General Evaluation Of The Degree Of Exposure And Damage To The Cerebellopontine Angle Region By The Postlabyrithine Approach And The Suboccipital-retrosigmoid Approach

Objective General evaluation of the degree of exposure and damage to the cerebellopontine angle region by the postlabyrithine approach and suboccipital retrosigmoid approach, being familiar with anatomic structure of this region and providing theory reference for the choice of the clinical operative approach.Methods The postlabyrithine approach and suboccipital-retrosigmoid approach were mimicked in 5 adult Chinese cadaveric heads(10 sides) perfusion specimen under microscope. After that, observing the anatomic structure of the cerebellopontine angle region, evaluating the degree of exposure to the cerebellopontine angle region by the postlabyrithine approach and suboccipital-retrosigmoid approach according to Ammirat standard, measuring and calculating the area of the cerebellopontine angle region by Horgan way. Then, the evaluation of the degree of damage to the cerebellopontine angle region by two operative approaches was relatively scored.Results The operative distance to internal auditory foramen on postlabyrinthine approach was (19.18±0.65)mm, the degree of exposure to cerebellopontine angle region was scored 3, the exposed area to cerebellopontine angle was 304±39.74mm~2, the score of the damaging degree was 1 ; But correspondingly they were (37.74±1.11)mm, 1 , 401.80±75.02mm~2 and 3 on suboccipital-retrosigmoid approach respectively. Compared with the latter approach, the postlabyrinthine approach obviously shortened the operative distance, but the score of the degree of explore and the exposed area to cerebellopontine angle region sharply decreased. however, the score of the damaging degree was highly increased correspondingly. All of the indexesindices have statistic meaning(P<0.05).Conclusion The postlabyrinthine approach has complicated operative procedure, little exposed area, more degree of damage to the cerebellopontine angle region compared with the suboccipital-retrosigmoid approach. The latter can be easily operated and has more exposed area, little degree of damage to the cerebellopontine angle region and is suitable to be spread in clinical work as well as the first choice to the desease of the cerebellopontine angle region.