A New Method of Directing Endoscope Pathway in Single-Nostril Transpheoidal Approach for Safety by Using Volume Rendering With Thin-Section Computed Tomographic Image.

OBJECTIVE: This study aims to locate important structures surrounding the sella node and measure the distances and angles between signalized points by using both three-dimensional reconstruction technique and volume-rendering. These distances and angles can provide more accurate reference for surgeries in pituitary adenomas.

METHODS: Ninty volunteers' skulls were scanned and thin-section computed tomographic images were displayed. The highest point of saddle node on double sides were marked as point A (right) and A1 (left), the highest point of posterior Clinton process on double side as B (right) and B1 (left). And the point of alas minor ossis sphenoridalis with sohenoidal creast was marked as point O. For the latter can not been distinguished in images, point O was used to replace the anterior nasal spine, which can accurately locate the median sagittal plane. The result of three-dimensional reconstruction is used to measure the distance between O and A, A1, B, B1 and angles between OA, OA1, OB, OB1 and their projection line on the standard horizontal plane (α, α1, β, β1). Analyzing the difference by examining the significance difference between both sides can also help the authors to determine whether there is a symmetric difference.

RESULTS: The distance of OA was measured as 23.2 (6.5) mm [range, 11.2-45.2 mm; 95% confidence interval (CI), 21.9-24.4 mm]. The distance of OA1 was measured as 23.4 (5.7) mm (range, 9.9-47.2 mm; 95% CI, 22.2-24.6 mm). The distance of OB was measured as 31.1 (5.5) mm (range, 17.8-45.2 mm; 95% CI, 30.0-32.2 mm). The distance of OB1 was measured as 31.2 (6.0) mm (range, 10.1-47.8 mm; 95% CI, 30.0-32.5 mm). The angle of α was measured as 81.1 (10.0)° (range, 60-137.5°, 95% CI, 79.0-83.2°). The angle of α1 was measured as 81.3 (8.5)° (range, 60-97.4°, 95% CI, 79.5-83.1°). The angle of β was measured as 91.5 (5.2)° (range, 74.9-102.2°, 95% CI, 90.5-92.6°). The angle of β1 was measured as 91.0 (6.6)° (range, 74.7-104.7°, 95% CI, 89.2-92.0°).

CONCLUSIONS: The above results can facilitate the location of these structures and minimize surgical trauma to optic chiasm and carotid artery surrounding. The method is especially effective in promising more secure and accurate direction to guide surgeons during surgeries in pituitary adenomas.