经乙状窦后入路切除小型听神经瘤术中听力保留及听觉脑干反应和蜗神经复合动作电位监测

Hearing preservation and intraoperative auditory brainstem response and cochlear nerve compound action potential monitoring in the removal of small acoustic neurinoma via the retrosigmoid approach.

作者信息

Yamakami I, Yoshinori H, Saeki N, Wada M, Oka N

机构信息

Neurosurgery, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuoku, Chiba, Japan 260-8670.

出版信息

J Neurol Neurosurg Psychiatry. 2009 Feb;80(2):218-27. doi: 10.1136/jnnp.2008.156919. Epub 2008 Oct 31.

DOI:10.1136/jnnp.2008.156919

PMID:18977821

Abstract

OBJECTIVE

Hearing preservation is the main focus of small acoustic neurinoma (AN) removal. Refinement of intraoperative auditory monitoring may improve postoperative hearing. We have introduced a newly designed intracranial electrode enabling continuous monitoring of the cochlear nerve compound action potential (CNAP). We performed simultaneous monitoring of the auditory brainstem response (ABR) and CNAP during retrosigmoid small AN removal, and clarified the surgical outcome and the usefulness of CNAP monitoring.

METHODS

Twenty-two consecutive patients with a small AN underwent retrosigmoid tumour removal with attempting hearing preservation. ABR and CNAP were simultaneously monitored during tumour removal.

RESULTS

AN was totally removed in all patients without facial palsy. Preservation rate of useful and serviceable hearing was 82% and 91%, respectively. During microsurgical tumour removal, various surgical equipments and procedures intensified artefacts of ABR, and reliable ABR monitoring with distinct wave V was obtained in 9/22 patients. Unaffected by artefacts, reliable CNAP monitoring was obtained more frequently (in 20/22 patients) than ABR (p = 0.0005). CNAP on completion of tumour removal predicted hearing preservation with no false positive or negative (100% sensitivity and 100% specificity). CNAP changed dynamically and stepwise with surgical manipulations.

CONCLUSION

The retrosigmoid approach using auditory monitoring for a small AN can accomplish total tumour removal with an excellent hearing preservation rate. CNAP provides reliable auditory monitoring more frequently than ABR, reflects the intraoperative auditory function almost in real-time, predicts postoperative hearing with excellent sensitivity and specificity, and is more useful for monitoring in the removal of small AN with hearing preservation.

摘要

目的

保留听力是小型听神经瘤（AN）切除的主要关注点。术中听觉监测的改进可能会改善术后听力。我们引入了一种新设计的颅内电极，能够连续监测蜗神经复合动作电位（CNAP）。我们在乙状窦后小型AN切除术中同时监测听觉脑干反应（ABR）和CNAP，并阐明了手术结果以及CNAP监测的实用性。

方法

连续22例小型AN患者接受乙状窦后肿瘤切除术，试图保留听力。在肿瘤切除过程中同时监测ABR和CNAP。

结果

所有患者的AN均被完全切除，无面神经麻痹。有用听力和实用听力的保留率分别为82%和91%。在显微手术切除肿瘤过程中，各种手术设备和操作增强了ABR的伪迹，22例患者中有9例获得了具有明显V波的可靠ABR监测。不受伪迹影响，获得可靠CNAP监测的频率（22例患者中有20例）高于ABR（p = 0.0005）。肿瘤切除完成时的CNAP预测听力保留，无假阳性或假阴性（灵敏度100%，特异度100%）。CNAP随着手术操作动态且逐步变化。