Experimental And Clinical Research On The Value Of F Wave Assisted Electrophysiological Monitoring In The Protection Of Facial Nerve Function During The Microoperation For Acoustic Neurinomas

Chapterl Establishment of the chronic and pressure-induced SD rat models for acoustic neurinomasObject To establish the chronic and pressure-induced SD rat models of acoustic neurinomas for the purpose of further experimental research on acoustic neurinoma related electrophysiology, function and pathomorphology of facial nerves and cochlear nerves.Methods Based on our mesurements to "the distances between mid-posterior clinoid process and the bottom of petrous bone" (definited as "distance of petrous bone") in human and SD rats, respectively, the diameters of "acoustic neurinomas"(sac) in model rats have been validated at the proportion of 10:1 for human versus SD rats by the tumors' hierarchical grading system in human(Koos critieria). Under microscope, the self-made sacculus-catheter, which was made up from condom and 1.8F microcatheter used for patients' endovascular intervention, was inserted into right CPA of the rats via suboccipital retrosigmoid approach. The sac was then infused to the setting extent at the speed of 1μl/min and the posterior end of the catheter was ligated and put through 2cm long subcutaneous channel in back. 48 SD rats were averagely operated for little, middle and large tumor models, and 6 rats were used as seudo-operation group. Before and after operation, the model rats were carried on BAEP electrophysiologic examination, respectively. MRI scanning and afterwards anatomic observation were also conducted when the model rats were fed to one week after operation.Results BAEP and MRI scanning for the model rats show that the models are successful except two rats died in large tumor group, One died of acute brainstem crisis, the other died of intracranial infection 5 days...