Meningiomas involving the optic canal: pattern of involvement and implications for surgical technique

Abstract

<jats:sec> <jats:title>Object</jats:title> <jats:p>Juxtasellar meningiomas frequently extend into the optic canal. Removing these meningiomas from the optic canal is crucial for favorable visual outcome.</jats:p></jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>The authors performed a retrospective analysis of 45 patients with anterior and middle fossa meningiomas with involvement of the optic pathway in whom surgery was performed by the senior author (O.A.M.) during the period from 1993 to 2007. Extent of resection and recurrence rates were determined by pre- and postoperative MR imaging studies. Visual outcomes were evaluated with full ophthalmological examinations performed before and after surgery.</jats:p></jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>Forty-five patients (31 women and 14 men) were involved in this study; their mean age was 51.6 years. Patients were followed for a mean of 29.8 months (range 6–108 months). No surgery-related death occurred. The average tumor size was 3.1 cm. Total resection of the tumor (Simpson Grade I) was achieved in 32 patients (71.1%). Gross-total resection (Simpson Grades II and III) was achieved in 13 patients (28.9%). Only 1 patient harboring a left cavernous sinus meningioma had tumor recurrence and underwent repeat resection. Meningiomas extended into 58 optic canals in these cases; 13 patients showed extension into both optic canals. Visual disturbance was the main presenting symptom in 37 patients (82.2%); 8 patients had normal vision initially. Visual improvement after surgery was seen in 21 (57%) of 37 patients and in 27 (34.6%) of 78 affected eyes. Vision remained unchanged in 48 (61.5%) of 78 eyes. Transient postoperative visual deterioration occurred in 2 eyes (2.6%), with recovery to baseline over time. Only 1 (1.3%) of 78 eyes had permanent visual deterioration after surgery. The visual outcome was affected mainly by the tumor size, the preoperative visual status, and the duration of symptoms.</jats:p></jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>Involvement of the optic canal in meningiomas is frequent. It occurs in a wide variety of anterior skull base meningiomas and it can be bilateral. It is a prominent factor that affects the preoperative visual status and postoperative recovery. Decompression of the optic canal and removal of the tumor inside is a crucial step in the surgical management of these tumors to optimize visual recovery and prevent tumor recurrence.</jats:p></jats:sec>

Impact of anterior clinoidectomy on visual function after resection of meningiomas in and around the optic canal

“…GTR was achieved in 46 % of patients, depending upon tumor invasiveness and location. These data are highly comparable to other previous studies [6, 14]. The anterior clinoid process may be tumor-invaded, in those cases, anterior clinoidectomy may play a crucial role in reducing tumor recurrence [6, 9].…”

“…Quite regularly, these tumors extend into the optic canal. Surgical decompression of the optic nerve is the only option to preserve visual function and has been described in various single- or double-center series [4, 13, 14]. Depending on the invaded structures, optic nerve decompression can be achieved after complete tumor removal, but may also be the main surgical intention in terms of local debulking [1].…”

“…Some authors favor optic canal unroofing or even a more extended optic canal drilling including anterior clinoidectomy, although the risk of optic nerve injury either by direct injury of the drill itself or the resulting heat and the risk of a laceration of the carotid artery cannot be denied [2]. Other authors advocate purely soft tissue decompression including the use of angled endoscopes to control hidden corners [1, 5, 8, 12, 14]. …”

Sphenoid wing meningiomas: Surgical strategies and evaluation of prognostic factors influencing clinical outcomes

“…Despite extensive coagulation, the hyperostotic bone as well as its dural covering may provide a nidus for regrowth of the tumor [29,30]. Encasement of optic nerve or internal carotid artery influences total resection rate and increases risks of further neurologic deficits [31]. Resection of tumors with rich blood supply and adherence to optic nerve and tract, cerebral vessel and osseous tissue requires better exposure, more exercises to cranial nerve and vascular structures, which might increase the risk of surgical complications, prolong recovery time and even induce permanent damage in neurological function.…”

Internal and external spheno-orbital meningioma varieties: different outcomes and prognoses

“…The surgical management of these symptoms has remained controversial; some authors advocating for a wait and see approach [3,4]. Nevertheless, several surgical teams adopted a new point of view, thus giving rise to functional outcomes and prescribing complete resection associated with proptosis correction and visual conservation [5,6]. Nonetheless, this condition remains a surgical challenge with a double purpose of functional preservation and oncological resection.…”