Minimally Invasive Drainage of Intracerebral Hemorrhage. A South American Experience with the MISTIE Procedure.

BACKGROUND: Intracerebral hemorrhage (ICH) is the second most common subtype of stroke but is associated with greater rates of disability or mortality. One of the factors of a poor prognosis is large hematoma volume. The MISTIE III trial with the aim of decreasing clot size showed that the greater the ICH reduction, the higher likelihood of lower mortality without a net increase in the proportion of patients with severe disability. Our aim is to describe our experience with treating selective patients with ICH per the MISTIE trial protocol in a university hospital in Argentina during 4 years. METHODS: A retrospective analysis was performed of consecutive patients with ICH treated at a single university tertiary-care center from 2017 to 2021 with the MISTIE protocol. RESULTS: We deployed this procedure in 7 patients with a median age of 61 years, median National Institutes of Health Stroke Scale score of 14, an ICH volume of 35 mL and median ICH score of 2. Five of 7 patients achieved the target goal of hematoma reduction; 4 of the patients had a total independence level and 1 needed minimal help at 12 months after discharge. Five patients had a good functional outcome (modified Rankin Scale score 0-3 and extended Glasgow Outcome Scale score 4-8) and 2 patients had died but neither because of consequences of thrombolysis of the intracerebral hemorrhage. We did not find bleeding complications during catheter placement, alteplase infusion, or after catheter removal. CONCLUSIONS: The procedure can be carried out safely in Latin American centers that have experience in managing neurocritical patients.

Navigated multiplanar osteotomies for spinal primary bone tumors.

BACKGROUND: Establishing the proper diagnosis and rendering appropriate treatment of spinal primary bone tumors (SPBT) can result in definitive cures. Notably, malignant, or benign SPBT (i.e., with aggressive local behavior) generally require en bloc resection. Osteotomies of the vertebral body in more than 1 plane may avoid critical structures, preserve nerve functions, and reduce the volume of healthy bone resected. Here, our objective was to report how we planned and performed navigated multiplanar osteotomies for en bloc resection of 14 SPBT. METHODS: We performed a retrospective analysis of 14 patients with malignant or locally aggressive benign SPBT operated on consecutively between 2014 and 2019 utilizing preoperative 3D planning/navigation. Tumors were resected in an en bloc fashion utilizing multiplanar osteotomies. Patients were followed for a minimum of 12 postoperative months. RESULTS: Diagnoses included three benign but locally aggressive bone tumors (i.e., all osteoblastomas) and 11 primary sarcomas (i.e., six chordomas and five chondrosarcomas). Eleven tumors involved the sacrum and the other three, the thoracic spine. In 12 patients, the en bloc margins were classified as marginal (<1 cm), and in two patients, as wide (>1 cm). Intraoperative navigation facilitated the performance of 40 osteotomies in 14 patients (median = 2.9, range = 2-6). CONCLUSION: Navigated multiplanar osteotomies increased the precision and safety of en bloc resections for 14 primary spinal bone tumors SPBT that included 11 malignant and three benign/locally aggressive lesions.

Safety margin for the preservation of the nasoseptal artery during trans-nasal endoscopic approach.

BACKGROUND: The introduction of the nasoseptal flap for the reconstruction of extended endoscopic approaches decreased the incidence of postoperative fistula. In order to preserve the septal vascular pedicles, many have started to prepare the flap systematically, prior to the opening of the sphenoid rostrum. The aim of this study is to obtain an average measure of the location of the posterior septal artery using the upper edge of the choana as a landmark. METHODS: Ten cadaveric heads, fixed with formaldehyde and injected with colored silicone, were studied. The course, branching pattern and dominance of the branches of the posterior septal artery were recognized, as well as the distance in of its superior and lower branches respect to the medial upper edge of the choana. RESULTS: In all cases, the posterior septal artery enters as an only vessel through the sphenopalatine foramen. In its sphenoid segment, over the sphenoid rostrum, the posterior septal artery divides into its upper and lower branches, in most cases, laterally to the sphenoid ostium (70%, N.=14). The lower branch was dominant in 60% of the cases (N.=12). Regarding the mean distance in millimeters from the medial upper edge of the choana to the superior branch, it was 14.45±0.4102 (18-11.5) and, to the lower branch, 10.9±0.4682 (14-7). CONCLUSIONS: A rostrum opening to 15 mm over the upper edge of the choana is safe to avoid vascular complications, and to be able to prepare a viable nasoseptal flap only if it is necessary.

