ENDOSCOPIC ENDONASAL RESECTION OF ANTERIOR CRANIAL BASE MENINGIOMAS

Endoscopic endonasal resection of olfactory tract hamartoma for pediatric epilepsy

BACKGROUND

Non-hypothalamic glioneural hamartomas are rare entities known to cause medically refractory epilepsy. Olfactory bulb hamartomas, in particular, are exceptionally rare.

METHODS

We describe a case of an olfactory bulb hamartoma that was surgically resected at our institution. We also performed a literature review of all glioneural hamartomas and discuss the clinical presentation, diagnosis, and management of these lesions.

RESULTS

Herein, we present the unusual case of a typically developing 17-year-old boy with a near life-long history of drug-resistant epilepsy, found to have a 0.8 × 1.0 cm right olfactory bulb hamartoma. Endoscopic endonasal trans-cribriform resection of the lesion led to seizure freedom in the 6-month follow-up period (Engel class 1 outcome). Comprehensive literature review revealed only one other sporadic case, which was also successfully treated with total surgical resection.

CONCLUSIONS

Our case of an olfactory bulb hamartoma adds to the limited literature currently available, illustrating key clinical characteristics of these exceedingly rare lesions and outlining an effective, minimally invasive, and low-morbidity treatment strategy.

Long term results with medpor® reconstruction of the anterior skull base at a single institute

OBJECTIVES

To evaluate a technique of multi-layered CSF repair following endonasal anterior skull base surgery using medpor graft.

DESIGN

Retrospective review of consecutive case series from a single centre.

SUBJECTS

68 cases of repair of CSF leaks utilising medpor identified from a larger prospectively maintained database of endonasal endoscopic procedures at our centre.

METHODS

Retrospective review of a database of consecutive anterior skull base cases from 2016-2022, and further data collection from electronic hospital records.

RESULTS

During follow up there were 7 cases of post-op CSF leak (10.3%). There were no radiological complications, and no cases of medpor removal or extrusion. Rates of infection were low, there were 3 (4.4%) cases of confirmed bacterial meningitis within our cohort. The mean length of stay was 4.7 days (median 3 days), with 16 cases discharged on the first post-operative day.

CONCLUSIONS

Our experience of using medpor in anterior skull base reconstruction demonstrates that medpor is a readily available, easily handled, and reliable graft option with relatively low rates of infection and post-op CSF leak. Its use reduces the use of autologous graft materials and the associated donor site morbidity. Our long term follow up data further demonstrates the safety and efficacy of this technique.

Narrative review of patient-specific 3D visualization and reality technologies in skull base neurosurgery: enhancements in surgical training, planning, and navigation

Recent advances in medical imaging, computer vision, 3-dimensional (3D) modeling, and artificial intelligence (AI) integrated technologies paved the way for generating patient-specific, realistic 3D visualization of pathological anatomy in neurosurgical conditions. Immersive surgical simulations through augmented reality (AR), virtual reality (VR), mixed reality (MxR), extended reality (XR), and 3D printing applications further increased their utilization in current surgical practice and training. This narrative review investigates state-of-the-art studies, the limitations of these technologies, and future directions for them in the field of skull base surgery. We begin with a methodology summary to create accurate 3D models customized for each patient by combining several imaging modalities. Then, we explore how these models are employed in surgical planning simulations and real-time navigation systems in surgical procedures involving the anterior, middle, and posterior cranial skull bases, including endoscopic and open microsurgical operations. We also evaluate their influence on surgical decision-making, performance, and education. Accumulating evidence demonstrates that these technologies can enhance the visibility of the neuroanatomical structures situated at the cranial base and assist surgeons in preoperative planning and intraoperative navigation, thus showing great potential to improve surgical results and reduce complications. Maximum effectiveness can be achieved in approach selection, patient positioning, craniotomy placement, anti-target avoidance, and comprehension of spatial interrelationships of neurovascular structures. Finally, we present the obstacles and possible future paths for the broader implementation of these groundbreaking methods in neurosurgery, highlighting the importance of ongoing technological advancements and interdisciplinary collaboration to improve the accuracy and usefulness of 3D visualization and reality technologies in skull base surgeries.

Olfaction preservation in olfactory groove meningiomas: a systematic review

Olfactory groove meningiomas (OGM) are a skull base neoplasm that represents between 8 and 13% of all intracranial meningiomas. Approach selection focuses on achieving frontal lobe decompression, gross total resection and vision preservation. Recently, there has been a focus on olfaction and considering its preservation as a quality-of-life outcome measure. An electronic search of the databases Medline, Scopus, Embase, Web of Science and Cochrane library databases was performed and data extracted according 2020 Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) statement. Six articles were selected for inclusion mainly based due to reporting quantitative outcomes for olfaction assessed by a smell identification test (e.g. sniffin' sticks). Objective olfaction preservation can be achieved with a variety of surgical approaches. More research which includes objective assessment of olfactory function and ideally as well QoL outcome measures is needed to further optimize the treatment pathways in OGM patients.

Strategy of skull base reconstruction after endoscopic transnasal pituitary adenoma resection

Objective

Endoscopic endonasal surgery (EES) is commonly performed for resection of lesions of the anterior/middle cranial fossa region. Cerebrospinal fluid (CSF) leakage is a major complication. Skull base reconstruction after EES is challenging. We describe our reconstruction strategy and technique and analyze its outcomes.

Methods

We retrospectively analyzed 703 patients with pituitary adenoma who underwent EES in our center from January 2020 to August 2022. Clinical, imaging, operative, and pathologic data were recorded from the medical records and analyzed. Skull base reconstruction was performed to achieve the following three goals: seal the original leak, eliminate dead space, provide blood supply, and early ambulation. Reconstruction was tailored to individual patients based on grade of CSF leakage encountered during surgery.

Results

The number of patients with a grade 0, 1, 2, and 3 intraoperative CSF leak was 487, 101, 86, and 29, respectively. Overall incidence of postoperative CSF leakage was 0.14% (1/703). Fascia sutured and vascularized nasoseptal flap were selected for all grade 3 CSF leaks. One patient who experienced postoperative CSF leakage developed intracranial infection and were treated with lumbar CSF drainage that failed; eventually re-exploration surgery for repair was required. Other patients did not have complications such as CSF leak and infection. 29 patients with grade 3 CSF leakage did not complain of severe nasal complications after operation. No perioperative complications related to the strategy (overpacking, infections, or hematomas) occurred. Incidence of postoperative CSF leak according to intraoperative leak grade was as follows: grade 0, zero; grade 1, zero; grade 2, 1.16% (1/86); and grade 3, zero.

Conclusion

The principles of sealing the original leak, eliminating dead space, providing blood supply, and early ambulation are key in skull base reconstruction after EES. Individualization of these principles can significantly reduce the incidence of postoperative CSF leakage and intracranial infection and reduce the use of lumbar CSF drainage. Skull base suture technique is safe and effective in patients with high-flow cerebrospinal fluid leaks.

Evolution of Radiographic Changes of a Vascularized Pedicled Nasoseptal Flap after Endonasal Endoscopic Skull Base Surgery

BACKGROUND AND PURPOSE

There is active research involving the radiographic appearance of the skull base following reconstruction. The purpose of this study was to describe the radiographic appearance of the vascularized pedicle nasoseptal flap after endoscopic skull base surgery across time.

MATERIALS AND METHODS

We performed chart and imaging review of all patients with intraoperative nasoseptal flap placement during endoscopic skull base surgery at a tertiary academic skull base surgery program between July 2018 and March 2021. All patients underwent immediate and delayed (>3 months) postoperative MR imaging. Primary outcome variables included flap and pedicle enhancement, flap thickness, and flap adherence to the skull base.

RESULTS

Sixty-eight patients were included. Flap (P = .003) enhancement significantly increased with time. Mean nasoseptal flap thickness on immediate and delayed postoperative scans was 3.8 and 3.9 mm, respectively (P = .181). The nasoseptal flap adhered entirely to the skull base in 37 (54.4%) and 67 (98.5%) patients on immediate and delayed imaging, respectively (P < .001).

