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To describe a single-layer fascia patchwork closure (FPWC) without nasoseptal flap (NSF) and compare postoperative cerebrospinal fluid (CSF) leakage between FPWC using NSF and single-layer FPWC without NSF for the extended endoscopic transsphenoidal transtuberculum transplanum approach. Forty-five cases of suprasellar tumor in 42 patients were treated with extended endoscopic transsphenoidal removal, resulting in extensive, high-flow CSF leakage. Following the intradural procedure for treatment of various suprasellar tumors, fascia lata was inlaid subdurally on the cranial base defect and patch-sutured around its entire circumference under endoscope visualization, using an average of 17 stitches. Septal bone or hydroxyapatite plate was used for the hard support material against pulsatile intracranial pressure. NSF was added in the earlier 17 cases. Closure was completed without NSF in the more recent 28 cases when the Valsalva maneuver confirmed watertight closure. Two recent cases required NSF after Valsalva maneuver and were included in the FPWC + NSF group. Postoperative CSF leakage did not occur in the FPWC + NSF group but occurred in 2 patients in the single-layer FPWC group (7.1%) (P = 0.52). There was no significant difference in CSF leakage between single-layer FPWC and FPWC + NSF. The mean suturing time for FPWC was 85.8 minutes, and the shortest was 39 minutes in a recent case (mean, 17 stitches; n = 35, video analysis). Single-layer FPWC may be a viable technical option for effective skull base reconstruction after the extended endoscopic transsphenoidal transtuberculum transplanum approach. [ABSTRACT FROM AUTHOR]

Traditional microsurgical approaches for addressing intraventricular craniopharyngioma provide limited access to the retrochiasmatic area and tumors with significant lateral or rostrocaudal extensions. Extended endoscopic endonasal approaches can effectively overcome many of limitations, yet they require a favorable working angle between the optic chiasm and pituitary gland, as well as the involvement of the third ventricle floor by the tumor. Herein, the authors describe the surgical nuances of a keyhole technique for resecting third ventricle craniopharyngiomas via a fully endoscopic minimally invasive trans-eyebrow supraorbital translaminar approach (ESOTLA). A case description detailing the key surgical steps and application of the approach is provided, along with a series of cadaveric photographs to highlight the relevant anatomy and step-by-step dissection process. The patient is a 44-year-old man who presented with polyuria, low urine specific gravity, and panhypopituitarism. Brain magnetic resonance imaging revealed a solid-cystic heterogeneous-enhanced retrochiasmatic mass within the third ventricle, consistent with craniopharyngioma. A 1-stage ESOTLA was indicated based on the narrow pituitary-chiasm angle and the high functional status of the patient. Near-total resection was achieved, and no new postoperative neurologic or endocrine change was observed. Targeted therapy was implemented based on the histologic result, and the most recent surveillance magnetic resonance imaging showed no evidence of the residual tumor. By combining a keyhole approach with variable-angle endoscopic visualization through a smaller bony and soft tissue exposure, ESOTLA can provide enhanced illumination within the third ventricle, potentially addressing cosmetic concerns and limited exposure area/angle of freedom associated with its conventional microsurgical counterpart. [ABSTRACT FROM AUTHOR]

Nervus intermedius (NI) arises from the superior salivary nucleus, solitary nucleus, and trigeminal tract. It leaves the pons as 1 to 5 roots and travels between the facial and vestibulocochlear nerves before merging with the facial nerve within the internal auditory canal. The mastoid segment of the facial nerve then gives rise to a sensory branch that supplies the posteroinferior wall of the external auditory meatus and inferior pina. This complex pathway renders the nerve susceptible to various pathologies, leading to NI neuralgia. Here, the authors present an unusual intraoperative finding of an atrophic NI in a patient with refractory NI neuralgia and a history of ipsilateral sudden-onset central facial palsy and microvascular decompression for trigeminal neuralgia. The patient underwent NI sectioning via the previous retrosigmoid window and achieved partial ear pain improvement. The gross size of the NI is compared with a cadaveric specimen through stepwise dissection. This case highlights the potential significance of subtle central ischemic events and subsequent atrophy of NI in the pathogenesis of NI neuralgia, as well as the ongoing need to investigate the therapeutic efficacy of nerve sectioning. [ABSTRACT FROM AUTHOR]

Intracranial aneurysms (IAs) located in the midline region represent formidable challenge owing to their deep location. The objective of this study was to assess feasibility and identify the limitations of endoscopic endonasal clipping of IAs. We further aimed to describe the locations and characteristics of aneurysms that may be amenable for endoscopic endonasal clipping; thus outlining the indications of these approaches. Fifteen latex-injected cadaveric heads were used for endoscopic endonasal exposure of anterior and posterior cerebral circulations. An aneurysm simulator model with 2 different sizes was used at the common sites for IAs to emulate a real surgery. Key measured parameters included "exposure of vessels and their respective perforators," "ability to gain proximal/distal control," and "possibility of clip placement" according to the size, direction, and location of the aneurysm model. Maneuverability of instruments and the need for pituitary gland transposition were assessed and recorded as well. Exposure of the anterior communicating artery complex and the common sites of posterior circulation aneurysms were feasible. The size, location, and direction of the aneurysm model had an impact on obtaining proximal and/or distal control, and the ability of clip placement. Clipping of midline aneurysms of the posterior circulation is feasible via endoscopic endonasal approach. Small-sized ventrally and medially directed aneurysm models carried a better probability of getting proximal and/or distal control, as well as better overall ability to place a clip. The endonasal route seems to provide a limited condition for proper management of anterior circulation aneurysms. [ABSTRACT FROM AUTHOR]

