High incidence of optic canal involvement in tuberculum sellae meningiomas: rationale for aggressive skull base approach

Case of acute optic nerve compression caused by tuberculum sellae meningioma with optic canal involvement

We present detailed ophthalmic findings in a case of tuberculum sellae meningioma with acute visual symptoms due to optic canal involvement. A 62-year-old Japanese woman reported a 1-week history of headaches and blurred vision in her left eye. Her visual acuity was 0.3 in the left eye with no ophthalmoscopic abnormalities. A relative afferent pupillary defect and inferior temporal field defect were found in the left eye. Pattern visual evoked potentials were undetectable in the left eye. Enhanced magnetic resonance imaging showed a 9 mm intracranial lesion around the left optic nerve anterior to the chiasm. She was diagnosed with granulomatous inflammation because of the increased cell counts and protein concentration in the cerebrospinal fluid. She was treated with steroid pulse therapy, and her visual acuity and visual field defect improved to normal in 3 weeks. However, 16 months after the onset, she suffered from headaches again and had a complete loss of vision in her left eye. There was no response to steroid pulse therapy. Enhanced magnetic resonance imaging revealed that the lesion had extended into the left optic canal, and emergency tumor removal surgery was carried out. The histopathological diagnosis was meningioma. One month after the surgery, her left visual acuity improved to 1.2, and her visual field was almost normal. Pattern visual evoked potentials were present but had a prolonged P₁₀₀ latency of 170 ms. A thinning of the ganglion cell complex was detected by optical coherence tomography. Ophthalmologists should be aware that a small tuberculum sellae meningioma can cause acute visual symptoms due to optic canal involvement. Early consultation with a neurosurgeon is necessary. Visual evoked potentials and optical coherence tomography are sensitive and helpful in following patients with optic nerve compression.

The Importance and Timing of Optic Canal Exploration and Decompression During Endoscopic Endonasal Resection of Tuberculum Sella and Planum Sphenoidale Meningiomas

BACKGROUND:

Suprasellar meningiomas often invade the optic canals (OCs). The feasibility of removing these tumors through a minimal-access endonasal route has been demonstrated, but the importance, safety, and timing of OC exploration and decompression are not well described.

OBJECTIVE:

To create a simple decision-tree algorithm for OC exploration and decompression in the endonasal endoscopic surgery for planum sphenoidale and tuberculum sella meningiomas.

METHODS:

We identified a consecutive series of 8 planum sphenoidale and tuberculum sella meningiomas resected endonasally. “Late” OC exploration and decompression was performed in 4 of 8 patients. The extent of resection, visual outcome, and complications were recorded.

RESULTS:

Five patients had OC invasion on magnetic resonance imaging. Endoscopic inspection did not reveal additional OC invasion. The OC was opened bilaterally in 2 patients and unilaterally in 2 patients. Gross total resection was achieved in 6 of 7 patients in whom it was the goal. Vision improved in 3 patients (3 of 3 OCs opened) and was stable in 4 (1 of 4 OCs opened). In 1 patient, the bitemporal hemianopsia improved, but there was unilateral deterioration (no OC invasion) because the tumor was extremely adherent to 1 optic nerve. After an average follow-up of 20.9 months, all patients had an Glasgow Outcome Scale score of 5, and there were no cerebrospinal fluid leaks.

CONCLUSION:

Exploration and decompression of the OC are feasible, safe, and important to optimize visual outcome and to minimize recurrence in planum sphenoidale and tuberculum sella meningiomas resected endonasally. It may not be important to open the canal early during surgery because tumor debulking can be performed without manipulating the optic nerves. Early decompression, however, is technically feasible.

Endoscopic skull base surgery: a comprehensive comparison with open transcranial approaches

Little data exists comparing endoscopic endonasal approaches to pathology of the anterior skull base with more traditional transcranial and transsphenoidal microscopic approaches. In order to more fully characterize the role of endoscopy in the management of pathology of the anterior cranial base, we conducted a systematic review of case series and case reports documenting surgical and clinical outcomes. We found that for craniopharyngiomas, clival chordomas, esthesioneuroblastomas and giant pituitary adenomas, the endonasal endoscopic approach can result in equivalent or higher rates of gross total resection than open approaches. For meningiomas, however, open transcranial approaches are still able to achieve higher rates of total resection. CSF leak rates are higher for patients undergoing endoscopic surgery for meningiomas and craniopharyngiomas, but not for chordomas, esthesioneuroblastomas or giant pituitary adenomas. In certain patients, the endonasal endoscopic approach may be a safe and effective alternative for the treatment of a wide variety of skull base pathology, particularly those with small midline tumours.

