内镜下经鼻蝶窦入路至鞍上区的解剖与临床初步应用

Extended endoscopic endonasal transsphenoidal approach to the suprasellar region:an anatomic study and clinical application

目的研究内镜下扩大经鼻蝶窦入路至鞍区、鞍上区的显露范围,及手术入路中重要的解剖标志与其相互位置关系。结合该入路切除鞍结节脑膜瘤的临床应用体会,探讨内镜在此区域手术中面临的主要问题和解决办法。方法选择10例灌注尸头标本,采用显微镜解剖2例,其中冠状位和矢状位切开各1例;另8例标本模拟经鼻蝶窦入路。在内镜和显微镜下扩展显露鞍前及鞍上区的主要解剖标志,并研究其相互位置关系。对2例女性鞍结节脑膜瘤病人,采用神经导航经鼻蝶窦入路手术,肿瘤切除过程中和切除后分别应用成角内镜观察肿瘤周围结构及切除情况,肿瘤切除后以脂肪、人工硬膜及明胶海绵重建鞍底。结果内镜下在颅前窝向外侧显露的主要限制是两侧的眶内侧壁和视神经管;选择三个平面测量向侧方的显露范围,分别为筛骨鸡冠后缘平面(19.1±2.65)mm,鞍结节前方10mm的蝶骨平台平面(23.2±2.35)mm,两侧视神经管内口平面(13.1±2.18)mm。内镜下可清晰显示双侧视神经、视交叉、垂体柄、前交通动脉复合体等颅内结构。2例鞍结节脑膜瘤病人均达到肿瘤全切除,视力部分改善,术后均出现脑脊液漏,再次经原入路手术修补后痊愈。结论采用单纯内镜或内镜辅助的经鼻蝶窦入路可更直接达到鞍前及鞍上区病变,避免了经过重要的神经血管结构及对脑组织的牵拉。颅底骨质磨除位置和范围以及颅底的修补和重建是采用该入路需要解决的主要问题。

Objective To define the exposure extent of the sellar and suprasellar regions under the endoscope, important anatomical landmarks and their interrelations via an extended endoscopic endonasal transsphenoidal approach, and explore main problems faced by surgeons in the operation in this area and means by which the surgeons solve these problems by means of clinical experience accumulated in resecting tuberculum sellae meningiomas via this approach. Methods Ten human cadaver heads, in which the arteries and veins were injected with latex, were dissected to evaluate the surgical key steps and the advantages and limitations via extended endoscopic endonasal transphenoidal approach. Two adult cadaveric heads were sectioned longitudinally and coronally, respectively and studied by microscopy, 8 specimens were sectioned with endoscope via simulated endonasal transsphenoidal approach and selected measurements were obtained. The surgical exposure of main landmarks in the presellar and suprasellar region was extended under endoscope and microscope, and the interactions between the landmarks were studied. Two women patient with suprasellar mass underwent tumor removal via an endonasal approach by the guidance of neuronavigation with the operating microscope and endoscope alternatively. Suprasellar exposure was facilitated by removal of the posterior planum sphenoidale. The extent of tumor removal was verified with angled endoscopes in all the patients. The surgical dural defects were repaired with abdominal fat and collagen sponge. Results The exposure in anterior skull base was limited by the medial wall of orbits on both sides and optic canal. The average width between the medial orbits was measured to be 19.1±9.65 mm at the crista galli level, 23.2±9.35 mm at the planum sphenoidale level, and 13.1±9.18 mm at the level of the intracranial opening of the optic canal. The tumors were totally removed and the vision improved partly post operation in both cases. Both patients required a reoperation after the surgery because of cerebrospinal fluid leakage. Conclusion The major potential advantage of the endoscopic endonasal approach to the supra sellar region is that it provides a direct anatomical route to the lesion without traversing any major neurovascul.ar structures and traction of the brain tissue. However, a large intraoperative cerebrospinal fluid leakage, which necessitates precise and effective dural closure, is a big problem that should be solved properly.