Surgery of the Skull Base

The region of the skull base was long considered a surgical barrier because of its complex anatomy. With few exceptions, the region immediately beyond the dura or bony skull base constituted a "no man's land" for the surgeon working from the other direction. A major reason for this was the high morbidity associated with operative procedures in that area using traditional dissection techniques. This situation changed with the advent of the operating microscope. Used initially by ear, nose and throat specialists for resective and reconstructive surgery of the petrous bone and parana sal sinuses, the operating microscope was later introduced in other areas, and neurosurgeons began using it in the mid-1960s. With technical equality thus established, the groundwork was laid for taking a new, systematic, and interdisciplinary approach to surgical problems of the skull base. Intensive and systematic cooperation between ear, nose and throat surgeons and neurologic surgeons had its origins in the departments of the University of Mainz bindly supported by our chairmen Prof. Dr. Dr. hc Kurt Schiirmann (Department of Neurosurgery) and Prof. Dr. W. Kley (Depart­ ment of Ear, Nose and Throat Diseases, Head and Neck Surgery). The experience gained from this cooperation was taught in workshops held in Hannover from 1979 to 1986, acquiring a broader interdisciplinary base through the participation of specialists from the fields of anatomy, patholo­ gy, neuroradiology, ophthalmology, and maxillofacial surgery.

References.- Surgical Anatomy of the Skull Base (SA).- Anatomy of Malformations of the Anterior Skull Base.- Nasal Fistulas, Nasal Cysts, Meningoceles.- Dermal Sinus.- Gliomas and Encephaloceles.- Anatomy of the Skin and Scalp in the Frontobasal Approach.- Frontal Belly of the Epicranial Muscle.- Nerves.- Arteries.- Veins.- Frontal Squama and Frontal Sinus.- Frontal Sinus Mucosa and Blood Vessels.- Dura Mater of the Anterior Cranial Fossa.- Floor of the Anterior Cranial Fossa.- Olfactory Fossa.- Endofrontal Foveae and Eminence.- Pneumatization.- Anatomy of Optic Nerve Decompression.- Anatomy of the Orbit and Adjacent Skull Base.- Anatomy of the Cavernous Sinus.- Anatomy of the Sellar Region.- Anatomy of the Temporal Fossa.- Anatomy of the Infratemporal Fossa and Infratemporal Plane.- Anatomy of the Temporomandibular Joint.- Anatomy of the Pterygoid Process and Pterygoid Fossa.- Anatomy of the Pterygopalatine Fossa.- Middle Skull Base and Its Openings Viewed from Below.- Anatomy of the Auditory Tube.- Anatomy of the Masticatory Space and Peripharyngeal Space.- General.- Fasciae.- Spaces.- Parapharyngeal Space.- Masticatory Space, Arteries and Nerves.- Anatomy of the Carotid Canal Region.- Anatomy of the Jugular Foramen.- Hypoglossal Nerve.- Accessory Nerve.- Vagus Nerve.- Glossopharyngeal Nerve.- Surgical Importance.- Carotid Sinus Branches.- Parapharyngeal Space.- Arteries.- Common Carotid Artery.- Carotid Bifurcation.- Carotid Triangle and Its Relation to the Carotid Bifurcation.- Cervical Portions of the Internal and External Carotid Arteries.- Carotid Sinus and Carotid Arteries, Diameters.- Carotid Tortuosity.- Primitive Hypoglossic Artery, Postoccipital Artery.- Ascending Pharyngeal Artery.- Veins.- Internal Jugular Vein.- Anatomy of the Middle Cranial Fossa with Reference to the Subtemporal Approach, Transtentorial Approach, and Middle Fossa Approach.- Tentorial Notch.- Arachnoid.- Cerebellopontine Angle.- Abducent Nerve.- Facial Nerve.- Internal Acoustic Meatus.- Vestibulocochlear Nerve.- Glossopharyngeal Nerve.- Glossopharyngeal Neuralgia.- Glossopharyngeal Nerve — Its Course in the Parapharyngeal Space.- Vagus Nerve.- Accessory Nerve.- Hypoglossal Nerve.- Anatomy of the Clivus.- Extracranial Surgical Approaches.- Transoral-Transpalatine Approach.- Occipital Condyles.- Atlas in Adults.- Axis.- Anterior Surface of the Axis.- Atlantodental Joint.- Transverse Ligament of the Atlas.- Cruciform Ligament of the Atlas.- Apical Ligament of the Dens.- Tectorial Membrane.- Anterior and Posterior Longitudinal Ligaments.- Alar Ligament.- Vertebral Artery, Transverse Part.- Vertebral Artery, Axoatlantic Part.- Atlantic Part.- Vertebral Artery, Entry into the Subarachnoid Space.- Arterial Supply of the CNS at the Craniocervical Junction.- Radicular Arteries.- Anterior Spinal Artery.- Posterior Inferior Cerebellar Artery.- References.- Surgery of the Anterior Skull Base (AS).- Surgery of Malformations of the Anterior Skull Base.- Technique for the Surgical Removal of Nasal Fistulas, Cysts, and Meningoceles.- Remarks on Craniofacial Surgery.- References.- Surgery of Traumatic Lesions of the Anterior Skull Base.- Operative Technique.- Principles of Duraplasty in the Region of the Skull Base.- Techniques of Fronto-Orbital Repair of Circumscribed Dural Injuries of the Anterior Skull Base.