Endoscopic Endonasal Approaches for Anterior Skull Base Meningiomas.

Introduction: Large anterior skull base (ASB) meningiomas are occasionally highly vascular, and are supplied predominantly by the anterior and posterior ethmoidal arteries which are branches of the ophthalmic artery. Effective preoperative embolization of these lesions is thwarted by concerns of retrograde embolization of the ophthalmic artery with visual loss or blindness. The standard goal of early intraoperative devascularization of these meningiomas at the basal dural attachment is often difficult until there has been substantial tumor decompression. As such, resection of these lesions is often coupled with lengthy operative times and significant blood loss. Endoscopic transnasal approaches provide direct access to the ethmoidal arteries, and ASB meningiomas are largely devascularized early on in the course of surgical resection. However, endoscopic resection of larger ASB meningiomas has been associated with lengthy resection times, subtotal resection, and increased rate of postoperative CSF leak. In an effort to decrease operative time and blood loss we have adopted a surgical strategy that incorporates endoscopic transnasal devascularization of the tumor as a means to complement the strengths of an open surgical approach. We present our institutional experience with two cases in which we treated large (>4 cm) ASB meningiomas with a combined approach—endoscopic transnasal sacrifice of the anterior and posterior ethmoidal arteries followed by open subfrontal resection.

ABSTRACTBACKGROUND: Endoscopic transnasal surgery has gained rapid global acceptance over the last two decades. The growing literature and understanding of anterior skull base endoscopic anatomy, in addition to new dedicated endoscopic instruments and tools, have helped to expand the use of the transnasal route in skull base surgery.OBJECTIVE: Report our early experience in expanded endoscopic transnasal surgery (EETS) and approach to skull base neoplasms.DESIGN: Descriptive, retrospective case series.SETTING: Major tertiary care center.PATIENTS AND METHODS: A retrospective case review was conducted at King Saud University Medical City between December 2014 and August 2019. Cases with skull base neoplasms that underwent EETS were included. EETS was defined as endoscopic surgical exposure that extended beyond the sellar margins (prechiasmatic sulcus superiorly, clival recess inferiorly, cavernous carotid lines laterally). Routine transsphenoidal pituitary neoplasms, neoplasms of sinonasal origin and meningoencephaloceles were excluded.MAIN OUTCOME MEASURES: Preoperative clinical assessment, imaging results, surgical approach, and hospital course were all retrieved from the patient electronic charts. Clinical follow-up, perioperative complications, and gross residual tumor rates were documented and reviewed.SAMPLE SIZE AND CHARACTERISTICS: 45 cases of EETS, 13 males and 32 females with mean age of 39.0 (17.7) years (range 2–70 years).RESULTS: The series comprised a wide range of pathologies, including giant pituitary adenoma (8 cases), meningioma (23 cases), craniopharyngioma (4 cases), chordoma (4 cases), optic pathway glioma (2 cases), epidermoid neoplasms (2 cases), astrocytoma (1 case), and teratoma (1 case). For the entire series, gross total resection was achieved in 25/45 operations (55.5%). Postoperative cerebrospinal fluid leak was the most common complication observed in 9 patients (20%) which were all managed endoscopically. Major vascular complications occurred in 2 patients (4.4%) and are described. Other complications are outlined as well. No mortality was observed.CONCLUSIONS: EETS to the skull base can be done with results comparable to traditional approaches. More work is needed to expand our experience, improve outcomes, and educate the public and medical community in our region about the usefulness of this approach.LIMITATIONS: Sample size and study design.CONFLICT OF INTEREST: None.

