A Simple Scoring System to Predict the Resectability of Skull Base Meningiomas via an Endoscopic Endonasal Approach

Tuberculum Sellae Meningioma: Report of Two Cases and Literature Review of Limits of the Transcranial and Endonasal Endoscopic Approaches

BACKGROUND

Tuberculum sellae (TS) meningioma is one of the most frequent meningiomas of the anterior skull base. Herein we perform a review of the literature concerning the preferred surgical approaches to TS meningiomas; in addition, we describe two explicative cases, operated on by our group using different approaches, with the aim to critically revise surgical indications and contraindications.

METHODS

In October 2021, two female patients with tuberculum sellae meningioma were treated at the Policlinico Gemelli of Rome. The patients presented with visual deterioration. Surgery was performed using the fronto-temporal approach and transsphenoidal approach. The visual function before and after surgery was evaluated as the main outcome parameter of the surgical treatment of these tumors.

CONCLUSIONS

Tuberculum sellae meningioma can be safely resected using the transcranial approach and the transsphenoidal endoscopic approach with preservation and even improvement of visual function after surgery. The relationship of the tumor with the optic nerves, optic canal, and anterior cerebral artery complex are important issues that have to be considered when dealing with tuberculum sellae meningioma. Both transcranial and endonasal approaches, in experienced hands, can allow complete resection of the lesion.

A Scoring System That Predicts Difficult Lipoma Resection: Logistic Regression and Tenfold Cross-Validation Analysis

Introduction

Most lipomas are readily dissected and removed. However, some cases can pose surgical difficulties. This retrospective study sought to identify clinical and radiological risk factors that predict difficult lipoma resection and can be used in a clinically useful scoring system that predicts difficulty preoperatively.

Methods

The study cohort consisted of all consecutive patients who underwent resection of pathology-confirmed lipoma during 2016–2018 at a tertiary care referral center in Tokyo, Japan. Surgical difficulty was defined as difficulty separating some/all of the tumor from the surrounding tissue by hand and inability to extract the tumor in one piece. Descriptive, univariate, and multivariate logistic regression analyses were conducted to identify predictive factors. The predictive accuracy of the scoring system that included these factors was assessed by tenfold cross-validation analysis. Receiver-operating curve (ROC) analysis was conducted to identify the optimal cutoff score for predicting surgical difficulty.

Results

Of the 86 cases, 36% involved surgical difficulty. Multivariate analysis showed that subfascial intramuscular location (odds ratio 42.7, 95% confidence interval 3.0–608.0), broad touching of underlying structures (46.5, 3.7–586.0), in-flowing blood vessels (9.3, 1.1–78.5), and unclear boundaries (109.0, 1.1–1110.0) significantly predicted surgical difficulty. These factors were used to construct a 0–4 point scoring system (with one point per variable). On cross-validation, the accuracy of the scoring system was 82.4% (Cohen’s kappa of 0.57). ROC analysis showed that scores ≥ 2 predicted surgical difficulty with sensitivity and specificity of 55% and 98%, respectively.

Conclusions

Our scoring system accurately predicted lipoma resection difficulty and may help operators prepare, thereby facilitating surgery.

Management of Skull-Base Meningiomas With Extracranial Extensions: Clinical Features, Radiological Findings, Surgical Strategies, and Long-Term Outcomes

Objectives:

The aim of this research was to summarize the clinical and prognostic features of the skull-base meningiomas with extracranial extensions, and enhance the management of skull-base communicative meningiomas.

Methods

We retrospectively studied the medical records and analyzed the follow-up information of 53 patients who have done surgery for skull-base meningiomas with extracranial extensions in West China Hospital of Sichuan University from 2009 to 2020.

Results

The incidence of skull-base meningiomas with extracranial extensions was 0.74%. The average diagnosis age was 45.9 years, with a 1:3.1 men to women ratio. WHO grade I was seen in 84.9% of patients, and higher grades were found in 15.1%. Heterogeneous enhancement, high bone invasion rate, high incidence of peritumoral edema, and high dural tail sign rate were typical imaging features. Routine craniotomy and endoscopic endonasal approach were adopted, and gross total resection was performed in 62.3% of cases with 20.8% postoperative complication rates. The average follow-up time was 61.5 months, with a recurrence rate of 34.9%. By survival analysis, the extent of resection (p = 0.009) and the histological grade (p = 0.007) were significantly related to the prognosis. Adjuvant radiotherapy proved beneficial in patients with subtotal resection (p = 0.010) and high-grade meningiomas (p = 0.018).

