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Background: The endoscopic endonasal approach provides an option to approach the medial and inferior orbital apex, with less manipulation of intraorbital structures. Method: We described the advantages, complications, caveats, and indications of the endoscopic endonasal approach to the orbital apex. An intraorbital extraconal cavernous malformation is shown as example. Conclusion: The endoscopic endonasal approach is a good corridor to the medial and inferior orbital apex, providing good exposure and little manipulation of the intraorbital contents. [ABSTRACT FROM AUTHOR]

The petrous apex is a difficult to reach surgical area due to its deep position in the skull base and many vital surrounding structures. Petrous apex pathology ranges from extradural cholesterol granulomas, cholesteatomas, asymmetric pneumatization, and osteomyelitis to intradural meningiomas and schwannomas. Certain lesions, such as cholesterol granulomas, can be managed with drainage while neoplastic lesions must be completely resected. Surgical options use open, endoscopic, and combined techniques and are categorized into anterior, lateral, and posterior approaches. The choice of approach is determined by the nature of the pathology and location relative to vital structures and extension into surrounding structures and requires thorough preoperative evaluation and discussion of surgical goals with the patient. The purpose of this state-of-the-art review is to discuss the most commonly used surgical approaches to the petrous apex, and the anatomy on which these approaches are based.

Abstract Objective Surgery of the pediatric skull base has multiple unique challenges and has seen recent rapid advances. The objective of this review is to assess key issues in pediatric skull base surgery (SBS), including anatomic limitations, surgical approaches, reconstruction techniques, postoperative care, complications, and outcomes. Data Sources PubMed literature review. Review Methods A review of the literature was conducted to assess the challenges, recent advances, and reported outcomes in pediatric SBS. Results The pediatric skull base presents multiple anatomic challenges, including variable patterns of pneumatization, narrow piriform aperture width, and narrow intercarotid distance at the level of the cavernous sinus but not the superior clivus. These issues may be particularly challenging in patients less than 2 years of age. Endoscopic endonasal approaches in the sagittal and coronal plane have been applied to the pediatric skull base while open approaches may still be necessary in the setting of extensive intracranial or orbital disease, as well as disease lateral to critical neurovascular structures. While the nasoseptal flap was initially called into question for pediatric cases, it has been shown through multiple reports to be a feasible and robust reconstructive option. Complications and outcomes often depend upon the pathology. In children, response to noxious stimuli, ability to avoid Valsalva, and adherence to nasal precautions is variable. The use of lumbar drains is more common in pediatric than adult patients. Conclusion While the pediatric skull base presents unique challenges, outcomes data support that endoscopic endonasal approaches are a pertinent surgical technique in appropriately selected patients. Level of Evidence 3a

Abstract Background Invasive growth of pituitary macroadenomas to the suprasellar region occurs commonly. Pituitary adenomas show varying growth patterns when the sellar diaphragm is absent, and they are often confused with other common tumors in the sellar region. This article explores the clinical features of suprasellar pituitary adenomas with defects of the sellar diaphragm (SPADSD) and evaluates the efficacy of the endoscopic endonasal approach (EEA) for treatment of such tumors. Methods We performed a detailed examination of records from 19 patients collected prior to surgery. After relevant diseases were excluded, the tumor properties were evaluated according to imaging characteristics. Diagnoses were verified using EEA surgery. The concept of SPADSD was put forward. Postoperative recovery was followed to determine whether EEA is suitable for the treatment of such tumors. Results In the 19 patients with SPADSD, we found that the tumors were less stressed on the pituitary, and tumors in the suprasellar region often had irregular shapes. During surgery, we took extended supra-saddle approaches and confirmed that unrestricted growth of the tumor was caused by defects in the diaphragm of the sella turcica to the suprasellar region. Recovery was good after surgery, confirming the efficacy of EEA for treatment of these tumors. Conclusion SPADSD has different clinical features from those of other pituitary tumors and requires careful screening prior to surgery. Endoscopic surgery is the preferred procedure for this type of tumor.

Background and Aims: Lesions in craniovertebral junction (CVJ) are approached either through transnasal or transoral route. Endoscopic transnasal route reduces significant morbidity, and nasopalatine line (NPL) predicts the inferior-most limit of surgical dissection. The purpose of the present study was to measure the NPL in the cadavers, which is beneficial for the endoscopic transnasal anterior approach to access odontoid process and anterior CVJ, especially in surgical decompression of medulla oblongata. Materials and Methods: The present study was done on forty midline sagittal head-and-neck specimens obtained from 10% formalin-fixed cadavers in the Department of Anatomy, Rajarajeswari Medical College and Hospital, Bangalore. Using slide calipers, the hard palate line (HPL), which extends from the anterior nasal spine of maxillary bone to the posterior nasal spine of palatine bone and NPL which extends from the inferior-most point of nasal bone to the posterior nasal spine were measured. In addition, HPL was extended to the lower limit of the anterior margin of the foramen magnum, and NPL was further extended posteriorly to the ventral surface of the second cervical vertebra to know the inferior limit of transnasal endoscopic access for surgeries on ventral skull base lesions. Results: The average of HPL and its extension to foramen magnum was found to be 45.83 mm and 40.97 mm respectively. The NPL and its extension to the ventral surface of C2 vertebra were found to be 58.22 mm and 37.18 mm, respectively. Conclusion: HPL & NPL provide useful information for the neurosurgeons to access the lesions in the ventral CVJ and to achieve a good outcome.

IntroductionThe endoscopic endonasal approach (EEA) is a safe and effective treatment for pituitary adenomas (PAs). Since extracapsular resection (ER) of PAs improves tumor resection and endocrine remission rates, the interface between the pseudocapsule and gland draws increasing attention. However, it is difficult to precisely dissect the tumor along the exact boundary, and complete removal of the tumor increases the risks of normal tissue damage and cerebrospinal fluid (CSF) leakage. In this study, we investigated the extracapsular resection as well as the pseudocapsule histology to evaluate the effectiveness and safety of pseudocapsule-related surgical interventions.MethodsFrom December 2017 to December 2019, 189 patients of PAs via EEA in our single center were analyzed retrospectively. The images, operative details, and clinical follow-up of patients were collected. Sixty-four patients underwent pseudocapsule-based ER, and 125 patients also underwent traditional intracapsular resection (IR) with or without intensive excision for FPAs. The clinical characteristics, tumor resection, endocrinological outcomes, and postoperative morbidities of the two groups were compared. Informed consent for publication of our article was obtained from each patient. Histological examination of pseudocapsule was performed using hematoxylin and eosin and reticulin staining.ResultsThe gross total recession was 62 (96.9%) in the ER group and 107 (85.6%) cases in the IR group, whereas the endocrine remission rate was 29/31 (93.5%) and 40/53 (75.5%) cases, respectively. Anterior pituitary functions were not aggravated postoperatively in any patient, but transient diabetes insipidus (DI) occurred more in the IR group (64.0%) than in ER (48.4%). Pseudocapsule specimens were obtained in 93 patients, and clusters of small cell aggregation were detected in 11 pseudocapsule specimens (11.8%) whereas other patients showed no remarkable developed pseudocapsule. Intraoperative CSF leak occurred more in the ER group (28.1%) than in the IR group (13.6%), but no difference was seen between two groups postoperatively. No case of intracranial hematoma or pituitary crisis occurred in both groups. After a mean follow-up of 22.8 months, tumor recurrence was observed in 4 (2.1%) cases.ConclusionPseudocapsule-based extracapsular resection of PAs via EEA is an effective and safe procedure to achieve complete resection with high and sustained endocrine remission and without deteriorating pituitary function.

