Meningiomas petroclivais são tumores da base do crânio desafiadores para ressecção cirúrgica devido a sua localização profunda e relação com estruturas neurovasculares vitais. Geralmente são lesões benignas, mas podem envolver ou infiltrar o osso da base do crânio, dura-máter, tronco encefálico e todas as estruturas neurovasculares desta região, tornando a remoção total difícil sem causar déficits neurológicos. O objetivo deste estudo é revisar uma série de casos de meningiomas petroclivais tratados cirurgicamente em centro de referência de base de crânio, considerando os fatores determinantes para a escolha da abordagem. A casuística foi analisada com coleta retrospectiva dos dados. Devido à dificuldade de acesso, essas lesões geralmente requerem diferentes abordagens cirúrgicas e apresentam dificuldades cirúrgicas distintas. Embora as abordagens fronto-órbito-zigomática, petrosas, incluindo présigmoide retrolabiríntica, translabiríntica e petrosectomia total, e a retrossigmoide sejam as mais utilizadas para ressecção destes tumores, não foi realizado até o presente momento estudo comparativo que determine qual abordagem apresenta maior grau de ressecção cirúrgica associada a menor taxa de morbidade. / Petroclival meningiomas are challenging skull base tumors for surgical resection because of its deep location and their relationship to vital neurovascular structures. They are usually benign, but may involve or infiltrate the bone of the skull base, dura, brain stem and all neurovascular structures in this region, making it difficult to completely remove without causing neurological deficits. The aim of this study is to review a surgical series of petroclival meningioma treated in a referral center for skull base tumors, considering the determining factors to the choice of approach. The casuistry was analyzed with retrospective data collection. Due to difficult access, these injuries usually require different surgical approaches and have different surgical difficulties. Although the fronto-orbital-zygomatic, petrous, including retrolabyrinthine pre-sigmoid, translabyrinthine and total petrosectomy, and retrosigmoid are frequently used for resection of these tumors, it has not been realized to date comparative study to determine which approach has greater degree of surgical resection associated with lower morbidity rate.

abstract: During the past five decades neurosurgery has made great progress, with marked improvements in patient outcomes. These noticeable improvements of morbidity and mortality can be attributed to the advances in innovative technologies used in neurosurgery. Cutting-edge technologies are essential in most neurosurgical procedures, and there is no doubt that neurosurgery has become heavily technology dependent. With the introduction of any new modalities, surgeons must adapt, train, and become thoroughly familiar with the capabilities and the extent of application of these new innovations. Within the past decade, endoscopy has become more widely used in neurosurgery, and this newly adopted technology is being recognized as the new minimally invasive future of neurosurgery. The use of endoscopy has allowed neurosurgeons to overcome common challenges, such as limited illumination and visualization in a very narrow surgical corridor; however, it introduces other challenges, such as instrument "sword fighting" and limited maneuverability (surgical freedom). The newly introduced concept of surgical freedom is very essential in surgical planning and approach selection and can play a role in determining outcome of the procedure, since limited surgical freedom can cause fatigue or limit the extent of lesion resection. In my thesis, we develop a consistent objective methodology to quantify and evaluate surgical freedom, which has been previously evaluated subjectively, and apply this model to the analysis of various endoscopic techniques. This model is crucial for evaluating different endoscopic surgical approaches before they are applied in a clinical setting, for identifying surgical maneuvers that can improve surgical freedom, and for developing endoscopic training simulators that accurately model the surgical freedom of various approaches. Quantifying the extent of endoscopic surgical freedom will also provide developers with valuable data that will help them design improved endoscopes and endoscopic instrumentation. / Dissertation/Thesis / Ph.D. Neuroscience 2014