Endoscopic endonasal versus open transcranial resection of anterior midline skull base meningiomas

OBJECTIVE

To assess the advantages and limitations of the endoscopic endonasal approach to anterior skull base meningiomas, a minimally invasive approach that avoids extensive bone drilling, brain retraction, and manipulation of nerves and critical vessels, versus open transcranial surgery.

METHODS

A MEDLINE (2000-2010) search was performed to identify series for either olfactory groove meningiomas or tuberculum sellae (TS) or planum sphenoidale meningiomas. Statistical analyses of categorical variables such as extent of resection, morbidity, and visual outcome were performed using χ(2) and Fisher exact tests.

RESULTS

The literature review included 60 studies, involving 1426 patients. Open surgery achieved a higher rate of gross total resection (GTR) for both olfactory groove (P < 0.001) and TS and planum (P < 0.001) meningiomas. Postoperative cerebrospinal fluid (CSF) leak occurred more frequently in the endoscopic cohort (P < 0.001). Other postoperative complications occurred more frequently in the open cohort, although this difference was not statistically significant. There were no significant differences in postoperative visual outcome between the groups.

CONCLUSIONS

Based on the current literature, open transcranial approaches for olfactory groove and TS and planum sphenoidale meningiomas still result in higher rates of total resection with lower postoperative CSF leak rates. The endoscopic endonasal approach may be safe and effective for certain skull base meningiomas; careful patient selection and multilayer closure techniques are essential.

Complications of anterior clinoidectomy through lateral supraorbital approach

OBJECTIVE

We reviewed the surgical complications from our recent experience in vascular and tumor patients who underwent anterior clinoidectomy through the lateral supraorbital (LSO) approach.

METHODS

Between June 2007 and January 2011, a total of 82 patients with neoplastic and vascular lesions underwent anterior clinoidectomy by the senior author (J.H.) through the LSO approach. We analyzed the operative videos paying particular attention to the surgical technique used for removal of the anterior clinoid process (ACP) and compared the microsurgical nuances to postoperative complications related to anterior clinoidectomy.

RESULTS

Forty-five patients were treated for aneurysms; 35 patients for intraorbital, parasellar, and suprasellar tumors; and 2 patients for carotid-cavernous fistulas. Intradural anterior clinoidectomy was performed in 67 (82%) cases; in 15 (18%) cases an extradural approach was used. In 51 (62%) cases, ACP was removed completely, whereas in the remaining 31 (38%) a tailored anterior clinoidectomy was performed. Four (5%) patients had new postoperative visual deficits and 3 (4%) experienced a worsening of preoperative visual deficits. Twelve (15%) patients improved their preoperative visual deficits after intradural anterior clinoidectomy. Ultrasonic bone device is a useful tool but may damage the optic nerve when performing anterior clinoidectomy. There was no mortality in our series.

CONCLUSION

Anterior clinoidectomy can be performed through an LSO approach with a safety profile that is comparable to other approaches. Ultrasonic bone dissector is a useful tool but may lead to injury of the optic nerve and should be used very carefully in its vicinity.

Anterior interhemispheric approach for tuberculum sellae meningioma

BACKGROUND

The tuberculum sellae meningioma (TSM) arises from the tuberculum sellae, chiasmatic sulcus, and limbus sphenoidale.

OBJECTIVE

To retrospectively analyze patients with TSM who underwent surgery via an anterior interhemispheric approach, with special attention to visual outcomes.