Surgical Indication Optimization of Brain Metastases Based on the Evolutionary Analysis of Karnofsky Performance Status.

BACKGROUND AND OBJECTIVE: Surgical resection of brain metastases (BM) offers the highest rates of local control and survival; however, it is reserved for patients with good functional status. In particular, the presence of BM tends to oversize the detriment of the overall functional status, causing neurologic deterioration, potentially reversible following symptomatic pharmacological treatment. Thus, a timely indication of surgical resection may be dismissed. We propose to identify and quantify these variations in the functional status of patients with symptomatic BM to optimize the indication of surgical resection. PATIENTS AND METHODS: Historic, retrospective cohort analysis of adult patients undergoing BM microsurgical resection, consecutively from January 2012 to May 2016, was conducted. The Karnofsky performance status (KPS) variation was recorded according to the symptomatic evolution of each patient at specific moments of the diagnostic-therapeutic algorithm. Finally, survival curves were delineated for the main identified factors. RESULTS: One hundred and nineteen resection surgeries were performed. The median overall survival was 243 days, while on average it was 305.7 (95% confidence interval [CI]: 250.6-360.9) days. The indication of surgical resection of 10% of the symptomatic patients in our series (7.5% of overall) could have been initially rejected due to pharmacologically reversible neurologic impairment. Survival curves showed statistically significant differences when KPS was stratified following pharmacological symptomatic treatment (p < 0.0001), unlike when they were estimated at the time of BM diagnosis (p = 0.1128). CONCLUSION: The preoperative determination of the functional status by KPS as an evolutive parameter after the nononcologic symptomatic pharmacological treatment allowed us to optimize the surgical indication of patients with symptomatic BM.

Neurocirugía en época de COVID-19. Protocolo de actuación / Neurosurgery in the time of COVID-19. Action protocol

El manejo de pacientes debido a la aparición del nuevo coronavirus 2019 (COVID-19) representa un desafío para los equipos médicos y quirúrgicos, ya que modificó el funcionamiento de los sistemas de salud en casi todo el mundo. Para contribuir a la re organización del sistema de salud, el Servicio de Neurocirugía del Hospital Italiano de Buenos Aires trabajó en adoptar distintas medidas en concordancia con las tomadas a nivel institucional y nacional; por lo que se analizó la bibliografia publicada, asi como las normas dictadas por el comité de crisis de nuestra institucion. A su vez realizamos una breve encuesta dirigida a neurocirujanos de america latina para conocer como se manejaban actualmente en relación a niveles de protección y realización de cirugias. La actual pandemia de COVID-19 es el mayor desafío que enfrentan los sistemas nacionales de salud en los últimos tiempos. Los neurocirujanos podemos contribuir a la reducción del riesgo de infección nosocomial de los trabajadores de la salud al adaptar distintos protocolos en pacientes con COVID-19.

Patient's management due to the appearance of new coronavirus 2019 (COVID-19) represents a challenge for medical and surgical departments, since it modified the running of health systems in almost all the world. In order to help in this new situation, the Neurosurgical Department of our institution has adopted different measures in accordance with those taken at institutional and national level. In order to do this, we made a literature review and we added to this, the norms dictated by the crisis committee of our hospital. We also carried out a brief survey among neurosurgeons from Latin America to find out how they managed protection levels in relation to surgery. COVID-19 pandemic is certainly one of the greatest challenge national health systems face in a century. Adapting different protocols in neurosurgical patients with COVID-19 can contribute in reducing the risk of nosocomial infection of health workers.

Early Report on the Impact of COVID-19 Outbreak in Neurosurgical Practice Among Members of the Latin American Federation of Neurosurgical Societies.

