Pituitary Unit of the Department of Neurosurgery and Gamma Knife Radiosurgery, IRCCS San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Via Olgettina 60, 20132, Milan, Italy.
Pituitary. 2018 Feb;21(1):98-106. doi: 10.1007/s11102-017-0842-6.
Chiasmapexy is a poorly described surgical procedure adopted to correct the downward displacement of suprasellar visual system (SVS) into an empty sella (ES) causing visual worsening. The aim of our study is to define the indications for extradural and intradural chiasmapexy.
A systematic literature review has been performed on MEDLINE database (US National Library of Medicine), including only articles that depicted cases of surgically treated patients affected by ES and progressive delayed visual worsening. Moreover, we have reported three cases of secondary ES syndrome (SESS) with visual worsening treated in our Department with transsphenoidal (TS) microsurgical intradural approach. Finally, we have compared the results of extradural and intradural chiasmapexy described in literature.
The etiology of visual impairment is different in primary and secondary ESS. In primary ESS (PESS) the only predisposing factor is a dehiscence of diaphragma sellae, and the anatomical distortion caused by displacement of optic chiasm or traction of pituitary stalk and infundibulum may determine a direct injury of neural fibers and ischemic damage of SVS. In PESS the mechanical elevation of SVS performed through extradural approach is sufficient to resolve the main pathologic mechanism. In SESS, arachnoidal adhesions play an important role in addition to downward herniation of SVS. Consequently, the surgical technique should provide elevation of SVS combined to intradural release of scar tissue and arachnoidal adhesions. In treatment of SESS, the intradural approaches result to be more effective, guaranteeing the best visual outcomes with the lowest complications rates.
The intradural chiasmapexy is indicated in treatment of SESS, instead the extradural approaches are suggested for surgical management of PESS.
视神经交叉固定术是一种描述不佳的手术程序，用于矫正视交叉向下移位至空蝶鞍（ES），导致视力恶化。我们研究的目的是定义硬膜外和硬膜内视神经交叉固定术的适应证。
我们在 MEDLINE 数据库（美国国立医学图书馆）上进行了系统的文献综述，仅包括描述接受 ES 伴进行性延迟性视力恶化的手术治疗患者的病例的文章。此外，我们报告了我们科室治疗的 3 例继发性 ES 综合征（SESS）伴视力恶化的病例，采用经蝶窦（TS）显微外科硬膜内入路治疗。最后，我们比较了文献中描述的硬膜外和硬膜内视神经交叉固定术的结果。
视觉损害的病因在原发性和继发性 ESS 中不同。在原发性 ES（PESS）中，唯一的易感因素是鞍隔的破裂，视交叉或垂体柄和漏斗的移位引起的解剖学扭曲可能导致神经纤维的直接损伤和 SVS 的缺血性损伤。在 PESS 中，通过硬膜外入路进行的 SVS 的机械抬高足以解决主要的病理机制。在 SESS 中，蛛网膜粘连除了 SVS 的向下突出外，也起着重要的作用。因此，手术技术应提供 SVS 的抬高，并结合瘢痕组织和蛛网膜粘连的硬膜内松解。在 SESS 的治疗中，硬膜内入路的效果更好，能保证最好的视觉效果和最低的并发症发生率。
硬膜内视神经交叉固定术适用于 SESS 的治疗，而硬膜外入路则适用于 PESS 的手术治疗。