CONCLUSIONS

Our findings demonstrate heterogeneity of the nasoseptal flap appearance after skull base reconstruction. While it is important for surgeons and radiologists to evaluate variations in flap appearance, the absence of enhancement and lack of adherence to the skull base on immediate postoperative imaging do not appear to predict reconstructive success and healing, with many flaps "self-adjusting" with time.

Giant Non-Functioning Pituitary Adenomas: Treatment Considerations

Giant pituitary adenomas are a subgroup of pituitary adenomas defined by a diameter greater than 4 cm, and they account for 5-14% of adenomas in surgical series. Because of their growth patterns and locations, often involving critical neurovascular structures, they represent a true surgical challenge, and gross total resection is difficult to achieve. There is no consensus on the optimal surgical strategy for giant pituitary adenomas, and, often, integrated multi-staged treatment strategies have been considered. Transcranial or transsphenoidal approaches, alone or combined, according to tumor and patient features are the two main routes. Each of these strategies has pros and cons. The conventional transcranial approach has for a long time been considered the first choice for the removal of giant pituitary adenomas. Currently, with endoscopic techniques, it is also possible to remove lesions that involve the intradural compartment and the adjacent neurovascular structures with the use of extended approaches. Our policy for the management of these lesions is to adopt the endoscopic endonasal approach as the first choice unless the tumor presents significant intracranial extension that results in it being outside the visibility and maneuverability of the endoscopic endonasal route. In these latter cases, we agree that the transcranial approach is more appropriate. However, accurate preoperative evaluation and refined treatment plans for each patient are mandatory to define a proper strategy in order to achieve the most effective long-term result.

Single Versus Double Hadad-Bassagasteguy Flap in Expanded Endoscopic Skull-Base Surgery

The reconstruction of dural defects, after endoscopic removal of skull-base lesions, remains challenging when a large defect or a high flow intraoperative cerebrospinal fluid (CSF) leak is observed. The aim of this study is to describe our preliminary experience with a double Hadad-Bassagasteguy (H-B) flap technique for skull-base repair, comparing its efficacy with the use of a single H-B flap in our series. A retrospective chart review was conducted on patients who underwent exclusive endoscopic endonasal skull-base surgery at our Referral Skull Base Center from December 2014 to January 2018. Data on patient demographics, pathology, preoperative and postoperative imaging, intraoperative findings, surgical route, defect size, reconstruction techniques and repair materials, were analyzed. Patients were divided into double and single H-B flap groups. In the single and double H-B groups, the postoperative CSF leak rates were 37.5% (6 of 16 patients) and 4.5% (1 of 22 patients), respectively. The difference between the two groups was statistically significant (p = 0.0470). In patients with defects > 4 cm or high-flow intraoperative CSF leakage related to the opening of the third ventricle, the double H-B flap was successfully placed with no occurrence of postoperative CSF leakage. The double H-B flap significantly reduced the postoperative CSF leakage rate after expanded transnasal skull-base surgery. Particularly in challenging cases, where a large skull-base defect or a high-flow intraoperative CSF leak was observed, this reconstructive method proved to be very effective, with no evidence of postoperative CSF fistulas.

Surgical management of tuberculum sellae meningioma: Transcranial approach or endoscopic endonasal approach?

Background

Tuberculum sellae meningioma (TSM), a common benign tumor in the sellae region, usually causes neurological deficits, such as vision impairment, by squeezing the peripheral neurovascular structures. Surgical management is recommended as the optimal strategy for TSM treatment and vision restoration. However, it remains challenging to resect TSM in the traditional transcranial approach (TCA). Recently, the endoscopic endonasal approach (EEA) has emerged as an effective option in skull base surgeries. Besides the effectivity, the advantages and limitations of EEA in TSM surgery remain controversial.

Object

We compared the surgical outcomes and complications between TCA and EEA surgeries to identify the principles in TSM surgical management.

Methods

Retrospective analysis was performed on the patients, who underwent TSM surgery in Wuhan Union Hospital between January 2017 and December 2021. The patients were assigned to TCA or EEA group according to the surgery they experienced. All patients were analyzed with the extent of tumor resection, vision outcome, postoperative complications, and follow-up results.

Results

A total of 112 patients were enrolled in this study, including 78 in TCA group and 34 in EEA group. The mean follow-up was 20.5 months (range 3–36 months). There were no statistically significant differences in patient demographic data, preoperative symptoms, and tumor characteristics between TCA and EEA groups. Both TCA and EEA surgeries are effective in TSM resection with relatively high gross total resection rates (85.9% in TCA vs. 91.2% in EEA, p > .05). Meanwhile, EEA surgery has a better outcome in vision restoration or stabilization than TCA surgery (74.6% in TCA vs. 93.1% in EEA, p < .05). Whereas EEA surgery causes more occurrences of cerebrospinal fluid (CSF) leakage than TCA surgery (0% in TCA vs. 11.8% in EEA, p < .05).

Conclusion

Both TCA and EEA surgeries are effective in TSM resection. EEA surgery has a better outcome in vision restoration or stabilization than TCA surgery, but induces higher risk of CSF leakage. As each approach has unique advantages and limitations, we must take all aspects into consideration, including approach feathers, tumor characteristics, and clinical requirements, to make the optimal choice in TSM surgical management.

Evolution in endoscopic endonasal approach for the management of hypothalamic–pituitary region metastasis: A single-institution experience

Introduction

Endonasal endoscopic surgery has changed the treatment perspectives for different lesions of the hypothalamic–pituitary region. The metastases of the hypothalamic–pituitary region represent 0.4% of all intracranial metastatic tumors and account for only 1.8% of surgically managed pituitary lesions. The aim of tshis study is to describe a single-center institutional experience with 13 cases of hypothalamic–pituitary metastasis focused on presurgical workup, the evolution of the surgical technique, and postsurgical management according to our protocols, showing effects on progression-free and overall survival rates for this relatively uncommon location.

Material and Methods

We retrospectively reviewed the whole series of patients that received the endoscopic endonasal approach at the Division of Neurosurgery at the University of Naples “Federico II” undergoing surgery from January 1997 to December 2021. We identified 13 cases whose pathology reports revealed a metastatic lesion. Statistical analysis was performed to determine the Kaplan–Meier survival function and assess for log-rank differences in survival based on gender, surgical treatment, and postoperative therapy (p-value &lt; 0.02*).

Results

The pathology report disclosed lung adenocarcinoma (six cases, 46%), breast adenocarcinoma (two cases, 15.4%), clear cell renal carcinoma (one case, 7%), melanoma (one case, 7%), colorectal adenocarcinoma (one case, 7%), uterine cervix carcinoma (one case, 7%), and follicular thyroid carcinoma (one case, 7%). A standard endoscopic endonasal approach was performed in 10 patients (76.9%), while an extended endonasal procedure was performed in only three cases (23%). Biopsy was the surgical choice in five patients with infiltrative and invasive lesions and a poor performance status (38%), while in the cases where neurovascular decompression was necessary, a subtotal resection was achieved in five patients (38%) and partial resection in three patients (23%). Recovery of visual field defect was observed in six of seven patients with visual loss (85.7%), improvement of oculomotor nerve palsy occurred in four of seven patients with this defect (57.1%), while the impairment of oculomotor palsy was observed in three patients (42.9%). Visual function was stable in the other patients. The median progression-free survival and overall survival were 14 and 18 months, respectively. There were statistically significant differences in PFS and OS in patients who underwent adjuvant radiotherapy (p=0.019 is referred to OS and p=0.017 to PFS, respectively; p-value = 0.02).

Conclusions

The endoscopic endonasal approach is a viable approach for the management of hypothalamic–pituitary metastases as this surgery provides an adequate opportunity to obtain tissue sample and neurovascular decompression, both being crucial for continuing the integrated adjuvant therapy protocols.

Effects of cruciate embedding fascia-bone flap technique on grade II-III cerebral spinal fluid leak in endoscopic endonasal surgery

Background

Cerebral spinal fluid (CSF) leak remains an important issue in endoscopic endonasal surgery (EES). A standard protocol for skull base closure has not yet been established, and the application of rigid buttress has not been given sufficient attention. To emphasize the functions of support and fixation from rigid buttress in reconstruction, we introduced the cruciate embedding fascia-bone flap (CEFB) technique using autologous bone graft to buttress the fascia lata attachment to the partially sutured skull base dural defect and evaluated its efficacy in a consecutive case series of grade II–III CSF leaks in EES.

