Endoscopic transnasal surgery for planum and tuberculum sella meningiomas: decision-making, technique and outcomes

Optimizing Surgical Management of Anterior Skull Base Meningiomas: Imaging Modalities, Key Surgical Considerations, and Risk Mitigation Strategies

Skull base meningiomas present considerable challenges in surgical management due to their proximity to critical neurovascular structures. Anterior skull base meningiomas encompass olfactory groove, supra- and parasellar, anterior sphenoid ridge, cavernous sinus, and spheno-orbital tumors. The success of surgical resection and the likelihood of complications are influenced by several key factors, including the presence of an intact arachnoid plane, tumor size and consistency, peritumoral brain edema, cranial nerve involvement, vascular encasement, and invasion of critical areas such as the optic canal or cavernous sinus. These factors not only affect the feasibility of gross total resection but also play a pivotal role in determining functional outcomes and postoperative recovery. With the vast array of imaging modalities available, selecting the most appropriate investigations to assess these parameters and tailoring surgical strategies accordingly remain complex tasks. This review examines the critical surgical parameters, identifies the most effective imaging modalities for evaluating each, and provides key insights into how this analysis can guide surgical decision-making, mitigate risks, and minimize complications.

Tuberculum sellae meningiomas: surgical outcomes in 65 patients, review of the literature and proposal for an anatomical and radiological classification

Tuberculum sellae meningiomas (TSM) are challenging tumors due to their proximity to vital neurovascular structures. We propose a new classification system based on anatomical and radiological parameters. All patients treated for TSM, between January 2003 and December 2016, have been retrospectively reviewed. A systematic research was performed in PubMed database to review all studies comparing the performance of transcranial (TCA) and transphenoidal (ETSA) approaches. Overall, 65 patients were included in the surgical series. Gross total removal (GTR) was achieved in 55 patients (85%) and near total resection in 10 (15%). 54 patients (83%) showed a stability or an improvement of visual functions and 11 (17%) worsened. Postoperative complications were observed in seven patients (11%): CSF leak in one patient (1.5%); diabetes insipidus in two (3%); hypopituitarism in two (3%) third cranial nerve paresis and subdural empyema in one (1.5%). For the literature review, data about 10,833 patients (TCA N.=9159; ETSA N.=1674) were recorded; GTR was achieved in 84.1% (range 68-92%) of TCA and in 79.1% (range 60-92%) of ETSA; visual improvement (VI) occurred in 59.3% of TCA (range 25-84%) and in 79.3% of ETSA (range 46-100%); visual deterioration (VD) was registered in 12.7% of TCA (0-24%) and in 4.1% of ETSA (range 0-17%); a CSF-leak was observed in 3.8% of TCA (range 0-8%) while in ETSA in 18.6% of patients (range 0-62%); vascular injuries was reported in 4% (range 0-15%) of TCA and in 1.5% (range 0-5%) of ETSA. In conclusion, TSMs represent a unique category of midline tumors. The proposed classification system provides an intuitive and reproducible method in the choice of the most suitable approach.

Visual outcomes in tuberculum sellae meningiomas comparing transcranial and endoscopic endonasal approaches

Background

Tuberculum sellae meningiomas (TSM) account for 3-10% of intracranial meningiomas. Visual loss is the presenting symptom in up to 80% of cases. Surgical management poses a great challenge due to tumor proximity to neurovascular structures such as the optic nerve and the internal carotid artery (ICA); hence, there is controversy regarding the optimal approach. The aim of this study is to determine differences in visual outcomes between transcranial (TCA) and endoscopic endonasal (EEA) approaches.

Methods

A retrospective study including 29 patients with TSM surgically treated by TCA or EEA between 2011 and 2023 in a single referral center was conducted. Pre-and post-operative neuro-ophthalmologic evaluations, focusing on visual acuity and campimetry, were evaluated.

Results

Sixteen (55.16%) patients were intervened through a TCA and the remaining 13 (44.84%) via an EEA. The lesions in each group were similar in terms of pre- operative volume (15.12 vs 12.9 cm3, p = 0.497) and neurovascular invasion (optic canal invasion 48.26 vs 41.37%, p = 0.664; ICA 44.81 vs 31.03%, p = 0.797). There were no significant differences in visual outcomes between both approaches; TCA presented an improvement of 5.18 points in visual fields (p = 0.140), whereas EEA had an improvement of 17.39 points in visual acuity (p = 0.114).

Conclusion

EEA seems to offer greater improvement in visual acuity than TCA. However, the ideal approach should be individualized; taking into account the tumor's volume and invasiveness, as well as the patient's visual complaints.

