Mariniello Giuseppe, Bonavolontà Giulio, Tranfa Fausto, Maiuri Francesco
Department of Neurological Sciences, Neurosurgical Clinic, Federico II University School of Medicine, Naples, Italy.
Clin Neurol Neurosurg. 2013 Sep;115(9):1615-20. doi: 10.1016/j.clineuro.2013.02.012. Epub 2013 Mar 7.
Spheno-orbital meningiomas often present with visual deficit due to invasion of the optic canal by the tumor. This study discusses the reasons of visual impairment, the choice of the surgical approach according to the type of optic canal involvement, and the factors correlated to the visual outcome in patients harboring a spheno-orbital meningioma.
A surgical series of 60 spheno-orbital meningiomas is reviewed. The preoperative visual symptoms, the involvement of the optic canal in both neuroradiological studies and surgical descriptions, the different surgical approaches are reviewed. These data are correlated with the postoperative visual outcome.
The 60 spheno-orbital meningiomas were classified in 4 types according to the intraorbital tumor localization: type I, supero-lateral (18 cases); type II, inferomedial (8 cases); type III, orbital apex (22 cases); type IV, diffuse (12 cases). Thirty-six of the 60 patients (60%) had variable decrease of the visual acuity on the tumor side. Forty-three patients (71.6%) had tumor extension into the optic canal on imaging studies. On the whole, 36 patients among 43 with invasion of the optic canal (83.7%) had preoperative visual dysfunction; on the other hand, none among 17 patients without tumor invasion of the optic canal had visual dysfunction. The surgical approaches according to the tumor location were as follows. A supraorbital-pterional approach was used in the 8 inferomedial tumors, in the 22 orbital apex tumors, and in 9/12 diffuse tumors; these last two types had concentric involvement of the optic canal. Three diffuse tumors with significant extension in the infratemporal fossa were operated on via a frontotemporal-orbitozygomatic approach. A wide decompression of the optic canal was performed in all cases, excepting in two inferomedial tumors without optic canal invasion. The 18 patients with lateral tumors were approached via a lateral orbitocranial approach, including removal of the sphenoid wing and lateral orbital wall without bone flap; the resection of the lateral aspect of the optic canal was performed in the 3 cases with canal invasion. Postoperative improvement of the visual function was observed in 18 of 36 cases with visual dysfunction (50%). The rate of visual improvement was significantly higher in cases with lateral involvement (3/3 or 100%) than in those with concentric involvement of the optic canal (11/27 or 40.7%).
The invasion of the optic canal by the tumor is the main reason of visual dysfunction in patients with spheno-orbital meningiomas. A wide opening of the optic canal must be performed routinely in patients with orbital apex and diffuse orbital tumors, where there is concentric invasion of the optic canal wall. In these cases the supraorbital-pterional approach is the technique of choice. In selected cases with lateral intraorbital tumors and invasion of the lateral aspect of the optic canal the complete tumor resection coupled with good decompression of the optic nerve may be achieved via a less invasive lateral orbitocranial approach without craniotomy.
蝶眶脑膜瘤常因肿瘤侵犯视神经管而导致视力缺损。本研究探讨视力损害的原因、根据视神经管受累类型选择手术入路以及蝶眶脑膜瘤患者视力预后的相关因素。
回顾性分析60例蝶眶脑膜瘤的手术病例。复习术前视觉症状、神经影像学检查及手术描述中视神经管的受累情况、不同的手术入路。将这些数据与术后视力预后相关联。
60例蝶眶脑膜瘤根据眶内肿瘤定位分为4型：I型，眶上外侧（18例）；II型，眶内下（8例）；III型，眶尖（22例）；IV型，弥漫型（12例）。60例患者中有36例（60%）患侧视力有不同程度下降。43例（71.6%）患者影像学检查显示肿瘤侵犯视神经管。总体而言，43例视神经管受侵患者中有36例（83.7%）术前存在视觉功能障碍；另一方面，17例视神经管未受肿瘤侵犯的患者中无一例有视觉功能障碍。根据肿瘤位置选择的手术入路如下。8例眶内下肿瘤、22例眶尖肿瘤以及12例弥漫型肿瘤中的9例采用眶上翼点入路；后两种类型视神经管呈同心圆状受累。3例颞下窝有明显扩展的弥漫型肿瘤采用额颞眶颧入路手术。除2例未侵犯视神经管的眶内下肿瘤外，所有病例均对视神经管进行了广泛减压。18例外侧肿瘤患者采用外侧眶颅入路，包括不做骨瓣切除蝶骨翼和外侧眶壁；3例视神经管受侵患者切除了视神经管外侧部分。36例视觉功能障碍患者中有18例（50%）术后视觉功能改善。外侧受累患者的视力改善率（3/3或100%）明显高于视神经管同心圆状受累患者（11/27或40.7%）。
肿瘤侵犯视神经管是蝶眶脑膜瘤患者视觉功能障碍的主要原因。对于视神经管呈同心圆状受累的眶尖及弥漫性眶部肿瘤患者，必须常规对视神经管进行广泛开放。在这些病例中，眶上翼点入路是首选技术。在某些眶内外侧肿瘤且视神经管外侧受侵的病例中，通过创伤较小的外侧眶颅入路且不做开颅手术，可实现肿瘤全切并对视神经进行良好减压。