Conclusions

Skull-base meningiomas with extracranial extensions were sporadic. According to the tumor location and communication way showed by the preoperative imaging, routine craniotomy or endoscopic endonasal approach with a reasonable skull-base repair strategy could be adopted to achieve the maximum tumor resection. Maximized resection, adjuvant radiotherapy, and low histological grade indicate a better prognosis.

Preoperative prediction of granulation pattern subtypes in GH-secreting pituitary adenomas

OBJECTIVE

The aim of this study was to establish a preoperative prediction method for sparsely granulated (SG) growth hormone (GH)-secreting pituitary adenoma, an aggressive tumour subtype with high recurrence risk, in acromegaly patients.

METHODS

Eighty-three patients with GH-secreting pituitary adenomas were included in this study. GH measurements, cytokeratin immunostaining and electron microscopy were performed to detect granulation patterns. Preoperative factors, including general, radiological and endocrinological features and acute octreotide suppression test outcomes, were compared between SG and densely granulated (DG) groups. The predictive capabilities of these features were analysed using a receiver operating characteristic (ROC) curve, and the most predictive features were combined to establish a grading scale.

RESULTS

Thirty-nine of the 83 patients had SG GH-secreting pituitary adenomas; 44 had DG tumours. SG tumours tended to occur in younger patients and have larger diameters and volumes, higher Knosp grades, lower GH indexes and normalized insulin-like growth factor-1 (IGF-1) level, and a lower ∆GH% after octreotide treatment. The tumour size, Knosp grade, GH index and ∆GH% after octreotide treatment had good predictive performance, with area under the curve (AUC) values ranging from 0.70 to 0.80. Combining four parameters, including diameter, Knosp grade, GH index and ∆GH% after octreotide treatment, we established a grading scale for predicting SG GH-secreting pituitary adenomas with an AUC of 0.84 and relatively high sensitivity and specificity.

CONCLUSIONS

We propose a predictive method for distinguishing SG and DG GH-secreting pituitary adenomas preoperatively. This method will help physicians identify candidates for presurgical medical treatment and neurosurgeons determine radical surgical strategies for high-risk tumours.

Transnasal Endoscopic Surgery for Suprasellar Meningiomas

Aim

Endoscopic trans-nasal surgery has evolved a long way from the days of narrow corridors with high rates of cerebrospinal fluid (CSF) leak to the present state of HD optics with better tissue differentiation, extended approaches, and use of vascularized flaps for defect closure. Trans-nasal approach is an established technique for pituitary tumors practiced worldwide. However, trans-nasal endoscopic excision of suprasellar meningiomas provides a tougher challenge in terms of instrument manipulation, tumor excision with good visual outcome, and a robust defect closure to prevent CSF leaks.

Materials and Methods

Out of 83 cases of midline anterior cranial fossa meningiomas operated over 14 years, our experience in 12 cases of suprasellar meningiomas for radical resection via the trans-nasal endoscopic route is discussed.

Results

Amongst these, six were excised via primary extended endoscopic trans-sphenoidal surgery, four cases had a residual lesion or recurrence after primary transcranial surgery, and two cases involved a combined transcranial and extended endoscopic approach. Visual improvement along with resolution of headache was seen in all patients postoperatively. None of the patients had CSF leak requiring further repair. Syndrome of inappropriate antidiuretic hormone was found in one patient, which was transient and easily corrected.

Conclusion

Trans-nasal endoscopic surgery for suprasellar meningiomas is an effective technique that provides results of tumor excision comparable to the transcranial approach in suitable cases. Visual outcome was found to be superior, and rates of CSF leak were remarkably reduced with vascularized flap. However, each case must be assessed individually and lateral extension beyond the optic canals with internal carotid artery encasement must be considered before planning surgery.