The aim of the present study was to compare the anatomy of the cavernous sinus via an endoscopic transnasal route with the anatomy of the same region explored by the transcranial route. The purpose was to identify and correlate the corresponding anatomic landmarks both through the endoscopic transnasal transsphenoidal and the microscopic transcranial views. Five fresh injected heads (10 specimens) were dissected by the endoscopic transnasal and microsurgical transcranial approaches. A comparison of different microsurgical corridors of the cavernous sinus with the corresponding endoscopic transnasal ones was performed. Through the endoscopic transnasal approach, it is possible to explore only some of the parasellar and middle cranial fossa subregions. Because of the complex multilevel architecture of the cavernous sinus, there is not always a correspondence between the surgical corridors bounded through the transcranial route and those exposed through the endoscopic transnasal approach. Nevertheless, some surgical corridors specific to the endoscopic transnasal route are evident: a C-shaped corridor is identifiable medial to the "intracavernous" internal carotid artery, whereas a wider triangular area is delineable lateral to the internal carotid artery; inside the latter, three more surgical corridors (a superior triangular space, a superior quadrangular space, and an inferior quadrangular space) can be described. Different surgical corridors can be defined during the endoscopic transnasal approach to the anteroinferior portion of the cavernous sinus, as already established for the transcranial route as well. Knowledge of these could be useful in decreasing morbidity and mortality during surgery in this region, these approaches being reserved to experienced transsphenoidal surgeons only.

Background:The endoscopic transnasal approach has been proven to have advantages on the removal of the tumors in pterygopalatine fossa (PPF) and infratemporal fossa (ITF). Herein, this study aimed to describe a modified approach for resection of the tumors in these areas, both in cadaveric specimen and clinical patients.Methods:The 20 adult cadaveric specimens and five patients with tumors in PPF and ITF were enrolled in this study. For the cadaveric specimens, ten were simulated anterior transmaxillary approach and ten were performed modified endoscopic transnasal transmaxillary approach. The exposure areas were compared between two groups and main anatomic structure were measured. Surgery was operated in the five patients with tumors of PPF and ITF to verify the experience from the anatomy. Perioperative management, intraoperative findings and postoperative complications were recorded and analyzed.Results:The modified endoscopic transnasal transmaxillary approach provided as enough surgical exposure and high operability to the PPF and ITF as the anterior transmaxillary approach did. The diameter of maxillary artery in the PPF was 3.77 ± 0.78 mm (range: 2.06–4.82 mm), the diameter of middle meningeal artery in the ITF was 2.79 ± 0.61 mm (range: 1.54–3.78 mm). Four patients who suffered schwannoma got total removal and one of adenocystic carcinoma got subtotal removal. The main complications were facial numbness and pericoronitis of the wisdom tooth. No permanent complication was found.Conclusions:With the widespread use of neuroendoscopy, the modified endoscopic transnasal transmaxillary approach is feasible and effective for the resection of tumors located in PPF and ITF, which has significant advantages on less trauma and complications to the patients.

The aim of this study is to retrospectively analyze 161 cases of surgically treated skull base chordoma, so as to summarize the clinical classification of this tumor and the surgical approaches for its treatment via transnasal endoscopic surgery. Between August 2007 and October 2013, a total of 161 patients (92 males and 69 females) undergoing surgical treatment of skull base chordoma were evaluated with regard to the clinical classification, surgical approach, and surgical efficacy. The tumor was located in the midline region of the skull base in 134 cases, and in the midline and paramedian regions in 27 cases (extensive type). Resection was performed via the transnasal endoscopic approach in 124 cases (77%), via the open cranial base approach in 11 cases (6.8%), and via staged resection combined with the transnasal endoscopic approach and open cranial base approach in 26 cases (16.2%). Total resection was achieved in 38 cases (23.6%); subtotal resection, 86 cases (53.4%); partial resection of 80-95%, 29 cases (18%); and partial resection <80%, 8 cases (5%). The clinical classification method used in this study seems suitable for selection of transnasal endoscopic surgical approach which may improve the resection degree and surgical efficacy of skull base chordoma. Gross total resection of skull base chordoma via endoscopic endonasal surgery (with addition of an open approach as needed) is a safe and viable alternative to the traditional open approach.

