Augmented reality for intracranial meningioma resection: a mini-review.

Augmented reality (AR) integrates computer-generated content and real-world scenarios. Artificial intelligence's continuous development has allowed AR to be integrated into medicine. Neurosurgery has progressively introduced image-guided technologies. Integration of AR into the operating room has permitted a new perception of neurosurgical diseases, not only for neurosurgical planning, patient positioning, and incision design but also for intraoperative maneuvering and identification of critical neurovascular structures and tumor boundaries. Implementing AR, virtual reality, and mixed reality has introduced neurosurgeons into a new era of artificial interfaces. Meningiomas are the most frequent primary benign tumors commonly related to paramount neurovascular structures and bone landmarks. Integration of preoperative 3D reconstructions used for surgical planning into AR can now be inserted into the microsurgical field, injecting information into head-up displays and microscopes with integrated head-up displays, aiming to guide neurosurgeons intraoperatively to prevent potential injuries. This manuscript aims to provide a mini-review of the usage of AR for intracranial meningioma resection.

MarLe: Markerless estimation of head pose for navigated transcranial magnetic stimulation.

Navigated transcranial magnetic stimulation (nTMS) is a valuable tool for non-invasive brain stimulation. Currently, nTMS requires fixing of markers on the patient's head. Head marker displacements lead to changes in coil placement and brain stimulation inaccuracy. A markerless neuronavigation method is needed to increase the reliability of nTMS and simplify the nTMS protocol. In this study, we introduce and release MarLe, a Python markerless head tracker neuronavigation software for TMS. This novel software uses computer-vision techniques combined with low-cost cameras to estimate the head pose for neuronavigation. A coregistration algorithm, based on a closed-form solution, was designed to track the patient's head and the TMS coil referenced to the individual's brain image. We show that MarLe can estimate head pose based on real-time video processing. An intuitive pipeline was developed to connect the MarLe and nTMS neuronavigation software. MarLe achieved acceptable accuracy and stability in a mockup nTMS experiment. MarLe allows real-time tracking of the patient's head without any markers. The combination of face detection and a coregistration algorithm can overcome nTMS head marker displacement concerns. MarLe can improve reliability, simplify, and reduce the protocol time of brain intervention techniques such as nTMS.

Quantification of tumor induced motor cortical plasticity using navigated transcranial magnetic stimulation in patients with adult-type diffuse gliomas.

Introduction: The evaluation of brain plasticity can provide relevant information for the surgical planning of patients with brain tumors, especially when it comes to intrinsic lesions such as gliomas. Neuronavigated transcranial magnetic stimulation (nTMS) is a non-invasive tool capable of providing information about the functional map of the cerebral cortex. Although nTMS presents a good correlation with invasive intraoperative techniques, the measurement of plasticity still needs standardization. The present study evaluated objective and graphic parameters in the quantification and qualification of brain plasticity in adult patients with gliomas in the vicinity of the motor area. Methods: This is a prospective observational study that included 35 patients with a radiological diagnosis of glioma who underwent standard surgical treatment. nTMS was performed with a focus on the motor area of the upper limbs in both the affected and healthy cerebral hemispheres in all patients to obtain data on motor thresholds (MT) and graphical evaluation by three-dimensional reconstruction and mathematical analysis of parameters related to the location and displacement of the motor centers of gravity (ΔL), dispersion (SDpc) and variability (VCpc) of the points where there was a positive motor response. Data were compared according to the ratios between the hemispheres of each patient and stratified according to the final pathology diagnosis. Results: The final sample consisted of 14 patients with a radiological diagnosis of low-grade glioma (LGG), of which 11 were consistent with the final pathology diagnosis. The normalized interhemispheric ratios of ΔL, SDpc, VCpc, and MT were significantly relevant for the quantification of plasticity (p < 0.001). The graphic reconstruction allows the qualitative evaluation of this plasticity. Conclusion: The nTMS was able to quantitatively and qualitatively demonstrate the occurrence of brain plasticity induced by an intrinsic brain tumor. The graphic evaluation allowed the observation of useful characteristics for the operative planning, while the mathematical analysis made it possible to quantify the magnitude of the plasticity.

Radiation-induced cerebral cavernous malformation: is it just a childhood disease?