Objective: The cavernous sinus (CS) has 4 compartments: superior, inferior, posterior, and lateral. Among these, the lateral compartment is the most common location for residual tumor, given the risk of neurovascular injury. The authors' study aimed to delineate the anatomical landmarks in this area and illustrate the technical nuances of the lateral transcavernous approach., Methods: Twenty-two colored silicone-injected specimens were dissected via an endoscopic endonasal approach to the lateral compartment of the CS. The anatomical landmarks and the internal carotid artery (ICA) mobilization technique were investigated. Two illustrative cases are provided., Results: The lateral compartment of the CS is bounded by the carotid-oculomotor membrane (COM) and optic strut as the roof and the petrolingual ligament and lingual process as the floor. It is divided into 2 asymmetrical subcompartments: the upper, larger subcompartment, located superior to the abducens nerve, accommodates the lateral parasellar ligament (LPL), inferolateral trunk (ILT), and branches of the tentorial artery; and the lower, smaller subcompartment, inferior to the abducens nerve, accommodates only the sympathetic nerve branches as they join the abducens nerve. The LPL is a well-defined ligamentous band and was identified in 38 (86%) hemispheres with 2 distinct configurations: 1) robust LPL (59%), with highly compacted ligamentous bands tightly adherent to the ICA; and 2) dispersed LPL (27%), with less compaction and adherence to ICA. The main attachment of the LPL to the cavernous ICA was most commonly observed at the horizontal ICA segment (55%), followed by the anterior (18%) and posterior (14%) genua. The ILT, as the main vessel in the lateral compartment, was identified in 41 (93%) hemispheres and originated from the horizontal ICA segment (80%) or the anterior genu (14%), from either the lateral (52%) or inferior (41%) aspect of the cross-section of the ICA. In 64% of hemispheres, the LPL wrapped the ILT, abducens nerve, and sympathetic nerve to form a broad and firm neurovascular-ligamental complex. Transection of the LPL, ILT, and COM enables medial ICA mobilization and enhances access to the lateral compartment of the CS, potentially increasing the exposure width by 6 ± 1 mm., Conclusions: This study provides valuable insights into the anatomical intricacies of the lateral compartment of the CS and underscores the potential benefits of the endoscopic endonasal lateral transcavernous approach. Further clinical applications are essential for validating these findings and optimizing surgical outcomes.

Pediatric orbital and skull base pathologies encompass a spectrum of inflammatory, sporadic, syndromic, and neoplastic processes that require a broad and complex clinical approach for both medical and surgical treatment. Given their complexity and often multicompartment involvement, a multidisciplinary approach for diagnosis, patient and family counseling, and ultimately treatment provides the best patient satisfaction and clinical outcomes. Advances in minimally invasive surgical approaches, including endoscopic endonasal and transorbital approaches allows for more targeted surgical approaches through smaller corridors beyond more classic transcranial or transracial approaches., Competing Interests: Disclosure All authors confirm there are no commercial or financial conflicts of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Given their rarity, the clinical course of patients undergoing trigeminal schwannoma (TS) resection remains understudied. The objective of this study is to describe clinical characteristics and outcomes in patients undergoing surgical resection for TS in a multi-institutional cohort. This is a retrospective study of patients undergoing TS resection at two institutions between 2004 and 2022. Patient, radiographic, and clinical characteristics were reviewed and analyzed with standard statistical methods. Thirty patients were included. The median patient age was 43 (IQR: 35-52) years, and 14 (47%) patients were female. Median clinical and radiographic follow-ups were 43 (IQR: 20-81) and 47 (IQR: 27-97) months respectively. The most common presenting symptoms were trigeminal hypesthesia (57%) and headaches (30%), diplopia (30%), and ataxia/cerebellar signs (30%). The median maximum tumor diameter was 3.3 (IQR: 2.5-5.4) cm. Most tumors were Samii type C (50%) and mixed cystic-solid (63%). Surgical approaches included endoscopic endonasal (33%), supratentorial (30%), combined/staged (20%), infratentorial (10%), and anterior petrosal (7%) approaches. Gross-total resection was achieved in 16 (53%) patients. Radiographic tumor recurrence was noted in four patients at a median of 79 (range 5-152) months. Twenty-six (87%) patients reported improvements in at least one symptom by last follow-up. The most common perioperative complication was new cranial nerve deficit, with 17% of patients having a transient deficit and 10% having a permanent cranial nerve deficit. Surgical resection of TS showed good progression-free survival and symptom improvement, but was associated with cranial nerve deficits., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The endoscopic endonasal approach (EEA) provides a direct trajectory to ventral skull base lesions, avoidance of brain retraction, and clear visualization of cranial nerves as they exit skull base foramina. Despite these benefits, the EEA is not without complications. Here, we review published literature highlighting complications associated with the EEA including cerebrospinal fluid (CSF) leak, cranial nerve (CN) dysfunction, pituitary gland dysfunction, internal carotid artery (ICA) injury, infection, and others; we place special emphasis on discussing the prevention of these complications. As widespread adoption of the EEA continues, it becomes critical to educate surgeons regarding potential complications and their prevention while identifying gaps in the current literature to guide future research and advances in clinical care.

Objective: This study aimed to describe the experience of a single institution in China in treating adenoid cystic carcinoma of the nasopharynx. Methods: We reviewed the previous literature and conducted a retrospective analysis of 12 patients who diagnosed with nasopharyngeal adenoid cystic carcinoma (NACC) in clinical data, treatment, and follow-up data during 2019 to 2021. Results: Patients ranged in age from 32 to 68 years (mean 40.7 years, median 48.5 years), with a male to female ratio of 5:7. Most of our patients have T4a and T4b diseases (50% and 25%, respectively). A quarter of patients develop distant metastases. Among the 12 patients, 7 of them have positive margins under the microscope (7/12, 58.3%). The chief clinical manifestations were epistaxis, facial swelling, facial pain, headache ear stuffy, and hearing loss. If the tumors involved with cavernous sinus, brain stem infiltrated, and internal carotid artery circumvented, patients will undertake routine enhanced magnetic resonance imaging with Magnetic Resonance Angiography/Magnetic Resonance Venogram (MRA/MRV) to clearly show the lesion region. All patients underwent endoscopic endonasal approach. Fifty percent of patients received radiotherapy and 25% of patients received chemotherapy. None of the patients was lost and the follow-up time ranged from 16 to 45 months. The mean and median follow-up were 2.08 and 1.58 years. Two patients were dead of distant metastasis within 18 and 20 months after the surgery, and another patient with recurrent NACC died of hemorrhage. Conclusion: NACC is a rare malignant tumor that occurs in the nasopharynx, which can grow along the nerve, destroy the bone of the skull base, and metastasize to other organs. Up to now, there is no standard treatment. Our results show that endoscopic sinus surgery is a better choice for advanced or recurrent NACC., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Objective: Concomitant unruptured intracranial aneurysms (UIAs) in patients with craniopharyngioma (CP) pose a challenge for surgical management. This study presents the largest known single-institution case series to investigate the incidence of UIA in CP patients, with the aim of exploring the potential risk factors for the occurrence of UIA in CP patients and proposing treatment strategies., Methods: The authors retrospectively reviewed the records of 289 adult CP patients treated in their department between January 2020 and August 2022. Routine CT angiography (CTA) was performed preoperatively in all cases. Logistic regression analysis was used to identify the risk factors for the occurrence of aneurysms. Aneurysms with the following characteristics were considered to have a high risk of intraoperative rupture and required treatment before tumor resection: 1) preliminary assessment of a high inherent risk of rupture (risk of rupture in their natural progression); and 2) location close to the tumor, irregular shape, and/or growth toward the tumor, even if the preliminary assessment indicated a low inherent risk of rupture., Results: Twenty-three of 289 CP patients (7.96%, 95% CI 5.36-11.6) were diagnosed with both CP and UIA (CP-UIA). Hypertension (OR 4.148, 95% CI 1.654-10.398; p = 0.002), estrogen deficiency (OR 3.097, 95% CI 1.241-7.731; p = 0.015), and suprasellar tumor (OR 4.316, 95% CI 1.596-11.67; p = 0.004) were independent risk factors for intracranial aneurysms (IAs) in CP patients. Among the 23 CP-UIA patients, 6 (26.1%) with a high risk of aneurysm rupture underwent endovascular treatment (EVT) before tumor resection. Seventeen (73.9%) patients with a low risk of rupture underwent tumor resection only., Conclusions: The incidence rate of IA in patients with CP was higher than that in the general population. Routine preoperative CTA is advised for adult CP patients. Patients with papillary CP exhibited a higher proportion of CP-UIAs. Older age, hypertension, estrogen deficiency, and suprasellar tumor were independent risk factors for the occurrence of IAs in CP patients. IAs in CP patients are predominantly located in the C6 and C7 segments of the internal carotid artery and are often suitable for EVT. When treating CP-UIAs, tumor-related symptoms, risk of aneurysm rupture, the spatial relationship between the tumor and IA, and the approach for tumor resection should be considered.

