The otologic approach in the management of posterior petrous surface meningiomas.

PURPOSE: Report our experience in the management of posterior petrous surface meningiomas (PPSMs), and identify features that affect hearing, facial nerve (FN) function, and control of the disease. METHODS: Retrospective case series of 131 patients surgically managed for PPSMs. FN status, hearing and tumour radicality were assessed and compared between patients with tumours of different locations (Desgeorges classification) and internal auditory canal involvement (IAC). RESULTS: At the time of surgery 74.8% of patients had a hearing loss. Hearing was mostly unserviceable in tumors attached to the meatus. Pure tone audiometry did not correlate to IAC extension, while speech discrimination scores were statistically worse when the tumor occupied the IAC (unpaired t test, p = 0.0152). Similarly, extrameatal tumors undergoing removal by otic preserving techniques maintained postoperative hearing, whereas hearing worsened significantly in tumors involving the IAC (paired t test, p = 0.048). The FN was affected preoperatively in 11.4% of cases. Postoperative FN palsy was significantly correlated to the IAC involvement (Fisher's exact test, p = 0.0013), while it was not correlated to tumor size. According to the Desgeorges classification, a postoperative FN palsy complicated the majority of anteriorly extending tumors and, two-fifths of meatus centred tumors. 75% of posterior located tumors had a postoperative FN grade I HB. CONCLUSIONS: Since the involvement of the IAC by the tumor affects both hearing and FN function, the IAC is of primary importance in PPSMs and should be studied and addressed as much as the tumor location in the CPA.

Petrous bone cholesteatoma: classification, management and review of the literature.

OBJECTIVE: To discuss the classification of petrous bone cholesteatoma (PBC) and add a subclassification; to review the existing literature and to propose the ideal surgical management of PBC based upon the experience of the largest series published in the literature until now. STUDY DESIGN: Retrospective analysis. SETTING: Quaternary referral neuro-otologic private practice. MATERIALS AND METHODS: The data of 129 patients who underwent surgery for PBC between 1979 and 2008 were analyzed with respect to the classification, type of the approach used, facial nerve lesion and its management, recurrences and outcome. RESULTS: Out of the 129 PBC cases 64 were supralabyrinthine, 9 infralabyrinthine, 7 infralabyrinthine-apical, 48 massive and 1 apical. The facial nerve was involved in 95% of the cases. Hearing could not be preserved in 82% of the cases due to the extent of the lesions and the surgical approaches used. The internal carotid artery, jugular bulb and the lower cranial nerves were infrequently involved, but demanded careful identification and meticulous care to avoid complications. Obliteration of the cavities provided a safe solution for protection of the exposed dura and the vital neurovascular structures. Recurrences were observed in 5 cases. CONCLUSION: The classification of PBC is fundamental to choose the appropriate surgical approach; the facial nerve is involved in almost all the cases, radical removal takes priority over hearing preservation and cavity obliteration is important to protect the vital neurovascular structures which may be exposed.

Management of complex cases of petrous bone cholesteatoma.

OBJECTIVES: In a retrospective analysis of a quaternary referral neuro-otologic private practice, we identify complex cases of petrous bone cholesteatoma (i.e., cases with encasement of vital structures such as the internal carotid artery, jugular bulb, and sigmoid sinus, with further extension to the clivus, sphenoid sinus, or rhinopharynx), review surgical approaches and techniques of management of vital structures, and propose the ideal surgical management. METHODS: We performed a retrospective case study of 130 cases of petrous bone cholesteatoma submitted to surgery between 1979 and 2009 to identify the complex cases and their classification, approach used, outcomes, and recurrences. RESULTS: Of 130 cases. 13 were complex. Facial palsy was the presenting feature in 11 cases, 7 of which presented with grade VI palsy. A long duration of facial palsy (more than 3 years) was seen in 5 cases. Clival involvement was seen in 6 cases; 1 case extended to the sphenoid sinus, and 1 to the rhinopharynx. The internal carotid artery was encased in 11 cases in the vertical and the horizontal parts. The jugular bulb was involved in 7 cases. Modified transcochlear approaches or infratemporal fossa approaches were used in all cases. There were no recurrences. CONCLUSIONS: Classification is fundamental to choosing the right surgical approach. Transotic and modified transcochlear approaches hold the key to treating complex cases. Infratemporal fossa approach type B has to be used for extension into the clivus, sphenoid sinus, or rhinopharynx. Internal carotid artery, jugular bulb, and sigmoid sinus involvement should be identified before operation.