BACKGROUND: The COVID-19 pandemic has caused severe economic consequences by local governmental measures to contain the outbreak. We provide insight on the impact that health care restriction has made on neurosurgical activity in Latin Iberoamerica. METHODS: We performed an internet-based survey among presidents and members of the societies of the Latin American Federation of Neurosurgical Societies (FLANC). We blindly analyzed information regarding local conditions and their impact on neurosurgical praxis using SPSS software. RESULTS: Information came from 21 countries. Sixteen society presidents reported having suspended regular activities and deferring local scheduled congresses, 14 reported mandatory isolation by government, and 4 instituted a telemedicine project. Four-hundred eighty-six colleagues, mean age 49 years, reported a mean 79% reduction in their neurosurgical praxis. Seventy-six percent of neurosurgeons have savings to self-support for 3-6 months if restrictions are long lasting. CONCLUSIONS: Stopping activities among societies of the FLANC, together with a drop of 79% of neurosurgical praxis, adds to deficits in provider's protection equipment and increasing demand for attention in the health care systems, representing a huge financial risk to their sustainability. Neurosurgeons should be involved in local policies to protect health and economy. Telemedicine represents an excellent solution, avoiding another pandemic of severe diseases across all-specialties as nonessential care can turn essential if left untreated. Financial support and ethics code review is needed to battle this new disease, designated the occupational disease of the decade, that continues to scrag the health care system. Times of crisis are times of great opportunities for humanity to evolve.

Cirugía mínimamente invasiva en el tratamiento de fracturas tóracolumbares / Minimally invasive surgery in the treatment of thoracolumbar fractures

Objetivo: Analizar y describir una serie de fracturas tóraco-lumbares traumáticas tratadas con cirugía mínimamente invasiva. Material y métodos: Analizamos una serie de 26 pacientes con fracturas traumáticas tóraco-lumbosacras entre 2010-2017. Las imágenes pre-operatorias fueron clasificadas usando la clasificación AO. Analizamos en forma pre y post operatoria: escala visual analógica, volumen de pérdida sanguínea, duración de la hospitalización, complicaciones, cirugías asociadas en otros órganos, extracción de implantes en el largo plazo, estado neurológico pre y post quirúrgico y mortalidad.Los pacientes con historias clínicas completas, TAC pre-operatoria y un seguimiento mínimo de 12 meses fueron incluidos (18 hombres y 8 mujeres). La edad promedio fue de 28.7 años (21-84 años); seguimiento promedio de 28 meses (13-86 meses). Dieciocho pacientes fueron manejados con instrumentaciones percutáneas, 8 recibieron vertebroplastias, y en 5 casos se realizó además algún gesto de artrodesis. Resultados: La EVA mejoró 7 puntos promedio respecto al pre-operatorio; el promedio de sangrado fue de 40 mL, no observamos ningún caso de empeoramiento neurológico. La duración promedio de la hospitalización fue de 3.9 días. Cuatro enfermos necesitaron alguna cirugía en otro órgano producto de sus politraumatismos.Los tornillos percutáneos fueron removidos en 9 casos luego de la consolidación. Como complicaciones tuvimos: 1 hematoma retroperitoneal autolimitado, una fractura pedicular y una cánula de cementación rota adentro de un pedículo. Conclusión: La cirugía mínimamente invasiva en trauma espinal es una alternativa válida que permite estabilización, movilización precoz y logra buenos resultados en términos de control del dolor con baja tasa de complicaciones

Objective: To analyze and describe a series of trauma-related thoraco-lumbo-sacral vertebral fractures managed with minimally invasive surgery. Methods: We retrospectively review the charts and images of 26 patients with thoracolumbar spine fractures between 2010-2017. Pre-op images were assessed and fractures were classified according to the thoraco-lumbar trauma AO Spine classification. We analyzed pre and post-surgical visual analog scale (VAS), blood loss during surgery, hospital length of stay, complications, associated surgical procedures, long term post-op implant removal, pre and post neurological status and mortality.Patients with a complete case record, pre-op CT scans and minimum 12-month follow up were included (18 males and 8 females). Mean age was 28.7 years (21-84 years); mean post-op follow up was 28 month (13-86 months). Eighteen patients were managed with percutaneous instrumentation, 8 patients also received percutaneous vertebroplasty, and 5 patients underwent also some arthrodesis procedure. Results: VAS improved 7 points as compared to the pre-op score; mean blood loss was 40 mL, we did not observed any neurological deficit worsening. Mean hospital length of stay was 3.9 days. Four patients needed surgical procedures involving other organs due to politrauma. Percutaneous screws were removed in 9 cases after fracture consolidation. Complications were: one case of self-limiting retroperitoneal hematoma, one case of pedicle screw fracture and one cement broken cannula into the pedicle. Conclusion: Minimally invasive surgery in spine trauma is a valid option allowing stabilization, early mobilization, and leading to good outcomes in terms of pain control and a lower complication rate