Cerebral cavernous malformations (CCM) are clusters of dilated sinusoidal channels, lined by a single layer of endothelium. Acquired form of these lesions was related to previous radiation-therapy, and might be related to its pathophysiology, because the vascular endothelial growth factor has higher expression in the immature brain of the child. Consequently, although it occurs mainly in the paediatric population, it can happen in adults. We report a case of radiation-induced CCM in an adult patient presenting with aggressive behaviour and cerebral haemorrhage.

Impacto pronóstico de la utilización intensiva de tecnologías complementarias intraoperatorias en gliomas cerebrales. Revisión de la literatura y presentación de 1 caso

Introducción: El manejo de los gliomas cerebrales durante las últimas cuatro décadas ha sufrido cambios relevantes en su estudio y tratamiento. Dentro de estos cambios se encuentra el desarrollo de técnicas imagenológicas, neurofisiológicas e histopatológicas. El presente trabajo intenta estimar el impacto que la utilización de dichas tecnologías ha tenido sobre el pronóstico de los pacientes. Material y método: Revisión exhaustiva de la literatura en medios digitales e impresos abarcando mayormente publicaciones y comunicaciones desde la década de 1980 hasta el presente. Se expone 1 caso sometido recientemente a cirugía por los autores en el que se utilizaron varias de estas herramientas, presentando el análisis que se llevó a cabo en la planificación quirúrgica. Resultados: La literatura muestra mejorías consistentes pero discretas en el pronóstico asociado al uso de tecnologías complementarias intraoperatorias en gliomas cerebrales, relacionadas a la ayuda que prestarían en la extensión de la resección tumoral y en la preservación funcional. Conclusiones: La utilización intensiva de las tecnologías complementarias descritas parece recomendable si la planificación quirúrgica anticipa beneficios fundados en cuanto a morbi-mortalidad para un paciente en particular. Se debe ser cauto en anticipar y generalizar el impacto pronóstico global que puedan tener, beneficio que es consistente en la literatura pero que en estos momentos parece modesto en términos generales en especial para gliomas de alto grado.

Introduction: The management of cerebral gliomas during the last four decades has undergone relevant changes in terms of its study and treatment. Among these changes is the development of imaging, neurophysiological and histopathological techniques. The present study attempts to estimate the impact that the use of these technologies has had on the prognosis of patients. Material and Method: Comprehensive review of the literature in digital and print media covering mostly publications and communications from the 1980s to the present. 1 case recently submitted to surgery by the authors in which several of these tools were used is exposed, presenting the analysis that was carried out in the surgical planning. Results: The literature shows consistent but discrete improvements in the prognosis associated with the use of intraoperative complementary technologies in cerebral gliomas, related to the help they would provide in the extension of tumor resection and functional preservation. Conclusions: The intensive use of the complementary technologies described seems advisable if surgical planning anticipates well-founded benefits in terms of morbidity and mortality for a particular patient. Caution should be exercised in anticipating and generalizing the global prognostic impact they may have, a benefit that is consistent in the literature but currently seems modest in general terms especially for high grade gliomas.

Application of neuronavigation system in intracranial meningioma surgery: a retrospective analysis of 75 cases.

OBJECTIVE: Neuronavigation is an extremely common and useful system in intracranial surgeries. It is used to determine the pre-operative incision, perform the most appropriate craniotomy, and provide intraoperative guidance. However, its use in meningioma surgery is controversial, and there is a dilemma whether it is necessary. This study was performed to determine the effect of neuronavigation in meningioma surgery. MATERIALS AND METHODS: Information related to pre-operative clinical evaluation and use of neuronavigation, neuroimaging, intraoperative tumor and surgical related information, and post-operative outcomes of 75 consecutive patients with meningiomas between January 2015 and 2020 were retrospectively collected. The values between groups were statistically compared. RESULTS: There were no significant differences in pre-operative patient and tumor characteristics between the groups. In cases using neuronavigation, the mean operative time, craniotomy size, and blood loss during tumor resection were significantly lower, and post-operative hospital stay was shorter in these patients (p < 0.05). However, there were no differences in post-operative complications and clinical outcomes. CONCLUSION: The use of neuronavigation in meningioma surgery reduces blood loss during surgery, reduces the surgical time, and shortens the post-operative hospital stay. Thus, we conclude that the neuronavigation system is useful in meningioma surgery.