Objective: The traditional treatment of sellar Rathke cleft cysts (RCCs) generally involves transsellar drainage; however, suprasellar RCCs present unique challenges to appropriate management and technical complexity. Reports on overall outcomes for the endoscopic endonasal approach (EEA) for this pathology are limited. The EEA for RCCs allows three surgical techniques: marsupialization, fenestration, and fenestration with cyst wall resection., Methods: The authors performed a retrospective review of consecutive patients with RCCs that had been treated via an EEA at a single institution between January 2004 and May 2021. Marsupialization entailed the removal of cyst contents while maintaining a drainage pathway into the sphenoid sinus. Fenestration involved the removal of cyst contents, followed by separation from the sphenoid sinus, often with a free mucosal graft or vascularized nasoseptal flap. Cyst wall resection, either partial or complete, was added to select cases., Results: A total of 148 patients underwent an EEA for RCC. Marsupialization or fenestration was performed in 88 cases (59.5%) and cyst wall resection in 60 (40.5%). Cysts were classified as having a purely sellar origin (43.2%), sellar origin with suprasellar extension (37.8%), and purely suprasellar origin (18.9%). Radiological recurrence was demonstrated in 22 cases (14.9%) at an average 39.7 months' follow-up (median 45 months, range 0.5-99 months), including 13 symptomatic cases (8.8%). Cases with cyst wall resection had no significantly different rate of recurrence (11.7% vs 15.9%, p = 0.48) or postoperative permanent anterior pituitary dysfunction (21.6% vs 12.5%, p = 0.29) compared to those of fenestrated and marsupialized cases. There was no significant difference in postoperative permanent posterior pituitary dysfunction based on technique, although such dysfunction tended to worsen with cyst wall resection (13.6% vs 4.0%, p = 0.09). Based on cyst location, purely suprasellar cysts were more likely to have a radiological recurrence (28.6%) than sellar cysts with suprasellar extension (12.5%) and purely sellar cysts (9.4%; p = 0.008). Most notably, of the 28 purely suprasellar cysts, selective cyst wall resection significantly improved the long-term (10-year) recurrence risk compared to fenestration alone (17.4% vs 80.0%, p = 0.0005) without any significant added risk of endocrinopathy., Conclusions: Endoscopic endonasal marsupialization or fenestration of sellar RCCs may be the ideal treatment strategy, whereas purely suprasellar cysts benefit from partial cyst wall resection to prevent recurrence. Selective cyst wall resection reduced long-term recurrence rates without significantly increasing rates of hypopituitarism.

Introduction: Endoscopic endonasal surgery (EES) has been slower to gain popularity in early childhood due to anatomical challenges. We sought to describe the safety and efficacy of EES in early childhood. Methods: All patients younger than 7 years who underwent EES at a large Cranial Base Center from 2002 to 2019 were reviewed as a retrospective cohort study. Results: Thirty-six patients underwent EES before the age of 7 years. Four patients had two-stage EES. Two patients required combined transcranial and endonasal approaches. The mean age at the time of initial surgery was 4 years (range: 1–6). Twenty patients were male, and 16 were female. Of 21 tumors intended for resection, 11 patients had gross total resections, and 10 had near total (>95% tumor removed) resections. Nine patients (43%) had recurrences, of which 6 were craniopharyngiomas (p = 0.01). There was no difference in recurrence rates based on the degree of resection (p = 0.67). Three cerebrospinal fluid (CSF) leaks occurred following primary EES (8%). Following an increase in nasoseptal flap usage (31–52%) and CSF diversion (15–39%) in 2008, there was only one CSF leak out of 23 patients (4 vs. 15%; p = 0.54). Postoperatively, 1 patient developed a permanent new cranial neuropathy, and 1 patient developed a permanent visual field cut. Six patients developed permanent postoperative panhypopituitarism, of which all were craniopharyngiomas (p < 0.001). The mean follow-up was 64 months. Conclusions: Early childhood EES is both safe and technically feasible for a variety of pathologies. [ABSTRACT FROM AUTHOR]

Background: Surgery is currently the first-line treatment of Cushing's disease. Surgery for Cushing's patients requires technical specificity, especially if no adenoma is identified on dedicated preoperative pituitary MRI. Method: From 2006 to 2020, 683 patients with Cushing's disease were operated on with a mononostril endoscopic endonasal approach by the same two senior neurosurgeons. Here, we report the particularities of this challenging surgery. Conclusion: A rigorous and planned surgical strategy avoids the pitfalls of Cushing's disease surgery and leads to a high rate of endocrine remission. [ABSTRACT FROM AUTHOR]

Background: Meningoencephaloceles originating in the lateral recess of the sphenoid sinus can be difficult to access. Historically, the endoscopic transpterygoid approach was advocated, which carries additional morbidity given the dissection of the pterygopalatine fossa (PPF) contents to provide a direct line approach to the defect. Given our increased facility with angled endoscopes and instrumentation, we now approach this region in a less invasive manner. Methods: We describe the endoscopic modified transpterygoid approach (MTPA), a quicker approach to the lateral sphenoid recess which preserves the PPF contents through a single nostril corridor. Results: In the MTPA, the face of the sphenoid and anterior junction of the pterygoid plates are removed, allowing for mobilization of the PPF contents with the periosteum intact. Angled instrumentation is then used to resect the meningoencephalocele and repair the skull base defect in the lateral recess. If increased exposure is needed, this can be gained by sacrificing the sphenopalatine artery and even the vidian nerve, although this is rarely required. Conclusions: The MTPA obviates the need for PPF dissection and simplifies access to the lateral sphenoid recess while minimizing postoperative morbidity. This approach should be considered for accessing meningoencephaloceles and other benign lesions in this challenging location. [ABSTRACT FROM AUTHOR]

Background: Basilar invagination (BI) is a complex condition characterized by prolapse of the odontoid into the brain stem/upper cervical cord. This lesion is often associated with Chiari malformations, and rheumatoid arthritis (RA). Treatment options for BI typically include cervical traction, an isolated anterior transoral odontoidectomy, anterior endonasal odontoidectomy, an isolated posterior fusion, or combined anterior/posterior surgical approach. Case Description: A 45-year-old female with a Chiari I malformation and RA underwent a combined posterior C0-C5 posterior decompression/fusion, followed by an anterior odontoidectomy (i.e. endoscopic/endonasal under neuronavigation). Postoperatively, the patient's symptoms and neurological signs resolved. Conclusion: BI in was successfully managed with a combined posterior C0-C5 decompression/fusion followed by an anterior endoscopic/endonasal odontoidectomy performed under neuronavigation. [ABSTRACT FROM AUTHOR]

Background: Cases of acute sphenoid sinusitis complicated by septic cavernous sinus (CS) thrombosis and internal carotid artery (ICA) stenosis are rarely reported. Different causative pathogens have been reported for this condition. We present two extremely rare and special cases with diverse clinical presentations and outcomes. Case 1 involved a female patient with less extensive sinusitis, but critical ICA occlusion. Case 2 involved a male patient with extensive pansinusitis, meningitis, cerebritis, and vasculitis due to fungal infection, but less stenosis of the ICA lumen. Both patients underwent surgical debridement and received broad-spectrum antibiotics. Additional anti-fungal medication was also administered in Case 2. However, outcomes differed considerably between cases. Discussion: Case 1 recovered with minimal neurological deficits and had Glasgow Outcome Scale (GOS) and modified Rankin Scale (mRS) scores of 5 and 2, respectively; however, the Case 2 had GOS and mRS scores of 3 and 4, respectively. Although rare, septic CS thrombosis with ICA stenosis can lead to unexpected and severe neurological sequelae. Fungal infection can result in catastrophic complications and poorer prognosis. Conclusion: In addition to early detection, aggressive surgical debridement and adequate antimicrobial treatment are crucial to satisfactory outcomes in patients with septic CS thrombosis complicated with ICA stenosis. [ABSTRACT FROM AUTHOR]

Clinical studies have suggested the endoscopic endonasal approach (EEA) for aneurysm clipping as a feasible way to treat select intracranial aneurysms. Among neurosurgery, there is not a consensus on the utility of EEA aneurysm clipping. This review aims to define the anatomic feasibility of EEA for aneurysm clipping. Two databases (PubMed, Cochrane) were searched for anatomical studies assessing EEA for intracranial aneurysm clipping. Literature review was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Quantitative anatomical studies were included. Eleven studies met inclusion criteria. Vascular exposure and clip placement on vessels of interest were possible, although only one study assessed these parameters with physical aneurysm models. Anterior circulation vessels, although accessible in over 90% of specimens, had low successful clipping rates in a small and large aneurysm models. Small and large model posterior circulation aneurysms were more readily clipped. Proximal and distal controls were readily attainable in posterior circulation aneurysms, but not anterior. This current literature review highlights the relevance of anatomical studies in assessing the feasibility of the EEA for clipping intracranial aneurysms. As such, anterior circulation aneurysms are poor candidates for EEA given difficulties in clip placement and obtaining proximal control and distal control in small and large aneurysms. While our results suggest that clipping of posterior circulation aneurysms is feasible from a technical stand of view, further clinical experience is required to assess its feasibility in terms of safety and efficacy, balancing the indications with endovascular treatment options. [ABSTRACT FROM AUTHOR]

