Daniele Marchioni, Matteo Alicandri-Ciufelli, Alessia Rubini, Babara Masotto, Giacomo Pavesi and Livio Presutti
The aim of this study was to describe the first case series in which an exclusive endoscopic transcanal transpromontorial approach (EETTA) was used to treat small vestibular schwannomas (VSs) and meningiomas of the internal auditory canal (IAC).
The authors performed a retrospective review of patients who had undergone surgery using an EETTA to the IAC at 2 university tertiary care referral centers during the period from November 2011 to January 2015.
Ten patients underwent surgery via an EETTA for the treatment of VS in the IAC at the University Hospital of Modena or the University Hospital of Verona. The patients had Koos Grade I or II tumors and American Academy of Otolaryngology–Head and Neck Surgery (AAO-HNS) Class D hearing status preoperatively. Gross-total resection was achieved in all patients. No major complications such as cerebrospinal fluid leakage or hemorrhage were reported. In 7 of 10 (70%) patients, facial nerve function was normal immediately after surgery (Rough Grading System [RGS] Grade I). Two patients presented with a transitory facial palsy immediately after surgery (RGS Grade II–III) but experienced complete recovery during the follow-up period. The mean follow-up was 10 months.
The EETTA proved to be successful for the removal of VS or meningioma involving the cochlea, fundus, and IAC, with possible lower complication rates and less invasive procedures than those for traditional microscopic approaches. The potential for the extensive and routine use of this approach in lateral and posterior skull base surgery will depend on the development of technology and surgical refinements and on the diffusion of skull base endoscopic skills among the otolaryngological and neurosurgical communities.
Matteo Alicandri-Ciufelli, Giacomo Pavesi and Livio Presutti
Alberto Feletti, Alessandro Fiorindi, Vincenzo Lavecchia, Rafael Boscolo-Berto, Elisabetta Marton, Veronica Macchi, Raffaele De Caro, Pierluigi Longatti, Andrea Porzionato and Giacomo Pavesi
Despite the technological advancements of neurosurgery, the posterior part of the third ventricle has always been the “dark side” of the ventricle. However, flexible endoscopy offers the opportunity for a direct, in vivo inspection and detailed description of the posterior third ventricle in physiological and pathological conditions. The purposes of this study were to describe the posterior wall of the third ventricle, detailing its normal anatomy and surgical landmarks, and to assess the effect of chronic hydrocephalus on the anatomy of this hidden region.
The authors reviewed the video recordings of 59 in vivo endoscopic explorations of the posterior third ventricle to describe every identifiable anatomical landmark. Patients were divided into 2 groups based on the absence or presence of a chronic dilation of the third ventricle. The first group provided the basis for the description of normal anatomy.
The following anatomical structures were identified in all cases: adytum of the cerebral aqueduct, posterior commissure, pineal recess, habenular commissure, and suprapineal recess. Comparing the 2 groups of patients, the authors were able to detect significant variations in the shape of the adytum of the cerebral aqueduct and in the thickness of the habenular and posterior commissures. Exploration with sodium fluorescein excluded the presence of any fluorescent area in the posterior third ventricle, other than the subependymal vascular network.
The use of a flexible scope allows the complete inspection of the posterior third ventricle. The anatomical variations caused by chronic hydrocephalus might be clinically relevant, in light of the commissure functions.