Video Description: Aural rehabilitation via cochlear implantation (CI) in the vestibular schwannoma (VS) population is becoming increasingly commonplace in practice. When combined with microsurgical resection, alteration of tumor dissection is required to maintain integrity of the cochlear nerve for implantation. The present video highlights the surgical technique required to perform simultaneous CI and VS resection via a translabyrinthine approach.By Robert J. Macielak; Vivian F. Kaul; Daniel M. Prevedello and Oliver F. AdunkaReported by Author; Author; Author; Author [Extracted from the article]

This article, published in the Journal of Neurological Surgery, examines the impact of intracanalicular extension on the presentation and outcomes of large vestibular schwannomas (VSs). The study compares patients with VSs that extend into the internal auditory canal (IAC) to those without IAC extension. The results show that patients with IAC extension have higher rates of facial numbness at presentation, but there are no significant differences in other symptoms or preoperative cranial nerve function. In terms of postoperative outcomes, there is a trend towards better facial nerve outcomes and less dizziness in patients without IAC extension. The study suggests that further research is needed to understand the impact of IAC extension in larger tumors and whether a distinct disease process exists. [Extracted from the article]

The article titled "Fully Endoscopic Supraorbital Translaminar Approach: Step-by-Step Illustrative Description" discusses a surgical technique called the fully endoscopic supraorbital translaminar approach (ESOTLA) for the management of third ventricle tumors. The traditional microsurgical approaches have limitations in accessing certain tumors and pose risks to nearby neurovascular structures, prompting the exploration of alternative techniques. ESOTLA combines a minimally invasive keyhole approach with endoscopic visualization, providing enhanced illumination and a broader field of view within the third ventricle. This technique offers improved cosmetic and neurological outcomes compared to other approaches, although it has limitations for certain types of tumors. The article includes a detailed case description and photographs to guide the surgical process. [Extracted from the article]

This article discusses a pilot study that evaluates the utility of PSMA-PET (Prostate Specific Membrane Antigen Positron Emission Tomography) for the management of vestibular schwannomas (VS), which are benign tumors of the vestibulocochlear nerve. The study includes five patients with newly diagnosed or suspected recurrent VS, including one patient with bilateral schwannomas. The results show that PSMA-PET can be a potentially useful adjunct imaging modality in the evaluation and management of VS. Further studies are needed to explore the utility of PSMA-PET in differentiating actively growing tumors from dormant or slow-growing tumors and in identifying residual/recurrent neoplasms. [Extracted from the article]

Bilateral thalamic stroke is usually due to compromised artery of Percheron, an anatomical variation of the vascular supply of the thalamus. The stroke in this area is very uncommon, and is mainly due to top of the basilar syndrome. Other causes are extremely rare. We describe the case of a patient with a pituitary adenoma who underwent surgery and later presented with a bilateral thalamic infarct, suggesting compromise of the artery of Percheron. This would be the third case published in the literature about this complication. We present a literature review about the vascular supply of the thalamus, the artery of Percheron, and its involvement in pituitary surgery. [ABSTRACT FROM AUTHOR]

Background The optic canal is a bony channel that connects the anterior cranial fossa and orbit and contains the optic nerve and ophthalmic artery. It can be affected by several pathologies, leading to compression of the nerve nearby or inside the canal, leading to visual impairment. The usual technique to decompress the canal is through a craniotomy, but recently endoscopic endonasal approaches (EEAs) have surfaced as an interesting alternative due to direct access to the canal without the need for manipulation of neurovascular structures. Methods Six specimens were dissected. The right optic canal was drilled on the right side via the EEA, and the left optic canal was drilled via frontotemporal craniotomy. The amount of decompression was measured using a 3-dimensional reconstruction on computed tomography scans and compared. Results The EEA generated an average of 267.8 (221–294) degrees of decompression in the anterior portion of the canal versus 258.3 (219–300) degrees of decompression in the posterior portion of the canal, whereas the craniotomy generated an average of 229.3 (101–289) degrees of decompression in the anterior portion of the canal versus 250.3 (76–300) degrees of decompression in the posterior portion of the canal. There was no significant difference statistically. Conclusion The decision for an approach for optic canal decompression should be based on the site of the pathology and localization of canal involvement. Both techniques are equivalent in terms of proportion of nerve decompression. [ABSTRACT FROM AUTHOR]

Background: The medial opticocarotid recess (MOCR) is located in the posterior wall of the sphenoid sinus, medial to the junction of the optic canal (OC) and the carotid prominence (CP). There is controversy in the literature in relation to the presence of the MOCR and its constancy, which is relevant when approaching the skull base through an endoscopic route. Methods: The morphometric relations of the MOCR with the surrounding structures were studied in 18 cadaveric specimens after endoscopic endonasal approach (EEA). Results: The distance between both MOCR was 11.06 ± 1.14 mm; the distance between the MOCR and the lateral opticocarotid (LOCR) recess was 5.56 ± 0.85 mm; the distance between the MOCR and the suprasellar recess was 3.72 ± 0.49 mm; the angle between the MOCR plane and the OC 13.32 ± 2.30°; the angle between the MOCR plane and the CP 13.50 ± 2.68° and; the angle between the OC and the CP 26.81 ± 4.26°. All measurements showed low variability, with low standard deviation and interquartile range. No relations were found between any of the measurements. Conclusions: The MOCR may be used as a reference point for precise location of structures during EEA. Objective measurements may be especially useful in cases with distorted sphenoid bone anatomy. [ABSTRACT FROM AUTHOR]

