Abstract: Objective To investigate the strategy of internal auditory canal (IAC) management in retrosigmoid approach for vestibular schwannoma after accurate implementation of preoperative individualized assessment. Methods The clinical data of 149 patients with vestibular schwannoma who underwent resection via retrosigmoid approach at The First Affiliated Hospital of Chongqing Medical University were retrospectively analyzed from January 2018 to January 2022. The tumors in IAC were conventionally treated by drilling open the posterior wall of the IAC in 95 patients (the drilling open IAC group), and treated by scraping method in 54 patients (the scraping group). Tumor resection rate and postoperative complication rate were recorded, and facial nerve function was evaluated by House-Brackmann (H-B) grade at 6 months after surgery. Results In the patients who were treated with drilling open the posterior wall of the IAC, gross total resection (GTR) was performed in 37 cases (38.95%), near total resection (NTR) in 30 cases (31.58%), subtotal resection (STR) and majority resection in 28 cases (29.47%). Forty-seven cases (49.47%) of H-B grade Ⅰ-Ⅱ, 22 cases (23.16%) of Ⅲ and 23 cases (24.21%) of Ⅳ-Ⅵ were classified at 6 months after surgery. Incidence of complications:cerebrospinal fluid (CBF) leakage in 5 cases (5.26%), intracranial infection in 9 cases (9.47%), pulmonary infection in 13 cases (13.68%), and intermuscular venous thrombosis in 6 cases (6.32%). In patients who were treated with scraping method, GTR was performed in 12 cases (22.22%), NTR in 22 cases (40.74%), while STR and majority resection in 20 cases (37.04%). Twenty-one cases (38.89%) of H-B grade Ⅰ-Ⅱ, 16 cases (29.63%) of Ⅲ and 17 cases (31.48%) of Ⅳ-Ⅵ were classified at 6 months after the surgery. Incidence of complications:CSF leakage in 0 cases, intracranial infection in 4 cases (7.41%), pulmonary infection in 7 cases (12.96%), and intermuscular venous thrombosis in 3 cases (5.56%). Tumor resection rate (χ²=0.902, P=0.342), facial nerve function at 6 months after surgery (χ²=0.282, P=0.594), intracranial infection (χ²=0.185, P=0.667), pulmonary infection (χ²=0.015, P=0.901) and lower limb intermuscular venous thrombosis (χ²=0.035, P=0.851) were not statistically significant in 2 groups. Conclusions Conventionally drilling open the posterior wall of the IAC is the preferred method to deal with the IAC, and scraping can be used as a selective supplement after strict preoperative evaluation.

Key words: Neuroma, acoustic, Cerebellopontine angle, Ear, inner, Microsurgery

摘要： 目的 探讨听神经瘤乙状窦后入路手术前个体化评估以及术中内听道处理策略。方法 纳入2018年1月至2022年1月在重庆医科大学附属第一医院行乙状窦后入路手术的149例听神经瘤患者，术中常规磨开内听道后壁处理内听道内肿瘤95例（磨开内听道组）和掏刮法处理内听道内肿瘤54例（掏刮组），记录肿瘤切除率和术后并发症发生率，术后6个月采用House-Brackmann（H-B）分级评价面神经功能。结果 磨开内听道组肿瘤全切除37例（38.95%）、近全切除30例（31.58%）、次全切除和大部切除28例（29.47%），术后6个月H-B分级Ⅰ~Ⅱ级47例（49.47%）、Ⅲ级22例（23.16%）、Ⅳ~Ⅴ级23例（24.21%），并发症发生率占比脑脊液漏5例（5.26%）、颅内感染9例（9.47%）、肺部感染13例（13.68%）、下肢肌间静脉血栓6例（6.32%）；掏刮组肿瘤全切除12例（22.22%）、近全切除22例（40.74%）、次全切除和大部切除20例（37.04%），术后6个月H-B分级Ⅰ~Ⅱ级者21例（38.89%）、Ⅲ级16例（29.63%）、Ⅳ~Ⅵ级17例（31.48%），无一例发生脑脊液漏、颅内感染4例（7.41%）、肺部感染7例（12.96%）、下肢肌间静脉血栓3例（5.56%）；两组肿瘤切除率（χ²=0.902，P=0.342）、术后6个月面神经功能（χ²=0.282，P=0.594），以及颅内感染（χ²=0.185，P=0.667）、肺部感染（χ²=0.015，P=0.901）和下肢肌间静脉血栓（χ²=0.035，P=0.851）等并发症发生率差异均无统计学意义。结论 常规磨开内听道后壁是处理内听道内肿瘤的首选方式，掏刮法可以作为经过严格术前评估后的补充选择。

关键词: 神经瘤,听, 小脑脑桥角, 内耳, 显微外科手术