OBJETIVO: La neuronavegación ha tomado su lugar como un sistema muy común y útil para cirugías intracraneales. Este estudio se realizó para revelar su efecto en la cirugía de meningioma. MATERIALES Y MÉTODOS: Se recopiló retrospectivamente información relacionada con la evaluación clínica preoperatoria, neuroimagen, información relacionada con el tumor y la cirugía intraoperatoria y los resultados posoperatorios de 75 casos consecutivos con meningiomas entre enero de 2015 y 2020. Los valores entre grupos se compararon estadísticamente. RESULTADOS: No hubo diferencias significativas en las características preoperatorias de los pacientes y las características del tumor entre los grupos. En los casos en los que se utilizó neuronavegación, el tiempo operatorio medio, el tamaño de la craneotomía y la pérdida de sangre durante la resección del tumor fueron significativamente menores, y la estancia hospitalaria postoperatoria fue más corta en estos pacientes (p < 0.05). Sin embargo, no hubo diferencia en las complicaciones postoperatorias y los resultados clínicos. CONCLUSIÓN: El uso del sistema de neuronavegación en la cirugía del meningioma reduce la pérdida de sangre durante la cirugía, acorta el tiempo quirúrgico y reduce la estancia hospitalaria postoperatoria. Creemos que el sistema de neuronavegación es útil en la cirugía del meningioma.

Forearm and Hand Muscles Exhibit High Coactivation and Overlapping of Cortical Motor Representations.

Most of the motor mapping procedures using navigated transcranial magnetic stimulation (nTMS) follow the conventional somatotopic organization of the primary motor cortex (M1) by assessing the representation of a particular target muscle, disregarding the possible coactivation of synergistic muscles. In turn, multiple reports describe a functional organization of the M1 with an overlapping among motor representations acting together to execute movements. In this context, the overlap degree among cortical representations of synergistic hand and forearm muscles remains an open question. This study aimed to evaluate the muscle coactivation and representation overlapping common to the grasping movement and its dependence on the stimulation parameters. The nTMS motor maps were obtained from one carpal muscle and two intrinsic hand muscles during rest. We quantified the overlapping motor maps in size (area and volume overlap degree) and topography (similarity and centroid Euclidean distance) parameters. We demonstrated that these muscle representations are highly overlapped and similar in shape. The overlap degrees involving the forearm muscle were significantly higher than only among the intrinsic hand muscles. Moreover, the stimulation intensity had a stronger effect on the size compared to the topography parameters. Our study contributes to a more detailed cortical motor representation towards a synergistic, functional arrangement of M1. Understanding the muscle group coactivation may provide more accurate motor maps when delineating the eloquent brain tissue during pre-surgical planning.

Non-invasive insular stimulation for peripheral neuropathic pain: Influence of target or symptom?

OBJECTIVES: The posterior-superior insula (PSI) has been shown to be a safe and potentially effective target for neuromodulation in peripheral neuropathic pain (PNP) in humans and animal models. However, it remains unknown whether there is a measurable responder profile to PSI stimulation. Two factors were hypothesized to influence the response of repetitive transcranial magnetic stimulation (rTMS) of the PSI: differences in rTMS target (discrete subregions of the PSI) or PNP phenotype. METHODS: This is a secondary analysis from a randomized, double-blind, sham-controlled, cross-over trial assessing PSI-rTMS in PNP (N = 31, 5 days rTMS) (10.1016/j.neucli.2021.06.003). Active PSI-rTMS true responders (>50% pain reduction from baseline after active but not after sham series of treatment) were compared with not true responders, to determine whether they differed with respect to 1) rTMS neuro-navigational target coordinates, and/or 2) specific neuropathic pain symptom inventory (NPSI) clusters (pinpointed pain, evoked pain, and deep pain) at baseline. RESULTS: Mean rTMS target coordinates did not differ between true (n = 45.1%) and not true responders (p = 0.436 for X, p = 0.120 for Y, and p = 0.116 for Z). The Euclidian distance between true and not true responders was 4.04 mm. When comparing differences in responders between NPSI clusters, no participant within the evoked pain cluster was a true responder (p = 0.024). CONCLUSION: Response to PSI-rTMS may depend on pain cluster subtype rather than on differences in targeting within the PSI.

Assisted dorso-lumbar instrumentation with O-arm neuronavegation and minimally invasive surgery: clinical-surgical outcome.

