title: A comparative anatomic study of a modified temporal-occipital transtentorial transpetrosal-ridge approach and a transpetrosal presigmoid approach.
abstract: OBJECTIVE
  To evaluate the anatomic features of a modified temporal-occipital transtentorial transpetrosal-ridge approach versus the conventional approach for surgery of petroclival tumors.
  
  
  METHODS
  The conventional transpetrosal presigmoid approach or the modified temporal-occipital transtentorial transpetrosal-ridge approach was performed on different sides of the heads from 10 adult Chinese cadavers to compare incision site, exposure area, and operating space.
  
  
  RESULTS
  In the modified approach, only medial and median parts of the petrous ridge were removed. No significant differences in maximal visual angle and operative depth were found between the two approaches (P > 0.05). The modified approach required a much smaller bone window compared with the presigmoid approach. The exposure in the middle of the ventral brainstem in the modified approach was much greater than in the presigmoid approach. The angle required for exposure of the temporal lobe via the ventral medulla oblongata in the modified approach was much smaller than in the presigmoid approach (P < 0.05).
  
  
  CONCLUSIONS
  The modified temporal-occipital transtentorial transpetrosal-ridge approach is a feasible surgical approach to remove petroclival tumors.
authors: Department of Neurosurgery, the First Hospital of University of Ji Lin, Chang Chun, Ji Lin, People's Republic of China.
authors: Haifeng
authors: H
authors: Lin
authors: Gang
authors: G
authors: Zhao