Endonasal Endoscopic Approaches to the Paramedian Skull Base

• Published in: World neurosurgery 2014-12, Vol.82 (6), p.S121-S129
• Main Authors: de Lara, Danielle, Ditzel Filho, Leo F.S, Prevedello, Daniel M, Carrau, Ricardo L, Kasemsiri, Pornthep, Otto, Bradley A, Kassam, Amin B
• Format: Article
• Language: English
• Subjects: Endonasal approach; Endoscopy; Endoscopy - adverse effects; Endoscopy - methods; Humans; Infratemporal fossa; Middle cranial fossa; Nasal Cavity - anatomy & histology; Nasal Cavity - surgery; Neurosurgery; Neurosurgical Procedures - adverse effects; Neurosurgical Procedures - methods; Posterior fossa; Postoperative Complications - epidemiology; Postoperative Complications - therapy; Pterygopalatine fossa; Skull base; Skull Base - anatomy & histology; Skull Base - surgery
• ISSN: 1878-8750; 1878-8769
• DOI: 10.1016/j.wneu.2014.07.036

Objective To describe the technical and anatomic nuances related to endoscopic endonasal approaches (EEAs) to the paramedian skull base. Methods Surgical indications, limitations, and technical aspects pertaining to EEAs designed to access areas oriented in the coronal plane are systematically reviewed with special attention to caveats, pitfalls, and common complications and how to avoid them. Case examples are presented. Results The paramedian skull base may be divided into anterior (corresponding to the orbit and its contents), middle (corresponding to the middle cranial, pterygopalatine, and infratemporal fossae), and posterior (includes the craniovertebral junction lateral to the occipital condyles and the jugular foramen) segments. EEAs to the anterior segment offer access to the intraconal orbital space and the optic canal. A transpterygoid corridor typically precedes EEAs to the middle and posterior paramedian approaches. EEAs to the middle segment provide wide exposure of the petrous apex, middle cranial fossa (including cavernous sinus and Meckel cave), and infratemporal and pterygopalatine fossae. Finally, EEAs to the posterior segment access the hypoglossal canal, occipital condyle, and jugular foramen. Conclusions Approaches to the paramedian skull base are the most challenging and complex of all endoscopic endonasal techniques. Because of their technical complexity, it is recommended that surgeons master endoscopic endonasal anatomic approaches oriented to median structures (sagittal plane) before approaching paramedian (coronal plane) pathologies.