METHODS

Nine consecutive patients between April 2004 and December 2009 were examined. Visual impairment score (VIS) was used to analyze the visual status of the patients. A VIS is the sum of the scores in specific tables for visual acuity and visual field defects. Visual status was sequentially evaluated in the preoperative period and within 2 weeks of the operation. Any change in the VIS was considered an improvement or deterioration of visual function. All tumors were removed via an anterior interhemispheric approach. Following the wide dissection of the interhemispheric fissure, the tumor was first detached from its origin and debulked with the ultrasonic aspirator starting at the midline. The debulking continued until the arachnoid plane separating the nerve and tumor was visualized.

RESULTS

Gross total resection (Simpson I + II) was achieved in all 9 patients. The average VIS was 56.1 in the preoperative period and 26.3 in the postoperative period. Among 9 patients, 8 patients had an improvement of the VIS after surgery. VIS was unchanged in 1 patient, and no patients experienced visual deterioration. Other nonvisual complications, such as rhinoliquorrhea, venous infarction, and permanent anosmia, occurred in 3 patients.

CONCLUSION

Despite the small number of patients, a high resection rate and favorable visual outcome support the suitability of this approach for resection of TSM.

Surgical nuances for removal of tuberculum sellae meningiomas with optic canal involvement using the endoscopic endonasal extended transsphenoidal transplanum transtuberculum approach

Tuberculum sellae meningiomas frequently extend into the optic canals. Radical tumor resection including the involved dural attachment, underlying hyperostotic bone, and intracanalicular tumor in the optic canal offers the best chance of a Simpson Grade I resection to minimize recurrence. Decompression of the optic canal with removal of the intracanalicular tumor also improves visual outcome since this portion of the tumor is usually the cause of asymmetrical visual loss.

The purely endoscopic endonasal extended transsphenoidal approach offers a direct midline trajectory and immediate access to tuberculum sellae meningiomas without brain retraction and manipulation of neurovascular structures. Although the endoscopic approach has been previously criticized for its inability to remove tumor within the optic canals, complete Simpson Grade I tumor removal including intracanalicular tumor, dural attachment, and involved hyperostotic bone can be achieved in properly selected patients. Excellent visualization of the suprasellar region and the inferomedial aspects of both optic canals allows for extracapsular, extraarachnoid dissection of the tumor from the critical structures using bimanual microsurgical dissection.

In this report, the authors describe the operative nuances for removal of tuberculum sellae meningiomas with optic canal involvement using a purely endoscopic endonasal extended transsphenoidal (transplanum transtuberculum) approach. They specifically highlight the technique for endonasal bilateral optic nerve decompression and removal of intracanalicular tumor to improve postoperative visual function, as demonstrated in 2 illustrative cases. Special attention is also given to cranial base reconstruction to prevent CSF leakage using the vascularized pedicled nasoseptal flap.

Optic canal involvement in tuberculum sellae meningiomas: influence on approach, recurrence, and visual recovery

BACKGROUND

Tuberculum sellae meningiomas frequently extend into the optic canals.

OBJECTIVE

To emphasize the high frequency of optic canal (OC) involvement in tuberculum sellae meningiomas; the importance of opening the OC and of removing tumor within the canal; and the effect of this maneuver on visual outcome, recurrence rates, and surgical approach selection.

METHODS

A retrospective review of 58 patients with tuberculum sellae meningiomas treated surgically by the senior author (O.A.M) between 1993 and 2009 was performed. The frequency of involvement of the OC was documented, as well as the impact of removal of this part of the tumor on visual outcome and recurrence.

RESULTS

Total resection (Simpson grade 1) was achieved in 51 of 58 patients (87.9%). The tumor invaded the optic canal in 67%. Tumor resection from the optic nerve was achieved in all cases, and most (92%) underwent deroofing of the OC for this purpose. The dura over the tuberculum sella and/or planum sphenoidale was removed in all patients. Eighty-three percent required removal of affected hyperostotic bone. Vision was improved and/or spared in 88%. The average follow-up period was 23 months with 1 recurrence detected.

CONCLUSION

In the majority of cases, tuberculum sellae meningiomas extend into 1 or both OCs. Opening the OC for resection of the intracanalicular portion of the tumor enabled us to achieve excellent visual outcome. The supraorbital craniotomy remains the favored approach for removal of such tumors because it allows unroofing of both OCs, wide excision of the dura, and drilling of the affected bone.