Locatelli Marco, Caroli Manuela, Pluderi Mauro, Motta Federica, Gaini Sergio Maria, Tschabitscher Manfred, Scarone Pietro
Neurosurgery Department, Fondazione IRCCS Ospedale Maggiore Policlinico Ca' Granda Milano, Milan, Italy.
Surg Radiol Anat. 2011 Apr;33(3):257-62. doi: 10.1007/s00276-010-0734-1. Epub 2010 Oct 15.
The endoscopic transnasal, transsphenoidal approach is considered by many a valid option to reach the sellar region and, in selected cases, to decompress the optic nerve. However, few data are available in literature about the real effectiveness of the procedure and the extent of nerve decompression needed to obtain a clinical result. The aim of this anatomical study was to describe the most important landmarks of the endoscopic transsphenoidal approach to the optic nerve.
Six silicone-injected cadaver heads were dissected via the endoscopic transnasal approach, performing a bilateral optic nerve decompression. The lateral optocarotid recess (OCR) and optic canal were identified in each case. Moreover, the relationship between the ophthalmic artery at its origin and the optic nerve was examined.
Twelve decompressions of the optic nerve were performed, obtaining the following measurements: intercarotid distance 12 mm ± 1.5, median length of OCR 5 mm ± 1 and average length of optic nerve decompression 15 mm ± 2. The ophthalmic artery was observed emerging from the internal carotid artery (ICA) medially in six cases, ventrally in four cases and laterally in two cases.
A wide optic nerve decompression may be obtained with transsphenoidal approach. However, the risk of ophthalmic artery injury seems to be more relevant than with supratentorial approaches, due to the intimate relationship between artery and nerve on its inferior surface. Knowledge of anatomical landmarks, such as lateral OCR and the position of the ophthalmic artery, is useful to prevent this injury.
经鼻内镜经蝶窦入路被许多人认为是到达鞍区的有效选择，在某些特定情况下，还可对视神经进行减压。然而，关于该手术实际效果以及获得临床疗效所需的神经减压程度，文献中几乎没有相关数据。本解剖学研究的目的是描述经鼻内镜经蝶窦入路至视神经的最重要标志。
通过经鼻内镜入路对6个注入硅胶的尸头进行解剖，进行双侧视神经减压。在每个病例中识别外侧视神经颈动脉隐窝（OCR）和视神经管。此外，检查眼动脉起始处与视神经之间的关系。
共进行了12次视神经减压，获得以下测量结果：颈动脉间距12 mm±1.5，OCR中位长度5 mm±1，视神经减压平均长度15 mm±2。观察到眼动脉在6例中从颈内动脉（ICA）内侧发出，4例从腹侧发出，2例从外侧发出。
经蝶窦入路可实现广泛的视神经减压。然而，由于动脉与神经在下表面的密切关系，眼动脉损伤的风险似乎比经幕上入路更大。了解外侧OCR和眼动脉位置等解剖标志有助于预防这种损伤。
