The extracisternal approach in vestibular schwannoma surgery and facial nerve preservation

The classical surgical technique for the resection of vestibular schwannomas (VS) has emphasized the microsurgical anatomy of cranial nerves. We believe that the focus on preservation of the arachnoid membrane may serve as a safe guide for tumor removal. Method: the extracisternal approach is described in detail. We reviewed charts from 120 patients treated with this technique between 2006 and 2012. Surgical results were evaluated based on the extension of resection, tumor relapse, and facial nerve function. Results: Overall gross total resection was achieved in 81% of the patients. the overall postoperative facial nerve function House-Brackmann grades I-II at one year was 93%. There was no recurrence in 4.2 years mean follow up. Conclusion: the extracisternal technique differs from other surgical descriptions on the treatment of VS by not requiring the identification of the facial nerve, as long as we preserve the arachnoid envelope in the total circumference of the tumor.Clin DFVneuro, São Paulo, BrazilHosp Servidor Publ Estadual, Dept Neurocirurgia, São Paulo, BrazilUniv São Paulo, Fac Med, Hosp Clin, Dept Neurocirurgia, São Paulo, BrazilCtr Otorrino & Fonoaudiol São Paulo, São Paulo, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc

Experimental model of facial paralysis by nerve compression in primates (Callithrix sp.): A new model of facial paralysis in small nonhuman primates

Conclusion: We conclude that facial nerve injury induced by compression is associated with a reasonable time window (4 weeks) that allows possible neurotrophic effects to be analyzed. Additionally, there are no hints of cross-innervation by the contralateral facial nerve or parallel innervation by other nerves in the hemiface ipsilateral to the injured nerve. Objective: the aim of this work was to develop an experimental model of facial nerve injury in nonhuman primates (Callithrix sp.). Methods: in this study, individuals of the non-human primate species Callithrix sp. were subjected to three different types of facial nerve injury, and they were observed for 27 days after surgery by video to record their facial movements. Results: Two types of nerve compression caused severe initial facial paralysis followed by gradual recovery until normal levels were reached at the end of the evaluation period. Injury induced by nerve resection was followed by a complete lack of facial movement recovery.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fed Univ São Paulo UNIFESP, Otorhinolaryngol & Head & Neck Surg Dept, São Paulo, BrazilFed Univ São Paulo UNIFESP, Dept Physiol, São Paulo, BrazilFed Univ São Paulo UNIFESP, Otorhinolaryngol & Head & Neck Surg Dept, São Paulo, BrazilFed Univ São Paulo UNIFESP, Dept Physiol, São Paulo, BrazilFAPESP: FAPESP 2009/52805-7Web of Scienc