OBJECTIVE: To evaluate the clinical-surgical outcomes after dorso-lumbar instrumentation using O-arm assisted neuronavigation and minimally invasive surgery. METHOD: In this retrospective cohort, 104 patients who underwent dorso-lumbar instrumentation with the use of O-arm from September 2013 to May 2020 were studied. Variables investigated included: symptoms, number of screws, levels approached, bleeding, surgical time, hospital stay, complications and clinical improvement after the surgical procedure. RESULTS: The most frequent symptoms were: unilateral or bilateral radiculopathy of the pelvic extremities, paresthesia, mechanical low back pain and progressive decrease in strength. A total of 542 screws were placed, with the lumbar spine being the site with the highest prevalence. The average bleeding, surgical time, and hospital stay was: 50 ml, 160 minutes, and 24 hours, respectively. The most frequent complications were: Residual neuropathy, dura mater tear and surgical site infection. Clinical improvement at 24 hours, 4 weeks and 6 months was achieved in: 77.3%, 86.5% y 94.8% of the patients, respectively. CONCLUSIONS: Neuronavigation with the use of O-arm along with mini-open surgery approach results in good clinical-surgical outcomes in the correction of complex disorders of the dorso-lumbar spine.

OBJETIVO: Evaluar los resultados clínico-quirúrgicos de la instrumentación dorso-lumbar mediante neuronavegación asistida con O-arm y cirugía mínimamente invasiva. MÉTODO: En esta cohorte retrospectiva se estudiaron 104 pacientes sometidos a instrumentación dorso-lumbar con uso de O-arm, operados entre septiembre de 2013 y mayo de 2020. Las variables investigadas fueron sintomatología, cantidad de tornillos, niveles abordados, sangrado, tiempo quirúrgico, estancia hospitalaria, complicaciones y mejoría clínica posterior al procedimiento quirúrgico. RESULTADOS: La sintomatología más frecuente fue radiculopatía unilateral o bilateral de extremidades pélvicas, parestesias, lumbalgia mecánica y disminución progresiva de la fuerza. Se utilizaron en total 542 tornillos, siendo la columna lumbar el sitio de mayor prevalencia. Los promedios de sangrado, tiempo quirúrgico y estancia hospitalaria fueron de 50 ml, 160 minutos y 24 horas, respectivamente. Las complicaciones más frecuentes fueron neuropatía residual, rasgadura de la duramadre e infección del sitio quirúrgico. La mejoría clínica a las 24 horas, 4 semanas y 6 meses se logró en el 77.3%, el 86.5% y el 94.8% de los pacientes, respectivamente. CONCLUSIONES: La neuronavegación con O-arm junto con el abordaje quirúrgico de tipo mini-open permite buenos resultados clínico-quirúrgicos en la corrección de los trastornos complejos de la columna dorso-lumbar.

Posterior-superior insular deep transcranial magnetic stimulation alleviates peripheral neuropathic pain - A pilot double-blind, randomized cross-over study.

OBJECTIVES: Peripheral neuropathic pain (pNeP) is prevalent, and current treatments, including drugs and motor cortex repetitive transcranial magnetic stimulation (rTMS) leave a substantial proportion of patients with suboptimal pain relief. METHODS: We explored the intensity and short-term duration of the analgesic effects produced in pNeP patients by 5 days of neuronavigated deep rTMS targeting the posterior superior insula (PSI) with a double-cone coil in a sham-controlled randomized cross-over trial. RESULTS: Thirty-one pNeP patients received induction series of five active or sham consecutive sessions of daily deep-rTMS to the PSI in a randomized sequence, with a washout period of at least 21 days between series. The primary outcome [number of responders (>50% pain intensity reduction from baseline in a numerical rating scale ranging from 0 to 10)] was significantly higher after real (58.1%) compared to sham (19.4%) stimulation (p = 0.002). The number needed to treat was 2.6, and the effect size was 0.97 [95% CI (0.6; 1.3)]. One week after the 5th stimulation day, pain scores were no longer different between groups, and no difference in neuropathic pain characteristics and interference with daily living were present. No major side effects occurred, and milder adverse events (i.e., short-lived headaches after stimulation) were reported in both groups. Blinding was effective, and analgesic effects were not affected by sequence of the stimulation series (active-first or sham-first), age, sex or pain duration of participants. DISCUSSION: PSI deep-rTMS was safe in refractory pNeP and was able to provide significant pain intensity reduction after a five-day induction series of treatments. Post-hoc assessment of neuronavigation targeting confirmed deep-rTMS was delivered within the boundaries of the PSI in all participants. CONCLUSION: PSI deep-rTMS provided significant pain relief during 5-day induction sessions compared to sham stimulation.

