Minimally-invasive middle fossa craniotomy approach with endoscopic repair of superior canal dehiscence

• Published in: Operative techniques in otolaryngology--head and neck surgery 2017-03, Vol.28 (1), p.50-56
• Main Authors: Kozin, Elliott D., MD, Lee, Daniel J., MD
• Format: Article
• Language: English
• Subjects: Endoscopic ear surgery; Otolaryngology; Superior canal dehiscence; Superior canal dehiscence syndrome; Surgery
• ISSN: 1043-1810; 1557-9395
• DOI: 10.1016/j.otot.2017.01.009

Superior canal dehiscence (SCD) is a bony defect of the superior semicircular canal (SSC). SCD syndrome (SCDS) occurs when vestibular or auditory dysfunction accompanies SCD. While not all SCD patients are symptomatic, surgical repair is an option in patients with incapacitating symptoms and unresponsive to conservative treatment. Traditionally, repair of SCDS when involving the arcuate eminence can be achieved utilizing a middle fossa craniotomy (MFC) approach. However, approximately 30% of SCD cases have a medial arcuate eminence defect along a downsloping tegmen, making the defect difficult to visualize with the binocular microscope without a large craniotomy, extensive temporal lobe retraction and drilling of the skull base. As complete visualization of an arcuate eminence defect is essential for successful repair, we describe an operative approach to visualize the SCD that combines a small MFC and rigid angled endoscopy. The wide-field view and superior transillumination with skull base endoscopy can be achieved with a minimal access skin incision, small bony window, less dural dissection, reduced brain retraction, resulting in unequivocal identification of the entire arcuate eminence defect.