Methods

Data from consecutive patients diagnosed with sellar region lesions with grade II–III CSF leaks during EES were collected from May 2015 to May 2020. Skull base reconstructions were performed with the CEFB or the conventional pedicle vascularized nasoseptal flap (PNSF). Related clinical data were analysed. The combined use of the CEFB and PNSF was applied to an additional supplemental case series of patients with grade III leak and multiple high-risk factors.

Results

There were 110 and 65 patients included in the CEFB and PNSF groups, respectively. The CEFB demonstrated similar effects on the incidence of postoperative CSF leak (2.7%), intracranial infection (4.5%), and lumbar drainage (LD) placement (5.5%) as PNSF (3.1%, 3.1%, and 6.2%), but with less epistaxis (CEFB: 0%, PNSF: 6.2%) and nasal discomforts (CEFB: 0%, PNSF: 7.7%). The LD duration (CEFB: 6.67 ± 2.16 days, PNSF: 10.50 ± 2.38 days), bed-stay time (CEFB: 5.74 ± 1.58 days, PNSF: 8.83 ± 3.78 days) and hospitalization time (CEFB: 10.49 ± 5.51 days, PNSF: 13.58 ± 5.50 days) were shortened in the CEFB group. The combined use of CEFB and PNSF resulted in 0 postoperative CSF leaks in the supplemental case series of 23 highly susceptible patients.

Conclusion

This study suggested that the new CEFB technique has the potential to prevent postoperative CSF leak in EES. The results indicated that it can be used effectively without PNSF in suitable cases or applied in addition to a PNSF with high compatibility when necessary. Its effectiveness should be further verified with a larger cohort and better design in the next step.

Trial Registration Current Controlled Trials ChiCTR2100044764 (Chinese Clinical Trial Registry); date of registration: 27 March 2020. Retrospectively registered

Minimally invasive nummular approach to a giant meningioma of the anterior fossa

Background:

Several approaches are described for giant meningiomas of the anterior skull base. Recently, endonasal endoscopic approaches have been described as a minimally invasive (MI) alternative. However, the extension of dissection of the nose cavity and the risks of CSF leak do not fit in the MI prerogatives. We present an operative video illustrating a MI transcortical approach through a nummular craniotomy for a giant meningioma of the anterior fossa.

Case Description:

We report an 83-year-old female patient. On neurological examination, she was drowsy and hemiparetic on the left side. MRI scan demonstrated a giant anterior fossa lesion (7.6 × 6.2 × 6 cm). An 1.5 diameter craniotomy was placed in the right frontal region after MRI 3D reconstruction analysis. The first step was to debulk the core of the tumor with the ultrasonic aspirator. An important aspect is that the surgeon needs to rotate its positions around the patient in a 360° fashion for a total resection. The final step was to inspect the surgical cavity with the endoscope to check for any remaining tumor. The patient was discharged home 1 day after the surgery with no new deficits.

Conclusion:

Giant meningiomas of the anterior fossa are a different entity. When they reach the cortical surface, the surgical approach can be different from the common skull base meningiomas. We demonstrate that a MI transcortical approach can be a safe alternative for giant meningiomas, especially for high-risk patients, as the elderly ones.

Experience and modification of skull base reconstruction results in lower complications rates

OBJECTIVES

To investigate the efficacy of nasal septum bone flap combined with vascularized pedicle nasoseptal flap (VP-NSF) in the treatment of high-flow cerebrospinal fluid (CSF) leakage in the endonasal endoscopic skull base surgery.

METHODS

A total of 156 patients in group A used a multi-layer skull base reconstruction method of fat-absorbable artificial dura mater- fascia lata-VP-NSF, and were treated with drainage of the lumbar cistern after surgery, in addition, a total of 94 patients in group B used a multi-layer skull base reconstruction method of fat-absorbable artificial dura mater-nasal septal bone flap-VP-NSF, and no lumbar cistern drainage was performed after surgery. Analyzed and compared the differences of postoperative cerebrospinal fluid rhinorrhea, intracranial infection, re-repair, average bed rest time, pulmonary infection and deep venous thrombosis of lower extremities were analyzed and compared in the two groups.

RESULTS

In group A, 11 cases of cerebrospinal fluid rhinorrhea occurred after operation. In addition, 15 cases developed intracranial infection. During this period, there were 20 cases of pulmonary infection and 3 cases of deep venous thrombosis of lower extremities. In group B, there were 1 case of cerebrospinal fluid rhinorrhea (P < 0.05), 2 cases of intracranial infection (P < 0.05), 2 cases of pulmonary infection (P < 0.05), and 0 case of deep venous thrombosis of lower extremities (P > 0.05).

CONCLUSION

Nasal septum bone flap combined with VP-NSF is effective in the treatment of high-flow CSF leaks in the endonasal endoscopic skull base surgery, which can avoid postoperative lumbar cistern drainage and is worth popularizing.

Identification and Management of Aggressive Meningiomas

Meningiomas are common primary central nervous system tumors derived from the meninges, with management most frequently entailing serial monitoring or a combination of surgery and/or radiation therapy. Although often considered benign lesions, meningiomas can not only be surgically inaccessible but also exhibit aggressive growth and recurrence. In such cases, adjuvant radiation and systemic therapy may be required for tumor control. In this review, we briefly describe the current WHO grading scale for meningioma and provide demonstrative cases of treatment-resistant meningiomas. We also summarize frequently observed molecular abnormalities and their correlation with intracranial location and recurrence rate. We then describe how genetic and epigenetic features might supplement or even replace histopathologic features for improved identification of aggressive lesions. Finally, we describe the role of surgery, radiotherapy, and ongoing systemic therapy as well as precision medicine clinical trials for the treatment of recurrent meningioma.

Gamma Knife radiosurgery for tuberculum sellae meningiomas: a series of 78 consecutive patients

Outcomes of Gamma Knife radiosurgery (GKRS) for tuberculum sellae meningiomas (TSMs) have not been reported explicitly within any meningioma series. We present the first and largest TSM series with clinical, radiosurgical, and outcome features for 78 consecutive patients managed with GKRS. Patients who underwent GKRS for TSMs between 2005 and 2021 and had a minimum of 6 months of follow-up were included. Medical records, imaging studies, and follow-up examinations were evaluated retrospectively. A total of 78 patients with a median age of 50.5 years were included. SRS was conducted as an upfront treatment for 38 patients (48.7%). The median target volume was 1.7 cm³ (range, 0.1-14.6). During a median follow-up of 78.5 months, the cumulative PFS rates of the whole cohort at 1, 5, and 10 years by Kaplan-Meier analysis were 100%, 97.9%, and 94.5%, respectively. Of 47 patients with impaired vision, improvement and/or preservation of visual acuity, and visual field were achieved in 55.3% and 42.6%, respectively. No new-onset hormonal deficits were observed. Based on our data, SRS represents an effective and safe modality for unresected or recurrent/residual TSMs. SRS should be offered to patients who are not willing or not ideal candidates for surgery.

Anatomical Variations and Relationships of the Infratemporal Fossa: Foundation of a Novel Endonasal Approach to the Foramen Ovale

Objective  Access to the infratemporal fossa (ITF) is complicated by its complex neurovascular relationships. In addition, copious bleeding from the pterygoid plexus adds to surgical challenge. This study aims to detail the anatomical relationships among the internal maxillary artery (IMA), pterygoid plexus, V _3, and pterygoid muscles in ITF. Furthermore, it introduces a novel approach that displaces the lateral pterygoid plate (LPP) to access the foramen ovale. Design and Main Outcome Measures  Six cadaveric specimens (12 sides) were dissected using an endonasal approach to the ITF modified by releasing and displacing the LPP and lateral pterygoid muscle (LPTM) as a unit. Subperiosteal elevation of the superior head of LPTM revealed the foramen ovale. The anatomic relationships among the V ₃ , pterygoid muscles, pterygoid plexus, and IMA were surveyed. Results  In 9/12 sides (75%), the proximal IMA ran between the temporalis and the LPTM, whereas in 3/12 sides (25%), the IMA pierced the LPTM. The deep temporal nerve was a consistent landmark to separate the superior and inferior heads of LPTM. An endonasal approach displacing the LPP in combination with a subperiosteal elevation of the superior head of LPTM provided access to the posterior trunk of V ₃ and foramen ovale while sparing injury of the LPTM and exposing the pterygoid plexus. The anterior trunk of V ₃ traveled anterolaterally along the greater wing of sphenoid in all specimens. Conclusion  Displacement of the LPP and LPTM provided direct exposure of foramen ovale and V ₃ avoiding dissection of the muscle and pterygoid plexus; thus, this maneuver may prevent intraoperative bleeding and postoperative trismus.