Intraorbital foreign bodies (IOFBs) represent a clinical challenge: surgical management can be controversial and different strategies have been proposed. When removal is recommended, depending on the location and nature of the IOFB both external and endoscopic approaches have been proposed, with significantly different surgical corridors to the orbit and different morbidities. We performed a literature review of cases of IOFBs that received exclusive endoscopic transnasal surgical treatment to evaluate the role of this surgery in these occurrences. We also present a case of an intraorbital intraconal bullet that was successfully removed using an endoscopic transnasal approach with good outcomes in terms of ocular motility and visual acuity. A limited number of cases of IOFBs have been treated with an exclusive endoscopic transnasal approach. When in the medial compartment, this approach appears to be safe and effective. In our case, two months after surgery the patient showed complete recovery with no significant long-term sequelae. When feasible, an endoscopic transnasal approach for intraorbital foreign bodies represents a valid surgical technique with optimal outcomes and satisfactory recovery.

ObjectiveEvaluate the management of meningiomas surgically resected via an endoscopic transnasal approach by the South Australian Endoscopic Skull Base Unit in South Australia since 2004. The safety and efficacy of the procedure and areas for further refinement and improvement are analyzed.MethodRetrospective case series of 16 consecutive patients who underwent endoscopic transnasal resection of anterior skull base meningiomas in South Australia between 2004 and 2010.ResultsPreoperative symptoms, tumor size, tumor location, intraoperative time, intraoperative complications, defect closure techniques, postoperative complications, and length of hospital stay were assessed and compared. The results achieved by this unit are comparable with the published literature.ConclusionAnterior cranial fossa meningiomas can be safely removed endonasally and offer significant advantages over the traditional transcranial approach.

Olfactory groove meningiomas represent 10% of intracranial meningiomas and arise in the midline of the anterior cranial fossa along the dura of the cribriform plate and planum sphenoidale. Hyperostosis of the adjacent underlying bone is common, and further extension into ethmoid sinuses and nasal cavity can occur in 15%-25% of cases. Radical tumor resection including the involved dural attachment and underlying hyperostotic bone offers the best chance of a Simpson Grade I resection to minimize recurrence. Incomplete removal of involved hyperostotic bone can result in tumor recurrence at the cribriform plate with extension into the paranasal sinuses. Resection has traditionally been performed using a bifrontal or pterional approach, both of which require some degree of brain retraction or manipulation to expose the tumor. The endoscopic endonasal transcribriform approach offers the most direct and immediate exposure to the tumor without brain retraction and manipulation of neurovascular structures. An endonasal "keyhole craniectomy" is performed in the ventral skull base directly over the basal dural attachment, extending from the posterior wall of the frontal sinus to the planum sphenoidale and tuberculum sellae in the anteroposterior plane, and from one medial orbit to the other in the coronal plane. Excellent panoramic visualization of the keyhole skull base defect can be obtained with a 30° endoscope after performing a modified Lothrop procedure. Because the dural attachment is adjacent to the paranasal sinuses, early devascularization and total Simpson Grade I removal of the tumor including the dural attachment and underlying hyperostotic bone can be achieved in properly selected patients. This approach is also very suitable for meningiomas that have recurred or extended into the paranasal sinuses. Extracapsular, extraarachnoid dissection of the tumor from the frontal lobes and neurovascular structures can be performed using conventional bimanual microsurgical techniques. In this report, we review the surgical technique and describe our operative nuances for removal of olfactory groove meningiomas, including recurrent tumors with extension into the nasal cavity, using a purely endoscopic endonasal transcribriform approach. In addition, we discuss the advantages, limitations, patient selection, and complications of this approach. We specifically highlight our technique for multilayer reconstruction of large anterior skull base dural defects using fascia lata and acellular dermal allograft supplemented by bilateral vascularized pedicled nasoseptal flaps. Three new cases of endoscopically resected olfactory groove meningiomas are also presented.