Abordaje interhemisférico contralateral. Nota técnica / Contralateral interhemispheric approach. Technical note

El abordaje interhemisférico contralateral es una variante del abordaje interhemisférico transcalloso que permite optimizar el acceso a lesiones ubicadas en los ventrículos laterales o en sus paredes. La planificación del ángulo de entrada mediante neuronavegador nos permitió el manejo de un Cavernoma ubicado sobre el núcleo caudado e inmediato a la cápsula interna sin realizar callosotomía convencional ni comprometer las estructuras sensibles adyacentes.

Contralateral interhemispheric approach is a variant of the well-know interhemispheric transcallosal approach that allows to optimize the lateral wall ventricle lesions management. Neuronavigation planning allowed us to deal with a caudate nucleus cavernoma contiguous to internal capsule without conventional callosotomy and additional damage neither.

Integration of Spatial Information Increases Reproducibility in Functional Near-Infrared Spectroscopy.

As functional near-infrared spectroscopy (fNIRS) is developed as a neuroimaging technique and becomes an option to study a variety of populations and tasks, the reproducibility of the fNIRS signal is still subject of debate. By performing test-retest protocols over different functional tasks, several studies agree that the fNIRS signal is reproducible over group analysis, but the inter-subject and within-subject reproducibility is poor. The high variability at the first statistical level is often attributed to global systemic physiology. In the present work, we revisited the reproducibility of the fNIRS signal during a finger-tapping task across multiple sessions on the same and different days. We expanded on previous studies by hypothesizing that the lack of spatial information of the optodes contributes to the low reproducibility in fNIRS, and we incorporated a real-time neuronavigation protocol to provide accurate cortical localization of the optodes. Our proposed approach was validated in 10 healthy volunteers, and our results suggest that the addition of neuronavigation can increase the within-subject reproducibility of the fNIRS data, particularly in the region of interest. Unlike traditional approaches to positioning the optodes, in which low intra-subject reproducibility has been found, we were able to obtain consistent and robust activation of the contralateral primary motor cortex at the intra-subject level using a neuronavigation protocol. Overall, our findings support the hypothesis that at least part of the variability in fNIRS cannot be only attributed to global systemic physiology. The use of neuronavigation to guide probe positioning, as proposed in this work, has impacts to longitudinal protocols performed with fNIRS.

Awake surgery with cortical-subcortical mapping in diffuse gliomas adjacent to central lobe. Report of two cases and literature review.

INTRODUCTION: Diffuse gliomas are brain neoplasms with an infiltrative growing pattern to cortical and subcortical structures, frequently adjacent to eloquent areas; direct cortical and subcortical stimulation in awake craniotomy is a useful tool to achieve a gross total resection with the least neurological deficit. PRESENTATION OF CASES: A 24 years old male presented with tonic-clonic seizures. The magnetic resonance imaging (MRI) showed a left parietal glioma. Awake craniotomy was performed using neuronavigation system and brain mapping with cortical and subcortical stimulation. Functional areas were found at the rostral margin of the tumor; however, the rest of the tumor was almost totally resected. Patient was discharged without neurological deficit. A 29 years old male presented in two occasions generalized tonic-clonic seizures, with right hemiparesis. The MRI showed a left parietal glioma. Awake craniotomy was performed using neuronavigation system and brain mapping with cortical and subcortical stimulation, achieving a gross total resection. Patient was discharged without neurological deficit. CONCLUSIONS: Awake craniotomy with brain mapping by cortical and subcortical stimulation and neuronavigation, are the best assets to treat diffuse gliomas and achieve a gross total resection, ensuring the major disease-free interval and preserving the function of eloquent areas.

