To explore the individualized strategy of micro neurosurgery in the internal auditory canal (IAC) in order to maximize the benefits of patients.

A retrospective analysis was conducted on the clinical data of 27 patients with acoustic neuroma treated by neuroendoscopy-assisted microsurgery via suboccipital retrosigmoid approach from September 2021 to August 2022 in the Neurosurgery Department of The First Hospital of Chongqing Medical University. According to the extent of tumor growth into the internal auditory canal and the physical foundation of the patients, the patient were divided into the drilling open IAC group (18 cases) and the scraping group (9 cases). The operative time, the degree of tumor resection, the preservation of the facial nerve, and the control of postoperative infections were compared between the two groups.

Nine patients had complete resection of the tumor by drilling open the posterior superior wall of the internal auditory canal, 7 patients had near-total resection, and 2 patients had subtotal resection (tight adhesion to the brainstem). Two patients had complete resection of tumor by scraping method, 5 patients had near-total resection and 2 patients had subtotal resection. There was no statistically significant difference in the near-total and above resection rates between the 2 groups of patients (P>0.05). Intraoperative microscopic observation of the facial nerve was anatomically preserved in all patients. Comparing the operation time and hospitalization expenses between the two groups of patients, the differences were statistically significant (P<0.05). According to the House-Brackmann (H-B) facial nerve function classification, the facial nerve function in the three-month postoperative period was grade Ⅰ-Ⅱ in 9 patients, grade Ⅲ in 7 patients, and grade Ⅳ in 2 patients by the drilling method, and grade Ⅰ-Ⅱ in 5 patients, grade Ⅲ in 4 patients, and grade Ⅳ in 0 patients by the scraping method. The Intracranial infection occurred in 4 cases after surgery, including 3 cases in the drilling open IAC group and 1 case in the scraping group.

The scraping method is less time-consuming and has a lower postoperative complication rate than the drilling method, and the number of days of hospitalization and medical costs for patients with scraping are reduced accordingly. Through accurate preoperative evaluation, it is more beneficial to improve the curative effect of appropriate patients to use the scraping method to treat tumors in the internal auditory canal.