Objective:Surgical operation within the region of the jugular foramen presents a great challenge. The authors characterized the quantitative impact of surgical window parameters on the exposure of the jugular foramen via a trans-mastoidal approach.Methods:Computed tomography and magnetic resonance imaging data were used to establish a 3-dimensional model of the jugular foramen region. The mastoidale, posterior edge of the mastoid, and the superior edge of the bony external acoustic meatus were selected as points a, b, and c. The anterior edge of the tuberculum jugulare was selected as point d. The midpoints of line segments ab, ac, and bc were selected as points e, f, and g. Triangle abc was divided into triangles aef, beg, cfg, and efg. Surgical corridors of the triangular pyramid were outlined by connecting the above triangles to point d. Anatomic exposure was evaluated by measuring the area and volume of various structures within each route. Statistical comparisons were performed via analysis of variance.Results:The model allowed for adequate visualization of all structures. The areas of triangles beg and efg were greater than those of triangles aef and cfg (P<0.05). The volumes of triangular pyramids d-beg and d-cfg were greater than those of triangular pyramids d-aef and d-efg (P=0.000). Statistically significant differences were also observed for volumes of osseous, venous, and cranial nerve structures in all divided routes (P=0.000).Conclusion:Our results indicate that 3-dimensional modeling may aid in the quantification of surgical exposure and that division of the craniotomy window may allow for more precise operation.