Microsurgical Anatomy Of Posterior Wall Of Internal Auditory Canal And Its Clinical Application

Objective Simulation of the retrosigmoid approach,to explore the removal of posterior wall of the internal auditory canal by microscope involved in the important anatomic structures,and improve surgical skills,so that it can provide a reference for acoustic neuroma surgery,to reduce or even avoid the occurrence of surgical complications.Method(1)10 adult skulls specimens were used to observe the internal auditory canal junction and to measure the distance between them and the bony structures around them.(2)The anatomical study was carried out on the simulated sigmoid sinus of 5 adult Chinese skull specimens,and the adjacent structures were observed by microscope.(3)Removing the internal auditory canal posterior wall and observating,measureing the bottom of internal auditory canal.(4)Expanding the exposure of cerebellopontine angle,and then measuring the relevant data.Results the internal acoustic meatus is the opening of the cerebellopontine angle to the internal auditory canal.It is located in the anterior wall of theposterior fossa,and The temporal bone near the central part of the petrous cerebellum.The shape is most elliptic,the leading edge is smooth and the trailing edge is sharp.In the foreupward,the internal acoustic meatus is adjacent to the foramen of trigeminal nerve,and the jugular foramen is blow.The inside are the cerebellum and the brain stem.It is the channel of facial and vestibulocochlear nerves to cranial cavity.The length of the posterior wall of IAC is(9.14±0.45)mm,The width of the posterior wall of IAC is(3.95±0.34)mm;The length of Internal auditory canal transverse crest is(6.45±0.48)mm,and the length of the internal auditory canal vertical ridge is(2.36±0.82)mm.The upper and lower diameters of the internal acoustic meatus is(4.27±0.58)mm,the anteroposterior diameter is(6.86 + 1.28)mm.Conclusion Familiar with the anatomical structure of the internal auditory canal and the relationship between adjacent structures,CT scan of skull base was performed before operation,determine the internal auditory canal abrading range and fully grasping the removal of internal auditory skills,can reduce or even avoid complications when removal of The posterior wall of the internal auditory canal,Complete resection of acoustic neuroma,Improve total resection rate of tumor,retain neurological function as much as possible,Bring the gospel to the patient.