Estimulación cerebral profunda: tratamiento para pacientes con diagnóstico de trastorno obsesivo-compulsivo resistente / Deep brain stimulation: treatment for patients diagnosed with disorder obsessive-compulsive resistant

El trastorno obsesivo-compulsivo (TOC) afecta al 2% de la población general, llegando en ocasiones a causar un deterioro funcional severo y de la calidad de vida de las personas afectadas. Entre el 10 y el 30% de los pacientes con este trastorno no responde a los tratamientos recomendados: farmacológicos y terapia cognitivo-conductual. La Food and Drug Administration de los Estados Unidos (FDA) aprobó en el año 2008 la Estimulación cerebral profunda (ECP) para pacientes con TOC resistente a tratamiento. La ECP, utilizada frecuentemente para el tratamiento de la enfermedad de Parkinson refractaria, es una opción viable para los pacientes con TOC resistente, con efectos adversos poco frecuentes y transitorios. (AU)

Obsessive-compulsive disorder (OCD) affects 2% of the general population, sometimes resulting in severe impairment of functional capacity and quality of life of affected people. Between 10 and 30% of these patients do not respond to recommended treatments: pharmacological and cognitive behavioral therapy. In 2008, the FDA approved Deep Brain Stimulation (DBS) for patients with OCD resistant to treatment. DBS, frequently used for the treatment of refractory Parkinson's disease, is a viable option for the treatment of patients with resistant OCD, with infrequent and transient adverse effects. (AU)

Abordaje mínimamente invasivo para el tratamiento de tumores espinales intradurales extramedulares / Minimally invasive approach for the treatment of extramedullary intradural spinal tumors

Introducción: Describir la técnica de abordaje mínimamente invasiva para el tratamiento de tumores intradurales extramedulares en los diferentes segmentos espinales. Material y Métodos: Se detallan la planificación, posicionamiento, marcación, pasos técnicos del abordaje mínimamente invasivo, exéresis lesional y cierre de lesiones ID-EM a nivel cervical, dorsal, lumbar y sacro. Se proporcionan recomendaciones para descomplejizar maniobras quirúrgicas, acortar el tiempo operativo y evitar potenciales complicaciones. Conclusiones: El abordaje MISS es una opción segura y eficaz para el tratamiento quirúrgico de determinados tumores ID-EM.

Objective: To describe the technique of minimally invasive approach for the treatment of intradural extramedullary tumors in the different spinal segments. Material and Methods: The planning, positioning, skin marking, technical steps of the minimally invasive approach, lesion resection, and closure of ID-EM lesions at the cervical, dorsal, lumbar and sacral levels are detailed. Recommendations are provided to simplify surgical maneuvers, shorten operative time and avoid potential complications. Conclusions: The MIS approach is a safe and effective option for the surgical treatment of certain ID-EM tumors.

[Usefulness of minimally invasive spine surgery for the management of thoracolumbar spinal metastases]. / Utilidad de la cirugía espinal mínimamente invasiva en el manejo de las metástasis espinales toraco-lumbares.

OBJECTIVE: To describe the surgical results and evolution of patients who underwent minimally invasive spine surgery (MISS) for the treatment of thoracolumbar spinal metastases, using the NOMS (Neurological, Oncological, Mechanical, Systemic) assessment for the therapeutic decision. METHODS: Patients who underwent MISS technique for the treatment of thoracolumbar spinal metastases were prospectively enrolled at the Hospital Italiano de Buenos Aires, from June 2014 to June 2017. In all cases, the NOMS assessments were performed for therapeutic decision making. Surgical results were analyzed in terms of improvements in Karnofsky performance status, pain relief (VAS - visual analog scale), Frankel, blood loss, need for transfusions, complications, use of opioids and hospitalization length. A P < 0.05 value was considered statistically significant. RESULTS: During the study period 26 patients were included, 13 of them were women. The average age was 57-year-old (27-83 years). Breast cancer was the most frequent primary tumor (27%). The main symptom was pain (96%), although 12 patients presented with myelopathy (46%). High-grade epidural spinal cord compression requiring decompression was observed in 17 cases (65%). According to the SINS (spinal instability neoplastic score), most lesions were potentially unstable or unstable (89%) requiring MISS stabilization. After surgery, pain relief (VAS) and neurological recovery (Frankel) improved significantly in the 77% and 67% of the cases, respectively, with low intraoperative blood loss and without any transfusions. Only one minor surgical complication was presented (4%). The average of hospital stay was 5.5 days. CONCLUSION: In our series and using the NOMS as a therapeutic algorithm, MISS was effective for decompression and spinal stabilization, with a low rate of complications and rapid postoperative recovery.