INTRODUCCIÓN: Los gliomas difusos son neoplasias cerebrales con un patrón de crecimiento infiltrativo, frecuentemente adyacentes a áreas elocuentes. El mapeo cerebral con estimulación cortico-subcortical con el paciente despierto es una herramienta útil para lograr la mayor resección con el menor déficit posoperatorio. PRESENTACIÓN DE CASOS: Varón de 24 años con crisis tónico-clónicas. La resonancia magnética (RM) mostró un glioma parietal izquierdo. Se realizó cirugía con el paciente despierto y mapeo cerebral por estimulación cortical y subcortical directa. Se obtuvo una resección casi total, ya que se encontraron áreas fucionales en el borde rostral del tumor. El paciente egresó sin déficit neurológico. Varón de 29 años que presenta crisis tónico-clónicas generalizadas, acompañadas de hemiparesia derecha. La RM reportó un glioma parietal izquierdo. Se realizó cirugía con el paciente despierto y mapeo cerebral por estimulación cortical y subcortical directa. Se logró una resección total y el paciente egresó sin déficit. CONCLUSIONES: La cirugía con el paciente despierto con mapeo por estimulación directa y neuronavegación es la mejor opción en el tratamiento de los gliomas difusos, para lograr una resección máxima tumoral asegurando un mayor tiempo libre de enfermedad y la conservación de la función de áreas elocuentes.

Neuronavigation as a minimally invasive tool in the treatment of intracranial gunshot injuries.

Gunshot injury is the most common cause of penetrating brain injury. The in-hospital mortality for civilians with penetrating craniocerebral injury is 52-95%. There are many surgical techniques suitable for the treatment of survivors. We report a surgical technique consisting of neuronavigation guidance for wound treatment with smaller incisions and craniotomies, followed by bullet removal if feasible. We report case of a 15 year old male patient who sustained an accidental firearm injury to the occipital region, submitted to surgical treatment that consisted in a minimally invasive approach guided by neuronavigation. Immediate neurological examination showed inferior homonymous quadrantanopsia alone as a clinical finding. Patient was discharged after one week, and no complications arised in follow-up. We conclude that using neuronavigation as a tool was effective in the reported case and that minimally invasive neurosurgical techniques may be a safe and efficient option for the treatment of traumatic brain injuries caused by firearm projectiles.

Accuracy of pedicle screw insertion: a comparison between fluoroscopic guidance and navigation techniques / Acurácia da inserção de parafusos pediculares comparando fluoroscopia e navegação

ABSTRACT Objectives: To compare the accuracy of insertion of pedicle screws into the thoracic spine using fluoroscopic guidance or computer-assisted navigation techniques. Methods: Eight cadaveric thoracic spines were divided into two groups: the fluoroscopy group, in which pedicle screws were inserted with the guidance of a C-arm device, and the navigation group, in which insertion of the screws was monitored using computer-assisted navigation equipment. All procedures were performed by the same spinal surgeon. The rate of pedicle breach was compared between the two groups. Results: There was one intra-canal perforation in each group. Both perforations were medial in direction, and the breaches were 2 to 4 mm deep. There were no statistically significant differences in breach rate between the two groups. Conclusions: The accuracy of insertion of pedicle screws in the thoracic spine using computer-assisted navigation is equivalent to that achieved using fluoroscopic guidance. Computer-assisted navigation improves the safety of the surgical team during the procedure due to the absence of exposure to radiation. Therefore, there is a need for future randomized controlled trials to be conducted in the clinical setting to evaluate other outcomes, including duration of surgery and blood loss during the procedure. Level of evidence IV.

RESUMO Objetivos: Comparar a acurácia da inserção de parafusos pediculares na coluna torácica, utilizando fluoroscopia ou técnicas de navegação assistidas por computador. Métodos: Estudo experimental com cadáveres. Oito colunas torácicas proveniente de cadáveres foram divididas em dois grupos: no grupo Fluoroscopia os parafusos pediculares foram inseridos com orientação de um aparelho tipo C-arm, e no grupo Navegação o monitoramento foi feito com um equipamento de assistência por computador. Todos os procedimentos foram feitos pelo mesmo cirurgião de coluna. A taxa de violação do canal foi comparada entre os grupos. Resultados: Houve uma perfuração de canal em cada grupo, ambas mediais, com 2-4 mm de profundidade. Não houve diferenças significativas entre os dois grupos em termos de taxa de perfuração do canal. Conclusão: A acurácia na inserção de parafusos pediculares na coluna torácica é igual comparando-se a navegação assistida por computador e o método de monitoramento por fluoroscopia. Como a segurança do procedimento para a equipe cirúrgica é maior com o método da navegação, devido à ausência de exposição à radiação, há necessidade de se realizarem estudos clínicos controlados no ambiente clínico, que avaliem outros desfechos, como o tempo de cirurgia e de sangramento. Nível de evidência IV.