Endoscopic endonasal approach for suprasellar meningiomas: introduction of a new scoring system to predict extent of resection and assist in case selection with long-term outcome data

OBJECTIVE

The endoscopic endonasal approach (EEA) has gained increasing popularity for the resection of suprasellar meningiomas (SSMs). Appropriate case selection is critical in optimizing patient outcome. Long-term outcome data are lacking. The authors systematically identified preoperative factors associated with extent of resection (EOR) and determined the relationship between EOR and long-term recurrence after EEA for SSMs.

METHODS

In this retrospective cohort study, the authors identified preoperative clinical and imaging characteristics associated with EOR and built on the recently published University of California, San Francisco resectability score to propose a score more specific to the EEA. They then examined the relationship between gross-total resection (GTR; 100%), near-total resection (NTR; 95%-99%), and subtotal resection (STR; < 95%) and recurrence or progression with Kaplan-Meier survival analysis.

RESULTS

A total of 51 patients were identified. Radiographic GTR was achieved in 40 of 47 (85%) patients in whom it was the surgical goal. Significant independent risk factors for incomplete resection were prior surgery (OR 25.94, 95% CI < 2.00 to 336.49, p = 0.013); tumor lateral to the optic nerve (OR 13.41, 95% CI 1.82-98.99, p = 0.011); and complete internal carotid artery (ICA) encasement (OR 15.12, 95% CI 1.17-194.08, p = 0.037). Tumor size and optic canal invasion were not significant risk factors after adjustment for other variables. A resectability score based on the multivariable model successfully predicted the likelihood of GTR; a score of 0 had a positive predictive value of 97% for GTR, whereas a score of 2 had a negative predictive value of 87.5% for incomplete resection. After a mean follow-up of 40.6 ± 32.4 months (mean ± SD), recurrence was 2.7% after GTR (1 patient with atypical histology), 44.4% after NTR, and 80% after STR (p < 0.0001). Vision was stable or improved in 93.5% and improved in 67.4% of patients with a preoperative deficit. There were 5 (9.8%) postoperative CSF leaks, of which 4 were managed with lumbar drains and 1 required a reoperation.

CONCLUSIONS

The EEA is a safe and effective approach to SSMs, with favorable visual outcomes in well-selected cases. The combination of postoperative MRI-based EOR with direct endoscopic inspection can be used in lieu of Simpson grade to predict recurrence. GTR dramatically reduces recurrence and can be achieved regardless of tumor size, proximity or encasement of the anterior cerebral artery, or medial optic canal invasion. Risk factors for incomplete resection include prior surgery, tumor lateral to the optic nerve, and complete ICA encasement.

Minimally Invasive Approaches to Anterior Skull Base Meningiomas

Objective Anterior skull base meningiomas include olfactory groove, planum sphenoidale, and tuberculum sellae lesions. Traditionally, standard craniotomy approaches have been used to access meningiomas in these locations. More recently, minimally invasive techniques including supraorbital and endonasal endoscopic approaches have gained favor; however there are limited published series comparing the use of these two techniques for these meningiomas. Using our patent database, we identified patients who underwent these two approaches, and conducted a retrospective chart review to compare outcomes between these two techniques.

Methods A total of 32 patients who underwent minimally invasive approaches were identified: 20 supraorbital and 11 endoscopic endonasal. Radiographic images, presenting complaints and outcomes, were analyzed retrospectively. The safety of each approach was evaluated.

Results The mean extent of resection through a supraorbital approach was significantly greater than that of the endoscopic endonasal approach, 88.1 vs. 57.9%, respectively (p = 0.016). Overall, preoperative visual acuity and anopsia deficits were more frequent in the endonasal group that persisted postoperatively (visual acuity: p = 0.004; anopsia: p = 0.011). No major complications including cerebrospinal fluid (CSF) leaks or wound-related complications were identified in the supraorbital craniotomy group, while the endonasal group had two CSF leaks requiring lumbar drain placement. Length of stay was shorter in the supraorbital group (3.4 vs. 6.1 days, p < 0.001).

Conclusion Anterior skull base meningiomas can be successfully managed by both supraorbital and endoscopic endonasal approaches. Both approaches provide excellent direct access to tumor in carefully selected patients and are safe and efficient, but patient factors and symptoms should dictate the approach selected.