Purpose: Acromegaly is an acquired disorder usually caused by growth hormone-secreting pituitary adenoma, resolution of which requires correction of the excess hormone production. Recently, intraoperative magnetic resonance imaging (iMRI) was reported to be useful during the endoscopic endonasal approach (EEA) for pituitary adenoma. The present study was performed to quantitatively assess the role of iMRI in improving surgical outcomes in EEA for acromegaly. Methods: Twenty surgeries for acromegaly in EEA performed at Shinshu University Hospital between April 2016 and March 2020 were reviewed retrospectively. The inclusion criteria were cases without severe cavernous sinus tumor invasion (Knosp grade 0 – 3) or history of prior pituitary surgery. Fifteen consecutive patients were enrolled in this study. Clinical characteristics and postoperative clinical outcomes were compared between patients with and without use of iMRI during EEA for acromegaly. Results: Conventional navigation-guided surgery was performed in nine patients, and six underwent iMRI-guided EEA for acromegaly. Gross total resection (GTR) was obtained in the six (100%) patients in the iMRI group, and in four (44.4%) patients in the conventional group without iMRI. Postoperative clinical outcomes, including hormonal remission rate and surgical complications, were comparable between the two groups. Conclusion: Although iMRI significantly increased the GTR rate, we found no direct evidence of increased hormonal remission rate by use of iMRI. It is important to confirm complete tumor resection carefully with not only iMRI findings, but also with intraoperative high-definition endoscopic direct visualization to increase the hormonal remission rate of acromegaly. [ABSTRACT FROM AUTHOR]

Objectives: Cerebrospinal fluid (CSF) leaks and meningoencephaloceles originating in the lateral recess of the sphenoid sinus can be challenging. The traditional transpterygoid approach through the pterygopalatine fossa (PPF) is time consuming and places important structures at risk, which can lead to significant morbidity. We report a multi‐institutional experience using a simplified, endoscopic modified transpterygoid approach (MTPA), which spares the PPF contents in the management of lateral sphenoid sinus meningoencephaloceles and CSF leaks. Study Design: Multi‐Institutional, Retrospective Case Series. Methods: Patients with lateral sphenoid recess CSF leaks and meningoencephaloceles between 2014 and 2020 who underwent the MTPA at two academic medical centers were identified. Repair techniques and outcomes were evaluated. Results: Thirty‐three patients underwent the MTPA for management. Skull base reconstruction was performed using a free mucosal graft (24/33, 72.7%), nasoseptal flap (4/33, 12.1%), bone grafts (3/33, 9.1%), and abdominal fat grafts (2/33, 6.1%). Lumbar drains and perioperative intracranial pressure measurements were routinely employed. Postoperative complications were uncommon and included three patients (9.7%) with temporary V2 anesthesia, one patient (3.2%) with prolonged V2 anesthesia, and one patient (3.2%) with subjective dry eye, all of which resolved at 9 months postoperatively. There were no recurrent CSF leaks resulting in a 100% success rate. Average follow‐up was 13 months. Conclusion: The MTPA reduces morbidity and greatly simplifies access to the lateral sphenoid sinus for the management of CSF leaks and meningoencephaloceles, without compromising exposure. This technique avoids the need for extensive PPF dissection and should be considered for the management of benign lesions involving the lateral sphenoid sinus. Level of Evidence: 4 Laryngoscope, 131:2224–2230, 2021 [ABSTRACT FROM AUTHOR]

Objective: This paper highlights the management of 5 patients affected by symptomatic ecchordosis physaliphora (EP), treated via endoscopic endonasal transsphenoidal-transclival approach and contextual multilayer skull base reconstruction. A detailed analysis of each case is provided, along with the review of the current body of literature. Methods: A retrospective review of patients treated by means of endoscopic endonasal approach for EP from 2010 to 2020 in the Otolaryngology and Neurosurgery Departments of a tertiary-care referral center for endoscopic skull base surgery was analyzed. Only adult patients with a definitive histopathological and immunohistochemical diagnosis of EP were included in the study. A systematic literature review according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed for EP. Results: Five cases of EP were retrieved and included in the study. Four patients presented with CSF leakage: in two cases after minor head trauma, in one case with associated bacterial meningitis, and in one case as only referred symptom. One patient complained diplopia due to VI cranial nerve palsy. No complications or recurrences of the disease were observed after a median follow-up of 37.2 months (range, 18–72 months). A total of 27 studies were identified with the systematic literature review, encompassing 30 patients affected by symptomatic EP who were addressed to surgical treatment. Twenty-five patients underwent complete surgical removal of the EP, while in 5 cases, only subtotal resection was performed. Conclusions: EP might result in a "locus minoris resistentiae" of the skull base, predisposing, in rare cases, to CSF leakage and meningitis, spontaneously or after minor trauma. In cases of symptomatic EP, endoscopic endonasal transsphenoidal-transclival approach represents a safe and effective technique for both EP resection and contextual skull base reconstruction. [ABSTRACT FROM AUTHOR]

Background  A nasal access guide (NAG) for endoscopic endonasal approaches (EEAs) to the skull-base has been developed and approved for clinical use but its utility has not been formally investigated. Objective  The study aims to assess the effect of a NAG on endoscopic visualization during cadaveric dissection and to perform a workflow analysis with process-based performance measures in the operating room and their effect on clinical outcomes. Methods  Skull-base course participants were observed during hands-on cadaveric dissection with and without NAG. Instances of endoscope withdrawal for lens cleaning and inadequate visualization due to lens soiling were tabulated. Participants completed a Likert-scale survey examining the NAG utility and provided an overall grading. Surgical workflow and process-based performance on patients undergoing EEA to the skull-base was analyzed. Passage of powered and dissecting instruments, removal of endoscopes for cleaning, and dislodgment or migration of the device were reviewed. Postoperative assessments included mucosal trauma and synechiae formation. Results  Instances of endoscope soiling and manual cleaning were significantly reduced by 40% and 61% with the NAG during cadaveric dissection. The overall grading of the device was 2.75/3. Surgical workflow was observed in 35 patients. Average number of passes of endoscopes, instruments, and powered tools during a 10-minute observation period were 3,17, and 5 during the surgical approach, and 3, 18, and 1 during tumor dissection. Dislodgement of the device occurred in 25.7% and migration of the device in 2.8% of cases. Postoperative synechiae, exposed cartilage or septal perforation was not observed in follow up. Conclusion  NAG can significantly reduce inadequate visualization during EEA to the skull-base and has the potential to reduce instances of nasal trauma. Participants assessed its overall utility as being "excellent." [ABSTRACT FROM AUTHOR]

Objective  The carotico-clinoid foramen and interclinoid bridge are two anatomical variants of the sellar region. If these anatomical variants go unrecognized and are not managed safely by the surgeon during expanded endoscopic endonasal surgery for a posterior clinoidectomy, a carotid artery injury may occur. We summarize a method to safely navigate in the presence of the carotico-clinoid foramen and interclinoid bridge in an endoscopic endonasal approach. Study Design  The study involves cadaveric dissection and management of the anatomical variants. Setting  The study took place in a cadaveric dissection laboratory. Participants  The object of study is one cadaveric head. Main Outcome Measures  After discovering the two variants in both cavernous sinuses of a cadaveric head, we established a stepwise coping strategy to avoid carotid artery injury while performing an endoscopic endonasal bilateral interdural pituitary transposition, and we report the final view after endoscopic management. Results  Debulking of the middle clinoid process can decrease the obstacle effect, and the pituitary transposition can be performed medial to the ossified carotico-clinoid ligament. Disconnection of the interclinoid bridge is the prerequisite to an effective posterior clinoidectomy, and distinguishing the transition between the sellar diaphragm and the interclinoid bridge is essential. Conclusion  In the presence of both the carotico-clinoid foramen and the interclinoid bridge, a bilateral interdural pituitary transposition can still be performed, although preoperative strategic preparation, full inspection, and stepwise disconnections are of paramount importance in such a scenario to avoid cavernous carotid artery injury. [ABSTRACT FROM AUTHOR]

