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OBJECTIVE Chordomas represent one of the most challenging subsets of skull base and craniovertebral junction (CVJ) tumors to treat. Despite extensive resection followed by proton-beam radiation therapy, the recurrence rate remains high, highlighting the importance of developing efficient treatment strategies. In this study, the authors present their experience in treating clival and CVJ chordomas over a 29-year period. METHODS The authors conducted a retrospective study of clival and CVJ chordomas that were surgically treated at their institution from 1991 to 2020. This study focuses on three aspects of the management of these tumors: the factors influencing the extent of resection (EOR), the predictors of survival, and the outcomes of the endoscopic endonasal approaches (EEAs) compared with open approaches (OAs). RESULTS A total of 265 surgical procedures were performed in 210 patients, including 123 OAs (46.4%) and 142 EEAs (53.6%). Tumors that had an intradural extension (p = 0.03), brainstem contact (p = 0.005), cavernous sinus extension (p = 0.004), major artery encasement (p = 0.01), petrous apex extension (p = 0.003), or high volume (p = 0.0003) were significantly associated with a lower EOR. The 5-year progression-free survival (PFS) and overall survival (OS) rates were 52.1% and 75.1%, respectively. Gross-total resection and Ki-67 labeling index < 6% were considered to be independent prognostic factors of longer PFS (p = 0.0005 and p = 0.003, respectively) and OS (p = 0.02 and p = 0.03, respectively). Postoperative radiation therapy correlated independently with a longer PFS (p = 0.006). Previous surgical treatment was associated with a lower EOR (p = 0.01) and a higher rate of CSF leakage after EEAs (p = 0.02) but did not have significantly lower PFS and OS compared with primary surgery. Previously radiation therapy correlated with a worse outcome, with lower PFS and OS (p = 0.001 and p = 0.007, respectively). EEAs were more frequently used in patients with upper and middle clival tumors (p = 0.002 and p < 0.0001, respectively), had a better rate of EOR (p = 0.003), and had a lower risk of de novo neurological deficit (p < 0.0001) compared with OAs. The overall rate of postoperative CSF leakage after EEAs was 14.8%. CONCLUSIONS This large study showed that gross-total resection should be attempted in a multidisciplinary skull base center before providing radiation therapy. EEAs should be considered as the gold-standard approach for upper/middle clival lesions based on the satisfactory surgical outcome, but OAs remain important tools for large complex chordomas.

BACKGROUND Currently, different postoperative predictors of chordoma recurrence have been identified. Tumor growth rate (TGR) is an image-based calculation that provides quantitative information of tumor's volume changing over time and has been shown to predict progression-free survival (PFS) in other tumor types. OBJECTIVE To explore the usefulness of TGR as a new preoperative radiological marker for chordoma recurrence. METHODS A retrospective single-institution study was carried out including patients reflecting these criteria: confirmed diagnosis of chordoma on pathological analysis, no history of previous radiation, and at least 2 preoperative thin-slice magnetic resonance images available to measure TGR. TGR was calculated for all patients, showing the percentage change in tumor size over 1 mo. RESULTS A total of 32 patients were retained for analysis. Patients with a TGR ≥ 10.12%/m had a statistically significantly lower mean PFS (P

This thesis was scanned from the print manuscript for digital preservation and is copyright the author. Researchers can access this thesis by asking their local university, institution or public library to make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.

The aim of this study was to examine the strategies, instruments, and criteria of authentic evaluation that physical education teachers apply at the primary level, based on the planning and application of didactic sequences previously established for an intervention process. Initially and voluntarily, three physical education teachers participated from three different schools, one federal, one state, and one private, in Chihuahua State, Mexico. The research project was characterized as a multiple case study, where teachers participated in an authentic evaluation workshop and developed didactic sequences that were implemented to examine the application of strategies and instruments of authentic evaluation. The qualitative analysis of the observations, questionnaires, and interviews suggest that the application of these didactic sequences together with the use of authentic evaluation strategies, favored teaching performance and enriched the learning environment. The implications of the study point to the need to formalize and systematize the application of authentic evaluation strategies and instruments within basic education when these are causally related to the didactic sequences and the curriculum content.