Receptor Tyrosine Kinases as Candidate Prognostic Biomarkers and Therapeutic Targets in Meningioma

Meningioma (MGM) is the most common type of intracranial tumor in adults. The validation of novel prognostic biomarkers to better inform tumor stratification and clinical prognosis is urgently needed. Many molecular and cellular alterations have been described in MGM tumors over the past few years, providing a rational basis for the identification of biomarkers and therapeutic targets. The role of receptor tyrosine kinases (RTKs) as oncogenes, including those of the ErbB family of receptors, has been well established in several cancer types. Here, we review histological, molecular, and clinical evidence suggesting that RTKs, including the epidermal growth factor receptor (EGFR, ErbB1), as well as other members of the ErbB family, may be useful as biomarkers and therapeutic targets in MGM.

The Role of 3D Tractography in Skull Base Surgery: Technological Advances, Feasibility, and Early Clinical Assessment with Anterior Skull Base Meningiomas

Objective  The aim of this study is to determine feasibility of incorporating three-dimensional (3D) tractography into routine skull base surgery planning and analyze our early clinical experience in a subset of anterior cranial base meningiomas (ACM). Methods  Ninety-nine skull base endonasal and transcranial procedures were planned in 94 patients and retrospectively reviewed with a further analysis of the ACM subset. Main Outcome Measures  (1) Automated generation of 3D tractography; (2) co-registration 3D tractography with computed tomography (CT), CT angiography (CTA), and magnetic resonance imaging (MRI); and (3) demonstration of real-time manipulation of 3D tractography intraoperatively. ACM subset: (1) pre- and postoperative cranial nerve function, (2) qualitative assessment of white matter tract preservation, and (3) frontal lobe fluid-attenuated inversion recovery (FLAIR) signal abnormality. Results  Automated 3D tractography, with MRI, CT, and CTA overlay, was produced in all cases and was available intraoperatively. ACM subset : 8 (44%) procedures were performed via a ventral endoscopic endonasal approach (EEA) corridor and 12 (56%) via a dorsal anteromedial (DAM) transcranial corridor. Four cases (olfactory groove meningiomas) were managed with a combined, staged approach using ventral EEA and dorsal transcranial corridors. Average tumor volume reduction was 90.3 ± 15.0. Average FLAIR signal change was -30.9% ± 58.6. 11/12 (92%) patients (DAM subgroup) demonstrated preservation of, or improvement in, inferior fronto-occipital fasciculus volume. Functional cranial nerve recovery was 89% (all cases). Conclusion  It is feasible to incorporate 3D tractography into the skull base surgical armamentarium. The utility of this tool in improving outcomes will require further study.

Complications after 1002 endoscopic endonasal approach procedures at a single center: lessons learned, 2010-2018

OBJECTIVE

The endoscopic endonasal approach (EEA) has evolved into a mainstay of skull base surgery over the last two decades, but publications examining the intraoperative and perioperative complications of this technique remain scarce. A prior landmark series of 800 patients reported complications during the first era of EEA (1998-2007), parallel to the development of many now-routine techniques and technologies. The authors examined a single-institution series of more than 1000 consecutive EEA neurosurgical procedures performed since 2010, to elucidate the safety and risk factors associated with surgical and postoperative complications in this modern era.

METHODS

After obtaining institutional review board approval, the authors retrospectively reviewed intraoperative and postoperative complications and their outcomes in patients who underwent EEA between July 2010 and June 2018 at a single institution.

RESULTS

The authors identified 1002 EEA operations that met the inclusion criteria. Pituitary adenoma was the most common pathology (n = 392 [39%]), followed by meningioma (n = 109 [11%]). No patients died intraoperatively. Two (0.2%) patients had an intraoperative carotid artery injury: 1 had no neurological sequelae, and 1 had permanent hemiplegia. Sixty-one (6.1%) cases of postoperative cerebrospinal fluid leak occurred, of which 45 occurred during the original surgical hospitalization. Transient postoperative sodium dysregulation was noted after 87 (8.7%) operations. Six (0.6%) patients were treated for meningitis, and 1 (0.1%) patient died of a fungal skull base infection. Three (0.3%) patients died of medical complications, thereby yielding a perioperative 90-day mortality rate of 0.4% (4 deaths). High-grade (Clavien-Dindo grade III-V) complications were identified after 103 (10%) EEA procedures, and multivariate analysis was performed to determine the associations between factors and these more serious complications. Extradural EEA was significantly associated with decreased rates of these high-grade complications (OR [95% CI] 0.323 [0.153-0.698], p = 0.0039), whereas meningioma pathology (OR [95% CI] 2.39 [1.30-4.40], p = 0.0053), expanded-approach intradural surgery (OR [95% CI] 2.54 [1.46-4.42], p = 0.0009), and chordoma pathology (OR [95% CI] 9.31 [3.87-22.4], p < 0.0001) were independently associated with significantly increased rates of high-grade complications.

CONCLUSIONS

The authors have reported a large 1002-operation cohort of EEA procedures and associated complications. Modern EEA surgery for skull base pathologies has an acceptable safety profile with low morbidity and mortality rates. Nevertheless, significant intraoperative and postoperative complications were correlated with complex intradural procedures and meningioma and chordoma pathologies.

Extradural anterior temporal fossa approach to the paranasal sinuses, nasal cavities through the anterolateral and anteromedial triangles: Combined microscopic and endoscopic strategy

OBJECTIVE

To demonstrate the utility and limitations of the extradural endoscopic-assisted anterior temporal fossa approach to the pterygopalatine fossa (PPF), infratemporal fossa (ITF), paranasal sinuses (PS), parapharyngeal region (PPR), nasal cavities (NC), epipharynx (EP), and clivus.

METHODS

A frontotemporal orbitozygomatic craniotomy is performed. The dura is elevated from the cavernous sinus (CS). The anterior temporal fossa floor is drilled. Foramen rotundum and ovale are opened. The PPF is exposed and the lateral margin of inferior orbital fissure (IOF) is removed. The anterolateral triangle (ALT) is drilled and the vidian nerve (VN) is exposed. Drilling between the maxillary nerve (V2) and the VN provides access to the sphenoid sinus (SphS). The medial pterygoid plate is drilled exposing the EP. The maxillary sinus (MaxS) is opened anterior to the PPF. V2 is transposed laterally to enlarge the anteriomedial triangle (AMT). The orbital muscle of Muller is removed as well as the medial margin of the IOF, which opens the SphS. Anteriorly, the posterior ethmoid air cells are opened. Morphometric measurements evaluating the size of the ALT were done and the PS, NC, EP were explored with the endoscope.

RESULTS

The ALT and AMT triangle provides a wide exposure of the PPF, ITF, PPR. In addition, those triangles represent a deep entry point to explore the PS, NC, and EP.

CONCLUSION

The ALT and AMT are useful corridors to access to the SphS, MaxS, PS, NC, and EP via a transcranial approach. The use of the endoscope through this corridor widely extend the extradural anterior temporal fossa approach which may be considered as a valuable alternative to the extended endoscopic endonasal approach for selected skull base lesions extending both intracranial and into the PS, NC and EP.

Residual and Recurrent Disease Following Endoscopic Endonasal Approach as a Reflection of Anatomic Limitation for the Resection of Midline Anterior Skull Base Meningiomas

BACKGROUND

Endoscopic endonasal approaches (EEAs) to anterior skull base meningiomas have grown in popularity, though anatomic limitations remain unclear.

OBJECTIVE

To show the anatomic limits of EEA for meningiomas.