Objective  Presently, there are no standards for reporting outcomes of endoscopic endonasal skull base reconstruction (ESBR). This is problematic as a lack of consistent reporting makes synthesizing findings in systematic reviews and meta-analysis challenging. Thus, the aim of this study was to systematically review and describe the patterns of reporting outcomes in ESBR as a foundation for developing reporting guidelines. Study Design  Present study is a systematic review. Methods  Embase, PubMed, CINAHL, Cochrane Library, and Web of Science were searched for all publications with ≥25 patients and a focus on ESBR. The reporting patterns of each study's variables and outcomes were assessed. Results  A total of 112 studies were included in the review. The most commonly reported demographic variables were the number of included patients (n  = 112, 100%) and types of pathologies treated (n  = 104, 92.9%). Meanwhile, the most routinely described preoperative variable was history of prior treatment (n  = 48, 42.9%). Type of reconstruction was a commonly reported intraoperative variable (n  = 110, 98.2%), though the rate of intraoperative cerebrospinal fluid (CSF) leak was noted in only 76 studies (67.9%). With regard to postoperative outcomes, postoperative CSF leak rate was routinely provided (n  = 101, 90.2%), but reporting of other surgical complications was more inconsistent. Ultimately, of the 43 variables and outcomes reviewed, a median of 12 (range: 4–22) was reported in each study. Conclusion  There is significant heterogeneity in the outcomes reported in studies relating to ESBR. This highlights the need for the development of standard reporting guidelines to minimize bias and improve interstudy comparability. [ABSTRACT FROM AUTHOR]

Background and Importance Chondroblastoma is a benign primary bone tumor that typically develops in the epiphyses of long bones. Chondroblastoma of the craniofacial skeleton is extremely rare, with most cases occurring in the squamosal portion of the temporal bone. In this report, we describe the first case of chondroblastoma of the clivus presenting with cranial neuropathy that was treated with endoscopic endonasal resection. We review the literature on craniofacial chondroblastomas with particular emphasis on extratemporal lesions. Case Presentation A 27-year-old woman presented with severe headache, left facial dysesthesias, and diplopia. Physical examination revealed hypesthesia in the left maxillary nerve dermatome, and complete left abducens nerve palsy. Imaging demonstrated an expansile intraosseous mass originating in the upper clivus with extension superiorly into the sella turcica and laterally to involve the medial wall of the left cavernous sinus. The tumor was completely resected via an endoscopic endonasal approach, with postoperative improvement in lateral gaze palsy. Histopathology was consistent with chondroblastoma. Conclusion Chondroblastoma is a rare tumor of the craniofacial skeleton that should be included in the differential diagnosis of an osteolytic lesion of the clivus. Complete surgical resection remains the mainstay of treatment.

BackgroundThe endoscopic endonasal approach and extra-pseudocapsule resection may be the main progress in modern pituitary surgery. However, for pituitary macroadenomas, discerning the pseudocapsule in the posterior plane of the tumor may be difficult. When the anterior-inferior debulking is performed, the early subsidence of the thinning normal pituitary gland and enlarged diaphragm may obstruct the surgical dissection view.MethodWe describe the technique of using a micro retractor for the endoscopic endonasal posterior pseudocapsule resection of pituitary macroadenomas. This micro retractor that was 2 mm in width was placed at the 12 o’clock position on the nostrils, and the end was fixed in the flexible arms of the self-retaining retractor system. The head of the micro retractor elevated the herniated diaphragm sellae in order to continue the posterior pseudocapsule resection of the pituitary macroadenoma.ResultThe technique was performed very easily and no complication was observed.ConclusionThe use of this micro retractor can increase the view of the posterior margin of the adenomas to facilitate the pseudocapsule dissection.

Background: The endoscopic endonasal approach and extra-pseudocapsule resection may be the main progress in modern pituitary surgery. However, for pituitary macroadenomas, discerning the pseudocapsule in the posterior plane of the tumor may be difficult. When the anterior-inferior debulking is performed, the early subsidence of the thinning normal pituitary gland and enlarged diaphragm may obstruct the surgical dissection view. Method: We describe the technique of using a micro retractor for the endoscopic endonasal posterior pseudocapsule resection of pituitary macroadenomas. This micro retractor that was 2 mm in width was placed at the 12 o'clock position on the nostrils, and the end was fixed in the flexible arms of the self-retaining retractor system. The head of the micro retractor elevated the herniated diaphragm sellae in order to continue the posterior pseudocapsule resection of the pituitary macroadenoma. Result: The technique was performed very easily and no complication was observed. Conclusion: The use of this micro retractor can increase the view of the posterior margin of the adenomas to facilitate the pseudocapsule dissection. [ABSTRACT FROM AUTHOR]

The respiratory illness identified as coronavirus disease 2019 (COVID-19) has resulted in a pandemic illness that has changed the face of healthcare. As the COVID-19 pandemic continues, patients have continued to require neurosurgical interventions, and the endoscopic endonasal approach for surgery has continued to be a mainstay treatment of pituitary tumors and anterior skull base lesions. We sought to highlight the current lack of recommendations regarding testing protocols for neurosurgical patients. We implemented a novel testing protocol for our patient populations at increased risk and have proposed a model that can be used at other institutions to mitigate the risk of complications associated with some forms of COVID-19 testing. Patients with anterior skull base defects may be at risk with current COVID-19 testing protocols, and may benefit from alternative specimen collection strategies. [ABSTRACT FROM AUTHOR]

Background: Tuberculum sellae meningiomas (TSMs) adherent to neurovascular structures are particularly challenging lesions requiring delicate and precise microneurosurgery. There is an ongoing debate about the optimal surgical approach. Method: We describe technical nuances and challenges in TSM resection using the endoscopic endonasal approach (EEA) in two cases of fibrous tumors with adherence to neurovascular structures. The cases are illustrated with a video (case 1) and figures (cases 1 and 2). Conclusion: A dedicated team approach and precise microsurgical technique facilitate safe resection of complex TSMs through the EEA. [ABSTRACT FROM AUTHOR]

Object: The infrachiasmatic corridor is the most important surgical access route for craniopharyngiomas and was identified and used in clinical series. The aims of this study were to describe the characteristics that assist dissection and resection rates in endoscopic surgery of solid, cystic, and recurrent cases and their importance in the infrachiasmatic corridor in endoscopic surgery. Methods: One hundred operations on 84 patients with pathologically identified craniopharyngioma were included in the study. The MRI findings were evaluated, and the location of the lesions was classified as (1) infrasellar; (2) sellar; or (3) suprasellar. In the sagittal plane, we measured the longest diameter of cystic and solid components and the height of chiasm-sella. Images were assessed for the extent of resection and were classified as gross total resection. This was deemed as the absence of residual tumor and subtotal resection, which had residual tumor. Results: The infrasellar location was reported in 7/84 (8.3%) patients, the sellar location in 8/84 (9.5%), and the suprasellar location in 69/84 (82.1%) patients. The narrow and high chiasm-sella were observed in 28/69 (40.5%) and 41/69 patients (59.4%), respectively. The mean distance of the chiasm-sella was 9.46± 3.76. Gross total tumor resection was achieved in 60/84 (71.4%) and subtotal tumor resection was performed in 24/84 (28.6%) patients. The results revealed that suprasellar location (OR: 0.068; p = 0.017) and recurrent cases (OR: 0.011; p<0.001) were negative predictive factors on GTR. Increasing the experience (OR: 42,504; p = 0.001) was a positive predictor factor for GTR. Conclusion: An EETS approach that uses the infrachiasmatic corridor is required for skull base lesions extending into the suprasellar area. The infrachiasmatic corridor can determine the limitations of endoscopic craniopharyngioma surgery. This corridor is a surgical safety zone for inferior approaches. [ABSTRACT FROM AUTHOR]

A 61-year-old woman presented with diplopia and headache. The patient had a longstanding history of petrous bone cholesteatoma (PBC) on the left side and had undergone multiple surgeries to address it. Computed tomography (CT) revealed a radiolucent lesion with bony destruction in the left petrous apex. Magnetic resonance imaging of the lesion revealed a hypointense area on T1-weighted images and a hyperintense area on T2-weighted and abnormal diffusion-weighted images. A diagnosis of recurrent petrous apex cholesteatoma was made. The patient was treated by exteriorization using an endoscopic endonasal approach. The patient is in remission and doing well. The ideal treatment of PBC is complete excision, though exteriorization using an endoscopic endonasal approach is considered a second option when excision is not possible. [ABSTRACT FROM AUTHOR]