To explore the possibility of using different interactive resources through technology to help Generation Z Pre-A1 Beginner students develop self-learning skills when learning a foreign language. La presente investigación examina los factores que afectan a los estudiantes de la Generación Z, quienes son usuarios nativos de la tecnología, cuando utilizan tecnología como herramienta en su proceso de aprendizaje. Esta investigación se centró en cómo utilizar actividades de autoaprendizaje asistidas por tecnología para los estudiantes de la Generación Z de nivel principiante Pre A1. Se realizó una investigación cualitativa de Acción/Participación, que utilizó entrevistas y observaciones como herramientas de investigación. Se definieron dos preguntas de investigación (1) ¿Cómo ayudan los recursos interactivos a estudiantes principiantes Pre-A1-de la Generación Z a desarrollar habilidades de autoaprendizaje para aprender un idioma extranjero? (2) ¿Cuál es la percepción del profesor sobre el cambio de la dinámica de una clase para los estudiantes principiantes Pre-A1-de la Generación Z usando el método invertido (FLIP)? El investigador eligió una muestra inicial de 20 estudiantes, que cumplían con los criterios del rango de edad para la Gen-Z, utilizando una metodología no probabilística. Para recopilar datos, se realizaron dos entrevistas con el profesor y una entrevista con los estudiantes; también se realizó una observación de una clase. La investigación encontró cinco temas principales desde punto de vista del profesor y de los estudiantes: (1) la experiencia utilizando modelos de autoaprendizaje con tecnología, (2) preferencias y preparación de los participantes, (3) utilidad de la metodología y la tecnología de autoaprendizaje, (4) formación necesaria para el uso de la metodología de autoaprendizaje y herramientas tecnológicas, y (5) motivación para utilizar la metodología de autoaprendizaje y herramientas tecnológicas para el curso. La formación del profesor ha demostrado ser uno de los factores clave necesarios para una aplicación exitosa del modelo. Maestría

Bow hunter's syndrome is a rare clinical condition. It is caused by dynamic compression of the vertebral artery (VA) either at the level of the transverse foramina (V2 segment) or at the atlantoaxial level (V3 segment). We report a 54-year-old man with typical bow hunter's syndrome caused by compression at the level of C6/C7. He was successfully treated by anterolateral VA decompression without a need for stabilization. We present preoperative imaging (magnetic resonance imaging, computed tomographic angiography, and dynamic angiography) and a high-quality intraoperative video detailing each step of the surgical technique (high-definition video with annotations and audio track of the Doppler ultrasound used as intraoperative control). Furthermore, postoperative imaging and a video of the clinical outcome are presented. Adequate management of bow hunter's syndrome requires good pathophysiologic understanding of the disease and careful clinical examination. Dynamic angiography confirms the exact site of VA compression. Surgical decompression is the treatment of the cause. Surgical techniques include VA decompression by an anterolateral approach (V2 or V3) or a posterior approach (V3). Some authors advocate stand-alone stabilization, which is, however, only an indirect treatment and results in significant loss of head motion. Other nonsurgical treatments such as orthesis, medical therapy, or endovascular stenting have been only anecdotally reported. Bow hunter's syndrome is best treated by VA decompression. This may safely be achieved by good anatomic knowledge and a straightforward surgical technique. Here, the anterolateral approach is presented in detail in a high-definition surgical instruction video.

Pediatric chordomas are rare malignant neoplasms, and few data are available for optimizing therapeutic strategies and outcome. This study aimed at evaluating how best to manage them and to identify prognostic factors. This multicentric retrospective study included 40 children diagnosed with chordomas between 1966 and 2012. Clinical, radiological, and histopathological data, treatment modalities, and outcomes were reviewed. The median age was 12 years old. Most chordomas were histologically classical forms (45.5%) and were mostly located at the skull base (72.5%). The overall survival (OS) was 66.6% and 58.6%, and progression-free survival (PFS) was 55.7% and 52% at 5 and 10 years, respectively. Total resection was correlated with a better outcome (p = 0.04 for OS and PFS, log-rank). A histopathological/immunohistochemical grading system recently crafted for adults was applied. In a multivariate analysis, it significantly correlated with outcome (PFS and OS, p = 0.004), and the loss of BAF47 immunoexpression appeared to be a significant independent prognostic factor (PFS, p = 0.033). We also identified clinical and histopathological parameters that correlated with prognosis. A new grading system combined with the quality of surgical resection could help classify patients to postpone radiotherapy in case of low risk. Targeted therapy and reirradiation at recurrence may be considered as potential therapeutic strategies.