METHODS

Retrospective chart review for all patients that underwent EEA for anterior skull base meningiomas from 2005 to 2014.

RESULTS

A total of 100 patients averaged follow-up of 46.9 mo (24-100 mo). A total of 35 patients (35%) had olfactory groove, 33 planum sphenoidale (33%), and 32 tuberculum sella (32%) meningiomas. The average diameter was 2.9 cm (0.5-8.1 cm). Vascular encasement was seen in 11 patients (11%) and calcification in 20 (20%). Simpson Grade 1 (SG1) resection was achieved in 64 patients (64%). Only calcification impacted degree of resection (40% SG1, P = .012). The most common residual was on the anterior clinoid dura (11 patients [11%]). Six (6%) had residual superior/lateral to the optic nerve. Residual tumor was adherent to the optic apparatus or arteries in 5 patients (5%) each, and 3 patients (3%) had residual lateral to the mid-orbit. Rates of residual decreased over time. A total of 11 patients (11%) had tumor recurrence (mean of 40 mo): 4 (4%) on the anterior clinoid, 2 (2%) each on the lateral orbital roof, adherent to optic apparatus and superolateral to the optic nerve, and 1 (1%) was at the anterior falx.

CONCLUSION

Anterior skull base meningiomas can effectively be approached via EEA in most patients; tumors extending to the anterior clinoid, anterior falx, or superolateral to the optic nerve or orbital roof, especially if calcified, may be difficult to reach via EEA.

Comparison of Three Surgical Approaches for Frontobasal Meningiomas: Purely Endoscopic Endonasal, Purely Microscopic Bifrontal Transcranial, and Combined Endoscopic and Microscopic Supraorbital Transciliary Approaches

ABSTRACT

Surgical removal of frontobasal meningiomas (FBMs) can be achieved using different techniques, including endoscopic, transcranial, and combined approaches. The advantages and disadvantages of the outcomes of these approaches should be compared to provide the most convenient surgical treatment to the patient. This study aimed to compare 3 surgical approaches for FBMsin terms of outcomes and determine the superiority of each on the basis of anatomical, surgical, and clinical efficacy. Systematic review was performed to identify studies comparing techniques for the surgical removal of FBMs. Each group included 13 patients; 39 patients with FBMshad undergone surgery. These groups were endoscopic endonasal approach (EEA), microscopic bifrontal transcranial approach (MTA), and endoscopic plus microscopic combined supraorbital transciliary approach (STA) groups. Data on the demographics of patient population, pre- and post-operative neurological examination, tumor properties, imaging studies, and surgical complications were extracted. The mean age at the time of surgery for the patient population was 53.2 years. Among the groups, no statistically significant differences were observed with regard to sex (P = 0.582). The mean follow-up time was 56.7 months. A statistically significant difference was observed in the mean tumor volume among the groups; the MTA group showed the highest mean tumor volume. However, no significant difference was found in the mean tumor volume between EEA and STA groups. Regarding operation duration, the STA group had the shortest operation time (mean = 281.5 minutes), whereas the average surgical duration in MTA group was the longest (mean = 443.8 minutes). The average bleeding volume was highest in the MTA group (mean = 746.2 ml) and lowest in the EEA group (mean = 320.8 ml). Tumor removal was incomplete in three patients (two in the EEA group and one in the MTA group). Recurrence was detected in two cases. One patient with recurrence was operated using the endoscopic surgical approach, whereas the other patient underwent the microscopic bifrontal approach. Post-operative hyposmia/anosmia or decreased olfactory function was the most common complication observed in 5 patients, 2 patients each in the EEA and MTA groups and one in the STA group. The second most common complication was wound infection in one patient in the MTA group and two patients in the STA group (7.7%). Both cerebrospinal fluid (CSF) leakage and meningitis were present in two patients (5.1%), one patient each from the EEA and STA groups. Pre-operative visual disturbances were reported in 13 patients (33.3%), all of which resolved post-operatively No statistical differences were found among the groups. Mortality occurred in a patient in the MTA group (2.6%) caused by cardiac arrest on post-operative day 1. This is the first study comparing the surgical outcomes of three surgical approaches for FBMs. Although recent literature suggests that both endoscopic and transcranial approaches have their own advantages and disadvantages, the authors showed that none of the surgical approaches have obvious superiority over the others with regard to outcomes. Thus, the selection of the ideal surgical approach should be based on surgical experience and tumor characteristics.

Keyhole Superior Interhemispheric Approach to Midline Meningiomas of the Far Frontal Region of the Anterior Skull Base: Cadaveric Study and Illustrative Cases

OBJECTIVE

Unique challenges can present in the treatment of small to mid-sized meningiomas that arise from the region of the anterior most aspect of the falx cerebri including its junction with the anterior skull base, what we call the far frontal region. Although this region of the anterior skull base is considered in the surgical approach of olfactory groove meningiomas invading this space, important differences exist between these tumors and those of the far frontal region.

METHODS

Toward refining surgical selection, our cadaveric study details a minimally invasive keyhole superior interhemispheric approach to the far frontal region and 2 illustrative cases show the feasibility of this approach.

RESULTS

Our cadaveric study defines 5 steps of the approach from the incision, craniectomy, dural opening, approaching the skull base and ipsilateral exposure, and finally falcine resection and bilateral skull base exposure. Two illustrative cases with the approach confirmed visualization of the full extent of tumor and gross total resection with preservation of the unaffected olfactory bulb.

CONCLUSIONS

To the best of our knowledge, our anatomic study is distinctively unique in quantifying the working distance of the keyhole superior interhemispheric exposure and refining visualization of the far frontal region. We discuss these benefits and limitations (i.e., substantial involvement of tumor beyond midline) and differences with large meningiomas of the olfactory groove and far frontal region with significant posterior or lateral extension for which conventional exposures are appropriate.

Skull base reconstruction: A question of flow? A critical analysis of 521 endoscopic endonasal surgeries

INTRODUCTION

Post-operative CSF leak still represents the main drawback of Endoscopic Endonasal Approach (EEA), and different reconstructive strategies have been proposed in order to decrease its rate.

OBJECTIVE

To critically analyze the effectiveness of different adopted reconstruction strategies in patients that underwent EEA.

MATERIALS AND METHODS

Adult patients with skull base tumor surgically treated with EEA were retrospectively analyzed. Data recorded for each case concerned patient demographics, type of surgical approach, histotype, anatomical site of surgical approach, intra-operative CSF leak grade (no leak (INL), low flow (ILFL), high flow (IHFL)), reconstructive adopted strategy, Lumbar Drain positioning, post-operative CSF leak rate and intra/post-operative complications.

RESULTS

A total number of 521 patients (January 2012-December 2019) was included. Intra-operative CSF leak grade showed to be associated with post-operative CSF leak rate. In particular, the risk to observe a post-operative CSF leak was higher when IHFL was encountered (25,5%; Exp(B) 16.25). In particular, vascularized multilayered reconstruction and fat use showed to be effective in lowering post-operative CSF leaks in IHFL (p 0.02). No differences were found considering INL and ILFL groups. Yearly post-operative CSF leak rate analysis showed a significative decreasing trend.

CONCLUSION

Intra-operative CSF leak grade strongly affected post-operative CSF leak rate. Multilayer reconstruction with fat and naso-septal flap could reduce the rate of CSF leak in high risk patients. Reconstructive strategies should be tailored according also to the type and the anatomical site of the approach.

Endoscopic Endonasal Approach for Resection of Tuberculum Sellae Meningioma: A Promising Surgical Approach

BACKGROUND

Over the past decade, endoscopic approaches have been increasingly successful in removing various types of extra-dural lesions from the skull base. Resection of tuberculum sellae meningiomas (TSMs) is challenging. The endoscopic endonasal approach (EEA) for the removal of TSMs is currently an acceptable surgical approach in neurosurgery and, despite the surgical results, the indications and limitations of this approach remain controversial.

OBJECTIVE

This paper reviews the authors' experience and outcomes with the EEA for TSM, as well as postoperative complications.

METHODS

Retrospective analyses were performed on patients who underwent endoscopic surgical resection of TSMs involving the suprasellar region between January 2018 and March 2019.

