Surgical management of giant sphenoid wing meningiomas encasing major cerebral arteries

OBJECTIVE Sphenoid wing meningiomas are a heterogeneous group of tumors with variable surgical risks and prognosis. Those that have grown to a very large size, encasing the major cerebral arteries, are associated with a high risk of stroke. In reviewing the authors' series of giant sphenoid wing meningiomas, the goal was to evaluate how the extent of the tumor's invasion of surrounding structures affected the ability to safely remove the tumor and restore function. METHODS The authors conducted a retrospective study of a series of giant sphenoid wing meningiomas operated on between 1996 and 2016. Inclusion criteria were meningiomas with a globoid component ≥ 6 cm, encasing at least 1 major intradural cerebral artery. Extent of resection was measured according to Simpson grade. RESULTS This series included 12 patients, with a mean age of 59 years. Visual symptoms were the most common clinical presentation. There was complete or partial encasement of all 3 major cerebral arteries except for 3 cases in which only the anterior cerebral artery was not involved. The lateral wall of the cavernous sinus was invaded in 8 cases (67%) and the optic canal in 6 (50%). Complete resection was achieved in 2 cases (Simpson grades 2 and 3). In the remaining 10 cases of partial resection (Simpson grade 4), radical removal (> 90%) was achieved in 7 cases (70%). In the immediate postoperative period, there were no deaths. Four of 9 patients with visual deficits improved, while the 5 others remained unchanged. Two patients experienced transient neurological deficits. Other than an asymptomatic lacuna of the internal capsule, there were no ischemic lesions following surgery. Tumor recurrence occurred in 5 patients, between 24 and 168 months (mean 61 months) following surgery. CONCLUSIONS Although these giant lesions encasing major cerebral arteries are particularly treacherous for surgery, this series demonstrates that it is possible to safely achieve radical removal and at times even gross-total resection. However, the risk of recurrence remains high and larger studies are needed to see if and how improvement can be achieved, whether in surgical technique or technological advances, and by determining the timing and modality of adjuvant radiation therapy.

Isolated optic nerve gliomas: a multicenter historical cohort study

OBJECTIVE Isolated optic nerve gliomas (IONGs) constitute a rare subgroup of optic pathway gliomas (OPGs). Due to the rarity of this condition and the difficulty in differentiating IONGs from other types of OPGs in most clinical series, little is known about these tumors. Currently, due to lack of evidence, they are managed the same as any other OPG. METHODS The authors conducted a multicenter retrospective cohort study aimed at determining the natural history of IONGs. Included were patients with clear-cut glioma of the optic nerve without posterior (chiasmatic/hypothalamic) involvement. At least 1 year of follow-up, 2 MRI studies, and 2 neuro-ophthalmological examinations were required for inclusion. RESULTS Thirty-six patients with 39 tumors were included in this study. Age at diagnosis ranged between 6 months and 16 years (average 6 years). The mean follow-up time was 5.6 years. Twenty-five patients had neurofibromatosis Type 1. During the follow-up period, 59% of the tumors progressed, 23% remained stable, and 18% (all with neurofibromatosis Type 1) displayed some degree of spontaneous regression. Fifty-one percent of the patients presented with visual decline, of whom 90% experienced further deterioration. Nine patients were treated with chemotherapy, 5 of whom improved visually. Ten patients underwent operation, and no local or distal recurrence was noted. CONCLUSIONS Isolated optic nerve gliomas are highly dynamic tumors. Radiological progression and visual deterioration occur in greater percentages than in the general population of patients with OPGs. Response to chemotherapy may be better in this group, and its use should be considered early in the course of the disease.

Direct visualization of improved optic nerve pial vascular supply following tuberculum meningioma resection: case report

Tuberculum sellae meningiomas frequently produce visual loss by direct compression from tumor, constriction of the optic nerve (ON) under the falciform ligament, and/or ON ischemia. The authors hypothesized that changes in visual function after tumor removal may be related to changes in blood supply to the ON that might be seen in the pial circulation at surgery. Indocyanine green (ICG) angiography was used to attempt to document these changes at surgery. The first patient in whom the technique was used had a left-sided, 1.4-cm, tuberculum meningioma. Time-lapse comparison of images was done postsurgery, and the comparison of video images revealed both faster initial filling and earlier complete filling of the ON pial circulation, suggesting improved pial blood flow after surgical decompression. In follow-up the patient had significant improvements in both visual acuity and visual fields function. Intraoperative ICG angiography of the ON can demonstrate measurable changes in pial vascular flow that may be predictive of postoperative visual outcome. The predictive value of this technique during neurosurgical procedures around the optic apparatus warrants further investigation in a larger cohort.