Endoscopic endonasal surgery for anterior cranial fossa meningiomas

Meningiomas along the anterior skull base arise from the midline but have historically been resected via open cranial approaches with lateral to medial trajectories. The endoscopic endonasal approach (EEA) offers a direct, inferomedial approach which has demonstrated several superior qualities for their resection. These meningiomas include tuberculum sellae, planum sphenoidale, and olfactory groove meningiomas. While early gross total resection (GTR) was lower than open approaches, EEA has currently achieved comparable rates of GTR and significantly improved postoperative visual outcomes. Rate of cerebrospinal fluid (CSF) leak was one of the early complicating features preventing widespread use of EEA. However, CSF leak rates have dramatically fallen into a tolerable range with introduction of the vascularized nasoseptal flap. Olfactory groove meningiomas often present with anosmia which is persistent after endonasal approach. Rates of other complications have proven similar between EEA and open approaches and include: vascular injury, infection, morbidity, and mortality. With the appropriate team and experience, EEA for anterior skull base meningiomas is increasingly becoming the standard for resection of these lesions. However, there are certain anatomic considerations, patient features, and other aspects which may favor the open approach over EEA, and vice versa; these must be carefully and judiciously evaluated preoperatively. Overall, resection and recurrence rates are comparable, complication rates fall within a very acceptable range, and patients experience superior cosmesis and improved visual outcome with this approach.

Endoscopic transnasal resection of an anterior planum sphenoidale meningioma

Background:

Planum sphenoidale meningiomas comprise about 2% of all primary intracranial tumors. More often, they carry a significant surgical challenge due to their relation to the surrounding vital neurovascular structures. Endoscopic endonasal approach to such tumors holds multiple advantages to the transcranial counterpart in terms of coagulating the vascular supply, minimal brain retraction, and the ability to fully expose the tumor with the affected dura.

Case Description:

In this surgical video, we are presenting a case of a 28-year-old male, who presented to our hospital after he had one episode of a generalized tonic-clonic seizure that was controlled with an antiepileptic medication. Neurological examination was unremarkable including optic and olfactory nerves. Magnetic resonance imaging (MRI) showed a large anterior skull base mass located at the planum sphenoidale anteriorly. The patient underwent an endoscopic transnasal approach, drilling of the planum sphenoidale, and en bloc total resection of the tumor. In the follow-up office visit, the patient had no more seizures with preserved olfaction; MRI revealed no tumor residual.

Conclusion:

Planum sphenoidale meningiomas are surgically challenging due to its close proximity to important structures, such as pituitary gland, internal carotid arteries, and optic chiasm. Respecting the arachnoid plane and generous coagulation of vascular supply from the ethmoid arteries facilitate safe removal.

Surgical management of Tuberculum sellae Meningiomas: Myths, facts, and controversies

BACKGROUND

The optimal management of tuberculum sellae (TS) meningiomas, especially the surgical strategy, continues to be debated along with several controversies that persist.

METHODS

A task force was created by the EANS skull base section committee along with its members and other renowned experts in the field to generate recommendations for the surgical management of these tumors on a European perspective. To achieve this, the task force also reviewed in detail the literature in this field and had formal discussions within the group.

RESULTS

The constituted task force dealt with the practice patterns that exist with respect to pre-operative radiological investigations, ophthalmological and endocrinological assessments, optimal surgical strategies, and follow-up management.

CONCLUSION

This article represents the consensually derived opinion of the task force with respect to the surgical treatment of tuberculum sellae meningiomas. Areas of uncertainty where further clinical research is required were identified.

Tuberculum sellae meningiomas

Tuberculum sellae meningiomas are challenging tumors that can cause significant morbidity for patients because of their proximity to critical neurovascular structures. By studying the anatomy of the tuberculum, the manner in which these tumors grow and cause deficits becomes apparent, as also the challenges associated with surgical removal and management. The necessary preoperative workup and grading scales for preoperative evaluation of tuberculum meningiomas are discussed. Traditional open cranial approaches for resection are discussed and contrasted with the endoscopic endonasal approach. Finally, postoperative management, patient outcomes, and adjuvant therapy for management of residual tumor are considered.

Clinical Outcome after Endoscopic Endonasal Resection of Tuberculum Sella Meningiomas

BACKGROUND

In select cases, the endoscopic endonasal approach (EEA) has distinct advantages for resection of tuberculum sella meningiomas (TSM).

OBJECTIVE

To report the extent of resection (EOR), complication rates, and outcomes in a large series of TSM treated by the EEA.

METHODS

Twenty-five consecutive TSM cases treated by EEA from 2008 to 2016 were retrospectively reviewed. Patient history, imaging, volumetric EOR, complications, and outcomes are presented.

RESULTS

Mean patient age was 53.9 yr, with female predominance (84%). Preoperatively, 84% of patients had vision impairment and 68% had optic canal tumor invasion. The tumor was abutting or partially encasing the anterior cerebral artery in 14 (56%) and 3 (12%) patients, respectively. The supraclinoid internal carotid artery (ICA) was partially or completely encased in 4 (16%) and 4 (16%) patients, respectively. Gross total resection (GTR) was achieved in 19/25 (76%) cases. Complete ICA encasement was the most common reason for subtotal resection. Among patients without complete ICA encasement, GTR was achieved in 19/20 (95%) patients. Optic canal invasion, tumor volume, intratumoral calcifications, and partial vascular encasement were not limiting factors for GTR. Eighty-eight percent of patients with preoperative visual impairment had improvement or normalization of vision. No patient experienced permanent visual deterioration or new permanent pituitary dysfunction. Cerebrospinal fluid leakage occurred in 2 (8%) cases.