This study aims to assess the feasibility and reliability of our endoscopic trans-nasal technique for the repair of cribriform and sellar high-flow cerebrospinal fluid (CSF) leaks. A comparison between patients suffering from high-flow rhinorrhea and treated through a free grafting endoscopic technique or the "parachute" technique, our nasal packing proposal, was performed. Thirty-three patients were included. The mean age was 52 years (range: 36–68 years). The etiology of the CSF leaks was iatrogenic in 16 cases (48.5%), traumatic in 5 cases (15.2%), spontaneous in 11 cases (33.3%), and related to anterior skull base tumors in 1 case (3%). The bone defect affected the sphenoidal sinus in 20 cases (60.6%), the cribriform plate of the ethmoid in 10 cases (30.3%), and both the sphenoid and ethmoid in 3 cases (9.1%). The mean size of bone defects was 8.5 ± 3.9 mm. The median follow-up was 28 (64) months. A CSF leak recurrence occurred in no cases treated with the parachute technique and in 3 cases that underwent conventional endoscopic treatments. The CSF leak recurrences were associated with 2 iatrogenic and 1 post-traumatic fistula. All the CSF leak recurrences underwent the parachute technique, not showing second recurrences. Our results suggest that the parachute technique is simple, safe, and effective. We recommend it as an alternative treatment to vascular flaps for the treatment of high-flow and recurrent fistulas. [ABSTRACT FROM AUTHOR]

Objective  The endoscopic endonasal approach (EEA) has been shown to be an effective means to access sellar lesions. However, there are limited studies centered on evaluating olfactory function after surgery. In this study, we assessed the pre- and postoperative olfactory function of patients who underwent EEA for sellar and suprasellar lesions. The impact of nasoseptal flap use on olfaction was further analyzed. Study Design  A retrospective study. Setting  A tertiary-care referral center in Taiwan. Participants  Patients with sellar and suprasellar lesions who underwent EEA and pre- and postoperative olfaction assessment from August 2015 to March 2018 were included in the study. Main Outcome Measures  The patients' olfactory function was examined pre-and postoperatively using the Sniffin' Sticks odor identification test. Data regarding demographics, olfactory scores, pathology, reconstructive technique, graft usage, and extent of resection were retrieved. Results  A total of 106 patients (36 males and 70 females) were enrolled, with a mean age of 51 years. There were 76 pituitary tumors, 12 Rathke's cleft cysts, 7 craniopharyngiomas, 7 meningiomas, and 4 other lesions. The nasoseptal flap was used in 39 patients for skull base reconstruction, and these patients had no statistically significant change between pre- and postoperative olfactory scores (p  = 0.283). Moreover, a statistically significant improvement of olfactory scores was found in patients in whom the nasoseptal flap was not used. Conclusion  Olfactory function may be reliably preserved after EEA, with or without nasoseptal flap harvest and use. [ABSTRACT FROM AUTHOR]

Introduction: Sphenoid sinus can be considered a key element in advanced sinus and skull base surgery. Due to its importance, many researchers tried to document its characteristics and evaluate possible differences among different races and populations. Materials and Methods: This study was conducted between March 2017 and December 2018 on 60 fresh adult cadavers in Tehran Forensic Medicine Center, Tehran, Iran. The evaluated variables were distances between nasal spines, posterior wall of the sphenoid, pituitary gland, and the distance between the anterior and posterior ethmoid artery and optic nerve, which were calculated using a flexible ruler through the direct length in millimeter. Another important variable was dehiscence, which was evaluated in optic and carotid artery canals. Results: After dissecting 120 sphenoid sinuses, the carotid artery was dehiscent in 24 (20%) cases, and optic nerve dehiscence was observed in 15 (12.5%) cadavers. The mean distance between the anterior wall of the sphenoid sinus and the anterior nasal spine was determined at 73.3±1.3 mm (rang: 58.3-87 mm), and the mean distance between the anterior part of the middle of the pituitary gland and the anterior nasal spine was estimated at 81.1±1.6 mm. Conclusion: According to our finding, the dehiscence of the key structural organs may be more prevalent in the Persian sphenoid sinus, which should be considered carefully in the management of related pathologies. [ABSTRACT FROM AUTHOR]

Objectives/Hypothesis: Although vidian neurectomy (VN) is associated with decreased lacrimation, its impact on dry eye quality‐of‐life is not well‐defined. Endoscopic endonasal transpterygoid approaches (EETA) may require vidian nerve sacrifice. Study Design: A prospective cohort trial. Methods: A prospective trial evaluating VN during EETA on lacrimation by phenol red thread testing and dry eye severity by the five‐item Dry Eye Questionnaire (DEQ‐5) was performed. Preservation of the contralateral vidian nerve allowed comparison between the eye subjected to VN and the control eye postoperatively. Results: Twenty‐one subjects were enrolled with no preoperative difference in lacrimation between eyes (P =.617) and overall mild dry eye severity. Although the control eye had no difference in lacrimation pre‐ and postoperatively, decreased tearing was noted in the VN eye at 1 month (20.8 mm vs. 15.8 mm, P =.015) and at 3 months (23.2 mm vs. 15.8 mm, P =.0051) postoperatively. Overall, no difference was noted in the DEQ‐5 score for dry eye severity between the pre‐ and postoperative measures. However, six patients were noted to have moderate to severe dry eye severity postoperatively and five of these six had decreased lacrimation (<20 mm) preoperatively. Patients with decreased tearing preoperatively demonstrated significantly worse postoperative DEQ‐5 scores when compared to patients with normal tearing (P <.0056). Conclusions: VN during EETA results in decreased tearing but is not associated with increased dry eye severity overall. However, patients with decreased tearing preoperatively are at risk for increased dry eye severity and should be counseled for this risk. Level of Evidence: 2 Laryngoscope, 131:1487–1491, 2021 [ABSTRACT FROM AUTHOR]

Since there are many approaches for successful craniopharyngioma resection, how to choose a suitable approach remains problematic. The aim of this study was to summarize experience of approach selection and outcomes of craniopharyngioma resection in our institute. The data of 182 primary craniopharyngiomas between January 2013 and June 2019 were retrospectively reviewed. Craniopharyngiomas were classified into intrasellar, intra-suprasellar, suprasellar, and intra-third ventricle types based on the location. The surgical approaches, extent of resection, endocrine and ophthalmological outcomes, and complications were evaluated. Gross total resection (GTR) was achieved in 158 (86.8%) patients, near-total resection (NTR) in 20 (11%), and partial resection (PR) in 4 (2.2%). New-onset hypopituitarism occurred in 90 (49.5%) and new-onset diabetes insipidus in 48 (26.4%). Visual function was improved in 110 of the 182 patients, unchanged in 52, and deteriorated in 20. For intra-suprasellar and suprasellar tumors, patients in the endoscopic endonasal approach (EEA) group had higher GTR rate, lower incidence of new-onset hypopituitarism, and better visual outcome than patients in transcranial approach group, but no significant difference in the incidence of new-onset diabetes insipidus was found. There were no surgery-related deaths, and the common complications included permanent oculomotor nerve palsy, hemorrhage, and cerebrospinal fluid leaks. During the follow-up period, tumor recurrence or regrowth occurred in 6.6% of the cases. Tumor location is key for choosing an optimal surgical approach for craniopharyngioma resection. The EEA should be considered as the first choice for intra-suprasellar and suprasellar craniopharyngiomas to achieve better visual outcomes and fewer pituitary hormonal disorders. [ABSTRACT FROM AUTHOR]

