神经内镜下经筛蝶入路视神经管减压术相关解剖及影像学研究

Anatomical and imaging studies of optic canal decompression via a trans ethmoid-sphenoid approach under neuroendoscope

目的提高神经内镜下经筛蝶入路行视神经管减压术的安全性与准确性。方法选用6例(12侧)成人头颅干性标本,行眼眶三维CT扫描并重建,在CT图片上测量并利用公式计算相关参数;分别沿水平面和矢状面切开头颅标本,测量相关解剖学参数。对比CT影像与实体解剖两种方法所测得的相关数据。选用6例(12侧)灌注头颅湿性标本,模拟神经内镜下经筛蝶入路视神经管减压术,内镜下进行观察和测量。结果视神经管颅口、眶口、管中段处的周长分别为(16.42±1.56)mm、(17.32±1.60)mm和(13.58±1.42)mm。内镜下视神经管颅口、眶口及管中段可磨除内壁的最大有效宽度分别为(7.82±2.63)mm、(8.05±2.77)mm和(6.92±2.01)mm。鞍结节隐窝中心点和视神经管颅口内侧壁中点连线与横坐标之间的角度为(17.23±1.34)°。在视神经管眶口处,眼动脉位于视神经正下方2侧(16.7%)和外下方10侧(83.3%)。结论神经内镜下经筛蝶入路视神经管减压术是一种入路直接、减压充分的微创手术。术前仔细阅读CT影像资料并作相关测量,结合多种定位方法能提高手术准确性。

Objective To improve the safety and accuracy of optic canal decompression via a trans ethmoid-sphenoid approach under neuroendoscope. Methods Three dimensional CT scan and reconstruction of the optic canal were performed respectively on 6 dry cadaver heads（12 sides）. The related anatomic parameters were measured and calculated on CT images. Then the heads were cut open along the horizontal plane and sagittal plane in order, and the related anatomic parameters were also measured. The relative data measured by two methods, CT image and entity dissection, were compared. Simulated surgery of trans ethmoid-sphenoid neuroendoscopic optic canal decompression was performed on 6 fresh adult cadaver heads（12 sides）, and the anatomic landmarks of the approach were observed and recorded. Results The circumferences of the orbital opening, cranial opening and middle of the optic canal were（16.42 ± 1.56） mm,（17.32 ± 1.60） mm and（13.58 ± 1.42） mm. The maximum effective drilling widths of the medial wall of optic canal in orbital opening, cranial opening and middle of the optic canal were（7.82 ± 2.63） mm,（8.05 ± 2.77） mm and（6.92 ± 2.01） mm.The angle between the line linking the center point of the tubercular recess with the cranial opening of the optic canal and the horizontal coordinate was（17.23 ± 1.34）°. At the orbital opening of the optic canal, ophthalmic arteries were under the optic never in 2 sides（16.7%）and lateral-inferior portion in 10（83.3%）. Conclusions The endoscopic trans ethmoid-sphenoid optic canal decompression is a minimally invasive surgery with direct approach and complete decompression. Careful reading the CT images and making the related measurement preoperatively, using a variety of positioning methods can improve the accuracy of surgery.