Application of the grinding bone function of cut-ultrasound aspiration in internal auditory canal treatment of acoustic neuroma microsurgery

Abstract

Objective To investigate the safety and reliability of using the grinding bone function of cut-ultrasound aspiration (CUSA) to conduct internal auditory canal treatment during acoustic neuroma microsurgery. Methods From January 2014 to June 2015, the clinical data of 33 patients with acoustic neuroma resected via suboccipital retrosigmoid approach at the Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology were analyzed retrospectively. The posterior superior walls of the internal auditory canals in 21 patients (CUSA group) were ground by using CUSA during the operation, 19 patients treated with the posterior superior walls of internal auditory canal using the grinding drill from May 2012 to October 2013 were selected as a control group (grinding drill group) in the operation at the same time. Electrophysiological monitoring, such as cranial nerve and brainstem auditory evoked potential were performed during the operation. House-Brackmann facial nerve function grading system was used to assess the facial nerve function for all patients within 1 week before and after procedure. Results The tumors of 20 cases (95%) in the CUSA group were totally removed. The facial nerves were preserved anatomically in 21 cases (100%), and the practical hearing was preserved in 5 cases (24%). House-Brackmann facial nerve function grade at day 7 after procedure: grade Ⅰ in 5 cases, grade Ⅱ in 8 cases, and grade Ⅲ-Ⅴ in 8 cases. The good reservation rate of facial nerve function was 62% (13/21). In the grinding drill group, the tumors of 17 cases were totally removed (90%), the rate of anatomical preservation of facial nerve was 95% (18/19). House-Brackmann facial nerve function grade: grade Ⅰ in 3 cases, grade Ⅱ in 6 cases, and grade Ⅲ-Ⅴ in 10 in cases, and the good reservation rate of facial nerve function was 47% (9/19). There was significant difference in the good reservation rate of facial nerve function between the 2 groups (P<0.05). Conclusions The application of CUSA is safe and effective in treatment of internal auditory canals with acoustic neuroma microsurgery. It is beneficial to the total resection of tumors and the protection of facial nerves. Key words: Neuroma, acoustic; Microsurgery; Cut-ultrasound aspiration; Internal auditory canal