Introduction Malignancies of the clivus and petroclival region are mainly chordomas and chondrosarcomas. Although a spectrum of malignancies may present in this area, a finite group of commonly encountered malignant pathologies will be the focus of this review, as they are recognized to be formidable pathologies due to adjacent critical neurovascular structures and challenging surgical approaches. Objectives The objective is to review the literature regarding medical and surgical management of malignant tumors of the clival and petroclival region with a focus on clinical presentation, diagnostic identification, and associated adjuvant therapies. We will also discuss our current treatment paradigm using endoscopic, open, and combined approaches to the skull base. Data Synthesis A literature review was conducted, searching for basic science and clinical evidence from PubMed, Medline, and the Cochrane Database. The selection criteria encompassed original articles including data from both basic science and clinical literature, case series, case reports, and review articles on the etiology, diagnosis, treatment, and management of skull base malignancies in the clival and petroclival region. Conclusions The management of petroclival malignancies requires a multidisciplinary team to deliver the most complete surgical resection, with minimal morbidity, followed by appropriate adjuvant therapy. We advocate the combination of endoscopic and open approaches (traditional or minimally invasive) as required by the particular tumor followed by radiation therapy to optimize oncologic outcomes. [ABSTRACT FROM AUTHOR]

Objective: The main aim of our study was to analyze and compare the surgical anatomy pertinent to the dorsal transcranial transcondylar (far lateral approach) with that of the ventral endoscopic endonasal transcondylar (far medial approach) route. Methods: Eight cadaveric specimens were dissected and analyzed bilaterally. Brainstem exposure and surgical corridor areas were measured. In addition, we present three clinical scenarios to illustrate the clinical feasibility of the proposed surgical strategies. Results: The hypoglossal nerve, vertebral artery, and hypoglossal canal divide the lower third of the clivus into ventromedial and dorsolateral compartments. The far medial approach provides significantly larger exposure of the brainstem in the ventromedial compartment (464.6 ± 68.34 mm2) compared with the far lateral approach (126.35 ± 32.25 mm2), P < 0.01. The far lateral approach provides a wide exposure of the brainstem in the dorsolateral compartment (295.24 ± 58.03 mm2, 74% of the dorsolateral compartment). The exposure of the brainstem in the dorsolateral compartment is not possible using the endonasal route. The surgical corridor from one compartment to the other, through the lower cranial nerves, was significantly larger on the far lateral approach (78.19 ± 14.54 mm2) than on the far medial (23.77 ± 15.17 mm2), P = 0.03. Conclusions: The far medial approach offers a safe, wide exposure of the lower third of the clivus for lesions that expand ventromedial to the hypoglossal nerve. The far lateral approach is most suitable for lesions located dorsolateral to the lower cranial nerves. The vertebral artery and hypoglossal canal are the most important landmarks to guide surgical planning. A combined endonasal-transcranial approach should be considered for resection of extensive lesions involving both ventromedial and dorsolateral compartments. We strive to encourage skull base surgeons to integrate endoscopic and microscopic approaches to the posterior fossa. [ABSTRACT FROM AUTHOR]

Background: Pituitary adenomas are often encased in a histological pseudocapsule that separates the tumor from the normal gland. Transsphenoidal adenoma resection may be performed either in an intra- or an extracapsular technique. The extracapsular fashion offers anatomical orientation, removal of a security margin, reduced risk of opening the arachnoid layer with subsequent CSF flow and identification of invasion. Method: The sella turcica is approached through the classic endoscopic endonasal route. After opening the dura of the sellar floor, the interface between the compressed tissue and the normal gland is used as a surgical plane for dissection. Performing slight counter-traction with the suction tube, the cleavage plane is identified and stepwise unsealed in an atraumatic fashion with the cotton swab. Once the cleavage plane is partially loosened, repeated twisting movements are performed with the cotton swab to enucleate the pseudocapsule and adenoma. Conclusion: Both micro- and macroadenomas presenting a pseudocapsule may be resected in the extracapsular dissection technique with the cotton swab. Operating in an endoscopic three- to four hands technique enables to visualize the anatomic planes and perform twisting movements with the cotton swab separating pseudocapsule and tumor in order to enucleate the adenoma. [ABSTRACT FROM AUTHOR]

Purpose: Patients with oligodendrogliomas with allelic loss of chromosomal arm 1p and 19q have been shown, especially with anaplastic oligodendrogliomas, to have both a better initial and long-term response to chemotherapy as well as an improved overall survival. Effective treatment of patients with brain tumors requires accurate diagnostic techniques. MR imaging can be used to help differentiate between low- and high-grade tumors. We hypothesize that certain MR imaging characteristics can be used to differentiate between patients with and without 1p and 19q deletion. Methods: Using the clinical database at the University of Virginia Neuro-Oncology Center, we identified adult patients with grade II and III oligodendroglial tumors who underwent treatment from 2002 to 2007. Age at diagnosis, gender, tumor grade, chromosomal deletion status, duration of follow-up, and MR imaging characteristics were analyzed; the latter was read by a blinded neuroradiologist. Results: One hundred and four patients met the inclusion criteria. Of these patients, 44 manifested 1p/19q co-deletion and 60 patients lacked this deletion. The greatest cross-sectional area (mean) of the tumor measured 23.4 cm for patients with the co-deletion and 31.7 cm for patients with intact alleles ( p = 0.008). In addition, inner table thinning was noted directly adjacent to seven tumors with intact 1p and 19q alleles and in no tumors with the 1p/19q co-deletion ( p = 0.020). Amongst patients with pure oligodendrogliomas, those with 1p/19q co-deletion had tumors more often confined to a single lobe as compared with those patients without the co-deletion ( p = 0.023). Finally, tumors with intact alleles were more often found in the temporal lobe (45.0%) as compared with co-deleted tumors (22.7%) ( p = 0.011). Conclusion: MR imaging is a valuable imaging modality for differentiating between oligodendrogliomas with or without the 1p/19q deletion. While imaging will never replace definitive tissue diagnosis, imaging characteristics such as tumor size, location, and overlying skull thinning can assist clinicians in assessing patients with oligodendroglial tumors prior to surgical or medical intervention. [ABSTRACT FROM AUTHOR]