[Minimally invasive resection of spinal synovial cysts: Technical note]. / Resección mínimamente invasiva de quistes sinoviales espinales. Nota técnica.

OBJECTIVE: To present the treatment algorithm, surgical technique, and results of a series of patients with spinal synovial cysts operated with minimally invasive techniques (MIS). INTRODUCTION: Spinal synovial cysts originate from the dilation and potential rupture of the synovial sheath of a facet joint. Surgical resection is considered the treatment of choice in symptomatic patients. The use of MIS techniques could reduce the disruption of the facet joint involved, reducing the risk of postoperative instability. MATERIALS AND METHODS: We retrospectively evaluated 21 patients with spinal synovial cysts operated by MIS approach and decompression. We analyzed the signs, symptoms, surgical time, hospital stay, evolution, and complications. The visual analog scale (VAS) was used to evaluate pain and the Weiner scale and the modified Macnab criteria to measure the patient's postoperative satisfaction. RESULTS: A total of 21 patients were surgically treated with MIS technique; 76.2% (n = 16) did not require arthrodesis, the remaining 23.8% (n = 5) were fused. We performed 13 (61.9%) contralateral hemilaminectomies, 7 ipsilateral hemilaminectomies (33.3%), and 1 laminectomy in S1-S2. The average follow-up was 26 months; surgical time was 150.33 ± 63.31 min, with a hospital stay of 2.5 ± 1.78 days. The VAS decreased from 8.3 preoperatively to 2.3 postoperatively. Sixteen patients reported excellent results, four good and one regular in the scale of Macnab. 95.2% of patients perceived that the procedure was very/quite successful according to the Weiner scale. CONCLUSION: The minimally invasive approach is a safe and effective procedure for the complete resection of spinal synovial cysts. It provides excellent clinical-functional results by preserving muscles, ligaments, and joint facets.

Flow Diverter for the Treatment of Pseudoaneurysms of the Extracraneal Vertebral Artery: Report of Two Cases and Review of the Literature.

BACKGROUND: Pseudoaneurysms (PAs) of the extracranial vertebral artery (VA) are rare lesions, representing less than 1% of all aneurysms. Although these lesions may resolve spontaneously, they present a high rupture rate, so early preventive treatment is advised. CASE DESCRIPTION: Case 1: A 48-year-old woman presented with pain and cervical rigidity. An angiotomography showed a PA of the left VA at the level of the C2 transverse foramen, with mural thrombosis and bone remodeling of the left lateral mass. The PA was treated with the endovascular placement of a flow diverter stent. The patient was discharged 3 days after the procedure without complications. The last vascular imaging follow-up was performed 6 years after the procedure showing a patent left VA, with complete resolution of the aneurysm. Case 2: A 57-year-old woman was admitted referring cervicalgia after a polytraumatism. An angiotomography revealed a fracture of the C1 posterior arch, lateral mass, and left transverse foramen, on top of a left VA thrombosis due to a vascular dissection. Eleven months after the trauma, a left VA V3 segment arteriovenous fistula developed. It was treated with hydrocoils, with no complications. One month after the embolization, a left VA V3 segment PA was observed and treated with a flow diverter stent. An angiographic follow-up 2 years after the procedure showed a patent left VA, with complete resolution of the PA. CONCLUSION: The use of flow diverters seems to be a safe and effective therapeutic option for the treatment of PAs of the extracranial VAs.