Orientador: Yvens Barbosa Fernandes / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-16T16:15:22Z (GMT). No. of bitstreams: 1 Servelhere_KatianeRaisa_M.pdf: 843654 bytes, checksum: 95e8b6ec385ef7e99384966f0c1a4680 (MD5) Previous issue date: 2010 / Resumo: A base do crânio é uma região que pode ser afetada por vários tipos localizados de neoplasias. Os tumores nesta região podem ser benignos ou malignos e se localizar nas fossas anterior, média ou posterior do crânio. Embora sejam relativamente raros, são lesões potencialmente graves, em virtude das características anatômicas complexas da região e do risco inerente de um procedimento cirúrgico. A qualidade de vida nesses pacientes pode ser prejudicada não só pelo comprometimento neurológico, mas também por problemas psicossociais, como diminuição da autoconfiança e auto-estima, modificação nas atividades cotidianas, dependência, estigma e discriminação, dificuldade de interação social e desemprego. A escala SF-36 é um dos instrumentos mais utilizados para mensurar a qualidade de vida e foi aplicada em 38 indivíduos submetidos a tratamento cirúrgico de lesões expansivas benignas da base do crânio, entre seis meses e um ano após o procedimento operatório. Deste modo, o objetivo deste estudo foi avaliar a qualidade de vida em pacientes operados de tumor da base do crânio através da escala de qualidade de vida SF-36. Os 38 pacientes foram operados no Hospital das Clínicas da Universidade Estadual de Campinas. Os resultados revelaram que a idade média dos pacientes era de 49,7 anos, variando de 20 a 74 anos, prevalecendo o sexo feminino com 65,8% da amostra (25 mulheres). Para a amostra total, todos os domínios apresentaram pontuação acima de 50. Em seis dos oito domínios, bem como componentes físico e mental, as mulheres pontuaram melhor do que os homens, porém o único domínio que tendeu a significância foi LAF. Quando comparada idade, observamos que no grupo total pacientes com idade superior a 50 anos pontuaram melhor. Quando comparado sexo com idade, as mulheres até 50 anos tiveram melhor pontuação; em contrapartida, homens com idade superior a 50 anos pontuaram melhor do que as mulheres. Embora haja diferenças, estas não foram estatisticamente significantes. Desta forma, concluímos que não foi possível comprovar melhora significativa social, física, psicológica e funcional quando os grupos foram comparados. / Abstract: The skull base is a region that may be affected by different types of localized tumors. Tumors in this region can be benign or malignant and are located in the anterior fossa, middle or posterior fossa. Although relatively rare, they are potentially harmful, because of the complex anatomic features of these regions and the inherent risk of a surgical procedure. The quality of life of patients can be hampered not only by neurological impairment, but also by psychosocial problems such as decreased self-confidence and self-esteem, change in daily activities, dependency, stigma and discrimination, difficulty in social interaction and unemployment. The SF-36 scale is one of the most widely used scale to measure quality of life and it was applied in 38 individuals who underwent surgery to treat benign skull base tumors, between six months and one year after the surgical procedure. The purpose of this study was to evaluate the quality of life in patients undergoing tumor of the skull base resection by applying SF-36. The 38 patients were operated on the Hospital das Clínicas da Universidade Estadual de Campinas. The results revealed that the average age of patients was 49.7 years, ranging from 20 to 74 year-old. Female prevalence was 65.8% of the sample (25 women). All patients showed a total score above 50. In six of the eight domains as well as physical and mental components, women scored better than men, but the only area that tended to significance was LAF. When compared to age, we observed that overall patients aged over 50 years scored better. When compared with age and sex, women until 50 years had a better score. On the other hand, men aged over 50 years scored better than women. Although there are slight differences, these were not statistically significant. We concluded that no significant improvement occurred in social, physical, psychological and functional outcome when age and sex were compared. / Mestrado / Ciencias Biomedicas / Mestre em Ciências Médicas