The transclival endoscopic endonasal approach was used to completely remove a prepontine neuroenteric cyst in two different patients. Full clinical improvement without postoperative complication was achieved in both cases. The postoperative hospital stay was limited to 2 and 3 days. In comparison to posterolateral skull base approaches, the transclival endoscopic endonasal approach allows direct access to the prepontine cistern without unnecessary manipulation of neurovascular structures at the cerebellopontine angle. In contrast to transoral surgery, patients may have decreased risk of infection and can be fed orally immediately without the risks of palatal and oropharyngeal dehiscence. Neuronavigation technology, strict adherence to microsurgical principles, and significant endoneurosurgical experience are strongly recommended when approaching these challenging lesions. [ABSTRACT FROM AUTHOR]

Cystic mass lesions within the sella turcica are common, and they include cystic pituitary adenomas, craniopharyngiomas, Rathke’s cleft cysts, arachnoid cysts, and other entities. Until recently, such lesions were typically removed by a microsurgical transsphenoidal route. Given the increased use of the endoscope in transsphenoidal surgery, we evaluated the potential benefits of this tool in the treatment of such lesions. Between January 1997 and March 2005, 76 consecutive patients with sellar–suprasellar cystic lesions treated in three Neurosurgical Divisions underwent transsphenoidal removal in which the endoscope was used at least during the sellar step of the procedure (endoscope-assisted or fully endoscopic). The series consisted of 26 pituitary macroadenomas, 20 Rathke’s cleft cysts, 18 craniopharyngiomas, 10 arachnoid cysts, one craniopharyngioma associated with an adrenocorticotropic hormone-secreting adenoma, and one chordoid glioma. Rigid 4-mm endoscopes (0°, 30°, and/or 45°) were used, and the advantages and limits of the endoscope during the sellar step of the procedure were recorded. Endoscopic exploration after lesion evacuation was generally easier and of greatest efficacy when the residual cystic cavity was larger as opposed to smaller. The use of angled endoscopes was optimal in larger residual cavities. Early descent of the suprasellar cistern, bleeding inside the residual cyst cavity, and a small sella were the most common causes preventing thorough exploration of the residual cavity after its evacuation. In no cases did the endoscope cause injury during the sellar cavity exploration. Endoscopic exploration of the sellar cavity during transsphenoidal surgery offers both general and specific advantages in the treatment of a variety of different cystic sellar lesions. Its routine use during transsphenoidal surgery for such lesions is recommended to achieve maximal and safe tumor removal. [ABSTRACT FROM AUTHOR]

Background  Invasion depth influences the choice for extirpation of nasopharyngeal malignancies. This study aims to validate the feasibility of endoscopic endonasal resection of lesions with a posterolateral invasion. As a secondary goal, the study intends to propose a classification system of endoscopic endonasal nasopharyngectomy determined by the depth of posterolateral invasion. Methods  Eight cadaveric specimens (16 sides) underwent progressive nasopharyngectomy using an endoscopic endonasal approach. Resection of the torus tubarius, Eustachian tube (ET), medial pterygoid plate and muscle, lateral nasal wall, and lateral pterygoid plate and muscle were sequentially performed to expose the fossa of Rosenmüller, petroclival region, parapharyngeal space (PPS), and jugular foramen, respectively. Results  Technical feasibility of endonasal nasopharyngectomy toward a posterolateral direction was validated in all 16 sides. Nasopharyngectomy was classified into four types as follows: (1) type 1: resection restricted to the posterior or superior nasopharynx; (2) type 2: resection includes the torus tubarius which is suitable for lesions extended into the petroclival region; (3) type 3: resection includes the distal cartilaginous ET, medial pterygoid plate, and muscle, often required for lesions extending laterally into the PPS; And (4) type 4: resection includes the lateral nasal wall, pterygoid plates and muscles, and all the cartilaginous ET. This extensive resection is required for lesions involving the carotid artery or extending to the jugular foramen region. Conclusion  Selected lesions with posterolateral invasion into the PPS or jugular foramen is amenable to a resection via expanded endonasal approach. Classification of nasopharyngectomy based on tumor depth of posterolateral invasion helps to plan a surgical approach. [ABSTRACT FROM AUTHOR]