Transapical extension in difficult cerebellopontine angle tumors.

The transapical extension of the enlarged translabyrinthine approach is aimed at making the removal of certain tumors of the cerebellopontine angle simpler and with less morbidity. The extension is classified into 2 types--type I and type II--based on the extent of bone drilling around the internal auditory canal. Type I extension involves drilling for 300 degrees to 320 degrees around the canal and is indicated for large or giant vestibular schwannomas and vestibular schwannomas with significant extension anterior to the internal auditory canal. Type II extension entails complete removal of the bone around the canal for 360 degrees and is indicated for meningiomas of the posterior surface of the petrous bone extending anterior to the internal auditory canal. The extension allows better control over the anterior pole of the tumor, the displaced facial nerve, the prepontine cistern, and the venous vascularity of the cerebellopontine angle. The aim of this report is to present our experience with this extension.

History of Meniere's disease and its clinical presentation.

The term Meniere's disease is used to define either the classic triad of vestibular and cochlear symptoms and aural pressure from known or unknown causes or its clinical variants, vestibular and cochlear Meniere's disease. Some variants evolve after years into typical forms, whereas others do not. Some symptoms (positional vertigo) have been long underestimated in previous reports. The more we study our patients and correlate clinical findings and the natural history with pathologic studies on temporal bones and laboratory research, the more we will understand Meniere's disease and its causes. Some causes have already been identified as most probable. Extrinsic factors (inflammation, trauma, otosclerosis, autoimmunity, endocrine disorders, and such) interact with congenital (genetic) and developmental intrinsic factors (primary or secondary, acquired) into a multifactorial inheritance that is, to date, the best explanation for the basis of Meniere's disease. Endolymphatic hydrops is widely accepted as the pathologic substrate, but not all hydrops seems to be progressive or becomes clinically manifest. Endolymphatic hydrops is the result of a dysfunction in the mechanism of production/absorption of endolymph, which is mainly due to defective absorptive activity of the endolymphatic duct and sac. Hyperproduction of endolymph cannot be excluded in some cases. Ruptures of the labyrinthine membranes do not satisfactorily substantiate the multiform duration, recurrence, and repetitiveness of attacks of Meniere's disease, nor do they explain the entire complex of symptoms. It seems reasonable to explain symptoms of Meniere's disease on the basis of mechanical factors (as observed in temporal bone studies) associated with biologic and biochemical factors.

Cystic vestibular schwannoma: classification, management, and facial nerve outcomes.

OBJECTIVE: Review of postoperative morbidity and facial nerve outcomes of cystic vestibular schwannoma (CVS) patients compared with solid vestibular schwannoma (SVS) patients and a proposal for a new CVS classification system. STUDY DESIGN: Retrospective review. SETTING: Tertiary care facility. PATIENTS: Ninety-six patients with surgically treated CVS (1998-2008). Outcomes were assessed in a subpopulation of 57 patients with greater than or equal to 1-year follow-up compared with 57 SVS patients. INTERVENTION: Fifty-six CVS patients underwent the enlarged translabyrinthine approach with transapical extension (Type I), and 1 patient underwent a transcochlear/transzygomatic approach. MAIN OUTCOME MEASURE: Preoperative and postoperative (at least 1 yr) House-Brackmann facial nerve (HBFN) grade evaluation. RESULTS: Favorable HBFN grades (I-III) were observed in 46 (81%) CVS patients, and unfavorable HBFN grades (IV-VI) were seen in 11 (19%) CVS patients. Comparison of tumor size and 1-year HBFN grades showed significant, moderate to strong, Pearson correlation (0.38). Comparison of long-term facial nerve outcomes with a sample of 57 matched SVS patients showed no significant difference (p = 0.74). When the tumor was adherent to the facial nerve and a dissection plane could not be developed between the cyst wall and the nerve, only subtotal resection could offer the CVS patients a normal facial nerve outcome. CONCLUSION: In most CVS cases, complete resection should be foreseen. Central and thick-walled tumors can be removed in almost all cases. However, when peripheral thin-walled, adherent, cystic tumors are confronted and the cysts are medially or anteriorly located, we recommend subtotal resection, leaving portions of the cyst walls on neurovascular structures and on the facial nerve. This surgical strategy allows us to improve facial nerve outcomes and to reduce complications.