Learning objectives
Provide an overview of the endoscopic expanded endonasal approach (EEA) to the skull base and its applications, with a focus on sella/parasellar lesions Examine the role of imaging in patients who are being considered for EEA Highlight radiographic features critical for surgical planning and intraopertive guidance Present unique findings on post-operative imaging studies after EEA
Background
Rationale Expanded endonasal approach (EEA) is a minimally invasive, endoscopic technique increasingly utilized to allow access to the ventral skull base from crista galli to the odontoid (Fig. 1) and laterally as far as the middle/infratemporal fossae, without disturbing the face or skull. This technique has the advantage of avoiding the retraction or transgression of important neurovascular structures that traditional posterior or lateral approaches cross. Sella and Parasellar Lesions Sella and parasellar lesions are among the most commonly accessed lesions using EEA. Traditional pterional and...
Imaging findings OR Procedure details
Typical Imaging Protocols for EEA Preoperative MRI Axial T1, T2, T2 FLAIR Sagittal T1 Coronal T1, T2 T2 3D FIESTA Post Contrast Axial, Sagittal, Coronal T1 with Fat supression Axial 3D Volume SPGR CT CT Angiogram 1.25mm with sagittal and coronal reconstructions Postoperative MRI Axial T1, T2 FLAIR, GRE Sagittal T1 Post Contrast Axial, Sagittal, Coronal T1 with Fat supression Axial 3D Volume SPGR CT Noncontrast 5mm Intraoperative Imaging An intraoperative navigational system is utilized to register preoperative images with the patient's head position in...
Conclusion
Expanded endonasal approach (EEA) is a new and rapidly evolving minimally invasive technique for treating skull base pathology. Preoperative planning and intraoperative guidance using a combination of CT and MRI helps to identify the relationship of skull base lesions to important neurovascular structures and to the posterior paranasal sinuses. A key anatomic landmark is the medial opticocarotid recess (mOCR), an osseous indentation between the carotid canal and optic canal as viewed from the sphenoid sinus. The mOCR marks the middle clinoid process, the lateral border...
Personal Information
I would like to sincerely thank Dr. William Rothfus for his guidance in the conception and creation of this presentation, Dr. Vikas Agarwal for his assistance and advice throughout the project, and Dr. Moshin Rahman for his help in the initiation of this project. I would also like to thank the Department of Neurosurgery at UPMC, most notably Dr. Amin Kassam, Dr. Paul Gardner and Dr. Daniel Prevedello for their time and assistance in this project. Notice: Information contained within this presentation is the sole...
References
Carrau R, Jho H, Ko Y. Transnasal-transsphenoidal endoscopic surgery of the pituitary gland. Laryngoscope (1996); 106: 914-918. Cavallo L, Messina A, Cappabianca P, et al. Endoscopic endonasal surgery of the midline skull base: anatomical study and clinical considerations. Neurosurg Focus (2005); Jul 15;19(1):E2 Cavallo L, Messina A, Gardner P, et al. Extended endoscopic endonasal approach to the pterygopalatine fossa: anatomical study and clinical considerations. Neurosurg Focus (2005); Jul 15;19(1):E5 Clemente C. Gray's Anatomy of the Human Body, ed 30. Baltimore: Lippincott Williams & Wilkins; (1985);...