Three-dimensional anatomic analysis of retrosigmoid approach with thin-section computed tomographic image.

Objective: This study aimed to locate and measure the distances between important structures of the retrosigmoid approach using both three-dimensional reconstruction technique and volume-rendering technique.

Methods: We scanned skulls of 120 volunteers to get the final result with thin-section computed tomographic image.

Results: The distance of AC was measured as 39.46 (4.22) mm (range, 15.80-50.80 mm; 95% confidence interval (CI), 38.69-40.22 mm). The diameter of internal auditory pore was measured as 5.39 (0.77) mm (range, 3.40-8.20 mm; 95% CI, 5.25-5.53 mm). The distance of AB was measured as 41.10 (4.22) mm (range, 34.90-51.30 mm; 95% CI, 39.43-42.77 mm). The distance of BC was measured as 5.93 (1.31) mm (range, 4.10-7.50 mm; 95% CI, 5.70-6.17 mm). The vertical distance was measured as 2.33 (0.26) mm (range, 1.87-2.80 mm; 95% CI, 2.23-2.42 mm).

Conclusions: These abovementioned results can help to locate these structures to help in minimizing surgical trauma to the nerve and blood vessels.