From external to internal auditory canal: surgical anatomy by an exclusive endoscopic approach.

Surgical approaches to the inner ear and internal auditory canal (IAC) are well known and well documented. The objective of this study is to analyze the morphology, and surgical and anatomic findings of an exclusive endoscopic transcanal approach (EETA) to the IAC. Cadaveric dissections were performed on 11 temporal bones, approaching the internal auditory meatus directly through the external ear canal and avoiding mastoidectomy. In all cases, it was possible to dissect the internal carotid artery and jugular bulb with a 0° endoscope, and with good control of these two structures. The medial wall of the bony labyrinth guaranteed good landmarks for IAC dissection, such as the spherical recess, and the labyrinthine tract of the facial nerve. The IAC can be thoroughly visualized in the cadaver using EETA, avoiding mastoidectomy, extensive temporal bone tissue removal and external incisions. Clinically based reports will be required in future to strengthen our preliminary results.

Endoscopic transnasal craniotomy and the resection of craniopharyngioma.

OBJECTIVES/HYPOTHESIS: To describe the utility of a large transnasal craniotomy and its reconstruction in the surgical management of patients with craniopharyngioma. STUDY DESIGN: Observational retrospective cohort study. METHODS: Retrospective review of patients treated in an academic neurosurgery/rhinology practice between 2000 and 2007. Patient characteristics (age, sex, follow-up), tumor factors (size, position extension, previous surgery), type of repair (pedicled mucosal flaps, free mucosal grafts), and outcomes (visual, endocrine, and surgical morbidity) were defined and sought in patients who had an entirely endoscopic resection of extensive craniopharyngioma (defined as requiring removal of the planum sphenoidale in addition to sella exposure in the approach). RESULTS: Seven patients had an entirely endoscopic resection of extensive craniopharyngioma during the study period. Mean age was 23.4 years (standard deviation +/- 16.3). Mean tumor size was 3.2 cm (standard deviation +/- 2.0). The majority of these pathologies had extensive suprasellar disease, and two (28.6%) had ventricular disease. Cerebrospinal fluid leak rate was 29% (2 of 7). These leaks occurred only in reconstructions with free mucosal grafts. There were no cerebrospinal fluid leaks in patients who had vascularized pedicled septal flap repairs. CONCLUSIONS: The endoscopic management of large craniopharyngioma emphasizes recent advancements in endoscopic skull base surgery. The ability to provide exposure through a large (4 cm+) transnasal craniotomy, near-field assessment of neurovascular structures, and the successful reconstruction of a large skull defect have significantly advanced the field in the past decade. The use of a two-surgeon approach and bilateral pedicled septal mucosal flaps have greatly enhanced the reliability of this approach.