The Analysis Of Intraoperative Neurophysiological Monitoring In Cerebellopontine Angle Tumor Surgery

Objective:In the surgery of cerebellopontine angle tumors resection,face and auditory nerve damage is still inevitable postoperative complications.Intraoperative neurophysi-ological monitoring techniques play a more and more important role in the modern skull base surgery and functional neurosurgery.Clinical cases were retrospectively sum-marized in this article,through our analysis,the application of different neurophysiolo-gical monitoring techniques in cerebellopontine angle tumors surgery,the postoperative surface,the influence of the auditory nerve to retain and functional status.Methods:Collected from september 2012 to December 2015,during the period of hos-pitalization,diagnosis of cerebellopontine angle tumor,a total of 45 patients with space-occupying lesions.Analysis of the clinical history,the auxiliary examination data,all through the pillow under the sigmoid sinus approach after tumor resection,intra-operative give face,auditory nerve monitoring,identify facial nerve contorts carefully,and according to the intraoperative monitoring surface,auditory nerve function after surgery for prompt assessment,observe the recovery,and presence of complications,and postoperative follow-up collect all relevant data on t test.Results:In 45 patients with cerebellopontine angle tumor surgery,37 cases of acoustic neuroma,6 cases of meningioma,epidermoid cyst in 2 cases.Need fully exposed in the process of removal,the anatomy of the cerebellopontine angle,facial nerve sponta-neous EMG recording of all kinds of mechanical operation or the facial motion caused by ischemic stimulus,to prompt may damage in the process of operation risk,when monitoring waveform amplitude decreases,monitors have a sequential sputter,remind the performer must pay attention to the facial nerve,should immediately stop operation or adjustment.Evoked EMG to identify facial nerve contorts and anatomical position,after the removal of the facial nerve stimulation brain stem end,identification of neural function prognosis.Evoked responses of stimulus intensity,relative volatility is different also.Operation at the end of the stimulus intensity had obvious correlation with post-operative facial nerve function,P<0.01.The smaller the stimulus intensity,the better prompt of postoperative facial nerve function.Electrical stimulation of 1～3 v,prompt the facial nerve intact;Electrical stimulation of 5～10 v,suggest possible damage;Elec-trical stimulation quantity>15 v,prompt irreversible damage to facial nerve function.To pull in the contralateral BAEP monitoring found that tumor-nerve bundle,appear V wave lengthen the incubation period,amplitude decreases,sometimes even wave-form disappear,Ⅲ～Ⅴ,Ⅰ～Ⅴ IPL extended,and the most significant change,usually in 1.0～1.2 ms,after tumor resection,and as far away from the nerve,the waveform can quickly recover,reflect the brainstem function change is caused by intraoperative mecha nical pull,not seen obvious obstacles of brainstem function,which generally in good condition.Conclusions:Currently,the development of radiologists,microscopic operation and the introduction of microsurgical technique,the progress in the field of neural anesthesiolo-gy,at the same time,including the use of intraoperative neural electrophysiological monitoring and cerebellopontine Angle tumor incidence and death rates have dropped sharply,its treatment strategy is also a significant change occurred.The purpose of the cerebellopontine angle tumors,already from the removal of the tumor,prolonging life into cranial nerve preservation anatomical and functional integrity.The application of the neurophysiological monitoring techniques,improving the doctors of cranial nerve injury mechanism of the understanding and awareness,not only improve the doctor’s surgery skills,and reduce the risk of intraoperative nerve injury.Facial nerve EMG monitoring can prompt the facial position and direction,roughly when the operation to avoid damage to nerve provides a judgment,and to assess the postoperative facial nerve function.The contralateral BAEP V wave and wave latency,Ⅰ～Ⅴ、Ⅲ～Ⅴ peak between the incubation period is the main index,intraoperative monitoring by intra-operative observation wave crest,the incubation period of change,reflecting the auditory and brainstem function.