CONCLUSION

The EEA for resection of TSM provides high rates of GTR and visual improvement with a low rate of complications. Direct contact or partial encasement of the ICA and anterior cerebral artery does not limit the EOR.

The Endoscopic Endonasal Management of Anterior Skull Base Meningiomas

Introduction  The endoscopic endonasal approach (EEA) might seem an "unnatural" route for intradural lesions such as meningiomas. The aim of this study is to critically revise our management of anterior skull base meningiomas to consider, in what cases it may be advantageous. Material and Methods  Each consecutive case of anterior skull base meningioma operated on through an EEA or combined endoscopic-transcranial approach at our institution, between 2003 and 2017, have been included. Tumors were classified on the basis of their location and intra or extracranial extension. Follow-up consisted of an MRI (magnetic resonance imaging) and a clinical examination 3 months after the surgery and then repeated annually. Results  Fifty-seven patients were included. The most common location was the tuberculum sellae (62%), followed by olfactory groove (14%), planum sphenoidale (12%), and frontal sinus (12%). Among these, 65% were intracranial, 7% were extracranial, and 28% both intra and extracranial. Radical removal was achieved in 44 cases (77%). Complications consisted in 10 CSF (cerebrospinal fluid) leaks (17.6%), 1 overpacking (1.7%), and 1 asymptomatic brain ischemia (1.7%). Visual acuity and campimetric deficits improved respectively in 67 and 76% of patients. Recurrence rate was of 14%. Conclusions  EEA presents many advantages in selected cases of anterior skull base meningioma. However, it is hampered by the relevant risk of CSF leak. We consider that it could be advantageous for planum/tuberculum sellae tumors. Conversely, for olfactory groove or frontal sinus meningiomas, it can be indicated for tumors with extracranial extension, while its role is still debatable for purely intracranial forms as considering our surgical results, it could be advantageous for midline planum/tuberculum sellae tumors. Conversely, it can be of first choice for olfactory groove or frontal sinus meningiomas with extracranial extension, while its role for purely intracranial forms is still debatable.

Tuberculum sellae meningiomas: grading scale to assess surgical outcomes using the transcranial versus transsphenoidal approach

OBJECTIVE

Tuberculum sellae meningiomas (TSMs) are surgically challenging tumors that can severely impair vision. Debate exists regarding whether the transcranial (TC) or endoscopic transsphenoidal (TS) approach is best for resecting these tumors, and there are few large series comparing these approaches.

METHODS

A retrospective chart review was performed at 2 academic centers comparing TC and TS approaches with respect to vision, extent of resection, recurrence, and complications. The authors report surgical outcomes and propose a simple preoperative tumor grading scale that scores tumor size (1–2), optic canal invasion (0–2), and arterial encasement (0–2). The authors performed univariate, multivariate, and recursive partitioning analysis (RPA) to evaluate outcomes.

RESULTS

The TSMs were resected in 139 patients. The median follow-up was 29 months. Ninety-five (68%) cases were resected via a TC and 44 (32%) via a TS approach. Tumors treated via a TC approach had a higher tumor (p = 0.0007), artery (p < 0.0001), and total score (p = 0.0012) on the grading scale. Preoperative visual deficits were present in 87% of patients. Vision improved in 47%, stayed the same in 35%, declined in 10%, and was not recorded in 8%. The extent of resection was 65% gross-total resection, 23% near-total resection (95%–99% resection), and 12% subtotal resection (< 95%). A lower tumor score was significantly associated with better or stable vision postoperatively (p = 0.0052). The RPA confirmed low tumor score as the key predictor of postoperative visual improvement or stability. Multivariate analysis and RPA demonstrate that lower canal score (p < 0.0001) and TC approach (p = 0.0019) are associated with gross-total resection. Complications occurred in 20 (14%) patients, including CSF leak (5%) and infection (4%). There was no difference in overall complication rates between TC and TS approaches; however, the TS approach had more CSF leaks (OR 5.96, 95% CI 1.10–32.04). The observed recurrence rate was 10%, and there was no difference between the TC and TS approaches.

CONCLUSIONS

Tuberculum sellae meningiomas can be resected using either a TC or TS approach, with low morbidity and good visual outcomes in appropriately selected patients. The simple proposed grading scale provides a standard preoperative method to evaluate TSMs and can serve as a starting point for selection of the surgical approach. Higher scores were associated with worsened visual outcomes and subtotal resection, regardless of approach. The authors plan a multicenter review of this grading scale to further evaluate its utility.