Clinial Features, Individualized Treatment and Long-Term Surgical Outcomes of Skull Base Meningiomas With Extracranial Extensions

Object: Skull base meningiomas with extracranial extensions are rarely described. This study describes the clinical features, surgical management and clinical outcomes of these rare tumors and investigates risk factors associated with progression-free survival (PFS). Methods: The clinical data of 34 consecutive patients who underwent surgery for skull base meningiomas with extracranial extensions from 2007 to 2018 were retrospectively collected and analyzed. Results: The mean patient age was 47.9 ± 13.9 years; 50.0% were male. The most common symptoms on admission were ophthalmic. All patients underwent a multidisciplinary consultation before surgery, and received individualized surgical management. The gross total resection (GTR) rate was 55.9% (19/34). Twelve patients received post-operative adjuvant radiotherapy (RT). Twelve patients experienced tumor recurrence during the follow-up period. The median PFS duration was 54 months. The mean overall survival (OS) duration was 111 months. By univariate analysis, a higher histological grade (WHO grade II and III), Ki-67 LI ≥ 5 and the extent of resection (EOR) were significantly associated with tumor recurrence. Multivariate analysis revealed Ki-67 LI ≥ 5, the EOR and adjuvant RT as prognostic factor of PFS. Conclusions: These relatively rare meningiomas are difficult to resect and have a poor prognosis; they are more common in males and have a higher histological grade than intracranial meningiomas. Multidisciplinary collaboration and individualized surgical strategies are crucial for surgically managing these complex tumors. Total removal of the tumor remains challenging. Subtotal resection (STR) or partial resection (PR) followed by RT is a reasonable strategy when radical resection is infeasible. Adjuvant RT should be recommended especially for tumors with histopathological risk factors (Ki-67 LI ≥ 5 or high histological grade).

Computed tomographic imaging of meningiomas

Although magnetic resonance imaging (MRI) has surpassed computerized tomography (CT) as the imaging modality of choice, there are certain instances when CT should be a preoperative requisite for meningioma surgical resection. Given its superior bone definition and the propensity for meningiomas to invade bone (as evidenced by hyperostosis on imaging), CT can be extremely helpful to the surgeon when planning and evaluating postoperatively the extent of bone removal during tumor resection. Advances in CT imaging also allow for visualization of the adjacent arterial and venous vasculature to determine feasibility of resection and likelihood of adjuvant treatments such as radiosurgery to a tumor residuum. For skull base tumors high-resolution CT imaging as part of the standard neuronavigation sequences can help evaluate bony anatomy and planning of surgical approaches, in particular for cranial base tumors. Finally, 3D-CT imaging is important in the design of cranial prostheses, which may be required to repair defects as a result of resection.

Posterior fossa meningiomas: perioperative predictors of extent of resection, overall survival and progression-free survival

BACKGROUND

Posterior fossa meningiomas (PFMs) often represent surgical challenges due to their proximity to neurovascular structures. Factors predicting the extent of resection (EOR), overall survival (OS), and progression-free survival (PFS) were identified and integrated in a prediction tool to offer evidence-based personalized therapeutic strategies.

METHODS

All meningiomas managed surgically from 1990 to 2010 from a single-center were reviewed. A classification tree was created using the classification and regression tree recursive partitioning analysis that incorporated patient and tumor data available before surgery in order to predict the rates of gross total resection (GTR).

RESULTS

A total of 198 patients were identified (female-to-male ratio, 2.7; mean age, 59.1 years) and compared with 1271 supratentorial meningiomas (STMs) operated in the same institution during the same time period. GTR was achieved less often (59.6% versus 81.9%; p < 0.01) in PFMs than STMs. Preoperative neurological symptoms were predictive of higher Simpson grades (OR, 2.19 [1.05; 4.58]; p = 0.04). Age was associated with reduced OS (OR, 1.08 [1.04;1.12]; p < 0.001). A KPS ≥ 70 was associated with higher survival rates (OR, 2.70 [2.19;2.92]; p = 0.02). Higher WHO grades were associated with reduced OS (OR, 3.56 [1.02;12.47]; p = 0.05). The GTR rate varies from 80% in patients without a preoperative deficit to 40% patients with a preoperative deficit, younger than 60 years old, and with adjacent bone invasion.

CONCLUSIONS

This study provides a classification tree of the predictors of EOR in PFMs, based upon preoperative demographic, clinical, and radiological variables. An evidence-based management protocol with estimated EORs may guide the decision-making process in PFMs.

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.