Orientador: Carlos Takahiro Chone / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-18T05:37:15Z (GMT). No. of bitstreams: 1 Sampaio_MarceloHamilton_D.pdf: 2255683 bytes, checksum: 64e5351d5d01506d6f0127054945558d (MD5) Previous issue date: 2010 / Resumo: Introdução: A Fístula liquórica da base anterior do crânio é a comunicação anormal entre a cavidade nasal ou os seios paranasais e o espaço subaracnóideo. Sua presença aumenta a incidência de complicações, como principalmente a meningite, com riscos de morte ou de seqüelas, como surdez, déficits motores e cognitivos. O diagnóstico precoce e correto da fistula liquórica é importante para que o tratamento cirúrgico seja realizado o mais brevemente possível. A detecção de liquor em fluidos nasais é realizada como método diagnóstico da fistula liquórica e baseia-se na pesquisa de proteínas específicas do líquor em secreções nasais, e pode ser feita através da pesquisa da ß2-transferrina, um teste imunológico caro e pouco disponível no Brasil. Recentemente foi descrita a quantificação nefelométrica da proteína ß-trace para a identificação da fístula liquórica, uma proteína específica do cérebro e presente em altas concentrações no líquor. Os dados da literatura sugerem a mesma sensibilidade e especificidade que a ß2-transferrina. Grande parte dos laboratórios de análises clínicas possuem o equipamento nefelômetro para a quantificação da proteína ß-trace. Objetivo: Determinar o valor de corte para a medida da concentração da proteína ß-trace e a previsibilidade do teste em confirmar ou não a presença de fístula liquórica em secreções nasais no dois lados da cavidade nasal. Métodos: Secreção nasal foi coletada de pacientes com suspeita de fístula liquórica e de voluntários saudáveis. Amostras de liquor puro foram usadas. O teste nefelométrico foi utilizado para determinar a concentração da proteína ß-trace nas amostras. Os achados durante a cirurgia endonasal endoscópica foram o padrão ouro para o diagnóstico da fístula liquórica. RESULTADOS: Foi encontrado um valor de corte entre 0,244 e 0,496 mg/L. Os valores preditivos positivo e negativo foram de 100%. As médias de concentração de proteína ß- trace no lado nasal acometido foram maiores que as médias de concentração de proteína ß- trace no lado nasal não acometido, com diferença estatisticamente significante. Conclusão: Concentrações de proteína ß-trace acima de 0,496 mg/L são altamente sugestivas da presença de liquor nas secreções nasais examinadas. O teste nefelométrico da proteína ß-trace pode prever o lado nasal acometido pela fístula liquórica. O teste da proteína ß-trace é uma boa / Abstract: Background: Cerebrospinal fluid (CSF) leak of the anterior skull base is an abnormal communication between the subarachnoid space and the nasal cavity or the paranasal sinus. Its presence increases the incidence of complications, as meningitis, with risk of sequels. The early and correct diagnosis of the CSF leaks is important in order to perform surgical treatment as soon as possible. The CSF detection in nasal fluids is performed as a diagnostic method of CSF leak, based on the detection of brain-specific proteins in nasal fluids, and could be made through the ß2-transferrin test, an expensive immunological test, not available to the majority of the Brazilian hospitals. Recently, the detection of ß-trace protein for identification of CSF leaks has been described. Literature data suggests the same sensibility and specificity to the ß2-transferrin, because ß-trace protein is also a specific brain protein and it is present in CSF in high concentrations. The majority of Brazilian laboratories of clinical analysis have the nephelometric equipment for ß-trace protein detection. Objective: To determine threshold values for ß-trace protein concentrations in nasal cavity secretions as a predictor of CFS leak. Methods: Nasal secretions were collected from patients with suspicion of CSF leak and from healthy volunteers. Pure CSF samples were used. A nephelometric assay was used to determine the ß-trace protein concentration in samples. The gold standard diagnostic method was the surgery. Results: Values between 0.244 and 0.496 mg/L were determined for the cut-off. Positive predictive value and negative predictive value were 100%. The concentration in the affected side were higher than the contralateral side. Conclusion: ß-trace concentrations above 0.496 mg/L are highly suggestive of the presence of cerebrospinal fluid in examined nasal secretion. ß-trace protein nephelometric test can predict the side of the CSF leak. The ß-trace protein test is a good alternative for the detection of CSF leak in Brazilian hospitals / Doutorado / Otorrinolaringologia / Doutor em Ciências Médicas

