surgical anatomy of skull base
DESCRIPTION
Surgical Anatomy of Skull Base. Dr. Supreet Singh Nayyar, AFMC For more presentations, visit www.nayyarENT.com. Topography of Skull Base. Boundaries : Anterior : Incisors upper teeth Posterior: Superior nuchal line Lateral : Upper lateral teeth Zygomatic arch - PowerPoint PPT PresentationTRANSCRIPT
Surgical Anatomy of Skull Base
Dr. Supreet Singh Nayyar, AFMC
For more presentations, visit www.nayyarENT.com
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Topography of Skull Base Boundaries : Anterior : Incisors upper teeth
Posterior: Superior nuchal line
Lateral : Upper lateral teeth Zygomatic arch Mastoid process
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Anterior Skull Base
Central Skull Base
Posterior Skull Base
Topography of Skull Base
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Skull Base Anatomy Review
Key Openings• Foramen spinosum• Foramen ovale• Foramen lacerum• Foramen rotundum• Foramen magnum• Foramen of vesalius• Jugular foramen
• Superior orbital fissure• Inferior orbital fissure• Optic canal• Vidian canal• Hypoglossal canal• Pterygopalatine fossa
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Skull Base Anatomy Review
Foramen magnum• Medulla oblongata• Vertebral arteries• Anterior/Posterior spinal arteries
Hypoglossal canal• Hypoglossal nerve• Hypoglossal artery
Jugular Foramen• Pars nervosa: CN IX, inferior petrosal sinus• Pars vascularis: CN X, XI, jugular bulb
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Skull Base Anatomy Review
Foramen Spinosum• Middle meningeal artery• Recurrent branch of
mandibular nerve
Foramen Ovale• Mandibular nerve• Accessory meningeal artery• Lesser petrosal nerve• Emissary veins
Foramen of Vesalius• Sphenoidal Emissary vein
Stylomastoid foramen•Facial nerve•Stylomastoid artery
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Skull Base Anatomy Review
Foramen Lacerum• Ascending pharyngeal artery- meningeal branch• Nerve of pterygoid canal
Pterygoid canal• Vidian nerve• Vidian artery
Foramen rotundum• Maxillary nerve• Artery of foramen rotundum• Emissary veins
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Receives: Superior opthalmic veinInferior opthalmic vein Sphenoparietal sinus
Drains via: Petrosal sinuses Basilar plexus Pterygoid plexus
Connection: Circular sinusContains: CN III, IV, V1, V2, VI
Skull Base Anatomy Review
Cavernous Sinus
Meckel’s Cave• Posterior aspect of cavernous sinus• Gasserian ganglion (sensory root ganglion of CN V)
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Skull Base Anatomy Review
Superior Orbital Fissure• CN III, IV, V1, VI• Middle meningeal artery- orbital branch• Recurrent meningeal artery• Superior ophthalmic vein
Inferior Orbital Fissure• Infraorbital artery, vein, and nerve (V2 branch)
Optic Canal• Optic nerve• Ophthalmic artery
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Central Skull Base
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Central Skull Base
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1- Pharyngeal Area2- Tubal Area3- Neurovascular Area
4- Auditory Area5- Articular Area6- Infratemporal Foss
Pharyngeal Area Roof of Nasopharynx
Boundaries of Nasopharynx : * Anterior * Lateral & Posterior * Inferior
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Pharyngeal Area Pharyngobasilar fasia Fossa of Rosenmullar * Location- above & behind medial end ET * Depth- 2.5 cm * Apex- Carotid canal opening (post) & f. ovale, f. spinosum (lat) * Base- below Foramen lacerum
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Tubal AreaEustachian Tube
Scaphoid fossa Runs b/w petrous bone & greater wing sphenoid Opening- nasopharynx Paratubal muscles
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Neurovascular AreaImportant structures are:
Carotid sheath & its contents
Styloid apparatus
Facial Nerve
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Carotid Sheath Compact network of aerolar tissue Carotid canal to arch of aorta Encloses : ICA above & CCA below IJV Vagus nerve Carotid Canal : ICA & Carotid plexus sympathetic nerve Parts of ICA
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Divided into three compartments
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Jugular Foramen
Compartments Contents ( lateral to medial )
Anterior * IX Nerve* Inferior petrosal Sinus
Middle * XI Nerve* X Nerve
Posterior * IJV
Styloid Apparatus
Bone- Styloid bone
Ligaments- * Stylohyoid * Stylomandibular
Muscles- * Stylohoid * Stylopharyngeus * Styloglossus
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Facial Nerve Arise from Stylomastoid Foramen
Branches: i) Post auricular nerve ii) Digastric branch iii) Temporofacial branch iv) Cervicofacial branch
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Auditory Area Petrotympanic fissure of Glaser:
* Chorda tympani
* Ant br of tympanic artery
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Infratemporal Fossa Location : below middle cranial fossa
Boundaries
Contents: * Med & Lat Pterygoid M * Maxillary A * Maxillary V * Pterygoid Venous Plexus * Br of Mandibular N
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Pterygopalatine Fossa Small inverted pyramid shaped fossa
Location
Boundaries
Communications
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Anterior Cranial Base
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Anterior Cranial Base from inside
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Floor of Anterior Cranial Fossa
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Depth of Olfactory fossa (Keros classification)
* Type I – 1-3mm * Type II- 4-7mm * Type III- 8-17mm
Thank you
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