RESULTS

Three patients underwent resection of their TSM by the EEA. Tumors in the suprasellar region were completely resected. Patients recovered normally with uneventful postoperative outcomes and were followed-up for at least six months after surgery with no neurological deficits noted.

CONCLUSIONS

The EEA for resection of TSMs is feasible, safe, and effective, with fewer complications and lower mortality than other surgical methods. This a promising surgical approach.

Surgical anatomy and nuances of the extended endoscopic endonasal transtuberculum sellae approach: pearls and pitfalls for complications avoidance

BACKGROUND

Using the expanded endoscopic transtuberculum approach (EETA), the nuances of this technique have rendered a safe, direct, and feasible ventral corridor for the treatment of extending suprasellar pathologies. This study illustrates surgical landmarks and strategies of paramount importance for complications avoidance.

METHODS

This study presents the surgical anatomy and nuances of EETA, which can be used to remove large pituitary adenomas with suprasellar extension. Special references to cadaveric dissections highlight anatomical landmarks and surgical key points for complications avoidance.

CONCLUSION

The EETA represents a versatile route for the treatment of sellar/suprasellar pathologies. Although, sizeable extrasellar pituitary tumors still pose a threat due to displacement/encasement of surrounding structures, necessitating accurate knowledge of correlative operative anatomy with traditional landmarks. Complete resection of extrasellar components is essential to avoid postoperative apoplexy.

Endoscopic Endonasal Approach to Giant Pituitary Adenomas: Surgical Outcomes and Review of the Literature

OBJECTIVE

To present the outcomes of endoscopic endonasal surgery for giant pituitary adenomas and discuss the extent of resection to minimize morbidity and mortality.

METHODS

We retrospectively reviewed medical records of 44 patients with giant pituitary adenomas who underwent endoscopic endonasal surgery. Clinical presentation, laboratory results, imaging studies, clinical outcomes, extent of resection, and complications were collected and analyzed. Factors affecting long-term outcome according to surgical technique were identified and analyzed.

RESULTS

Radical resection (RR) was defined as either gross total resection or near-total resection (90%-100% of the tumor). There were 28 patients (63.6%) who underwent RR, 10 patients (22.7%) who underwent subtotal resection, and 6 patients (13.6%) who underwent partial resection. Visual improvement was achieved in 27 patients (81.8%). Thirteen patients (72.2%) with pituitary dysfunction had improvement in at least 1 preoperative endocrinological dysfunction. RR rates for dumbbell and multilobular tumors were 44.4% and 28.6%, respectively. Surgical complications were observed in 14 (31.8%) patients. Major vascular injury occurred in 3 patients (6.8%). Mean follow-up period was 38.5 months (range, 1-70 months). No patients with RR had recurrence or residual tumor progression. Ten patients (22.7%) received adjuvant radiation therapy after resection. Two patients were reoperated on for tumor regrowth, and 3 patients (including the 2 patients with tumor regrowth) were lost to follow-up.

CONCLUSIONS

Long-term follow-up results and low recurrence rate of tumors indicate that RR is effective to decrease morbidity and mortality.

Endoscopic approaches to skull base malignancies affecting the anterior fossa

Anterior skull base malignancies are rare and comprise distinct histological entities. Surgery encompasses the traditional craniofacial resections (CFR), and more recently, endoscopic endonasal approaches (EEA) or a hybrid cranioendoscopic (CEA) technique. Although the CFR is still considered the "gold-standard;" there is growing evidence supporting that EEA yield equivalent oncologic outcomes with less morbidity in well-selected cases. Therefore, this article aims to review the current state-of-art in addressing anterior cranial base malignancies using expanded endoscopic endonasal approaches (EEA) with particular references to surgical anatomy and nuances of hybrid cranioendoscopic techniques. Cadaveric dissections and illustrative cases are presented to detail our current surgical technique allied with tailored adjuvant therapies, and treatment strategies are further discussed based on tumor histology.

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.

Single surgeon experience with minimally invasive supraorbital craniotomy versus bifrontal craniotomy for anterior skull base meningiomas

Background:

Anterior skull base meningiomas (ASBMs) account for about 10% of meningiomas. Bifrontal craniotomy (BFC) represents the traditional transcranial approach to accessing meningiomas in these locations. Supraorbital craniotomy (SOC) provides a minimally invasive subfrontal corridor in select patients. Here, we present our series of ASBM accessed by SOC and BFC by a single surgeon to review decision-making and compare outcomes in both techniques.

Methods:

Thirty-three patients were identified with ASBM. Age, tumor characteristics, presenting symptoms, postoperative complications, and outcomes were analyzed.

Results:

Bifrontal and SOC were performed in 13 and 20 patients, respectively. Mean follow-up time was 98.4 months. Patients undergoing SOC had smaller tumor size, located farther from the posterior table of frontal sinus, had less peritumoral edema, and decreased length of stay compared to patients undergoing BFC. Extent of resection was slightly better with BFC (99.8%) compared to SOC (91.8%), although this difference did not reach statistical significance. Recurrence-free survival and rate of re-do surgeries were not different between two groups. BFC was associated with higher rates of postoperative encephalomalacia.

Conclusion:

SOC provides an excellent surgical option for ASBMs providing comparable extent of resection, minimal manipulation of brain, and excellent cosmetic outcomes for patients. The patient selection is key to maximize the benefits from this approach.

Aggressive resection of craniopharyngioma achieved by drilling the tuberculum sellae/planum sphenoidale using a frontal basal interhemispheric approach: A review of 55 cases

OBJECTIVE

The frontal basal interhemispheric approach (FBIA) is preferable for resection of craniopharyngioma (CP), achieving desirable total resection rates in early reports of lesions located in the suprasellar region to the third ventricle. For tumours that have created a larger obstruction of the tuberculum sellae and planum sphenoidale, aggressive resection in the intrasellar region and medial wall of the cavernous sinus is not feasible compared to improving tumour visualization by drilling the tuberculum sellae and planum sphenoidale. In a report of drilling the sellar tuberculum and sphenoid planum, drilling allowed the direct visualization of tumours invading the intrasellar region and medial wall of the cavernous sinus. Reconstructing the opening of the sellar-sphenoid cavity is achieved by microsuturing a piece of the pericranium/dura around the dural edge of the defective dura of the open sphenoid sinus and sellar cavity to prevent cerebrospinal fluid (CSF) leakage.

PATIENTS AND METHODS

The FBIA with drilling of the tuberculum sellae and planum sphenoidale was performed to remove the tumours that invaded the intrasellar region and cavernous sinus in 55 patients from January 2014 to October 2019 at our institution. The pre- and postoperative pituitary hormone levels and vision were evaluated as effective standards after surgery and compared using paired t-tests. The different rates of CSF leakage between the packing and microsuture groups were compared by χ² test, p < 0.05.

RESULTS

In all patients with a mean 37-month follow-up (range, 3-2 months), 43 (78.2%) patients returned to their normal life or school independently, 7 (12.7%) patients were able to perform normal activities with minor complaints or effort, and 4 (7.3%) patients could care for themselves or only required occasional assistance. One (1.8%) death occurred, attributed to CSF leak-related meningitis at 5 months after surgery. Postoperative CSF leakage occurred in eight (19.0%) of 42 patients with packed bone wax or pieces of muscle to the sphenoid sinus. Of 13 patients with a piece of the periosteum/dura microsutured around the defective dura of the sellar region and open sphenoid sinus, one (7.7%) of 13 patients experienced CSF leakage in the perioperative period. With statistical analysis, there was a potential risk for postoperative CSF leakage in the bone wax and muscle piece in the open sphenoid sinus, whereas microsuture manoeuvres were effective for avoiding the risk of postoperative CSF leakage (χ² = 8.865, p < 0.005). The microsutures closed the open sphenoid sinus such that it was water-tight. Postoperative visual acuity and the visual field were not affected by the increased intrasellar exposure or the open sphenoid sinus achieved by drilling the tuberculum sellae and planum sphenoidale.

CONCLUSION

Tuberculum sellae/planum sphenoidale drilling via FBIA is feasible to enhance the direct visualization of CP resection, which expands the intrasellar region with a direct resection of recurrent tumours in the sellar cavity and adhering to the medial wall of the cavernous sinus. The potential risk of a CSF leakage seemed to be mitigated when using water-tight microsutures on a piece of the pericranium/dura around the edge of the defective dura in the sellar region and the open sphenoid sinus cavity.

