TechniqueHigh incidence of optic canal involvement in tuberculum sellae meningiomas: rationale for aggressive skull base approach
Introduction
A significant number of patients with TSM present with visual deficits. Despite the improvement of microsurgical techniques and refinement of microsurgical tools, the incidence of postoperative visual deterioration, although improved over in time [9], is still seen in a considerable number of patients. The current literature on the surgical management of TSM underemphasizes the incidence of OCI. Various preoperative factors such as the duration and severity of the visual symptoms, presence of optic atrophy, and intraoperative factors such as the tumor size, displacement pattern of the critical neurovascular structures, as well as the extent of surgical resection have been analyzed with regard to the visual outcome. However, OCI of the tumor has been mentioned in only a handful of articles and without much detailed analysis with respect to visual outcome. Its incidence ranges from 8% to 100% in the reported series [3], [8], [10], [17], [22].
In this study, we aimed to document the incidence of OCI in our series of TSM and assess its significance with respect to the preoperative visual status. In addition, we report on our patients' surgical outcome using the SBT described below, with a subanalysis of the significance of OCI.
Section snippets
Methods
Between June 1994 and June 2006, 31 patients with TSM have been operated by the senior author at the Cleveland Clinic. In 28 of the 31 patients, the tumor was approached via the SBT consisting of a standard pterional craniotomy, posterolateral orbitotomy with superior orbital fissure decompression, extradural anterior clinoidectomy, and opening of the falciform ligament and the optic nerve sheath (ONS). The details of the technique are described elsewhere [14]. In 2 patients, bilateral approach
Results
Visual deficit was present in 26 patients (83.8%), and OCI was detected in 24 (77.4%) (Table 1). Presence of OCI was strongly correlated with preoperative visual deficit (correlation coefficient, 0.392; P = .016).
Anterior clinoid process hypertrophy was documented in 11 patients (35.5%): in 11 (42.3%)of 26 patients with visual deficit compared to none in 5 patients without (correlation coefficient, 0.325; P = .037). Presence of ACPH showed a strong correlation with OCI as well (correlation
The significance of the OCI
In our experience, most (77.4%) of TSMs had extension of the tumor into the optic canal. The incidence was significantly higher in patients who presented with preoperative visual deficit (84.6%) compared to those whose vision was intact (40%).
Optic canal involvement may be appreciated in preoperative MRI in only a small number of the patients (Fig. 1) and is not visible in most mainly because of technical factors such as the slice thickness of the MRI. Given this observation of 77.4% incidence
Conclusions
There is a high incidence of OCI in TSM, and this correlates very strongly with the preoperative visual status. Because the OCI can be appreciated only in a small group of patients in preoperative MRI, lack of direct exploration of the optic canal may result in missing the small tumor extension in most of the cases. This may result in (1) unimproved or deteriorated vision or (2) higher recurrence as grade I or II resection will not be achieved.
Our results on visual outcome using the SBT
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2022, Journal of Clinical NeuroscienceAccuracy and Interrater Reliability of CISS Versus Contrast-Enhanced T1-Weighted VIBE for the Presence of Optic Canal Invasion in Tuberculum Sellae Meningiomas
2021, World NeurosurgeryCitation Excerpt :As these tumors grow, they will engulf and compress the surrounding neurovascular structures but will usually respect the arachnoid plane.22,24 Early surgical intervention is highly recommended for symptomatic patients, with these interventions aiming to adequately decompress the optic nerve with minimal manipulation of the optic apparatus.21,25,26 To achieve this goal, preoperative evaluation of optic canal invasion is critical to allow surgeons to plan the best approach and predict the visual prognosis.22,27
Current decision-making in meningiomas
2020, Handbook of Clinical NeurologyCitation Excerpt :Factors that may be predictive of postoperative visual status are age, severity and duration of visual symptoms, optic disc pallor, binocular involvement, size of the tumor, shape of the tumor, extent of resection, presence of an arachnoidal plane, and the presence of peritumoral edema (Ohta et al., 2001; Zevgaridis et al., 2001; Fahlbusch and Schott, 2002; Goel et al., 2002; Jallo and Benjamin, 2002; Pamir et al., 2005b; Mathiesen and Kihlstrom, 2006; Mahmoud et al., 2010; Mariniello et al., 2013). Tumor extension into the optic canal is a significant source of postoperative recurrence with visual impairment (Sade and Lee, 2009; Mahmoud et al., 2010; Attia et al., 2012a; Mariniello et al., 2013; Spektor et al., 2013; Nimmannitya et al., 2016). Optic canal invasion can be effectively addressed using standard or skull base approaches (Sade and Lee, 2009; Mahmoud et al., 2010; Attia et al., 2012a; Mariniello et al., 2013; Spektor et al., 2013; Nimmannitya et al., 2016).
Natural history of intracranial meningiomas
2020, Handbook of Clinical NeurologyTechnical Description of Minimally Invasive Extradural Anterior Clinoidectomy and Optic Nerve Decompression. Study of Feasibility and Proof of Concept
2019, World NeurosurgeryCitation Excerpt :In cases of tumoral diseases, optic nerve decompression not only improves the visual outcome but also increases the degree of possible tumor resection.25 Early optic nerve decompression is essential for enhancing visual recovery, especially in cases of tuberculum sellae and planum sphenoidale meningiomas in which optic nerve decompression has been recommended before tumor removal.35 Margalit et al.4 concluded that early decompression of the intracanalicular optic nerve allows identification and separation of the tumor from the nerve and allows removal of them from this area with minimal manipulation of the optic nerve.