Foramen venoso órbito cavernoso: foramen de Warwick / Cavernous orbital venous foramen: Warwick´s foramen

El foramen de Warwick o foramen venoso órbito cavernoso, es un foramen inconstante del ala mayor del esfenoides, situado entre la fisura orbitaria superior y el foramen rotundo. Comunica la órbita con la fosa craneal media y/o con la fosa pterigopalatina y permitiría el paso de la vena oftálmica inferior. La presencia del foramen venoso órbito cavernoso varía entre el 0,38 % y el 0,74 %. Se describe con forma redondeada o crescéntica (semilunar), unilateral o bilateral. El objetivo de este trabajo fue evidenciar la presencia y las características de foramen venoso órbito cavernoso en cráneos secos de individuos adultos chilenos de ambos sexos. Se analizaron 138 cráneos de individuos adultos y de ambos sexos, en búsqueda del foramen venoso órbito cavernoso para determinar la frecuencia, localización, forma, tamaño, orientación y distancias con respecto a la fisura orbitaria superior y el foramen rotundo. Los forámenes encontrados fueron fotografiados, explorados y medidos. La presencia del foramen venoso órbito cavernoso fue del 2,17 % de la muestra, encontrándose en forma unilateral (1,45 %) y bilateral (0,17 %). Con forma redondeada en 3 casos y semilunar en 1 caso. Con orientación hacia la órbita (2 casos) y hacia la fosa pterigopalatina (2 casos). También se evidenció que cuando está presente el foramen venoso órbito cavernoso, la separación entre la fisura orbitaria superior y el foramen rotundo es mayor que en su ausencia. Nuestro estudio demuestra la presencia del foramen venoso órbito cavernoso en la población chilena, con una frecuencia más alta que la observada en otras poblaciones. La localización, orientación y formas coinciden con la literatura, pero difiere en el tamaño (en forámenes redondeados). También pudimos determinar que la fisura orbitaria superior y el foramen rotundo tienden a encontrarse más cercanos en ausencia del foramen venoso órbito cavernoso y por lo tanto más distante cuando esta estructura está presente. Este hecho no está descrito en la literatura. Los resultados de este estudio son importantes para la anatomía, oftalmología, traumatología, imagenología, cirugía e identificación humana. Finalmente y en virtud de la TAI, proponemos llamar a este foramen, foramen venoso órbito cavernoso.

The Warwick's foramen or cavernous orbital venous foramen, is an inconstant foramen from the greater wing of the sphenoid bone, located between the superior orbital fissure and the rotundum foramen. It connects the orbit with the middle cranial fossa and/or with the pterygopalatine fossa and allows for the passage of the inferior ophthalmic vein. The presence of the cavernous orbital venous foramen varies between 0.38 % and 0.74 % in human skulls. It is described as having a rounded or crescentic (semilunar), unilateral or bilateral shape. The objective of the present work was to demonstrate the presence and characteristics of the cavernous orbital venous foramen in dry skulls of Chilean adult individuals of both sexes. One hundred and thirty-eight adult skulls of both sexes were analyzed in search of the cavernous orbital venous foramen to determine the frequency, location, shape, size, orientation and distances with respect to the superior orbital fissure and the rotund foramen. Found foramina were photographed, explored and measured. The cavernous orbital venous foramen was present in 2.17 % of the sample, and was both unilateral (1.45 %) and bilateral (0.17 %). It had a rounded and lunate shape in 3 and 1 cases, respectively. Moreover, it was orientated towards the orbit (2 cases) and towards the pterygopalatine fossa (2 cases). It was also evidenced that when the cavernous orbital venous foramen is present, the separation between the superior orbital fissure and the rotund foramen is greater than in its absence. Our study demonstrates the presence of the cavernous orbital venous foramen in the Chilean population, with a higher frequency than described previously. The location, orientation and observed forms agree with the literature, but differ in size (in rounded shape foramen). We could also determine that the superior orbital fissure and the rotundum foramen tend to be closer in the absence of the cavernous orbital venous foramen and, therefore, are more distant when this structure is present. This fact is not described in the literature. The results of this study are important for anatomy, ophthalmology, traumatology, imaging, surgery and human identification. Finally, and by virtue of the International Anatomical Terminology (IAT), we propose to call this structure the cavernous orbital venous foramen.