Objectives  The vidian nerve provides parasympathetic innervation to the nasal cavity and the lacrimal gland. Previous anatomic studies have primarily focused on preservation or severance of the vidian nerve proximal to the pterygopalatine ganglion (PPG). This study aimed to assess its neural fibers within the pterygopalatine fossa after synapsing at the PPG, and to explore potential clinical implications for endoscopic endonasal skull base surgery. Methods  An endonasal transpterygoid approach was performed on eight cadaveric specimens (16 sides). The PPG and maxillary nerve within the pterygopalatine fossa were divided. The vidian nerve was traced retrograde into the foramen lacerum, and postganglionic fibers distal to the PPG were dissected following the zygomatic nerve into the orbit. Potential communicating branches between the ophthalmic nerve (V1) and the PPG were also explored. Results  All sides showed a plexus of neural communications between the PPG and the maxillary nerve. The zygomatic nerve exits the maxillary nerve close to the foramen rotundum, piercing the orbitalis muscle to enter the orbit in all sides. The zygomatic nerve was identified running beneath the inferior rectus muscle toward a lateral direction. In 7/16 sides (43.75%), a connecting branch between V 1 and the pterygopalatine ganglion was observed. Conclusion  Neural communications between the PPG and the maxillary nerve were present in all specimens. A neural branch from V 1 to the PPG potentially contributes additional postganglionic parasympathetic function to the lacrimal gland. [ABSTRACT FROM AUTHOR]

Objective: Identify the benefits and caveats of combining minimal access approaches to the infratemporal fossa (ITF), such as the endoscopic transnasal, endoscopic transorbital, endoscopic transoral, and endoscopic sublabial transmaxillary approaches to address extensive lesions not amenable to a single approach. The study provides anatomical metrics including area of exposure and degree of surgical freedom. Methods: Five human cadaveric specimens (10 sides) were dissected to expose and methodically analyze the anatomical intricacies of the ITF using the following minimal access approaches: endoscopic transnasal transpterygoid (EETA), endoscopic sublabial transmaxillary, endoscopic transorbital via infraorbital foramen, and endoscopic transoral techniques. Area of exposure at the pterygopalatine fossa and surgical freedom at the ITF were obtained for each approach. Results: The endoscopic sublabial transmaxillary sinus and the combined approach afford a significantly greater exposure than an isolated EETA. The difference in exposure (mean) between the endoscopic sublabial transmaxillary and EETA was 1.62 ± 0.85 cm2 (p < 0.001), and the difference between the combined approach and EETA was 4.25 ± 0.85 cm2 (p < 0.001). Conclusions: Combining minimal access endoscopic approaches to the ITF can provide significantly greater exposure than an isolated EETA; thus, providing enhanced access to address lesions with extensive involvement of the ITF, especially those with superolateral and inferolateral extensions. In addition, some approaches may have an adjunctive role to the resection, such as the endoscopic transoral approach offering the potential for early control of the internal maxillary artery and its branches, some of which may be supplying the tumor in the ITF; or the endoscopic transorbital approach yielding a direct line of sight to the superior ITF and middle cranial fossa. Level of Evidence: NA. [ABSTRACT FROM AUTHOR]

Even for the most experienced neurosurgeons, foramen magnum meningiomas represent a surgical challenge owing to their delicate position surrounded by the brainstem, lower cranial nerves, and vertebral arteries. The treatment goal is gross total resection, but choosing the most appropriate approach is crucial. Basically, 3 surgical approaches are commonly used: posterolateral approach (far-lateral), anterolateral approach (extreme-lateral), and posterior midline approach. However, over the years, skull base surgery has evolved from standard open craniotomies to the use of microscopes and, more recently, to the development of endoscopic techniques. The endoscopic endonasal approach (EEA) permits a direct extradural route without brain retraction and shorter postoperative recovery. In contrast to the oral route, the soft palate and retropharyngeal soft tissues are preserved, allowing patients to resume a regular diet on the first postoperative day. Despite the advantages, the EEA is yet not widely used for treating foramen magnum meningiomas, even in cases where EEA use is possible. The EEA is feasible especially in cases with no vascular encasements and with a limited inferior extension allowing minimal manipulation of lower cranial nerves. Care must be taken with tumors with a more lateral and caudal extension (below the tip of the odontoid process), when a far lateral approach may be the best approach. In this surgical Video 1 , we present the surgical details with a stepwise narrative of the EEA for ventrolateral foramen magnum meningiomas through an illustrative case of a 48-year-old woman. Institutional informed consent was obtained for surgery and publication of this video. [ABSTRACT FROM AUTHOR]

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

Introduction Meningiomas—the most common extra-axial tumors—are benign, slow-growing dural-based lesions that can involve multiple cranial fossae and can progress insidiously for years until coming to clinical attention secondary to compression of adjacent neurovascular structures. For complex, multicompartmental lesions, multistaged surgeries have been increasingly shown to enhance maximal safe resection while minimizing adverse sequela. Here, we systematically review the extant literature to highlight the merits of staged resection. Methods PubMed, Scopus, and Web of Science databases were queried to identify articles reporting resections of intracranial meningiomas using a multistaged approach, and articles were screened for possible inclusion in a systematic process performed by two authors. Results Of 118 identified studies, 36 describing 169 patients (mean age 42.6 ± 21.3 years) met inclusion/exclusion criteria. Petroclival lesions comprised 57% of cases, with the most common indications for a multistaged approach being large size, close approximation of critical neurovascular structures, minimization of brain retraction, identification and ligation of deep vessels feeding the tumor, and resection of residual tumor found on postoperative imaging. Most second-stage surgeries occurred within 3 months of the index surgery. Few complications were reported and multistaged resections appeared to be well tolerated overall. Conclusions Current literature suggests multistaged approaches for meningioma resection are well-tolerated. However, there is insufficient comparative evidence to draw definitive conclusions about its advantages over an unstaged approach. There are similarly insufficient data to generate an evidence-based decision-making framework for when a staged approach should be employed. This highlights the need for collaborative efforts among skull base surgeons to establish an evidentiary to support the use of staged approaches and to outline those indications that merit such an approach. [ABSTRACT FROM AUTHOR]