Introdução: O uso do retalho nasosseptal (NS) para a reconstrução endoscópica da base do crânio foi fator fundamental para o avanço dos acessos endonasais expandidos. Objetivos: Aferir as dimensões do retalho NS e do defeito da base do crânio anterior (BCA) após ressecção craniofacial endoscópica e verificar a suficiência do retalho para cobrir o defeito. Estudar a anatomia da artéria septal (AS) e sua relação com o óstio do seio esfenoide. Métodos: Estudo anatômico do retalho NS em 14 cadáveres. Após ressecção craniofacial endoscópica, foi verificado a suficiência do retalho em cobrir o defeito na BCA. A AS foi dissecada e estuda quanto ao número de ramos presentes no pedículo e sua distância em relação ao óstio do seio esfenoide. Estudo radiológico com tomografia computadorizada de 30 pacientes para a comparação entre medidas do retalho NS e as do defeito na BCA. Resultados: O retalho foi suficiente para cobrir o defeito na BCA nas 14 dissecções. Em 71,4% dos casos, dois ramos da AS foram encontrados no pedículo. A distância média entre o primeiro ou único ramo ao óstio do esfenoide foi de 9,3mm. No estudo radiológico, a média da área reconstrutora do retalho (17,12cm2) foi constantemente maior que a média da área do defeito (8,64cm2) (p<0,001). A diferença entre o comprimento superior do retalho e a distância anteroposterior do defeito foi menor ou igual a 5mm em 26,7% dos casos. A comparação entre a largura anterior do retalho e a distância interorbitária anterior revelou que em 33% dos casos a diferença foi 5mm. A incorporação da mucosa do assoalho da fossa nasal ao retalho aumentou essa diferença em mais 10mm em todos os casos. Conclusões: As dimensões do retalho NS são suficientes para cobrir o defeito na BCA. A extremidade anterior do comprimento anteroposterior do defeito apresenta maior risco de falha de cobertura. A incorporação da mucosa do assoalho da fossa nasal ao retalho é importante para diminuir o risco de falha de cobertura anterior na largura do defeito. Em geral, é mais comum a presença de dois ramos da AS no pedículo / Introduction: Use of the nasoseptal (NS) flap for endoscopic skull base reconstruction was an essential contribution for the evolution of the expanded endonasal approaches. Objectives: Measure the dimensions of the NS flap and the anterior skull base (ASB) defect after endoscopic craniofacial resection and verify if the flap is sufficient to cover the defect. Study the anatomy of the septal artery (SA) and its relation with the sphenoid ostium. Methods: Anatomical study of the NS flap in 14 cadavers. After endoscopic craniofacial resection, the sufficiency of the flap to cover the ASB defect was assessed. The SA was dissected and studied regarding the number of branches in the pedicle and the distance between the artery and the sphenoid ostium. Radiological study using CT scans of 30 patients for comparison among measurements of the NS flap and the ASB defect. Results: The flap was sufficient to cover the ASB in all 14 dissections. In 71.4% of the cases, 2 branches of the SA were found in the pedicle. The distance between the first or the only single branch of the SA to the sphenoid ostium was 9.3mm. In the radiological study, the reconstruction area of the flap (17.12cm2) was constantly larger than the defect area (8.64cm2) (p<0.001). The difference between the superior length of the flap and the anterior-posterior distance of the defect was 5mm in 26.7% of the cases. Comparison between the flap anterior width and the defect anterior width revealed that in 33% the difference was 5mm. The incorporation of the nasal floor mucosa to the flap increased that difference in more than 10mm in all cases. Conclusions: The dimensions of the NS flap are sufficient to cover completely the ASB defect. The anterior edge of the anterior-posterior length of the defect presents increased risk for failure in coverage. The additional width provided by the incorporation of the nasal floor mucosa to the flap is important to decrease the risk of failure in coverage of the anterior defect width. In general, it is more common to find 2 branches of the SA in the pedicle

We present surgical clipping of a giant middle cerebral artery aneurysm. The patient is a 64-year-old woman who suffered subarachnoid hemorrhage in 2005. She was treated with coiling of the aneurysm at an outside institution. She presented to our clinic with headaches and was found on angiography to have giant recurrence of the aneurysm. To allow adequate exposure for clipping, we performed the surgery through a cranio-orbito-zygomatic (COZ) skull base approach, which is demonstrated. The surgery was performed in an operating room/angiography hybrid suite allowing for high quality intraoperative angiography. The technique and room flow are also demonstrated.