Neuronavegación En La Planificacion Prequirúrgica Y En La Cirugia De La Epilepsia Refractaria / Neuronavigation In Pre Surgical Planning And Surgery Of Refractory Epilepsy

RESUMEN Introducción: La epilepsia es una de las patologías neurológicas crónicas más frecuentes, con una incidencia de 50/100.000/año y una prevalencia entre 0,5 y 2% a nivel mundial. Un tercio de estos pacientes son resistentes al tratamiento con fármacos antiepilépticos, lo que se conoce como epilepsia refractaria. La mayoría de estos pacientes sufren de epilepsias focales secundarias a lesiones epileptogénicas evidenciadas cada vez más frecuentemente en correlación directa con las nuevas técnicas de neuroimagen cerebral. La cirugía de la epilepsia es el único tratamiento que podría curar la epilepsia de los pacientes con epilepsia refractaria. El objetivo de la cirugía de la epilepsia es remover la zona epileptogénica con preservación de las áreas elocuentes, y aquí la experiencia quirúrgica y la tecnología de neuroimagen juegan un papel capital. Objetivos: Demostrar la utilidad de la neuronavegación en la planificación prequirúrgica y en la cirugía de la epilepsia refractaria. Método: Estudio descriptivo transversal y analítico, en base a 47 cirugías realizadas (12 resectivas, 32 paliativas y 3 diagnósticas) en pacientes con epilepsia refractaria y edad media de 9,93 años (SD 4,1). En 27 pacientes (57.44%) se utilizó el neuronavegador. En el grupo de pacientes operados con neuronavegación disminuyó el tiempo quirúrgico en 47.17 minutos (p = 0,022), la cantidad de hemorragia en 111.41 mililitros (p = 0,011) y los días de hospitalización en 6.68 días (p = 0,005), en comparación con el grupo intervenido sin neuronavegación. Las complicaciones en el grupo con neuronavegación fueron del 29,63% en comparación con 65% en el grupo intervenido sin neuronavegación (p = 0,034). Conclusiones: En nuestra serie, el uso del neuronavegador en la planificación y desarrollo de la cirugía tuvo un impacto significativo al reducir la cantidad de hemorragia perdida, el tiempo quirúrgico, los días de hospitalización, y las complicaciones postquirúrgicas.

Abstract Introduction: Epilepsy is one of the more frequent neurologic disorders, with an incidence of 50/100,000/year and prevalence between 0.5 and 2% worldwide. A third of these patients suffer focal epilepsy due to epileptogenic lesions evident by Neuroimaging new techniques. Epilepsy surgery is the only treatment that can cure refractory epilepsy. Its goal is to remove the epileptogenic lesion with preservation of eloquent areas, and in this case both surgical experience and neuroimaging technology play a pivotal role. Objective: To demonstrate utility of neuronavigation in presurgical planning and surgery of refractory epilepsy. Method: Descriptive, cross sectional and analytic study of 47 performed surgeries (12 resective, 12 palliative and 3 diagnostic) in patients with refractory epilepsy with an average age of 9.93 years (SD 4.1). In 27 patients (57.44%) neuronavigation was used. In patients operated with assistance of neuronavigation, surgical time diminished in 47.17 minutes (p=0.022), hemorrhage in 111.41 ml (p=0.011) and days of hospitalization in 6.68 days (p=0.005) comparing with group without neuronavigation. Complications in the group with neuronavigation were 29.63% compared with 65% in the group without it. (P=0,034). Conclusions: In this study, using neuronavigation in planning and performing surgery in reducing the amount of blood loss, surgical time, days of hospitalization and post surgical complications.

ACCURACY OF PEDICLE SCREW INSERTION: A COMPARISON BETWEEN FLUOROSCOPIC GUIDANCE AND NAVIGATION TECHNIQUES.

