramount landmarks. The posterior genu of the ICA was imbedded in the carotid canal. The landmarks of the junction of the cartilaginous ET and bony ET were the sphenoid spine and Foramen spinosum. Conclusions The anatomical segmentation of the ET provides the basis for safe and effective transection of the ET in skull base surgery. An understanding of the complex relationships of the ET and petrous segment of the ICA is paramount for surgically dealing with disease located within the region of the ET and petrous segment of the ICA. Level of Evidence NA Laryngoscope, 124:2655–2664, 2014

Juan C Fernandezmiranda - One of the best experts on this subject based on the ideXlab platform.

  • the modular concept in skull base surgery anatomical basis of the median paramedian and lateral corridors
    Acta bio-medica : Atenei Parmensis, 2021
    Co-Authors: Alice Giotta Lucifero, Juan C Fernandezmiranda, Maximiliano Nunez, Nunzio Bruno, Nicola Tartaglia, Antonio Ambrosi, Gian Luigi Marseglia, R Galzio, Sabino Luzzi
    Abstract:

    Introduction A thorough understanding of skull base anatomy is imperative to perform safely and effectively any skull base approach. In this article, we examine the microsurgical anatomy of the skull base by proposing a modular topographic organization in the median, paramedian, and lateral surgical corridors in relation to transcranial and endoscopic approaches. Methods Five dry skulls were studied focusing on the intracranial and exocranial skull base. Two lines were drawn parallel to the lateral border of the cribriform plate of the ethmoid bone and Foramen Lacerum, respectively. Lines 1 and 2 delimited the median, paramedian and lateral corridors of the skull base. The bony structures that formed each corridor were carefully reviewed in relation to the planning and execution of the skull base transcranial and endoscopic approaches. Results The midline corridor involves the crista galli, cribriform plate, planum and jugum sphenoidale, chiasmatic sulcus, tuberculum sellae, sellar region, dorsum sellae, clivus, and Foramen magnum. The paramedian corridor includes the fovea ethmoidalis, the root of the lesser and greater sphenoid wing, anterior clinoid process, Foramen Lacerum, the upper half of the petro-occipital suture, and jugular tubercle. The lateral corridors include the orbital plates, sphenoid wings, squamosal and petrous parts of the temporal bone, caudal aspect of the petro-occipital suture, internal auditory canal, jugular Foramen, the sulcus of the sigmoid sinus. Conclusion In-depth three-dimensional knowledge of skull base anatomy based on the modular concept of the surgical corridors is critical for the planning and execution of the transcranial and endoscopic approaches.

  • endoscopic endonasal transclival transcondylar approach for Foramen magnum meningiomas surgical anatomy and technical note
    Neurosurgery, 2015
    Co-Authors: Eric W Wang, Paul A Gardner, Carl H Snyderman, Weihsin Wang, Kumar Abhinav, Juan C Fernandezmiranda
    Abstract:

    BACKGROUND: The endoscopic endonasal approach provides a direct route to ventral Foramen magnum (FM) lesions like meningiomas, which are difficult to access. Endonasal access at the FM is limited laterally by the occipital condyles and inferiorly by the C1 anterior arch and the odontoid process, which may need partial resection. OBJECTIVE: We investigated the surgical anatomy and technical nuances for endonasally increasing the surgical corridor at the FM region both laterally and inferiorly. Unique to our report, we quantified the amount of required medial condyle resection to obtain exposure of the lateral aspects of the FM. METHODS: Five fresh human head silicone-injected specimens underwent endonasal inferior transclival, transcondylar approaches. The lateral limit of medial condyle resection was defined using a vertical line extending inferiorly from Foramen Lacerum and its intersection with the occipital condyle. The condylectomy was limited posteriorly by the cortical bone surrounding the hypoglossal canal. The volume of the resected condyle (cubic centimeters) for 10 sides was measured using the pre- and postdissection computed tomography-volumetric analysis. RESULTS: The mean percentage condylar volume resected during a unilateral medial condylectomy was 18% (9.7%-28.3%). The surgical corridor was extended inferiorly in all specimens without violating the transverse ligament by drilling the superior aspects of C1 anterior arch and the exposed odontoid tip. These operative nuances were successfully applied in the operating room. CONCLUSION: Anatomical landmarks can reliably guide an endonasal anteromedial condyle resection. Minimal condyle resection is required to widen lateral access at the FM, which minimizes the risk of craniocervical instability.

  • eustachian tube and internal carotid artery in skull base surgery an anatomical study
    Laryngoscope, 2014
    Co-Authors: Paul A Gardner, Carl H Snyderman, Carlos D Pinheironeto, Juan C Fernandezmiranda, Jianfeng Liu, Barry E Hirsch, Eric W Wang
    Abstract:

    Objectives/Hypothesis The eustachian tube (ET) is an important landmark in skull base surgery, which has a close relationship with the petrous segment of the internal carotid artery (ICA). The goal of the current study was to establish the detailed anatomic relationship of the ET and petrous segment of the ICA. Study Design Anatomical study. Methods Six silicon-injected adult cadaveric heads (12 sides) were dissected using a lateral infratemporal fossa approach (type C) and endoscopic endonasal approach. The ET and ICA were exposed; their detailed relationships were demonstrated. High-quality pictures were obtained. Results In the anterior genu/Foramen Lacerum segment of the ICA, the vidian nerve was an important landmark. The cartilaginous ET was divided into four segments, from anterior to posterior: nasopharyngeal, pterygoid, Lacerum, and petrosal segment. The anterior and inferior wall of the carotid canal was consistently between the horizontal ICA and petrous segment of the cartilaginous ET. In the posterior genu of the ICA, the bony part of the ET, and the tendon of the tensor tympani muscle were paramount landmarks. The posterior genu of the ICA was imbedded in the carotid canal. The landmarks of the junction of the cartilaginous ET and bony ET were the sphenoid spine and Foramen spinosum. Conclusions The anatomical segmentation of the ET provides the basis for safe and effective transection of the ET in skull base surgery. An understanding of the complex relationships of the ET and petrous segment of the ICA is paramount for surgically dealing with disease located within the region of the ET and petrous segment of the ICA. Level of Evidence NA Laryngoscope, 124:2655–2664, 2014