La morphométrie géométrique permet la visualisation dynamique 3D de la base du crâne et une prévision de leurs variations liées à la croissance. Le but de ce travail est de proposer des méthodes fiables et précises pour estimer l’âge fœtal et caractériser un stade de développement par sa conformation osseuse. Les os temporal, occipital et sphénoïde de 33 fœtus âgés de la 19ème à la 24ème semaine d’aménorrhée (S.A.) ont été reconstruits en 3D et 44 landmarks ont été positionnés. L’étude par morphométrie géométrique a permis de déterminer les maxima de variation morphologique, ainsi que d’étudier les trajectoires ontogénétiques. Les formules établies permettent l’estimation de l’âge à ±2,44 semaines. Les points de césure classiquement utilisés en anthropologie ont été confirmés. Nous avons établi une chronologie des conformations entre la 19ème, la 27ème et la 41ème S.A. L’os sphénoïde et occipital présentent un rythme de croissance commun alors que l’os temporal diffère. Nous avons confirmé ces structures anatomiques comme étant des critères indirects de maturation permettant d’estimer l’âge. / Geometric morphometric techniques allow the 3D visualization of the skull base and a forecast of their related growth variations. The aim of this work is to provide reliable and accurate methods to estimate fetal age and stage of development characterized by bone conformation. The temporal bone, occipital and sphenoid in 33 fetuses aged from the 19th to the 24th week of amenorrhea (W.A) were reconstructed in 3D and 44 landmarks were positioned. Geometric morphometrics was used to determine the maxima of morphological variation and ontogenetic trajectories. The established formulas allow the estimation of age at ±2.44 weeks. Hyphenation points conventionally used in anthropology have been confirmed. We have established a chronology of the conformations between 19th, 27th and 41st WA. The sphenoid and the occipital bone have a common growth rate, while the temporal bone differs. We confirmed these anatomical structures as indirect criteria of maturation to estimate age.

A introdução dos endoscópios na otorrinolaringologia determinou um grande avanço tecnológico, permitindo a sistematização da cirurgia endoscópica nasossinusal funcional. A possibilidade de trabalhar nos limites das cavidades nasossinusais com boa iluminação e visibilidade permitiu a expansão dessa cirurgia para abordar lesões da base do crânio e no interior da cavidade craniana, ampliando consideravelmente as suas indicações e a gravidade das suas complicações. Dentre estas complicações as lesões vasculares e ou de nervos cranianos estão entre as principais causas de morbidade. A artéria frontobasilar medial (AFM) é o primeiro ramo cortical do segmento pós-comunicante da artéria cerebral anterior e possui percurso próximo a base anterior do crânio. Havendo penetração intracraniana através da base anterior do crânio, durante uma cirurgia endoscópica endonasal, a AFM pode ser lesionada causando graves complicações. O objetivo deste estudo foi analisar as relações da AFM com a base anterior do crânio e reparos anatômicos utilizados em cirurgia endonasal, através de imagens obtidas por angiotomografia de crânio. E também identificar os locais de maior proximidade da AFM com a base anterior do crânio, sugerindo áreas de maior risco de lesão em cirurgia endonasal. Foram analisados 52 exames de angiotomografia de crânio, realizados no período de 2013 a 2015. O software OsiriXÒ foi utilizado para fazer as medições entre a AFM e os pontos de referência nos planos sagital e coronal, na ordem cronológica em que os exames foram coletados. A AFM descreveu um trajeto descendente, próximo a linha média (distancia média de 1,5 mm), se aproximando do plano esfenoidal (distancia média de 1,8 mm) e depois um trajeto ascendente à medida que se dirige para porção anterior do crânio, com distância média de 4,4mm na região da parede anterior do seio esfenoidal e de 12mm na região onde se encontra a artéria etmoidal anterior. Considerando o ângulo de trabalho na cirurgia endonasal e a os locais de maior proximidade da AFM com a base anterior do crânio, as regiões do etmoide posterior e plano esfenoidal foram as áreas de maior risco de sua lesão Study of the relations between medial orbitofrontal artery and anterior skull base performed by computed tomography angiography / The introduction of endoscopes in otolaryngology determined a great technological advance, allowing the systematization of the endoscopic endonasal sinus surgery. The possibility of working at the nasal cavity boundaries with good illumination and visibility allowed the expansion of this surgery to address lesions of the skull base and inside the cranial cavity, considerably broadening its indications and the severity