Background Cerebrospinal fluid (CSF) leakage associated with incomplete sealing of the dura mater is a major complication of intradural procedures. Objective To compare the efficacy and safety of adjunctive TachoSil (Takeda Pharma A/S, Roskilde, Denmark) with current practice for the prevention of postoperative CSF leaks in patients undergoing elective skull base surgery involving dura mater closure. Methods Patients were intraoperatively randomized to TachoSil or current practice immediately before primary dura closure by suturing ± duraplasty. Choice of adjunctive treatment in the current practice group was at the surgeon's discretion. Primary efficacy endpoint was occurrence of clinically evident verified postoperative CSF leak or clinically evident pseudomeningocele within 7 weeks after surgery or treatment failure (third application of trial treatment or use of other treatment). Results A total of 726 patients were randomized to TachoSil (n = 361) or current practice (n = 365). More current practice patients had sutures plus duraplasty for primary dura closure compared with TachoSil (49.6% vs 35.7%) and fewer had sutures only (45.5% vs 63.2%). The primary endpoint of estimated leak rate favored TachoSil with events in 25 (6.9%) patients vs 30 (8.2%) current practice patients; however, this was not statistically significant (odds ratio: 0.82; 95% confidence interval: 0.47, 1.43; P = .485). Both treatments were well tolerated with similar frequency of adverse events. Conclusion Very low rates of postoperative CSF leaks can be achieved in patients undergoing skull base surgery of various indications. Although the study did not meet its primary endpoint, TachoSil appears to be safe and effective for the prevention of CSF leaks and associated complications.

The vertebral artery (VA) at the cranio-vertebral junction is in its third segment (V3) and has a complex course between the transverse foramen (TF) of C2 and the foramen magnum (FM) dura. There are two main routes which permit to safely expose and control the VA: the posterolateral and the anterolateral approaches. The most important technical trick for a safe exposure of the VA is the preservation of the periosteal sheath surrounding the VA and its venous plexus. The access to the VA gives the possibility of release of extrinsic intermittent VA compression (Bow Hunter syndrome) and of course to revascularize the vertebro-basilar system by a venous graft bypassing an occlusive lesion, an aneurysm, or a tumor. The VA control gives also a better access to FM tumors through the posterolateral approach or to CVJ tumors through the anterolateral approach, or to jugular foramen (JF) tumors through the juxtacondylar approach, which is an anterolateral approach extension. Mortality and morbidity related to the VA exposure should be very limited, including only painful stiffness of the sterno-mastoid muscle due to overstretching of the accessory nerve.

The suboccipital segment of the vertebral artery that courses at the craniovertebral junction level, also called the V3 segment, extends from the transverse foramen of the axis to the dura mater of the foramen magnum. This segment is composed of three portions: a vertical portion, located between the C2 and C1 transverse foramina; a horizontal portion, above the posterior arch of the atlas; and finally an oblique portion, along the step formed medially by the bone of the C1 posterior arch. The vertebral artery is tightly anchored at the dura mater of the foramen magnum along its course through it; this junction is called the distal dural ring. Along its course, the vertebral artery V3 segment is surrounded by a venous plexus inside a periosteal sheath. The relative positions of the vertical and horizontal portions are variable, depending on head turning. In neutral position, both segments are perpendicular while they become more and more parallel as the head is turned toward the contralateral side. Many anatomical variations are present at this level; these are important to know and to detect preoperatively for working in safe conditions. It is relatively common that the vertebral arteries are of different sizes. A small vertebral artery is either hypoplasic, if the vessel participates to form the basilar trunk, or atretic, if it ends by the PICA or another vessel. Abnormal course of the vertebral arteries, persisting congenital anastomoses, duplications or fenestrations can also be present, as well as a lot of variations of the PICA.

The anterolateral approach grants a unique surgical trajectory to the cranio-vertebral junction that is in an inferior to superior and posterior to anterior direction. In addition to the cervical vertebrae, including C1 and C2 that are seen from a lateral perspective, the ALA allows exposure of the lower clivus and jugular foramen from below. Detailed knowledge of the 3D surgical anatomy, especially of the vertebral artery, is paramount for safe dissection and exposure through an ALA. In our practice, it is most often used to resect chordomas and other bony lesions of the CVJ. Endoscopic assistance as a surgical tool is an important adjunction that can enhance the exposure provided by the ALA in order to reach deep tumor extensions.