The clivus is a region characterized by complex anatomy, with vascular and neural structures that are located in close proximity. Different pathologies can affect this area, and traditional surgical approaches were open approaches. Recently, the endoscopic transnasal technique has been introduced, and currently represents a good alternative for the surgical management of these lesions. This is a preliminary report on patients treated endoscopically for clival lesions by the authors' Skull Base Team. This was a retrospective chart review of patients who underwent an endoscopic exclusive transnasal approach (EEA) or a transoral one (TO) for clival lesions between June 2015 and November 2017at our Skull Base Referral Center. Patient characteristics and symptoms, preoperative neuroradiological evaluation, surgical approach, complications, and postoperative results were evaluated. Nine patients (6 females and 3 males; age range 6-82years, mean 50.8years) underwent EEA or TO. From histological analysis, we found chordomas (6/9 subjects), chondrosarcoma (1/9), craniopharyngioma (1/9), and eosinophilic granuloma (1/9). Three patients had previously been operated for a parasellar chondrosarcoma (1/9), a pituitary macroadenoma (1/9), or a chondroid chordoma (1/9). The lesions were totally (2/9) or sub-totally (5/9) resected, debulked (1/9), or analyzed with a biopsy (1/9). Reconstruction was accomplished with a multilayer technique (7/9), or with a gasket-seal (1/9), using a mucoperichondrial graft, a single/double nasoseptal flap, a middle turbinate flap, a fascia lata, or a synthetic fascia. One patient (11.1%) was re-operated on due to cerebrospinal leakage, without further complications. Two patients (22.2%) were re-operated on due to chordoma regrowth. Adjuvant chemotherapy was administered to 1/9 patient with progressive healing. All of the other patients underwent proton-beam radiotherapy with no documented tumor growth (median follow-up: 20 months; range 5.1-29.9months). Clival lesions represent a heterogeneous group of lesions located in a very complex and difficult area. EEA and TO approaches are safe and mini-invasive, with lower morbidity and with postoperative complications when compared to the traditional open approaches, according to the extent and type of pathology.

Transnasal endoscopic transsphenoidal approaches constitute an essential technique for the resection of skull base tumors in adults. However, in the pediatric population, sellar and suprasellar lesions have historically been treated by craniotomy. Transnasal endoscopic approaches are less invasive and thus may be preferable to craniotomy, especially in children. In this case series, the authors present their institutional experience with transnasal endoscopic transsphenoidal approaches for pediatric skull base tumors. The authors retrospectively reviewed pediatric patients (age ≤ 18 years) who had undergone transnasal endoscopic transsphenoidal approaches for either biopsy or resection of sellar or suprasellar lesions between 2007 and 2016. All operations were performed jointly by a team of pediatric neurosurgeons and skull base otolaryngologists, except for 8 cases performed by one neurosurgeon. The series included 42 patients between 4 and 18 years old (average 12.5 years) who underwent 51 operations. Headache (45%), visual symptoms (69%), and symptoms related to hormonal abnormalities (71%) were the predominant presenting symptoms. Improvement in preoperative symptoms was seen in 92% of cases. Most patients had craniopharyngiomas (n = 16), followed by pituitary adenomas (n = 12), Rathke cleft cysts (n = 4), germinomas (n = 4), chordomas (n = 2), and other lesion subtypes (n = 4). Lesions ranged from 0.3 to 6.2 cm (median 2.5 cm) in their greatest dimension. Gross-total resection was primarily performed (63% of cases), with 5 subsequent recurrences. Nasoseptal flaps were used in 47% of cases, fat grafts in 37%, and lumbar drains in 47%. CSF space was entered intraoperatively in 15 cases, and postoperative CSF was observed only in lesions with suprasellar extension. There were 8 cases of new hormonal deficits and 3 cases of new cranial nerve deficits. Length of hospital stay ranged from 1 to 61 days (median 5 days). Patients were clinically followed up for a median of 46 months (range 1-120 months), accompanied by a median radiological follow-up period of 45 months (range 3.8-120 months). Most patients (76%) were offered adjuvant therapy. In this single-institution report of the transnasal endoscopic transsphenoidal approach, the authors demonstrated that this technique is generally safe and effective for different types of pediatric skull base lesions. Favorable effects of surgery were sustained during a follow-up period of 4 years. Further refinement in technology will allow for more widespread use in the pediatric population.