OBJECTIVES: To compare the accuracy of insertion of pedicle screws into the thoracic spine using fluoroscopic guidance or computer-assisted navigation techniques. METHODS: Eight cadaveric thoracic spines were divided into two groups: the fluoroscopy group, in which pedicle screws were inserted with the guidance of a C-arm device, and the navigation group, in which insertion of the screws was monitored using computer-assisted navigation equipment. All procedures were performed by the same spinal surgeon. The rate of pedicle breach was compared between the two groups. RESULTS: There was one intra-canal perforation in each group. Both perforations were medial in direction, and the breaches were 2 to 4 mm deep. There were no statistically significant differences in breach rate between the two groups. CONCLUSIONS: The accuracy of insertion of pedicle screws in the thoracic spine using computer-assisted navigation is equivalent to that achieved using fluoroscopic guidance. Computer-assisted navigation improves the safety of the surgical team during the procedure due to the absence of exposure to radiation. Therefore, there is a need for future randomized controlled trials to be conducted in the clinical setting to evaluate other outcomes, including duration of surgery and blood loss during the procedure. Level of evidence IV.

OBJETIVOS: Comparar a acurácia da inserção de parafusos pediculares na coluna torácica, utilizando fluoroscopia ou técnicas de navegação assistidas por computador. MÉTODOS: Estudo experimental com cadáveres. Oito colunas torácicas proveniente de cadáveres foram divididas em dois grupos: no grupo Fluoroscopia os parafusos pediculares foram inseridos com orientação de um aparelho tipo C-arm, e no grupo Navegação o monitoramento foi feito com um equipamento de assistência por computador. Todos os procedimentos foram feitos pelo mesmo cirurgião de coluna. A taxa de violação do canal foi comparada entre os grupos. RESULTADOS: Houve uma perfuração de canal em cada grupo, ambas mediais, com 2-4 mm de profundidade. Não houve diferenças significativas entre os dois grupos em termos de taxa de perfuração do canal. CONCLUSÃO: A acurácia na inserção de parafusos pediculares na coluna torácica é igual comparando-se a navegação assistida por computador e o método de monitoramento por fluoroscopia. Como a segurança do procedimento para a equipe cirúrgica é maior com o método da navegação, devido à ausência de exposição à radiação, há necessidade de se realizarem estudos clínicos controlados no ambiente clínico, que avaliem outros desfechos, como o tempo de cirurgia e de sangramento. Nível de evidência IV.

Clinical Application of an Open-Source 3D Volume Rendering Software to Neurosurgical Approaches.

BACKGROUND: Preoperative recognition of the anatomic individualities of each patient can help to achieve more precise and less invasive approaches. It also may help to anticipate potential complications and intraoperative difficulties. Here we describe the use, accuracy, and precision of a free tool for planning microsurgical approaches using 3-dimensional (3D) reconstructions from magnetic resonance imaging (MRI). METHODS: We used the 3D volume rendering tool of a free open-source software program for 3D reconstruction of images of surgical sites obtained by MRI volumetric acquisition. We recorded anatomic reference points, such as the sulcus and gyrus, and vascularization patterns for intraoperative localization of lesions. Lesion locations were confirmed during surgery by intraoperative ultrasound and/or electrocorticography and later by postoperative MRI. RESULTS: Between August 2015 and September 2016, a total of 23 surgeries were performed using this technique for 9 low-grade gliomas, 7 high-grade gliomas, 4 cortical dysplasias, and 3 arteriovenous malformations. The technique helped delineate lesions with an overall accuracy of 2.6 ± 1.0 mm. 3D reconstructions were successfully performed in all patients, and images showed sulcus, gyrus, and venous patterns corresponding to the intraoperative images. All lesion areas were confirmed both intraoperatively and at the postoperative evaluation. CONCLUSIONS: With the technique described herein, it was possible to successfully perform 3D reconstruction of the cortical surface. This reconstruction tool may serve as an adjunct to neuronavigation systems or may be used alone when such a system is unavailable.

Neuronavegación en exéresis de linfangioma orbitario / Neuronavigation in exeresis of orbital lymphangioma

El linfangioma es un tumor benigno raro y predominante en la infancia, debido a su crecimiento puede comprometer al órgano donde se desarrolla, se han propuesto varias opciones de trata-miento, sin embargo, la cirugía continúa siendo la primera opción. La neuronavegación permite realizar exéresis con gran precisión y de utilidad en cirugía ocular, por lo que disminuye el riesgo de secuelas después de una exéresis de linfangioma orbitario.

Lymphangioma is a benign tumor predominantly in childhood, due to growth that can compromise the organ where it grows. Several treatment options, have been proposed however,surgery remains the first choice. Neuronavigation allows successful excision and use in eye surgery,which decreases the risk of sequels following excision of orbital lymphangioma.