of its complications. Among these complications, vascular lesions and cranial nerves are among the main causes of morbidity. The medial orbitofrontal artery (MOFA) the first cortical branch of the post-communicating segment of the anterior cerebral artery and has a path near the anterior skull base. If there is an intracranial penetration through the anterior skull base, during endonasal surgery, the MOFA can be injured causing serious complications. The objective of this study was to analyze the MOFA relations with the anterior skull base and anatomical repairs used in endonasal surgery, through images obtained by computed tomography angiography. And also identify the sites of greater proximity of the MOFA with the anterior skull base, suggesting areas of greater risk of injury in endonasal surgery. It was studied 52 examinations of skull computed tomography angiography performed between 2013 and 2015. The OsiriXÒ software was used to make the measurements between the MOFA and the reference points in the sagittal and coronal planes, in the chronological order in which the exams were collected. The MOFA described a descending path, close to the midline (average distance of 1.5 mm), approaching the sphenoid plane (average distance of 1.8 mm) and then an ascending path as it is directed towards the anterior portion of the skull, with an average distance of 4.4 mm in the region of the anterior wall of the sphenoid sinus and 12 mm in the region where the anterior ethmoid artery is located. Considering the angle of work in endonasal surgery and the places of greater proximity of the MOFA with the anterior skull base, the regions of the posterior ethmoid and sphenoid plane were the areas of greatest risk of its lesion

A introdução dos endoscópios na otorrinolaringologia determinou um grande avanço tecnológico, permitindo a sistematização da cirurgia endoscópica nasossinusal funcional. A possibilidade de trabalhar nos limites das cavidades nasossinusais com boa iluminação e visibilidade permitiu a expansão dessa cirurgia para abordar lesões da base do crânio e no interior da cavidade craniana, ampliando consideravelmente as suas indicações e a gravidade das suas complicações. Dentre estas complicações as lesões vasculares e ou de nervos cranianos estão entre as principais causas de morbidade. A artéria frontobasilar medial (AFM) é o primeiro ramo cortical do segmento pós-comunicante da artéria cerebral anterior e possui percurso próximo a base anterior do crânio. Havendo penetração intracraniana através da base anterior do crânio, durante uma cirurgia endoscópica endonasal, a AFM pode ser lesionada causando graves complicações. O objetivo deste estudo foi analisar as relações da AFM com a base anterior do crânio e reparos anatômicos utilizados em cirurgia endonasal, através de imagens obtidas por angiotomografia de crânio. E também identificar os locais de maior proximidade da AFM com a base anterior do crânio, sugerindo áreas de maior risco de lesão em cirurgia endonasal. Foram analisados 52 exames de angiotomografia de crânio, realizados no período de 2013 a 2015. O software OsiriXÒ foi utilizado para fazer as medições entre a AFM e os pontos de referência nos planos sagital e coronal, na ordem cronológica em que os exames foram coletados. A AFM descreveu um trajeto descendente, próximo a linha média (distancia média de 1,5 mm), se aproximando do plano esfenoidal (distancia média de 1,8 mm) e depois um trajeto ascendente à medida que se dirige para porção anterior do crânio, com distância média de 4,4mm na região da parede anterior do seio esfenoidal e de 12mm na região onde se encontra a artéria etmoidal anterior. Considerando o ângulo de trabalho na cirurgia endonasal e a os locais de maior proximidade da AFM com a base anterior do crânio, as regiões do etmoide posterior e plano esfenoidal foram as áreas de maior risco de sua lesão Study of the relations between medial orbitofrontal artery and anterior skull base performed by computed tomography angiography / The introduction of endoscopes in otolaryngology determined a great technological advance, allowing the systematization of the endoscopic endonasal sinus surgery. The possibility of working at the nasal cavity boundaries with good illumination and visibility allowed the expansion of this surgery to address lesions of the skull base and inside the cranial cavity, considerably broadening its indications and the severity of its complications. Among these complications, vascular lesions and cranial nerves are among the main causes of morbidity. The medial orbitofrontal artery (MOFA) the first cortical branch of the post-communicating segment of the anterior cerebral artery and has a path near the anterior skull base. If there is an intracranial penetration through the