Extracellular Vesicles from a Novel Chordoma Cell Line, ARF-8, Promote Tumorigenic Microenvironmental Changes When Incubated with the Parental Cells and with Human Osteoblasts.

Chordomas are rare, generally slow-growing spinal tumors that nonetheless exhibit progressive characteristics over time, leading to malignant phenotypes and high recurrence rates, despite maximal therapeutic interventions. The tumors are notoriously resistant to therapies and are often located in regions that complicate achieving gross total resections. Cell lines from these tumors are rare as well.

How I do it: safe resection of a complex type 3 foramen magnum meningioma with dorsal displacement of the neurovascular bundle.

Background: We describe techniques for safe resection of a Type 3 foramen magnum meningioma with dorsal displacement of the accessory nerve rootlets and vertebral artery which limits ventral access to the tumor.

Method: Partial sectioning of the accessory nerve rootlets may help create larger working space. Topical lidocaine placement on the rootlets of the spinal accessory nerve may mitigate trapezius muscle contraction and facilitates further progress throughout tumor resection.

The effect of SARS-CoV-2 on the incidence of post-operative venous sinus thrombosis following skull base procedures.

Purpose: Sinus thrombosis is a common post-operative finding after posterior fossa surgery performed in the vicinity of the dural venous sinuses. The SARS-CoV-2 virus has been shown to confer an increased risk of venous thromboembolic events owing to eliciting a hyper-inflammatory and pro-thrombotic state. In this study, we examine the incidence of post-operative venous sinus thrombosis in patients undergoing peri-sigmoid posterior fossa surgery in the pre- and post-COVID era and investigate whether COVID infection confers an increased risk of sinus thrombosis.

Comparative Anatomy of the Contralateral Transmaxillary Approach Alone and With Ipsilateral Transpterygoid Extension: Quantitative Insights on Surgical Exposure and Maneuverability in the Petroclival Region.

Background And Objectives: Beyond qualitative evidence legitimizing endoscopic corridors through contralateral transmaxillary (CTM) and endonasal ipsilateral transpterygoid (ITP) corridors to the petrous apex and petroclival region, surgical feasibility by direct quantitative comparative anatomy is sparse. Our cadaveric study addresses this by performing the CTM approach followed by ITP extension to quantify the extent of petrous apex resection, instrument maneuverability, and working distance to petrous apex.

Methods: Anatomic dissections were performed bilaterally on 5 latex-injected human cadaveric heads (10 petrous bones).

Refining the predictive value of preoperative apparent diffusion coefficient (ADC) by whole-tumor analysis for facial nerve outcomes in vestibular schwannomas.

Background: Apparent diffusion coefficient (ADC) in MRI has been shown to correlate with postoperative House-Brackmann (HB) scores in patients with vestibular schwannoma despite limited methodology. To rectify limitations of single region of interest (ROI) sampling, we hypothesize that whole-tumor ADC histogram analysis will refine the predictive value of this preoperative biomarker related to postoperative facial nerve function.

Methods: Of 155 patients who underwent resection of vestibular schwannoma (2014-2020), 125 patients were included with requisite clinical and radiographic data.

How I do it: hearing preservation in large vestibular schwannomas using vestibular nerve fiber preservation technique.

Background: To improve hearing function after resection of large vestibular schwannomas, we describe a strategy of vestibular-nerve-fiber preservation. Anatomical considerations and stepwise dissection are described.

Method: Steps include locating the vestibular nerve at the brainstem and identifying a dissection plane between nerve fibers and tumor capsule.

High-Throughput Screening of Epigenetic Inhibitors in Meningiomas Identifies HDAC, G9a, and Jumonji-Domain Inhibition as Potential Therapies.

 Epigenetics may predict treatment sensitivity and clinical course for patients with meningiomas more accurately than histopathology. Nonetheless, targeting epigenetic mechanisms is understudied for pharmacotherapeutic development for these tumors. The bio-molecular insights and potential therapeutic development of meningioma epigenetics led us to investigate epigenetic inhibition in meningiomas.

Surgical outcomes in large vestibular schwannomas: should cerebellopontine edema be considered in the grading systems?

Purpose: Large (> 3 cm) vestibular schwannomas pose complexity in surgical management because of narrow working corridors and proximity to the cranial nerves, brainstem, and inner ear structures. With current vestibular schwannoma classifications limited in information regarding cerebellopontine edema, our retrospective series examined this radiographic feature relative to clinical outcomes and its possible role in preoperative scoring.