Relación entre la arteria septal posterior y el borde superior de la coana / Relationship between the posterior septal artery and the superior border of the choana

Introducción: El colgajo pediculado nasoseptal (CPNS) ha sido un elemento fundamental en el avance del abordaje transnasal endoscópico (TNE) para tratar lesiones de la base de cráneo desde la fosa anterior hasta el clivus y la unión occipitocervical. El CPNS provee un tejido viable, vascularizado, extenso y versátil el cual es capaz de adherirse al hueso y sellar el defecto dural disminuyendo así el riesgo de fístula de líquido cefalorraquídeo (LCR) en el postoperatorio, del más del 20% a menos del 5%. Tanto para el CPNS primario como para colgajo de rescate es necesario preservar el pedículo vascular por lo que es fundamental el conocimiento anatómico de la localización de la arteria septal posterior y sus ramas, así como los reparos anatómicos para reconocerla en el intraoperatorio. Objetivo: Establecer la relación entre la arteria septal posterior (ASP) y el borde superior de la coana para definir un margen de seguridad durante la apertura del rostro esfenoidal preservando la ASP y sus ramas. Material y métodos: Estudio observacional, descriptivo, retrospectivo de corte transversal. Angiotomografía cerebral (ATC) con contraste endovenoso realizadas en pacientes mayores a 18 años de ambos sexos para el estudio de lesiones vasculares intracraneales. Las ATC fueron realizadas en un tomógrafo Aquilion ONE 320 (Toshiba, Japan). Para la visualización y medición de las imágenes se utilizó el software Alma Workstation V4.2.0.2 (Alma IT Systems). Se documentaron las variaciones anatómicas y se realizaron mediciones entre el borde superior de la coana y la arteria septal posterior en ambas fosas nasales (Fig 2 a y b). Resultados: De los 98 pacientes estudiados, 32 eran varones y 66 mujeres. La edad media fue de 62,6 con un rango de 19 a 90 años (Tabla 1). Se realizaron mediciones en ambos lados (196 ASP). La distancia media entre la ASP y el borde superior de la coana fue de 14,8 mm del lado izquierdo y 14,7 mm del lado derecho. La distancia media total fue de 14,82 (Tabla 1, Fig 4). Discusión: El borde superior de la coana es un reparo confiable por su constancia en la práctica quirúrgica. Otros autores han medido la distancia entre la rama superior de la ASP y el ostium esfenoidal en 8.2 ± 0.5 mm con un rango de 6.6 a 12.2 mm. Sin embargo el ostium no es un reparo tan confiable por su variable localización en el rostro esfenoidal. La distancia entre la ASP o su rama inferior y el arco de la coana, está descrita a 6.72 ± 2.64 mm con un rango de 2.34­12.64. Sin especificar entre la ASP o su rama inferior. Conclusión: La ASP se encuentra en promedio a aproximadamente 15 mm cefálico al borde superior de la coana. Esta distancia puede ser considerada como un margen de seguridad para evitar lesionar el pedículo vascular durante la confección del CPNS o bien para preservarlo durante la apertura del rostro esfenoidal en caso de requerirse un CPNS de rescate.

Accuracy in Percutaneous Transpedicular Screws Placement Using Biplane Radioscopy: Systematic Review and Meta-Analysis.

STUDY DESIGN: Systematic review and descriptive data meta-analysis. OBJECTIVE: The objective of this study was to appropriately establish the accuracy in the percutaneous transpedicular screws (PTS) placement using biplane radioscopy (Rx-2D). SUMMARY OF BACKGROUND DATA: The Rx-2D is a widely-used technique for PTS as it is practical, ubiquitous, and cost-effective. However, the reported "acceptable" accuracy attained by this method is widely variable ranging between 76% and 100%. METHODS: A systematic review was conducted to screen publications about PTS placement using Rx-2D guidance. PubMed/MEDLINE database was consulted using the search term "percutaneous pedicle screw" from 1977 to 2017. Previous meta-analysis and reference lists of the selected articles were reviewed. Accuracy values were assessed fulfilling the proposed criteria. Observational data meta-analysis was performed. Cochran's Q test was used to determine heterogeneity among data extracted from the series, which was quantified by I test. P-values≤0.05 were considered statistically significant. The results were depicted by Forest plots. Funnel plots were outlined to visualize a possible bias of publication among the selected articles. RESULTS: In total, 27 articles were included in the analysis. Results of the accuracy were as follow, 91.5% (n=7993; 95% CI, 89.3%-93.6%) of the screws were placed purely intrapedicular, and 96.1% (n=8579; 95% CI, 94.0%-98.2%) when deviation from the pedicle was up to 2 mm. CONCLUSIONS: This meta-analysis is the largest review of PTS placed with Rx-2D guidance reported up to date. We concluded that the procedure is a safe and reproducible technique. The key values obtained in this work set reliable references for both clinical and training outcome assessing.