Endoscopic management of anterior cranial fossa meningiomas

Endonasal skull base endoscopy

Midline meningiomas arising from the anterior skull base, particularly the planum sphenoidale and tuberculum sellae (TSM), present unique challenges due to their proximity to vital structures such as the optic apparatus. Traditionally approached via transcranial routes, these lesions often lead to chronic compression of optic nerves, resulting in visual impairment. With advancements in endoscopic skull base surgery, extended endonasal endoscopic (EEE) approaches have emerged as a viable alternative. This study aims to analyze the technical nuances and outcomes of EEE approach for excision of anterior skull base meningiomas presenting with visual impairment. Thirteen patients with TSM and visual impairment underwent EEE surgery at a single institute. Clinical, radiological, and ophthalmological evaluations were conducted pre- and post-operatively. Surgical techniques involved meticulous tumor excision, preservation of vital structures, and multi-layer skull base reconstruction. Visual outcomes, extent of resection, complications, and endocrine function were assessed. The study demonstrated significant visual improvement in 76.9% of patients, with no cases of permanent visual deterioration. Complete tumor excision was achieved in the majority, with near-total excision in selected cases due to adhesions or tumor characteristics. Complications included CSF rhinorrhea, meningitis, and transient visual field defects, all managed effectively. Endocrine function remained largely unaffected postoperatively, except for one case of diabetes insipidus. The EEE approach offers distinct advantages in accessing and excising anterior skull base meningiomas, particularly in achieving optic nerve decompression while preserving vision. Despite challenges associated with larger tumors and adhesions, careful surgical planning and techniques can optimize outcomes. This study contributes to the growing evidence supporting the efficacy and safety of EEE approaches in treating anterior skull base meningiomas, emphasizing the importance of surgical expertise and patient selection.

The aim of this study is to describe the case of a cavernous hemangioma extending from the orbital apex to the pterygopalatine fossa that was completely removed via an endoscopic transnasal approach. We report the case of a 48-year-old man who presented with right hemianopsia of the left eye. MRI revealed a 1.5 x 1.1 cm mass lesion extending from the infero-medial part of the left orbital apex to the pterygopalatine fossa. Removal of the lesion was performed via the endoscopic transnasal approach. Using this approach, a wide operative view of the entire extent of the lesion from the optic canal to the orbital apex and the pterygopalatine fossa was obtained, and complete removal of the lesion was performed safely. The pathological diagnosis was cavernous hemangioma. The endoscopic transnasal approach is a safe, effective, and less invasive therapeutic modality for the removal of lesions extending from the infero-medial part of the left orbital apex to the pterygopalatine fossa. With appropriate patient selection, this approach improves access and visualization, and it enables performance of operative procedures with much less risk than the conventional microscopic transcranial or transfacial approaches.

Conclusion: The endoscopic transnasal approach with IGS is a safe and effective technique, allowing completely resection of JPOF, with minimal morbidity and recurrence.Objectives: JPOF is a benign but locally aggressive fibro-osseous lesion. This study presents a series of JPOF cases, involving anterior skull base and orbit, treated by endoscopic transnasal approach with image guidance system (IGS) to resect the mass completely.Method: This study retrospectively reviewed the clinical presentations, surgical procedures, and complications of 11 patients with JPOF who were treated by endoscopic approach from May 2009 to April 2014. All patients were followed by endoscopic and CT scan evaluations during follow-up.Results: All of the 11 cases were boys, with a mean age of 11.8 years (range = 6–17 years). The size of mass in the paranasal sinus ranged from 2.5–4.6 cm in greatest dimension (mean = 3.7 cm), and the medial orbital wall and cranial base were involved in all patients. All 11 patients received successful operation and were relieved from symptoms without mortality and major complications. During follow-up (range from 17–67 months; mean follow-up = 25.8 months), only one patient was recurrent in local position. The skull base partial resected during surgery was found to rebuild after 1 year.