影响大型听神经瘤术后面神经功能的局部因素

Local factors influencing facial nerve functions after excision of large acoustic neuromas

目的探讨大型听神经瘤影响面神经功能的因素。方法对32例大型听神经瘤在面肌肌电图监护下行显微手术切除,记录肿瘤的大小、切除程度及显微镜下肿瘤的囊性变,肿瘤与面神经的位置关系及与面神经的黏连程度等因素。结果肿瘤均全切,面神经解剖保留率为96.9%。根据House-Brackmann面神经功能分级标准,术后6个月面神经功能保留率为Ⅱ级52.4%,Ⅲ级42.9%,Ⅳ级4.7%;术后1年为Ⅱ级66.7%,Ⅲ级28.6%,Ⅳ级4.8%。术后面神经功能与肿瘤的大小、囊性变及肿瘤与面神经的位置关系无关(P> 0.05),面神经与肿瘤的黏连程度与术后3 d和1周的面神经功能呈明显正相关(r= 0.560,P= 0.001;r= 0.478,P= 0.007)。结论对大型听神经瘤在保留面神经完整的前提下要尽可能全切,术后的面神经功能主要取决于面神经与肿瘤的黏连程度。

Objective To determine the local factors influencing facial nerve functions after excision of large acoustic neuromas. Methods Acoustic neuromas were microsurgically removed in 33 patients through retrosigmoid approach under electromyographic monitoring. The size of the tumor, the degree of the tumor resection, cystic formation of the tumor, the anatomical location of the tumor to the facial nerve, and the degree of adhesion formation between the facial nerve and the tumor were recorded. Results All of the tumors were totally removed. 96.9% facial nerves were anatomically preserved. According to House-Brackmann facial nerve grading system, gradeⅡ facial nerve preservation rate accounted for 52.4%, grade Ⅲ for 42.9%, grade Ⅳ for 4.8% at 6 months after the operation; grade Ⅱ for 66.7%, grade Ⅲ for 28.6%, and grade Ⅳ for 4.8% at one year after operation. The facial nerve function after excision of large acoustic neuromas were not statistically correlated with the size of the tumor, cystic formation of the tumor, and the anatomical location of the tumor to the facial nerve (P > 0.005), but statistically correlated with the degree of adhesion formation between the facial nerve and the tumor (3 days: r = 0.560, P = 0.001; 1 week: r = 0.478, P = 0.007). Conclusion For large acoustic neuromas, surgeons must attempt to resect the tumors as completely as possible, and reassure the integrity of the facial nerves. The facial nerve function after excision of large acoustic neuromas depends mainly on the adhesion degree between the facial nerve and the tumor.