anterior skull base, during endonasal surgery, the MOFA can be injured causing serious complications. The objective of this study was to analyze the MOFA relations with the anterior skull base and anatomical repairs used in endonasal surgery, through images obtained by computed tomography angiography. And also identify the sites of greater proximity of the MOFA with the anterior skull base, suggesting areas of greater risk of injury in endonasal surgery. It was studied 52 examinations of skull computed tomography angiography performed between 2013 and 2015. The OsiriXÒ software was used to make the measurements between the MOFA and the reference points in the sagittal and coronal planes, in the chronological order in which the exams were collected. The MOFA described a descending path, close to the midline (average distance of 1.5 mm), approaching the sphenoid plane (average distance of 1.8 mm) and then an ascending path as it is directed towards the anterior portion of the skull, with an average distance of 4.4 mm in the region of the anterior wall of the sphenoid sinus and 12 mm in the region where the anterior ethmoid artery is located. Considering the angle of work in endonasal surgery and the places of greater proximity of the MOFA with the anterior skull base, the regions of the posterior ethmoid and sphenoid plane were the areas of greatest risk of its lesion

Apparue à la fin des années 1990, la tractographie utilise le signal diffusion de l’imagerie par résonance magnétique (IRM) pour détecter l’orientation préférentielle des molécules d’eau et reconstruire l’architecture des tissus biologiques, notamment celle des fibres blanches intra cérébrales. Cette technique a suscité l’engouement de la communauté scientifique en permettant, pour la première fois, l’étude in vivo non invasive des structures anatomiques, et en particulier celle du cerveau. Néanmoins, la description de la trajectoire des fibres blanches reste imprécise dans les zones de croisement de fibres et pour les faisceaux de petite taille comme les nerfs crâniens. De multiples méthodes sont développées aux différents étapes d’acquisition et de post-traitement afin d’améliorer la résolution spatiale et angulaire et augmenter la précision de la reconstruction des fibres. En pratique clinique, la détection de la trajectoire des nerfs crâniens déplacés au contact des tumeurs de la base du crâne pourrait apporter une aide significative dans la stratégie chirurgicale et améliorer le résultat fonctionnel pour les patients.Après avoir rappelé les notions fondamentales nécessaires à la compréhension de chaque étape de la tractographie, nous en présentons l’ « état de l’art » dans le cas particulier des nerfs crâniens. A partir de 21 études de la littérature scientifique, nous détaillons tous les paramètres d’acquisition et de tracking, les algorithmes de reconstruction, le design des régions d’intérêt et le filtrage. Puis, nous développons notre propre pipeline de tractographie et montrons son impact sur la prise en charge chirurgicale à travers une série de 62 cas de tumeurs variées de la base du crâne et 2 vignettes cliniques illustratives. Enfin, nous proposons une nouvelle approche, la full-tractography, avec une utilisation potentielle en routine clinique, notamment lors du planning pré-chirurgical / Tractography is a recent imaging tool that used the diffusion signal from the magnetic resonance imaging (MRI) to detect the preferential orientation of water molecules within the tissues and particularly along white fibers of the brain. This technique has caught the attention of the scientific community describing non-invasively the in vivo white matter architecture. Nonetheless, its application to fiber crossing areas or to small-scale structures, such as cranial nerves, remains inaccurate. New methods are being developed for both the acquisition and post-processing steps to provide a higher angular and spatial resolution imaging, and improve the reconstruction of fibers. In the clinical setting, the detection of the trajectory of the cranial nerves displaced by skull base tumors could be a relevant asset for the surgical strategy and the functional outcome. After reminding the basics to understand each step involved in tractography, we present the current state-of-the-art for application to cranial nerves. From 21 selected studies, we report all parameters of acquisition and tracking, algorithms of reconstruction, the design of the regions of interest, and filtering. We then develop our tractography pipeline and show its value for the surgical management through a 62 case series of various skull base tumors and two clinical images. Finally, we propose a new full-tractography approach that could be implemented in routine, notably for presurgical planning