Methods: Of 230 patients who underwent surgical resection of vestibular schwannoma (2014-2020), we identified 107 patients with Koos grades 3 or 4 tumors for radiographic assessment of edema in the middle cerebellar peduncle (MCP), brainstem, or both.

Learning Surgical Skills Through Video-Based Education: A Systematic Review.

Background: Educational videos are a potent resource for the learning of surgical skills among different study cohorts. However, there is limited evidence on the effectiveness of different educational video interventions and their features.

Unlabelled: A systematic search of MEDLINE (via PubMed), Embase (via OVID), Cochrane libraries and Clinicaltrials.

Tailored Treatment Options for Cerebral Cavernous Malformations.

The diagnosis and treatment of cerebral cavernous malformations (CCMs), or cavernomas, continues to evolve as more data and treatment modalities become available. Intervention is necessary when a lesion causes symptomatic neurologic deficits, seizures, or has high risk of continued hemorrhage. Future medical treatment directions may specifically target the pathogenesis of these lesions.

A two-stage combined anterolateral and endoscopic endonasal approach to the petroclival region: an anatomical study and clinical application.

Object: The pretemporal transcavernous anterior petrosal (PTAP) approach and the combined petrosal (CP) approach have been used to resect petroclival meningiomas (PCMs). In this cadaveric anatomical study, a two-stage combined PTAP and endoscopic endonasal far medial (EEFM) approach (the PTAPE approach) was compared morphometrically to the CP approach. A case study provides a clinical example of using the PTAPE approach to treat a patient with a PCM.

Targeting DNA Methyl Transferases with Decitabine in Cultured Meningiomas.

Objective: Meningiomas are a common primary central nervous system tumor that lack a U.S. Food and Drug Administration-approved pharmacotherapy.

Endocrinological outcomes after transcranial resection of tuberculum sellae meningiomas: a systematic review and meta-analysis.

Tuberculum sellae meningiomas (TSMs) arise from the anterior skull base. Endocrine status after TSM resection is an important determinant of quality of life. We sought to better characterize the risk of postoperative endocrinopathy for patients with TSM undergoing open transcranial approach (TCA) microsurgical resection.

Nervus Intermedius Outcomes After Vestibular Schwannoma Surgery and Radiosurgery: A Single-Institution Experience.

Objective: Nervus intermedius (NI) dysfunction after the management of vestibular schwannoma (VS) is underreported and is experienced by patients undergoing stereotactic radiosurgery and surgical resection. The aim of this study was to present NI outcomes in a series of patients who underwent all treatment modalities for VS and to review the existing literature.

Methods: We performed a retrospective review of all patients with VS who were treated at our institution between January 1, 2008, and December 31, 2018.

Acute Sigmoid Sinus Compromise Following Skull Base Procedures: Is a "Laissez-Faire" Approach Best?

 Venous sinus compromise (VSC) of the sigmoid sinus can manifest as either venous sinus thrombosis, stenosis, or a combination of the two. It may occur following retro and presigmoid craniotomy, even in the absence of overt intraoperative sinus injury. Currently, the optimal management of VSC in the perioperative period is not well established.

Hydroxyapatite cement cranioplasty for reconstruction of translabyrinthine approach: aesthetic results, long-term satisfaction, quality of life, and complications.

Background: Translabyrinthine approaches (TLAs) for resection of skull base neoplasms are complex with variable reconstruction techniques. Fat grafts in conjunction with hydroxyapatite bone cement techniques have seldom been described in terms of possible superiority to other skull base reconstruction techniques. We sought to determine the impact of this skull base reconstruction technique on clinical outcomes and patient's satisfaction.

Combined biportal unilateral endoscopic endonasal and endoscopic anterior transmaxillary approach for resection of lesions involving the infratemporal fossa.

Background: Approaching tumors involving the infratemporal fossa (ITF) is technically challenging due to the complex relationships between several neurovascular structures and the deep-seated location of these lesions.

Methods: The authors describe in detail a minimally invasive approach to the ITF, consisting on a single-nostril endoscopic endonasal transmaxillary approach aided by an anterior transmaxillary port (EEA-ATMa). Anatomical landmarks and surgical tenets of this approach are highlighted and reviewed with the goal to guarantee successful tumor resection and avoid operative complications.

Comparative analysis of the combined petrosal and the pretemporal transcavernous anterior petrosal approach to the petroclival region.

Objective: The combined petrosal (CP) approach has been traditionally used to resect petroclival meningioma (PCM). The pretemporal transcavernous anterior petrosal (PTAP) approach has emerged as an alternative. A quantitative comparison of both approaches has not been made.