Minimally Invasive Resection of a Cervical Anterolateral Meningioma: 2-Dimensional Operative Video.

Intradural extramedullary spinal tumors were historically managed through traditional midline approaches. Although conventional laminectomy or laminoplasty provides a wide tumor and spinal cord exposure, they may cause prolonged postoperative neck pain and late kyphosis deformity. Minimally invasive ipsilateral hemilaminectomy preserves midline structures, reduces the paraspinal muscle disruption, and could avoid postoperative kyphosis deformity. A safe tumor resection through this approach could be complicated in large sized or anteromedullary located lesions. We present a surgical video of C3 antero located meningioma removed en bloc through a minimally invasive approach. The patient signed a written consent to publish video, recording, photograph, image, illustration, and/or information about him.

Minimally Invasive Single-Stage Removal of a Thoracic Dumbbell Tumor from a Posterior Approach: 2-Dimensional Operative Video.

Dumbbell-shaped thoracic tumors usually involve the spinal canal and the posterior thoracic cavity. Gross total resection is the treatment of choice, but techniques for surgical excision remain controversial. An anterolateral transthoracic approach may remove the paravertebral component of the tumor, but has limited or no control of the intracanal lesion. A combined posteroanterior approach requires a 2-stage surgery with significant morbidity. The preferred approach depends mainly on the tumor location, size, shape, and its specific anatomical relationship with the surrounding vital structures. We present a surgical video of a single-stage posterior minimally invasive approach for the management of a thoracic dumbbell tumor.

Lateral Transpsoas Approach for Lumbar Indirect Lateral Recess Decompression: 2-Dimensional Operative Video.

Neurogenic claudication is a common symptom of lumbar spinal stenosis; its pathophysiology is thought to be ischemia of the nerve roots secondary to compression from surrounding structures. The stenosis of the lateral recesses and neuroforamen can cause these symptoms and its surgical treatment is decompression. The placement of interbody cages that restore the disc space height may indirectly decompress the neuroforamen and alleviate the nerve impingement symptoms. In case of concomitant low-grade spondylolisthesis, interbody devices might also reduce the slippage. We present a technical surgical video of a minimally invasive lateral transpsoas fusion, relying on indirect decompression to treat a patient with neurogenic claudication secondary to grade 1 spondylolisthesis. The patient signed a written consent to publish a video, recording, photograph, image, illustration, and/or information about him.

Resección Mínimamente Invasiva de Quistes Sinoviales Espinales. Nota Técnica / Minimally Invasive Resection of Spinal Synovial Cysts. Technical note

Objetivo: Presentar el algoritmo de tratamiento, técnica quirúrgica y resultados de una serie de pacientes con quistes sinoviales espinales resecados con técnica mínimamente invasiva (MIS). Introducción: Los quistes sinoviales espinales se originan a partir de la dilatación y potencial ruptura de la vaina sinovial de una articulación facetaria. La resección quirúrgica es considerada el tratamiento de elección en pacientes sintomáticos. La utilización de técnicas MIS podrían disminuir la disrupción de la faceta articular comprometida reduciendo el riesgo de inestabilidad postoperatoria. Material y métodos: Se evaluaron retrospectivamente 21 pacientes con quistes sinoviales espinales operados mediante abordaje y descompresión MIS, se analizaron los signos, síntomas, tiempo quirúrgico, estadía hospitalaria, evolución y complicaciones. Se utilizó la escala visual analógica (EVA), para evaluar el dolor y la escala de Weiner y los criterios de Macnab modificados para medir la satisfacción posoperatoria del paciente. Resultados: Se trataron quirúrgicamente 21 pacientes (13 mujeres, 8 hombres), el 76,2% (n=16) de los pacientes de la serie no requirió artrodesis, el 23,8% (n=5) restante fue fusionado. Realizamos 13 (61,9%) hemilaminectomías contralaterales, 7 hemilaminectomías ipsilaterales (33,3%) y una laminectomía en el QS S1-S2 con técnica MIS. El seguimiento promedio fue de 26 meses, el tiempo de cirugía fue de 150,33 ± 63,31 min., con una estadía hospitalaria de 2,5 ± 1,78 días. La EVA disminuyó de 8,3 preoperatoria a 2,3 postoperatoria. Siguiendo la escala de Macnab; 16 pacientes refirieron resultados excelentes, 4 buenos y 1 regular, el 95,2% de los pacientes percibió que el procedimiento tuvo mucho/bastante éxito según la escala de Weiner. Conclusión: El abordaje mínimamente invasivo es un procedimiento seguro y eficaz para la resección completa de quistes sinoviales espinales. Proporciona resultados clínico-funcionales excelentes preservando músculos, ligamentos y facetas articulares.

