Microanatomical study on the brainstem ventral region via suboccipital far - lateral transcondylar approach

Objective To investigate the exposed areas in brainstem ventral region via the suboccipital far- lateral transcondylar approach.Method Ten(20 sides) adult cadaveric specimens which perfused with colored silicone were studied.Stepwise dissections via the suboccipital far- lateral transcondylar approach to ventral region of brainstem and the different exposures were compared by resecting the occipital condyle gradually.Results The inverse “U” shape could provide with a sufficient operative exposure.The deep layer structure intraoperative process by identifing with those anatomical markers of suboccipital triangle,transverse process of the atlas and rectus capitis lateralis was localized.Compared with the no - resecting occipital condyle,the exposures of ventral - lateral region of brainstem increased 10.9 mm and 12.6 mm,the operative depth deceased 13.5 mm and 20.5 mm by resecting occipital condyle from partial to total length respectively.Conclusions Suboccipital far - lateral transcondylar approach could improve the exposure extent of ventral region of brainstem by resecting occipital condyle,however it was improtant to decide an optimal extent of occipital condyle to resect intraoperatively accroding to the lesion feature. Key words: Dissection; Far - lateral transcondylar approach; Brainstem ventral region; Occipital condyle