经终板入路的显微解剖研究

Study on microanatomy of the lamina terminalis approach

目的 探讨经终板入路相关的显微解剖结构。方法 在手术显微镜下观测15例尸颅的终板、视上隐窝及相邻结构。结果 终板自前连合伸至视交叉中部,大部分区域厚度在0.25mm左右,平均曲长为（14.1×2.7）mm,最大宽度为5.0mm。视上隐窝位于视交叉后半中线区的上面,平均长度为（5.8×1.3）mm,前缘高度0～0.4mm,后缘高度0.6～2.4mm。相邻第三脑室的平均宽度为（2.21×1.1）mm。前交通动脉位于终板正上方者不足1/4。结论 经终板入路是打开终板后所获得的手术通路,大致呈梯形,后界是被后推的前交通动脉及两侧A1段;前界为视交叉后上缘;侧边为下丘脑组织及视束。中嵴或中央区高起是鉴别终板的重要标志,在视交叉前缘11mm后方沿中线上切开终板常是安全的。

Objective To study the relative microanatomical structures of the lamina terminalis approach. Methods The lamina terminalis, optic recess and adjacent structures were observed in 15 cadaveric heads under the operating microscope. Results The lamina terminalis stretches were downward from the anterior commissure to the mid-portion of the superior surface of the optic chiasma. The thickness of the lamina terminalis was about 0.25 mm. The mean length and maximal width of the lamina terminalis were (14. 1± 2. 7) mm and 5. 0 mm respectively. The optic recess was superior to the posterior half of the optic chiasma in the median line. The mean length of the recess was (5.8 ± 1.3) mm. The height of the anterior or posterior border was 0 - 0.4 mm and 0.6 -2.4 mm respectively. The mean width of the third ventricle near the recess was (2.2±1.1) mm. The anterior communicating artery superior right to the lamina terminalis was found only in less than one fourth of the cases observed. Conclusion The lamina terminalis approach is a surgical ladder-shaped interspace obtained when the lamina terminalis has been opened. The posterior border of the interspace is the anterior communicating artery and the bilateral A1 segments that have been pushed posteriorly. The anterior border is the posterior superior margin of the optic chiasma. The lateral border is the hypothalamic tissue and the optic tract. The median crest and the bulge of the central area are both important signs for the identification of the lamina terminalis. It is safe to incise the lamina terminalis on the midline at the point 11 mm posterior to the anterior margin of the optic chiasma.