Vestibular schwannoma removal through expanded transcanal transpromontorial approach: a multicentric experience

Purpose: Expanded Transcanal Transpromontorial Approach (ExpTTA) is an endomicroscopic technique that allow surgical excision of small and symptomatic neuromas limited to the internal auditory canal (IAC) or minimally invasive the cerebellopontine angle (CPA). ExpTTA is a safer alternative to the exclusive endoscopic technique as it allows a wider surgical field and better management of the auditory porus and CPA. Methods: We report a retrospective case series of 34 patients who underwent ExpTTA between 2017 and 2022 at the ENT Departments of the University Hospital of Modena, Bologna and Verona. Tumor size was defined according to the Koos staging and hearing function was classified according to the AAOHNS. A clinical evaluation of facial nerve (FN) function was performed using the House and Brackman scale (HBs). Results: Our cohort consists of 34 patients. At time of surgery all patients had a normal preoperative facial function. Gross total resection was achieved in all patients, without intraoperative complications, and FN continuity was preserved in all cases. No major complications were observed. Regarding post-operative FN function, at hospital discharge ten patients had impairment equal or greater than IV grade according to H&Bs. At 6 months after surgery only two patients presented with moderate/severe facial paralysis (grade IV H&Bs) and finally at 12-month follow-up all patients had a satisfactory recovery of nervous function (grade < III H&Bs). Conclusions: ExpTTA is a safe and effectively technique for treatment of small VS (Koos I, II and selected cases of Koos III) with low postoperative morbidity.