Background Patients with relapsed intracranial germinoma can achieve durable remission with standard chemotherapy regimens and/or reirradiation; however, innovative therapies are required for patients with relapsed and/or refractory intracranial nongerminomatous germ cell tumors (NGGCTs) due to their poor prognosis. Improved outcomes have been reported using reinduction chemotherapy to achieve minimal residual disease, followed by marrow-ablative chemotherapy (HDCx) with autologous hematopoietic progenitor cell rescue (AuHPCR). We conducted a phase II trial evaluating the response and toxicity of a 3-drug combination developed for recurrent intracranial germ cell tumors consisting of gemcitabine, paclitaxel, and oxaliplatin (GemPOx). Methods A total of 9 patients with confirmed relapsed or refractory intracranial GCT were enrolled after signing informed consent, and received at least 2 cycles of GemPOx, of which all but 1 had relapsed or refractory NGGCTs. One patient with progressive disease was found to have pathologically confirmed malignant transformation to pure embryonal rhabdomyosarcoma (without GCT elements), hence was ineligible and not included in the analysis. Patients who experienced sufficient responses proceeded to receive HDCx with AuHPCR. Treatment response was determined based on radiographic tumor assessments and tumor markers. Results A total of 7 patients achieved sufficient response and proceeded with HDCx and AuHPCR, and 5 subsequently received additional radiotherapy. A total of 2 patients developed progressive disease while receiving GemPOx. Myelosuppression and transaminitis were the most common treatment-related adverse events. With a mean follow-up of 44 months, 4 patients (3 NGGCTs, 1 germinoma) are alive without evidence of disease. Conclusions GemPOx demonstrates efficacy in facilitating stem cell mobilization, thus facilitating the feasibility of both HDCx and radiotherapy. [ABSTRACT FROM AUTHOR]

Background: Optimal initial exposure through an extended endoscopic endonasal approach (EEA) for suprasellar craniopharyngiomas ensures safe and unrestricted surgical access while avoiding overexposure, which may prolong the procedure and increase neurovascular adverse events. Method: Here, the authors outline the surgical nuances of a customized bony and dural opening through the transplanum/transtuberculum and transclival variants of the extended EEA to suprasellar craniopharyngiomas based on the tumor–pituitary stalk relationship. A stepwise cadaveric dissection and intraoperative photographs relevant to the approaches are also provided. Conclusion: Safe maximal resection of suprasellar craniopharyngiomas through extended EEAs can be feasibly and safely achieved by implementing of tailored ventral exposure. [ABSTRACT FROM AUTHOR]

Background: Many lesions in the anterior skull base may compress the optic nerve (ON), leading to vision loss, and even irreversible blindness. Although decompression of the optic nerve has traditionally been achieved transcranially, the endoscopic endonasal approach (EEA) is gaining traction as a minimally invasive approach recently. Method: We describe the key steps of an EEA ON decompression. The relevant surgical anatomy with illustration is described. Additionally, a video detailing our technique and instruments on an illustrative case is provided. Conclusion: Endoscopic endonasal approach ON decompression with a straight feather blade is a feasible, minimally invasive procedure to decompress the ON in the setting of anterior skull base mass lesions. [ABSTRACT FROM AUTHOR]

Trigeminal neuralgia (TN) is characterized by paroxysmal episodes of severe shocklike orofacial pain typically resulting from arterial compression on the trigeminal root entry zone. However, neurovascular conflict in more proximal parts of the trigeminal pathway within the pons is extremely rare. The authors present a case of microvascular decompression for TN caused by dual arterial compression on the dorsolateral pons, along with a brief literature review. Our patient was a 74-year-old man with episodic left-sided facial stabbing pain. Brain magnetic resonance imaging revealed a dual arterial compression on dorsolateral pons, the known site of the trigeminal sensory nucleus and descending trigeminal tract. Microvascular decompression was performed via a retrosigmoid approach. Complete pain relief and partial improvement of the facial hypesthesia were achieved immediately after surgery and the Barrow Neurological Institute (BNI) pain intensity score improved from V to I, and the BNI hypesthesia score decreased from III to II within a month following surgery. The literature review identified 1 case of TN secondary to an arteriovenous malformation in root entry zone with lateral pontine extension. One month following partial coagulation of the draining vein, the patient was reportedly able to reduce medication dosage by half to achieve an improvement of BNI pain intensity score from V to IIIa. Neurovascular compression in the trigeminal tract and nucleus is a rare but potential cause of TN. A thorough investigation of the trigeminal pathway should be considered during preoperative evaluation and intraoperative inspection, particularly if no clear offending vessel is identified. [ABSTRACT FROM AUTHOR]

This article, titled "The Infundibulochiasmatic Angle Indicates Favorability of Endoscopic Endonasal Approach in Type IV Craniopharyngioma: Case Study and Technical Note," discusses the use of the midline transsphenoidal route as an alternative approach for tumors of the third ventricle. The authors introduce the concept of the "infundibulochiasmatic angle," which is a measurement that supports the feasibility of the trans-lamina terminalis endoscopic endonasal approach (EEA) for resection of type IV craniopharyngiomas. The article is authored by Guilherme Finger, Maria Jose C. Ruiz, Eman H. Salem, Matthew D. Marquardt, Kyle C. Wu, Lucas P. Carlstrom, Ricardo L. Carrau, Luciano M. Prevedello, and Daniel M. Prevedello. [Extracted from the article]