- Techniques of Duraplasty for Comminuted Fractures of the Anterior Skull Base.- Treatment of Comminuted Fractures of the Lateral Facial Skeleton and Anterolateral Skull Base, Including Dural Injuries.- Decompression of the Optic Nerve After Trauma.- References.- Surgery of Inflammatory Complications in the Region of the Anterior Skull Base.- Treatment.- References.- Surgery of Space-Occupying Lesions of the Anterior Skull Base.- General Operative Techniques.- Extracranial Approach to the Anterior Skull Base.- Intracranial Approach to the Anterior Skull Base.- Combined Intra- and Extracranial (Craniofacial) Approach to the Anterior Skull Base.- Surgery of Space-Occupying Lesions of the Orbit and Adjacent Skull Base.- Operative Technique.- Special Operative Techniques.- Surgery of Benign Space-Occupying Lesions of the Anterior Skull Base.- Surgery of Malignant Space-Occupying Lesions of the Anterior Skull Base.- References.- Surgery of the Middle Skull Base (MS).- Surgery of Traumatic Lesions of the Middle Skull Base.- Surgical Approaches for Middle Skull Base Trauma.- Craniectomy (Extended Burr Hole Trephination).- Osteoplastic Craniotomy in Trauma.- Therapeutic Options in Carotid-Cavernous Fistula.- Transtemporal Extradural Approach to the Anterior Surface of the Petrous Pyramid and Internal Auditory Canal.- The Transmastoid Translabyrinthine Approach.- References.- Surgery of Inflammatory Disorders of the Middle Skull Base.- Principles for Cholesteatoma Removal.- Surgical Treatment of Otogenic Jugular Vein-Sigmoid Sinus-Transverse Sinus Thrombosis.- Otogenic Brain Abscess.- Surgical Treatment of Skull Base Osteomyelitis Associated with Necrotizing Otitis Externa.- References.- Surgery of Space-Occupying Lesions of the Middle Skull Base.- Surgery of Space-Occupying Lesions of the Sellar Region.- General Operative Techniques.- Special Operative Techniques.- References.- Surgery of Space-Occupying Lesions of the Lateral Middle Skull Base.- General Operative Techniques.- Special Operative Techniques.- References.- Surgery of the Posterior Skull Base (PS).- Surgery of the Internal Auditory Canal and Cerebellopontine Angle.- General Operative Techniques.- The Transtemporal Extradural Approach.- The Transmastoid Translabyrinthine Approach.- The Lateral Suboccipital (Retrosigmoid) Approach.- Special Operative Techniques.- Procedures on the Nerves of the Internal Auditory Canal and Cerebellopontine Angle.- Tumors of the Internal Auditory Canal and Cerebellopontine Angle.- Acoustic Neuroma.- Meningiomas of the Cerebellopontine Angle.- Epidermoid Tumor of the Cerebellopontine Angle.- Other Cerebellopontine Angle Tumors.- References.- Surgery of Tumors of the Lateral Posterior Skull Base and Petrous Bone.- General Operative Techniques.- Special Operative Techniques.- Neuromas of the Jugular Foramen and Hypoglossal Nerve.- Glomus Tumors.- References.- On the Problem of Paralytic Dysphagia Caused by Posterior Skull Base Tumors.- The Denecke Operation to Restore Swallowing and Speech in Unilateral Vagus Nerve Paralysis.- References.- Surgery of the Clivus (CL).- General Operative Techniques.- Extracranial Approaches.- Transsphenoidal Approach.- Transoral Approach.- Transcervical Approach.- Lateral Infratemporal Approach.- Posteroinferior Approach.- Intracranial Approaches to the Clivus.- Transfrontal Approach.- Frontotemporal, Subtemporal Approach to the Clivus.- Lateral Suboccipital Approach to the Clivus.- Medial Suboccipital Approach.- Combined Supra- and Infratentorial Approach to the Clivus.- References.- Surgery of the Craniocervical Junction (C J).- Operative Technique.- Ablative Procedures for Lesions of the Craniocervical Junction.- Transoral Approach.- Transcervical Approach.- Medial Suboccipital Approach.- Procedures to Stabilize the Craniocervical Junction.- Operative Techniques.- References.- Facial Nerve and Skull Base Surgery (FN).- General Operative Techniques.- Surgical Approaches to the Different Facial Nerve Segments.- Obtaining Grafts for Nerve Reconstruction.- Operative Technique.- Technique of Nerve Suture.- Operative Technique.- Special Operative Techniques.- Decompression of the Facial Nerve.- Operative Technique.- Methods of Direct Facial Nerve Reconstruction.- End-to-End Anastomosis in the Cerebellopontine Angle.- Intracranial-Extracranial Anastomosis.- Intracranial-Intratemporal Anastomosis.- Meatal Anastomosis.- Tympano-Mastoid Reconstruction.- Intratemporal-Extratemporal Reconstruction.- Intratemporal-Extratemporal Facial Nerve Reconstruction After Subtotal Petrosectomy and Total Parotidectomy Including Facial Nerve Resection.- Extratemporal Facial Nerve Reconstruction.- Methods of Indirect Facial Nerve Reconstruction.- Technique of Hypoglossal-Facial Anastomosis.- Technique of Faciofacial Anastomosis.- Secondary Plastic Surgery Measures for Facial Rehabilitation.- Operative Techniques.- References.