Chordoma is a rare slow-growing neoplastic bone lesion. However, they show an invasive local growth and high recurrence rate, leading to an overall survival rate of 65% at 5 years and 35% at 10 years. We conducted a pooled and meta-analysis comparing recurrence rate, post-operative-complications, and survival in patients undergoing either microsurgical (MA) or endoscopic approaches (EA). Search of literature was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify surgical series of clivus chordomas published between January 1990 and March 2018 on Pubmed, Scopus, and Cochrane. Two different statistical analyses have been performed: a pooled analysis and a single-arm meta-analysis of overall recurrence rate and subgroup meta-analysis of complications in the subgroups open surgery and endoscopic surgery. After full-text screening, a total of 58 articles were included in the pooled analysis and 27 studies were included for the study-level meta-analysis. Pooled analysis—the extent of resection was the only association that remained significant (subtotal: HR = 2.18, p = 0.004; partial: HR = 4.40, p < 0.001). Recurrence was more prevalent among the surgical patients (45.5%) compared to endoscopic ones (23.7%). Meta-analysis—results of the cumulative meta-analysis showed an overall rate of recurrence of 25.6%. MA recurrence rate was 31.8% (99% CI 14-52.8), EA recurrence rate was 19.4% (5.4-39.2). CSF leak rate for the endoscopic group was 10.3% (99%CI 5-17.3) and 9.5% (99%CI 1.2-24.6) for the open surgery group. The partial removal versus total removal has an influence on recurrence rate (p < 0.001). MA recurrence rate was 31.8%; EA recurrence rate was 19.4%. The extent of resection is confirmed as a statistically significant factor affecting the risk for recurrence both with the pooled analysis and with the meta-analysis. Meta-analysis demonstrated that older patients tend to recur more than young patients, especially in surgical group. [ABSTRACT FROM AUTHOR]

Purpose: Pituitary abscesses (PAs) are a rare clinical entity which may arise from normal pituitary tissue or underlying lesions within the gland. Rathke's cleft cysts (RCCs) are not commonly associated with the development of PA. Methods: Retrospective chart review of three patients with PAs within RCCs at a single university center and review of the literature. Results: Three cases are reported. The first case presented with fever and headache and a history of prior surgery due to RCC and a recent respiratory tract infection. The second case had a history of recent skin infections and presented with sudden onset headache and hypopituitarism. In the third case, chronic visual field impairment prompted an ophthalmologic evaluation resulting in a diagnosis of an adenoma and an infected RCC. In all three cases, an endoscopic endonasal approach was performed to drain infected tissue and allowed microbiological identification of gram-positive cocci, followed by treatment with antibiotics for at least three weeks. Cases in the literature are scarce and the diagnosis is usually made intraoperatively due to non-specific manifestations and imaging. PAs arising from underlying pituitary lesions are less common than primary PAs. Differential diagnosis should include pituitary apoplexy, hypophysitis and other cystic lesions. Conclusion: PAs occurring in RCCs are infrequent. Clinical manifestations are commonly subacute, without septic symptoms. Imaging is usually non-specific. Preoperative diagnosis is infrequent and a broad differential diagnosis should be considered. Empirical antimicrobial therapy should be initiated and adjusted after obtaining cultures to reduce the rate of recurrence and improve clinical outcomes. [ABSTRACT FROM AUTHOR]

Coil migration and extrusion outside the cranial compartment after embolization of cerebral aneurysms represents a very rare complication of the endovascular procedures and few cases are reported in the literature. Instability of the vascular malformation wall and the resolution of the intramural hematoma, especially in pseudoaneurysm, might generate extravascular migration of the coils in the first months after embolization. However, to the best of our knowledge, an extrusion of coil 10 years after embolization has never been reported. We reported the unique case of a patient with coil extrusion into the naso- and oropharynx 10 years after internal carotid artery pseudoaneurysm embolization. The pseudoaneurysm occurred after an internal carotid artery injury during an endoscopic endonasal surgery for a clival giant cell tumor.

Metastases involving the clivus and craniocervical junction (CCJ) are extremely rare. Skull base involvement can result in cranial nerve palsies, while an extensive CCJ involvement can lead to spinal instability. We describe an unusual case of clival and CCJ metastases presenting with VI cranial nerve palsy and neck pain secondary to CCJ instability from metastatic bladder urothelial carcinoma. The patient was first treated with an endoscopic endonasal approach to the clivus for decompression of the VI cranial nerve and then with occipitocervical fixation and fusion to treat CCJ instability. At the 6-month follow-up, the patient experienced complete recovery of VI cranial nerve palsy. To the best of our knowledge, the simultaneous involvement of the clivus and the CCJ due to metastatic bladder carcinoma has never been reported in the literature. Another peculiarity of this case was the presence of both VI cranial nerve deficit and spinal instability. For this reason, the choice of treatment and timing were challenging. In fact, in case of no neurological deficit and spinal stability, palliative chemo- and radiotherapy are usually indicated. In our patient, the presence of progressive diplopia due to VI cranial nerve palsy required an emergent surgical decompression. In this scenario, the extended endoscopic endonasal approach was chosen as a minimally invasive approach to decompress the VI cranial nerve. Posterior occipitocervical stabilization is highly effective in avoiding patient’s neck pain and spinal instability, representing the approach of choice.

Abstract Background Preservation of anatomic integrity and function of the cranial nerves during the removal of skull base tumors is one of the most challenging procedures in endoscopic endonasal surgery. It is possible to use intraoperative mapping and identification of the cranial nerves in order to facilitate their preservation. The purpose of this study was to evaluate the effectiveness of intraoperative trigger electromyography in prevention of iatrogenic damage to the cranial nerves. Methods Twenty three patients with various skull base tumors (chordomas, neuromas, pituitary adenomas, meningiomas, cholesteatomas) underwent mapping and identification of cranial nerves during tumor removal using the endoscopic endonasal approach in Department of Neurooncology of Federal State Autonomous Institution “N.N. Burdenko National Medical Research Center of Neurosurgery” of the Ministry of Health of the Russian Federation from 2013 to 2018. During the surgical interventions, mapping and identification of the cranial nerves were carried out using electromyography in triggered mode. The effectiveness of the method was evaluated based on a comparison with a control group (41 patients). Results In the main group of patients, 44 nerves were examined during surgery using triggered electromyography. During the study, the III, V, VI, VII, and XII cranial nerves were identified intraoperatively. Postoperative cranial nerve deficiency was observed in 5 patients in the study group and in 13 patients in the control group. The average length of hospitalization was 9 days. Conclusion We did not receive statistically significant data supporting the fact that intraoperative identification of cranial nerves using trigger electromyography reduces the incidence of postoperative complications in the form of cranial nerve deficits (p = 0.56), but the odds ratio (0.6) suggests a less frequent occurrence of complications in the study group. Based on our experience, the trigger electromyography methodology appears quite promising and requires further research.

This study aims to provide morphometric analysis of endoscopic endonasal approach (EEA) to the ventral-medial portion of posterior paramedian skull base. Furthermore, it aims to investigate the surgical exposure obtained through EEA with and without eustachian tube (ET) removal, emphasizing the role of contralateral nostril (CN) access. Five fresh adult head specimens were prepared for dissection. A predissection and a postdissection computed tomography study was performed. A surgically oriented classification into 4 regions was used: 1) tubercular region; 2) occipital condyle region; 3) parapharyngeal space (PPhS) region; and 4) jugular foramen (JF) region. The Student t -test was used to compare angulations and measures of EEA with access from the ipsilateral and CN, respectively, with and without ET removal. EEA to the ventral-medial portion of posterior paramedian skull base encompasses 2 medial trajectories (transtubercular and transcondylar) and 2 lateral pathways to the PPhS and JF. The CN access, without removal of the ET, allows a complete exposure of the petrous and intrajugular portion of the JF and superior PPhS without exposition of the parapharyngeal segment of internal carotid artery. The ipsilateral nostril approach with ET removal allows to obtain a wider exposure, reaching the medial sigmoid part of the JF. No significant differences exist in regard to transtubercular and transcondylar approaches. This study suggests that EEA to posterior paramedian skull base allows the realization of a corridor directed to the jugular tubercle, occipital condyle, medial PPhS, and ventral-medial JF. The CN approach with ET preservation can expose the petrous and intrajugular parts of the JF and PPhS. Case series are needed to demonstrate benefits and drawbacks of these approaches. [ABSTRACT FROM AUTHOR]