This article, published in the Journal of Neurological Surgery, discusses the management of giant arachnoid cysts (GACs), which are rare intracranial pathologies. The article presents a case study of a 33-year-old male patient with memory issues, bitemporal hemianopsia, and bilateral optic atrophy, who underwent an endoscopic transcortical transventricular fenestration procedure to treat the interpeduncular GAC. The patient experienced a complete resolution of their visual symptoms and made a smooth recovery after the procedure. The article highlights the importance of fenestration in decompressing the cyst and promoting cerebrospinal fluid flow to prevent symptomatic relapse. [Extracted from the article]

This video demonstrates a trochlear nerve decompression via a suboccipital supracerebellar infratentorial approach in a 40-year-old woman who was suffering from right-sided superior oblique myokymia as a result of compression of the trochlear nerve at its origin by the superior cerebellar artery with resolution of her myokymia following decompression.By Joshua Vignolles-Jeong; Guilherme Finger; Amanda Zakeri; Jonathan Tangsrivimol; Alexander Keister; Kyle C. Wu and Daniel M. PrevedelloReported by Author; Author; Author; Author; Author; Author; Author [Extracted from the article]

The treatment of spontaneous CSF rhinorrhea with a skull base defect size of less than 1 cm is amenable to repair by a two-layer technique. Repair is performed with an initial layer of collagen matrix placed subdurally, followed by an onlay-free mucosal graft. This two-layer repair was sufficiently robust for this patient with an underlying meningioma en plaque, and did not require an adjunct postoperative lumbar drain.By Moataz D. Abouammo; N. S. Maithrea; Mohammad Bilal Alsavaf; Joshua Vignolles-Jeong; Daniel M. Prevedello and Ricardo L. CarrauReported by Author; Author; Author; Author; Author; Author [Extracted from the article]

The article titled "Intradural Pituitary Hemitransposition: Technical Note and Case Series Illustration" discusses the challenges of accessing lesions in the retrosellar, interpeduncular cistern, and petroclival regions in neurosurgery. The authors propose the endonasal endoscopic intradural pituitary hemitransposition approach as an effective technique for resecting these lesions while preserving pituitary function. The approach involves mobilizing the pituitary gland to safely access the interpeduncular fossa through a midline transsphenoidal route. The article is authored by Joao Paulo Almeida, Guilherme Finger, Matthieu D. Weber, Mark A. Damante, Kyle C. Wu, Patrick Walz, Jeffrey R. Leonard, Ricardo L. Carrau, and Daniel M. Prevedello. [Extracted from the article]

This article discusses the creation of a module-based and structurally accurate 3D anatomical model for endoscopic skull base surgery. The model was created using a photogrammetry pipeline, which obtains graphical information about physical objects from photographs. The article explains the methods used to dissect cadaveric heads and acquire still images of the anatomical regions of interest. The 3D model allows for a more effective understanding of the intricate anatomical relationships seen at the ventral skull base and may reduce reliance on wet-laboratory learning environments in surgical education and training. [Extracted from the article]

This article, published in the Journal of Neurological Surgery, explores the relationship between human papillomavirus (HPV) and sinonasal adenoid cystic carcinoma (AdCC). The study analyzed fifteen specimens from patients with AdCC and found that while all the tumors were p16 patchy positive, they were HPV negative for the subtypes tested. The results suggest that there is no correlation between the HPV subtypes tested and AdCC, but indicate that p16 may be dysregulated in AdCC. Further investigation into the role of p16 in sinonasal AdCC is warranted. [Extracted from the article]

This article provides a systematic literature review of intracranial ectopic Rathke's cleft cysts (RCCs), which are benign congenital lesions located in the sellar and suprasellar regions. The authors present a case of a symptomatic ectopic retrosellar RCC that caused extensive clival erosion. The study includes data on patient demographics, clinical presentation, and treatment details. Surgical approaches varied depending on the cyst's location, and gross total resection was achieved in the majority of cases. The article concludes that further research is needed to better understand the natural history and long-term outcomes of these cysts. [Extracted from the article]

This article discusses the extended transplanum/transtuberculum endoscopic endonasal approach (EEA) for the surgical treatment of suprasellar tumors, specifically craniopharyngiomas. The study outlines the surgical techniques and steps involved in customizing the bone drilling and dural opening based on the tumor's relationship to the pituitary stalk. The article provides cadaveric dissection photos and intraoperative findings from three cases to illustrate the surgical nuances and minimal exposures required for different types of suprasellar craniopharyngiomas. The authors emphasize the importance of a customized approach to ensure a safe surgical corridor while minimizing unnecessary overexposure. [Extracted from the article]

This article discusses the management of hypophysitis, a rare and challenging inflammatory disorder. The study analyzed data from 12 adult patients with hypophysitis, examining their demographics, treatment modalities, laboratory findings, histopathological results, and radiological images. The results showed that corticosteroid therapy is the main treatment strategy, but diagnostic accuracy remains difficult due to the wide range of imaging findings. Younger patients have a higher risk of recurrence, and controlling blood glucose levels and body mass index is important in preventing recurrence. Surgical intervention can confirm the diagnosis and improve symptoms, and radiation therapy may be effective for resistant cases. [Extracted from the article]

This article describes a rare case of trigeminal neuralgia (TN) caused by compression on the trigeminal sensory nucleus and tract by an aberrant dual anastomotic artery loop. The patient, a 74-year-old male, experienced progressive episodic pain in the left forehead, eyelid, cheek, and jaw. Brain MRI revealed compression on the pons near the fourth ventricle caused by the left posterior inferior cerebellar artery (PICA) and an anastomotic loop connecting the anterior inferior cerebellar artery (AICA) and PICA. The patient underwent endoscopic-assisted microvascular decompression (MVD), which successfully relieved the pain. The article discusses the vulnerability of the trigeminal nerve to vascular forces and the effectiveness of MVD in reversing microstructural changes. It also highlights the need for further research on the mechanism and treatment of TN caused by vascular compression. [Extracted from the article]