Introduction: Spinal synovial cysts originate from the dilation and potential rupture of a facet joint's synovial sheath. Surgical resection is considered the treatment of choice in symptomatic patients; however, the use of minimally-invasive surgery (MIS) techniques could reduce any disruption of the facet joint involved, reducing the risk of postoperative instability. Objective: To present the treatment algorithm, surgical technique and results in a series of patients with spinal synovial cysts treated by MIS. Methods and Materials: We retrospectively evaluated 21 patients with spinal synovial cysts who underwent therapeutic MIS with decompression. Signs, symptoms, surgical time, hospital stay, course and complications were evaluated. A visual analog scale (VAS) was used to rate pain, while the Weiner scale and modified Macnab criteria were employed to measure patients' postoperative satisfaction. Results: Twenty-one patients were surgically treated with MIS, among whom 76.2% (n = 16) required no arthrodesis; the remaining 23.8% (n = 5) were fused. We performed 13 (61.9%) contralateral hemilaminectomies, seven ipsilateral hemilaminectomies (33.3%), and one laminectomy at S1-S2. The average follow-up was 26 months, surgical time 150.33 ± 63.31 minutes, and mean hospital stay 2.5 ± 1.8 days. The VAS pain rating decreased from 8.3 preoperatively to 2.3 postoperatively. Sixteen patients reported excellent results, four good and one fair. On the Macnab scale, all but one patient (1/21, 4.8%) perceived that the procedure had been very/quite successful. Conclusions: Minimally-invasive surgery is a safe and effective approach for the complete resection of spinal synovial cysts. It provides excellent clinical and functional results, by preserving muscles, ligaments and facet joints.

Una propuesta de clasificación del complejo arteria cerebelosa anteroinferior ­ arteria subarcuata basada en el desarrollo embriológico / A proposed classification of the anteroinferior cerebellar artery - subarcuate artery complex based on embryological development

Introducción: El recorrido del "loop subarcuato" de la arteria cerebelosa anteroinferior (ACAI) presenta múltiples variaciones que condicionan además su principal eferencia, la arteria subarcuata (ASA). El espectro de variaciones de este complejo ha sido referido en la literatura de forma inconexa y desorganizada. Material y Métodos: Se propuso una clasificación sistematizada de las variantes del complejo ACAI-ASA, basada en la interacción del hueso petroso y la ACAI en el periodo embrionario. La misma fue aplicada en una serie de pacientes estudiados mediante secuencia CISS (constructive interference in steady state) de resonancia magnética para categorizar las relaciones presentes en el ángulo pontocerebeloso (APC). Resultados: Se evaluaron 84 pacientes, incluyendo 161 APC. Todos los grados propuestos fueron identificados en la serie evaluada. Las proporciones encontradas en la gradación propuesta se mantuvieron en el rango de las publicaciones aisladas. Conclusión: La clasificación propuesta para el complejo ACAI-ASA permitió distinguir y objetivar consistentemente el espectro de variaciones.

Introduction: The pathway of the anterior inferior cerebellar artery's (AICA) "subarcuate loop" can vary extensively. This variability also affects its main branch, the subarcuate artery (SAA). The spectrum of variations observed with this combination of vessels is inadequately described in the literature. Methods and Materials: A systematized classification system for AICA-SAA complex variants was proposed, based upon interactions between the petrosal bone and the AICA in embryos. This classification scheme then was applied to a series of patients assessed by magnetic resonance CISS (constructive interference in steady state) sequences, to categorize the cerebellopontine angle (CPA) relationships. Results: Eighty-four patients were evaluated, encompassing 161 CPA. All the proposed grades were identified in the evaluated series. The proportions found with the proposed gradation system were within the range of previous publications. Conclusions: The AICA-SAA complex classification system that we proposed allowed for consistently distinguishing and objectifying the spectrum of variations seen in the subarcuate loop.