Recurrence of Anterior Skull Base Meningiomas After Endoscopic Endonasal Resection: 10 Years' Experience in a Series of 52 Endoscopic and Transcranial Cases

INTRODUCTION

Although the indication of endoscopic approaches for anterior skull base meningiomas (ASBM) has been progressively refined, there remains a paucity of data on recurrence rates after resection. To analyze and compare recurrence rates of ASBM resected through endoscopic endonasal (EEE) versus transcranial (TCA) approaches.

MATERIAL AND METHODS

We performed a retrospective analysis of patients submitted to the EEE or TCA approach for ASBM resection from May 2006 to January 2016 in our center. Clinical, radiological, and pathology data were retrieved for analysis. Tumor size, location, surgical technique, extent of resection, and tumor grade were assessed. The 2 groups were compared to identify predictors and differences regarding tumor recurrence.

RESULTS

Fifty-two patients (17 olfactory groove meningioma [OGM] and 35 tuberculum sellae meningioma [TSM]) were included; 26 (6 OGM and 20 TSM) underwent EEE and 26 (13 OGM and 13 TSM) TCA, with a mean follow-up of 41 months. Gross total resection was achieved in 38 (73%) patients (18 [69%] in EEE and 20 [77%] in TCA). Eight (15%) patients presented with recurrence: 5 (19%) in the EEE group and 3 (11.5%) in the TCA group without a statistical difference (P = 0.69). Among the recurrences, gross total resection had been achieved in 1 case of each group. In the EEE group, 1 patient underwent TCA for a recurrent tumor and another patient was referred for radiosurgery.

CONCLUSIONS

This study has shown an overall similar recurrence rate of ASBM regardless of the technique used. However, the analysis of larger series with longer follow-up is necessary to clearly define the indications and to fully validate the efficacy of EEE.

Defining the lateral limits of the endoscopic endonasal transtuberculum transplanum approach: anatomical study with pertinent quantitative analysis

OBJECTIVE

The extended endoscopic endonasal transtuberculum transplanum approach is currently used for the surgical treatment of selected midline anterior skull base lesions. Nevertheless, the possibility of accessing the lateral aspects of the planum sphenoidale could represent a limitation for such an approach. To the authors' knowledge, a clear definition of the eventual anatomical boundaries has not been delineated. Hence, the present study aimed to detail and quantify the maximum amount of bone removal over the planum sphenoidale required via the endonasal pathway to achieve the most lateral extension of such a corridor and to evaluate the relative surgical freedom.

METHODS

Six human cadaveric heads were dissected at the Laboratory of Surgical NeuroAnatomy of the University of Barcelona. The laboratory rehearsals were run as follows: 1) preliminary predissection CT scans, 2) the endoscopic endonasal transtuberculum transplanum approach (lateral limit: medial optocarotid recess) followed by postdissection CT scans, 3) maximum lateral extension of the transtuberculum transplanum approach followed by postdissection CT scans, and 4) bone removal and surgical freedom analysis (a nonpaired Student t-test). A conventional subfrontal bilateral approach was used to evaluate, from above, the bone removal from the planum sphenoidale and the lateral limit of the endonasal route.

RESULTS

The endoscopic endonasal transtuberculum transplanum approach was extended at its maximum lateral aspect in the lateral portion of the anterior skull base, removing the bone above the optic prominence, that is, the medial portion of the lesser sphenoid wing, including the anterior clinoid process. As expected, a greater bone removal volume was obtained compared with the approach when bone removal is limited to the medial optocarotid recess (average 533.45 vs 296.07 mm2; p < 0.01). The anteroposterior diameter was an average of 8.1 vs 15.78 mm, and the laterolateral diameter was an average of 18.77 vs 44.54 mm (p < 0.01). The neurovascular contents of this area were exposed up to the insular segment of the middle cerebral artery. The surgical freedom analysis revealed a possible increased lateral maneuverability of instruments inserted in the contralateral nostril compared with a midline target (average 384.11 vs 235.31 mm2; p < 0.05).

CONCLUSIONS

Bone removal from the medial aspect of the lesser sphenoid wing, including the anterior clinoid process, may increase the exposure and surgical freedom of the extended endoscopic endonasal transtuberculum transplanum approach over the lateral segment of the anterior skull base. Although this study represents a preliminary anatomical investigation, it could be useful to refine the indications and limitations of the endoscopic endonasal corridor for the surgical management of skull base lesions involving the lateral portion of the planum sphenoidale.