This article discusses a surgical approach called the Bernard George anterolateral transcervical approach for the treatment of upper anterior cervical spine tumors. The case study presented involves a 67-year-old man with a recurrent C2-3 chordoma. The surgical procedure involved making incisions and dissecting various muscles to access the tumor, which was subsequently resected. An expandable cage was then placed in the tumor cavity. The patient experienced improvement in quadriparesis with no new neurological deficits. The anterolateral transcervical approach provides unique and comprehensive access to the challenging ventral upper cervical region. [Extracted from the article]

This article, published in the Journal of Neurological Surgery, discusses two cases of frontoethmoidal osteoma, a rare type of benign bone tumor. The patients presented with neurological deficits and cerebral spinal fluid (CSF) leaks. Both cases were successfully treated with different surgical approaches, resulting in complete tumor resection and no complications or signs of CSF leak. The authors emphasize the need for more cases to better understand the epidemiology, clinical presentation, treatment strategies, and outcomes of this condition. The article also includes a literature review of eight previously reported cases. [Extracted from the article]

This article, published in the Journal of Neurological Surgery, provides a systematic review of the literature on adult traumatic encephaloceles, which are rare cases of brain tissue protrusion into a skull defect. The majority of encephaloceles occur in children, but this study focuses on adult-onset cases, specifically the extradiploic type that breaches the outer table of the skull. The authors describe a unique case of an adult-onset traumatic extradiploic encephalocele in the pterion involving the lesser wing of the sphenoid bone. The study includes patient demographics, clinical presentation, treatment details, and outcomes, highlighting the importance of considering encephaloceles in adult patients with skull base lytic lesions or enlarging skull masses. Surgical intervention was found to provide significant relief for persistent symptoms. [Extracted from the article]

This article discusses the impact of adjuvant and salvage radiation therapy in conventional type 2 chondrosarcomas (cCSA 2). The study analyzed a database of 71 patients with cCSA 2 and reviewed patient demographics, radiologic features, and treatment outcomes. The results showed that adjuvant radiation therapy significantly decreased the likelihood of disease progression, particularly after incomplete resection. Proton-based radiotherapy was found to be more effective than photon-based radiotherapy in controlling the disease. The study concludes that surgery followed by close follow-up is an acceptable decision for complete resection, and the use of radiation therapy is more beneficial after incomplete resection. [Extracted from the article]

This article examines the morphological characteristics and surgical outcomes in patients with Type I Chiari malformation (CMI). The study compares individuals diagnosed with CMI to the general population to identify any discernible differences in parameters such as cerebellar width, 4th ventricle dimensions, cerebellar-to-Pons distance, cerebellar height, tentorial angle, and McRae line. The results show significant morphological differences between CMI patients and the normal population in various aspects. Postoperatively, some improvements in measurements were observed, but not in all parameters. These findings can help inform surgical decisions for patients with CMI experiencing ambiguous symptoms. [Extracted from the article]

This article, published in the Journal of Neurological Surgery, discusses a novel surgical technique for reconstructing defects in the clival and craniovertebral junction (CVJ) regions of the skull base. The technique involves using a nasopharyngo-septal butterfly flap, which is a vascularized flap that provides adequate mucosal coverage for the reconstruction. The study was conducted on cadaveric heads and found that the flap was able to cover the entire clivus with CVJ in all 15 cadavers. This technique may be particularly useful when the traditional nasoseptal flap is not viable. [Extracted from the article]

This article discusses the use of intraoperative ultrasound (IUS) as an adjunct to the endoscopic endonasal approach (EEA) for the surgical resection of skull base lesions. The authors present a case study where a novel small-probe IUS was used to assist in the resection of a recurrent Rathke's cleft cyst (RCC) located in an atypical retrosellar region. The small-probe IUS provided real-time imaging feedback and enhanced visualization, allowing for accurate localization of the cyst and surrounding neurovascular structures. The authors conclude that IUS is a promising surgical adjunct that can potentially increase the extent of resection and decrease operation times. [Extracted from the article]

This article compares two surgical approaches, the endoscopic endonasal approach (EEA) and the midline suboccipital subtonsillar approach (STA), for accessing the jugular tubercle (JT) in the treatment of JT meningiomas. The study conducted on human cadaveric specimens measured three morphological variables: angle of attack (AoA), surgical freedom, and angle of endoscopic exposure (AoEE). The results showed that while STA offered greater surgical freedom, EEA provided superior visualization and AoEE. The choice of surgical approach should also consider the position of the lower cranial nerves in relation to the lesion. [Extracted from the article]

This article discusses the successful treatment of recurrent lymphocytic hypophysitis (LH) using fractionated stereotactic radiotherapy (FSRT). LH is a rare autoimmune inflammation of the pituitary gland that can mimic pituitary adenomas. The authors conducted a systematic literature review and found that FSRT can be a viable alternative treatment for refractory cases of LH. The study included eight patients, and seven of them achieved a complete clinical response after one course of radiation. FSRT offers long-term disease control while minimizing radiation exposure to nearby critical structures. However, further studies are needed to determine the long-term effects, optimal dose planning, and patient selection criteria for FSRT. [Extracted from the article]