Giant nasofrontal meningioma: endoscopic and transcranial approach followed by microvascularized vastus laterallis flap reconstruction

A 12-year-old girl presented with headache, nasal voice, and anosmia. Magnetic resonance imaging demonstrated a 11 × 9 × 8-cm tumor extending from the nasal cavity to the frontal lobes. Histological analysis was consistent with transitional meningioma WHO grade I. As far as we know, this is the first reported case of a giant olfactory groove meningioma invading the nasal cavity through the anterior cranial base. Complete surgical removal was accomplished with excellent result via a staged endoscopic and transcranial approach. A microvascularized vastus laterallis flap was used for reconstruction. Surgical options and technical details in the management of this lesion are reviewed.

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.

Microsurgical Transcranial Approach of 112 Paraoptic Meningiomas: A Single-Center Case Series

BACKGROUND

Predictors of visual outcomes after optic nerve decompression are controversial.

OBJECTIVE

To identify the predictors of poor visual outcomes after surgery of meningiomas responsible of a compressive optic neuropathy.

METHODS

We focused on paraoptic meningiomas (POMs), which gathered tuberculum sellae meningiomas (TSMs) and anterior clinoid meningiomas (ACMs) responsible for visual impairment or threatening visual function, that underwent surgery at our institution between January 2009 and December 2015 and analyzed the clinical and radiological findings of our patients.

RESULTS

Among 112 patients who underwent surgery for a POM, a preoperative visual deficit was present in 108 patients (96.4%). Six months after surgery, 79 patients (70.5%) had a visual improvement, 15 patients (13.4%) had an unchanged vision, and 18 patients (16.1%) had deteriorated vision. A preoperative visual deficit of 6 mo or more was a strong predictor of poor visual outcome after surgery (P = .034). Poor visual outcome after surgery was not significantly related to the size of the tumor (P = .057), the age of the patient (P = .94), or the tumor extension into the optic canal (P = .47).

CONCLUSION

The duration of preoperative visual deficit was found to be a strong predictor of poor visual outcomes after surgery in POMs Other predictors of poor visual outcomes are still needed and are currently under evaluation in a prospective study at our institution.

Closure of Skull Base Defects after Endonasal Endoscopic Resection of Planum Sphenoidale and Tuberculum Sellae Meningiomas

Background

The expanded endoscopic endonasal transplanum transtuberculum approach allows tumor removal by minimally invasive procedures. A large dural and bone defect is created during the surgical procedure, increasing the risk of postoperative cerebrospinal fluid (CSF) leakage.

Objective

The aim of this study is to describe a surgical technique and complications observed in patients undergoing endonasal resection of planum sphenoidale and/or tuberculum sellae meningiomas.

Methods

A retrospective analysis was performed of patients with planum sphenoidale and/or tuberculum sellae meningiomas after expanded endoscopic endonasal resection between June 2013 and August 2018, in which autologous grafts, fascia lata inlay, and nasoseptal flap onlay were used for closure of skull base defects.

Results

Ten patients were included in the analysis. No cases of postoperative CSF leakages or meningitis were reported, whereas two patients evolved with postoperative infectious complications (fungal ball in right frontal sinus and brain abscess). The skull base defect created for resection measured, on average, 3.58 cm².

Conclusion

Our experience suggests that closure of skull base defects using combined fascia lata inlay and nasoseptal flap onlay is effective for preventing postoperative CSF leakage in resection of planum sphenoidale and/or tuberculum sellae meningiomas, and offers high reproducibility due to its low cost.

Meningioma: A Review of Clinicopathological and Molecular Aspects

Meningiomas are the most the common primary brain tumors in adults, representing approximately a third of all intracranial neoplasms. They classically are found to be more common in females, with the exception of higher grades that have a predilection for males, and patients of older age. Meningiomas can also be seen as a spectrum of inherited syndromes such as neurofibromatosis 2 as well as ionizing radiation. In general, the 5-year survival for a WHO grade I meningioma exceeds 80%; however, survival is greatly reduced in anaplastic meningiomas. The standard of care for meningiomas in a surgically-accessible location is gross total resection. Radiation therapy is generally saved for atypical, anaplastic, recurrent, and surgically inaccessible benign meningiomas with a total dose of ~60 Gy. However, the method of radiation, regimen and timing is still evolving and is an area of active research with ongoing clinical trials. While there are currently no good adjuvant chemotherapeutic agents available, recent advances in the genomic and epigenomic landscape of meningiomas are being explored for potential targeted therapy.

Expanded endoscopic endonasal approach for extending suprasellar and third ventricular lesions

BACKGROUND

Expanded endonasal approaches can provide direct access to the midline skull base from the anterior cranial fossa to the ventral foramen magnum. Surgical strategies of bone drilling, dural opening, and intradural dissection can determine the area of surgical exposure and instrument handling, affecting the safety of devascularizing/debulking suprasellar tumors.

METHODS

We describe an expanded endoscopic endonasal approach for suprasellar lesions, with stepwise image-guided dissections highlighting surgical pearls and pitfalls to enhance surgical safety. This article presents transnasal intra-third-ventricular anatomy from trans-tuber cinereum, and trans-lamina terminalis approaches, comparing subchiasmatic and suprachiasmatic trajectories.

CONCLUSION

The rostral extension via endoscopic endonasal transsellar-transtubercular-transplanum approaches can provide a safe and feasible route for suprasellar lesions, in subchiasmatic, suprachiasmatic, and intraventricular regions.

Proximal Branches of the Anterior Cerebral Artery: Anatomic Study and Applications to Endoscopic Endonasal Surgery

BACKGROUND

The endoscopic endonasal approach is a surgical alternative for midline anterior skull base tumors. A detailed understanding of the proximal anterior cerebral artery (ACA) branches' anatomy from an endonasal perspective is essential for avoiding vascular complications.

OBJECTIVE

To evaluate, from an endonasal perspective, the anatomic variations of the ACA and its proximal branches, specifically the recurrent artery of Heubner (RAH), and the fronto-orbital (FOA) and frontopolar (FPA) arteries.

METHODS

We study the origin, course, branching pattern, diameter, and relationship between the proximal ACA branches and the optic apparatus and olfactory tract in 25 head specimens.

RESULTS

The RAH was present in all hemispheres and originated within 3 ± 1.5 mm of the AcomA, with a 0.4 ± 0.1 mm diameter. Based on its relationship with the A1 segment, we observed three RAH courses: anterior (40%), superior (22%), and posterior (38%). The FOA was present in all cases, a mean of 6 ± 4 mm from the AcomA, with a 0.7 ± 0.4 mm diameter. The FOA arose mainly from the A2 (70%), with three courses in relation to the olfactory tract: crossing its proximal third (54%), crossing its middle third (31%), and running parallel to it along the gyrus rectus (15%). The FPA was present in 92% of the hemispheres, a mean of 10 ± 5 mm from the AcomA, always arising from the A2 and coursing anteriorly within the interhemispheric fissure towards the frontal pole.

CONCLUSION

The RAH, FOA, and FPA can be differentiated by origin, course, and destination using the A1 segment, olfactory tract, and interhemispheric fissure, respectively, as surgical landmarks.

Results of Transcranial Resection of Olfactory Groove Meningiomas in Relation to Imaging-Based Case Selection Criteria for the Endoscopic Approach

BACKGROUND

Endoscopic endonasal surgery (EES) is increasingly used for olfactory groove meningiomas (OGMs). The role of EES for large (≥4 cm) or complex OGMs is debated. Specific imaging features have been reported to affect the degree of gross total resection (GTR) and complications following EES for OGMs. The influence of these factors on transcranial resection (TCR) is unknown.

OBJECTIVE

To examine the impact of specific imaging features on outcome following TCR to provide a standard for large and endoscopically less favorable OGMs against which endoscopic outcomes can be compared.

METHODS

Retrospective study of patients undergoing TCR for OGMs 2002 to 2016.