Background: The use of nasoseptal flaps (NSF) for defect reconstruction in endoscopic endonasal approaches (EEA) to cranial base pathology has markedly reduced rates of cerebrospinal fluid leak. However, the effect of NSF use on post-operative olfaction remains unclear. Objective: To evaluate the impact of NSF use during EEA on binarial and uninarial olfaction, and sinonasal quality of life (QOL). Methods: This was a prospective double-blinded randomized controlled trial. Patients undergoing EEA for sellar pathology were recruited from the University of Pittsburgh Medical Center from December 2014 to May 2017. Subjects were randomized pre-operatively to a side of NSF harvest. Olfaction and QOL were assessed pre-operatively and 6 to 12 months post-operatively using the University of Pennsylvania Smell Identification Test, "Sniffin' Sticks," and Sinonasal Outcomes Test 22. The side of dominant uninarial olfaction was determined using "Sniffin' Sticks." Results: Thirty-one patients were enrolled. Sixteen underwent EEA without NSF (control group) and 15 with NSF. A dominant side of olfaction was identified in 14 patients with NSF; 8 patients were randomized to NSF harvest on the dominant side and the remaining 6 on the non-dominant side. NSF elevation resulted in a 4% decrease in University of Pennsylvania Smell Identification Test scores, but was not statistically significant compared to controls. Similarly, NSF elevation on the side of dominant olfaction resulted in a 6% decrease, but was not statistically significant when compared to the non-dominant elevation group. Change in rhinologic QOL as determined by the Sinonasal Outcomes Test 22 was not significantly different between any of the groups. Conclusions: The use of NSF during EEA for sellar pathology does not have a significant effect on olfaction or rhinologic QOL. The presence of a dominant side of olfaction is not a primary consideration when deciding the side of NSF harvest. [ABSTRACT FROM AUTHOR]

Opinion Statement: Management of chordoma along the cranial-spinal axis is a major challenge for both skull base and spinal surgeons. Although chordoma remains a rare tumor, occurring in approximately 1 per 1 million individuals, its treatment poses several challenges. These tumors are generally poorly responsive to radiation and chemotherapy, leading to surgical resection as the mainstay of treatment. Due to anatomic constraints and unique challenges associated with each primary site of disease, gross total resection is often not feasible and is associated with high rates of morbidity. Additionally, chordoma is associated with high rates of recurrence due to the tumor's aggressive biologic features, and postoperative radiation is increasingly incorporated as a treatment option for these patients. Despite these challenges, modern-day surgical techniques in both skull base and spinal surgery have facilitated improved patient outcomes. For example, endoscopic endonasal techniques have become the mainstay in resection of skull base chordomas, improving the ability to achieve gross total resection, while reducing associated morbidity of open transfacial techniques. Resection of spinal chordomas has been facilitated by emerging techniques in preoperative imaging, intraoperative navigation, spinal reconstruction, and radiotherapy. Taken collectively, the treatment of chordoma affecting the skull base and spinal requires a multidisciplinary team of surgeons, radiation oncologists, and medical oncologists who specialize in the treatment of this challenging disease. [ABSTRACT FROM AUTHOR]

Background: The endoscopic endonasal trans‐lacerum approach (EETLA) is useful in handling skull base tumors around inferior petrous apex (IPA); however, its surgical corridor is exclusively a triangular space (supra‐eustachian triangle [SET]), between the internal carotid artery (ICA) and eustachian tube. Methods: We investigated correlation between SET size and extent of resection around the IPA (lateral extent of resection [EOR]) through a retrospective analysis of 15 surgeries using EETLA. Results: Of 15 cases (9 chordomas, 4 chondrosarcomas, and 2 meningiomas), 20 sides of IPA were affected by the tumor. When being restricted to sides with severe lateral tumor extension beyond the midpoint of petrous ICA (10 sides), the SET size was significantly broader in the group with lateral EOR of ≥90% (p value = 0.019). Conclusions: The SET size was a powerful index of tumor resectability in EETLA, especially in cases with severe tumor extension. The individual anatomical variations should be considered when determining EETLA application. [ABSTRACT FROM AUTHOR]

A next-generation networked operating room, Smart Cyber Operating Theater (SCOT), has been developed in cooperation with medical engineers that integrates standalone medical devices, including intraoperative magnetic resonance imaging (MRI) using the OPeLiNK communication interface. Here, we report the application of this newly developed advanced type of operating theater for the endoscopic endonasal approach (EEA), along with an evaluation of our initial experiences. The study population consisted of 18 patients with parasellar tumor. All patients underwent surgery via the EEA in SCOT. During all procedures, various types of intraoperative information, including electrophysiologic monitoring, anatomic orientation with navigation system, intraoperative MRI, and endoscopic images of the operative field, were collected and stored by OPeLiNK. Furthermore, the intraoperative information was shared with the surgical strategy desk, where a senior neurosurgeon can direct and manage the surgical procedure in real-time. We successfully completed the surgical procedures in SCOT in all cases. Using OPeLiNK, operators in SCOT were able to share various data, such as images obtained intraoperatively and surgical instrument position from navigation systems, as well as images of the surgical field, with senior neurosurgeons at the surgical strategy desk in all cases. Surgically relevant information from these sources was transmitted through an application and displayed to all surgical staff. The necessary nuances were reflected in the surgical procedures. SCOT, which is considered an innovative operation system in neurosurgery, enables both quality and safety in the EEA. Furthermore, the use of SCOT may also contribute to the education of young neurosurgeons. [ABSTRACT FROM AUTHOR]

Background: Most surgical teams currently consider that endoscopy has become the "gold standard" technique for the transsphenoidal approach to pituitary surgery. Pituitary adenomas are commonly benign tumours and should benefit from the least invasive approach. Method: In Foch Hospital, from 2006 to 2020, 2835 patients with pituitary adenomas were treated with a mononostril endoscopic endonasal approach. Here we describe the fine details of the nasal, sphenoidal and sellar steps of this technique. Conclusion: Complete preservation of the nasal corridor, luxation of the nasal septum and tailored sellar bone resection are essential for safe resection of pituitary adenomas. [ABSTRACT FROM AUTHOR]

Background: Skull base chordomas (SBC) are rare malignant tumors and few factors have been found to be reliable markers for clinical decision making and survival prognostication. The aim of the present work was to identify specific prognostic factors potentially useful for the management of SBC patients. Methods: A retrospective review of all the patients diagnosed and treated for SBC at the Fondazione IRCCS Istituto Neurologico "Carlo Besta" between January 1992 and December 2017 has been performed. Survival analysis was performed and a logistic regression model was used. Statistically significant predictors were rated based on their log odds in order to preliminarily build a personalized grading scale—the Peri-Operative Chordoma Scale (POCS). Results: Fifty-nine primary chordoma patients were included. The average follow-up from the first treatment was 82.6 months (95% CI, 65.5–99.7). POCS was built over PFS and MR contrast enhancement (intense vs mild/no, value 4), preoperative motor deficit (yes vs no, value 3), and the development of any postoperative complications (yes vs no, value 2). POCS ranges between 0 and 9, with higher scores being associated with reduced likelihood of survival and progression-free state. Conclusions: Our results show that preoperative clinical symptoms (motor deficits), surgical features (extent of tumor resection and surgeon's experience), development of postoperative complications, and KPS decline represent significant prognostic factors. The degree of MR contrast enhancement significantly correlated to both OS and PFS. We also preliminarily developed the POCS as a prognostic grading scale which may help neurosurgeons in the personalized management of patients undergoing potential adjuvant therapies. [ABSTRACT FROM AUTHOR]

Objective  This study proposes to present reference parameters for trigeminal (V) and facial (VII) cranial nerves (CNs)-triggered electromyography (tEMG) during endoscopic endonasal approach (EEA) skull base surgeries to allow more precise and accurate mapping of these CNs. Study Design  We retrospectively reviewed EEA procedures performed at the University of Pittsburgh Medical Center between 2009 and 2015. tEMG recorded in response to stimulation of CN V and VII was analyzed. Analysis of tEMG waveforms included latencies and amplitudes. Medical records were reviewed to determine the presence of perioperative neurologic deficits. Results  A total of 28 patients were included. tEMG from 34 CNs (22 V and 12 VII) were analyzed. For CN V, the average onset latency was 2.9 ± 1.1 ms and peak-to-peak amplitude was 525 ± 436.94 μV (n  = 22). For CN VII, the average onset latency and peak-to-peak amplitude were 5.1 ± 1.43 ms and 315 ± 352.58 μV for the orbicularis oculi distribution (n  = 09), 5.9 ± 0.67 ms and 517 ± 489.07 μV on orbicularis oris (n  = 08), and 5.3 ± 0.98 ms 303.1 ± 215.3 μV on mentalis (n  = 07), respectively. Conclusion  Our data support the notion that onset latency may be a feasible parameter in the differentiation between the CN V and VII during the crosstalk phenomenon in EEA surgeries but the particularities of this type of procedure should be taken into consideration. A prospective analysis with a larger data set is necessary. [ABSTRACT FROM AUTHOR]