RESULTS

Fifty patients (mean age 62.1 yr, mean maximum tumor diameter 5.04 cm and average tumor volume of 48.8 cm3) were studied. Simpson grade 1 and 2 resections were achieved in 80% and 12%, respectively. A favorable functional outcome (modified Rankin Scale [mRS] 0-2) was attained in 86%. The degree of resection, mRS, mortality (4%), recurrence (6%), infection (8%), and cerebrospinal fluid leak requiring intervention (12%) were not associated with tumor calcification, absence of cortical cuff, T2 hyperintensity, tumor configuration, tumor extension beyond midpoint of superior orbital roof, or extension to posterior wall of frontal sinus. There was no difference in resection rates but a trend towards greater complications between 3 arbitrarily divided groups of large meningiomas of increasing complexity based on extensive extension or vascular adherence.

CONCLUSION

Favorable outcomes can be achieved with TCR for large and complex OGMs Factors that may preclude endoscopic resection do not negatively affect outcome following TCR.

An Overview of Managements in Meningiomas

Meningioma is the most frequent primary tumor of the central nervous system. Important advances have been achieved in the treatment of meningioma in recent decades. Although most meningiomas are benign and have a good prognosis after surgery, clinicians often face challenges when the morphology of the tumor is complicated or the tumor is close to vital brain structures. At present, the longstanding treatment strategies of meningioma are mainly surgery and radiotherapy. The effectiveness of systemic therapy, such as chemotherapy or targeted therapy, has not been confirmed by big data series, and some clinical trials are still in progress. In this review, we summarize current treatment strategies and future research directions for meningiomas.

Methods of Skull Base Repair Following Endoscopic Endonasal Tumor Resection: A Review

Following the introduction of fully endoscopic techniques for the resection of pituitary tumors, there was a rapid expansion of the indications for endonasal endoscopic surgery to include extrasellar tumors of the skull base. These techniques offer significant advantages over traditional open surgical approaches to the skull base, including improved tumor resection, and better post-operative neurological outcomes. Following their introduction, however, the initial rate of post-operative CSF leak was unacceptably high. Post-operative CSF leak following skull base surgery is a major source of morbidity, and can lead to the development of life-threatening intracranial infection. The use of vascularized naso-septal flaps transformed the management of these patients, significantly reducing the rate of post-operative CSF leak and increasing the number of patients that could benefit from this less invasive treatment modality. Adequate repair of iatrogenic defects in the skull base is of crucial importance for patients with skull base tumors, as the development of a post-operative CSF leak, and the associated complications can significantly delay the administration of the adjunctive oncological therapies these patients require. In this review, we provide an overview of the latest evidence regarding skull base reconstruction following endoscopic skull base surgery, and describe the skull base repair technique in use at our institution.

Surgical nuances of the expanded endoscopic anterior skull base craniectomy for hyperostotic meningioma resection

BACKGROUND

The rostral expanded endoscopic approach (EEA) to anterior cranial fossa (ACF) has several advantages over transcranial/craniofacial surgery, providing early access to the vascular supply of tumors and reducing morbidities of craniotomy especially that of brain retraction. This article presents endoscopic landmarks and nuances for a wide ACF corridor, with stepwise image-guided dissections highlighting surgical tricks and techniques to enhance surgical safety.

METHODS

We describe an expanded endoscopic endonasal anterior skull base craniectomy for a recurrent large olfactory groove hyperostotic meningioma, with correlated cadaveric dissections.

CONCLUSION

The widening of rostral EEA can provide a safe and feasible route to access ACF. This article highlights the specific landmarks in endoscopic anatomy with reference to the angle of visualization and bayonetted instruments.

ICAR: endoscopic skull-base surgery

BACKGROUND

Endoscopic skull-base surgery (ESBS) is employed in the management of diverse skull-base pathologies. Paralleling the increased utilization of ESBS, the literature in this field has expanded rapidly. However, the rarity of these diseases, the inherent challenges of surgical studies, and the continued learning curve in ESBS have resulted in significant variability in the quality of the literature. To consolidate and critically appraise the available literature, experts in skull-base surgery have produced the International Consensus Statement on Endoscopic Skull-Base Surgery (ICAR:ESBS).

METHODS

Using previously described methodology, topics spanning the breadth of ESBS were identified and assigned a literature review, evidence-based review or evidence-based review with recommendations format. Subsequently, each topic was written and then reviewed by skull-base surgeons in both neurosurgery and otolaryngology. Following this iterative review process, the ICAR:ESBS document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:ESBS document addresses the role of ESBS in primary cerebrospinal fluid (CSF) rhinorrhea, intradural tumors, benign skull-base and orbital pathology, sinonasal malignancies, and clival lesions. Additionally, specific challenges in ESBS including endoscopic reconstruction and complication management were evaluated.

CONCLUSION

A critical review of the literature in ESBS demonstrates at least the equivalency of ESBS with alternative approaches in pathologies such as CSF rhinorrhea and pituitary adenoma as well as improved reconstructive techniques in reducing CSF leaks. Evidence-based recommendations are limited in other pathologies and these significant knowledge gaps call upon the skull-base community to embrace these opportunities and collaboratively address these shortcomings.

Combined Nasoseptal and Inferior Turbinate Flap for Reconstruction of Large Skull Base Defect After Expanded Endonasal Approach: Operative Technique

BACKROUND

Increasing indications for endoscopic endonasal approaches have led neurosurgeons to develop new reconstruction techniques for larger skull base defects. Vascularized grafts have been a great adjunction to reduce the rate of cerebrospinal fluid leak and can also be used to cover exposed critical structures such as the internal carotid artery. The nasoseptal flap and the inferior or middle turbinate flap are thus widely used in endoscopic skull base surgery, but may be insufficient for very large defects.

OBJECTIVE

To present a new mucosal flap used to cover large skull base defects in which the mucosa of the inferior turbinate, inferior meatus, nasal floor, and nasal septum is harvested in 1 piece keeping both vascular pedicles intact (inferior turbinate and septal arteries).

METHODS

We describe a surgical technique to harvest a combined inferior turbinate-nasoseptal flap.

RESULTS

Technical pearls and surgical pitfalls are described through 2 clinical cases in which the nasoseptal mucosa was partially damaged during a previous surgery, rendering the nasoseptal flap insufficient by itself. The flap is harvested thanks to 2 mucosal cuts: a first circular cut around the choanal arch and the junction between the hard and the soft palate, and a second one combining classical cuts of the nasoseptal flap and the inferior turbinate flap.

CONCLUSION

The inferior turbinate-nasoseptal flap can be a useful alternative in patients whose septal mucosa was partially damaged and/or with very large postoperative skull base defects.

Endoscopic endonasal resection of a large tuberculum sella meningioma

Over the past three decades, endoscopic endonasal surgery has unlocked new corridors to treat a wide spectrum of ventral skull base lesions. Tuberculum sella meningiomas represent one of the most ideal pathologies for ventral skull base access. Traditionally, these lesions were approached primarily through various subfrontal and frontal-lateral transcranial approaches that have unfortunately been shown to be associated with worsening visual decline postoperatively. The endoscopic endonasal approach is now being attempted by more surgeons and leverages an infrachiasmatic trajectory that provides direct access to the tuberculum sella where most of the vascular supply for these lesions can be taken early, facilitating more efficient surgical resection and mitigating the risk of optic nerve injury. Here we review a challenging case of a large (∼3 cm) tuberculum sella meningioma, encasing critical vessels off the circle of Willis and resected via an endoscopic endonasal approach. We discuss the technical nuances and relevant surgical anatomy of this approach and highlight important considerations in the safe and successful removal of these meningiomas. We show that certain tumors that appear to encase the supraclinoidal carotid artery can be fully resected via an endonasal approach with precise surgical technique and adequate exposure. Furthermore, this case illustrates the risk of injuring a key perforating vessel from the anterior communicating artery complex, called the subcallosal artery. Injury to this vessel is highly associated with tumors like the one presented here that extend into the suprachiasmatic space between the optic chiasm and the anterior communicating complex. Meticulous surgical dissection is required to preserve this perforating vessel as well as branches from the superior hypophyseal artery. Finally, we review our current closure techniques for these challenging approaches and discuss the use of a lumbar drain for 3 days to lower CSF leak rates.

The video can be found here: https://youtu.be/mafyXi5B0MA.