Descompressão dos segmentos timpânico e labiríntico do nervo facial via fossa craniana média / Decompression of the tympanic and labyrinthine segments of the facial nerve via middle cranial fossa

Introdução: A paralisia facial periférica caracteriza-se pela interrupção, definitiva ou temporária, do funcionamento da musculatura facial. Decorre de lesão ou mau funcionamento das fibras do nervo facial. É uma enfermidade que causa enorme impacto estético e funcional. O topodiagnóstico e o tratamento da paralisia facial periférica pode requer abordagem médica e fonoaudiológica; ser exclusivamente medicamentoso ou associado à terapia de reabilitação, ou ainda, medicamentoso e cirúrgico, seguido da reabilitação da mímica facial. A via FCM tem sido usada para a descompressão do NF quando a audição precisa ser preservada. Esse acesso pode ser realizado de forma isolada, ou combinado à via transmastóidea. Objetivo: Descrever uma técnica inovadora para a descompressão do nervo facial via fossa craniana média que permite a exposição direta dos segmentos labiríntico e timpânico do nervo facial, com a preservação da função da orelha interna. Métodos: Vinte cabeças extraídas de cadáveres adultos de ambos os gêneros, sem sinais de malformação, traumatismo, doença ou manipulação cirúrgica prévia foram usados neste estudo. Os pontos de referência utilizados foram a artéria meníngea média, o nevo petroso superficial maior, a eminência arqueada, o seio petroso superior, e o plano meatal seguido no ápice petroso a partir da sua porção mais anterior e medial. Foi feita a dissecação do plano meatal, com visualização do meato acústico interno, seguido no ápice petroso a partir da sua porção mais anterior e medial até a região do gânglio geniculado. Foi aberto o tégmen timpânico e identificada a porção timpânica do nervo facial. A dissecação seguiu no sentido retrógrado da porção timpânica do nervo facial em direção ao gânglio geniculado, até a sua porção labiríntica. A aracnoide do meato acústico interno era aberta, e depois de identificado o nervo facial, a bainha deste nervo era aberta em extensão exposta. Resultados: As distâncias médias, entre o canal semicircular...

Background: Peripheral facial palsy is characterized by the permanent or temporary interruption of the functioning of the facial muscles. The middle cranial fossa (MCF) approach has been used for the decompression of the facial nerve (FN) when hearing needs to be preserved. In this work, we describe an innovative technique for the decompression of the FN through the MCF approach that allows the direct exposure of the labyrinthine and entire tympanic segment of the FN, with the preservation of inner ear function. Methods: Twenty cadavers heads were used in this study. The reference landmarks used were the middle meningeal artery, the greater superficial petrosal nerve, the arcuate eminence, the inferior petrosal sinus and the meatal plane following the petrous apex from its most anterior and medial portion. Results: The tympanic segment of the FN presented, on average, a total length of 11 ± 0.67mm to the right, and 11.5 ± 0.60mm to the left. The longitudinal lengths of bone window in the tegmen tympani were 16.8±1.67mm to the right, and 16.8 ± 1.20mm to the left. The cross-sectional lengths of the bone window in the tegmen tympani were 5.5 ± 1.20mm and 5.0±1.75mm to the right and left sides, respectively. The average value of elliptical area formed by the longitudinal and transversal lengths of the bone window made in the tegmen tympani were 72.5 ± 22.5mm2 to the right, and 65.9 ± 30.3mm2 to the left. Conclusion: The proposed technique can be used for the surgical decompression of the tympanic, labyrinthine and meatal segments of the FN through the MCF, without imposing a risk to hearing, in addition to reducing the surgical time and the risk to patients.

Anatomical examination of the foramens of the middle cranial fossa / Examinación anatómica de los forámenes de la fosa craneal media

Three foramina can be identified in the greater wing of the sphenoid bone: The foramen rotundum (FR), foramen ovale (FO) and foramen spinosum (FS). In addition, there may be another foramen called foramen ovale accessorium or foramen vesalius (FV) which connects the middle cranial fossa to the fossa pterygoidea (pterygoid fossa). It is described as an opening with smooth walls in front and medial to foramen ovale which leads to an oblique channel directed towards the fossa pterygoidea. FV was present between FO and FR in 14 (31.8%) of 44 dry and 6 (33.3%) of 18 cadaver skullbase sides (total 20 (32.3%) of 62). The diameter values of foramens on both the right and the left side were observed to be almost symmetrical. FR's distance from the midline on the left side was greater than the right side. Also, the distance between FO and the petrous apex and the distance between FS and the petrous apex were greater on the left side. On the right side the distance between FO and FR, and the distance between FO and FS were greater. Also, the distance between FR and the petrous apex was greater on the right side. Anatomical variations in appearance size and distance of FR, FO, FS and FV are of great surgical importance. In conclusion, we can infer that the information provided with this study can help the neurosurgeon and anatomist to increase the knowledge about anatomy of middle cranial fossa.

Tres forámenes pueden ser identificados en el ala mayor del esfenoides: El foramen redondo (FR), foramen oval (FO) y el foramen espinoso (FS). Puede además existir otro foramen llamado foramen oval accesorio o foramen de Vesalio (FV), que conecta la fosa craneal media a la fosa pterigoidea. Se describe como una abertura con paredes lisas por anterior y medial al foramen oval, que conduce a un canal oblicuo dirigido hacia la fosa pterigoidea. FV estuvo presente entre FO y FR en 14 (31,8%) de 44 cráneos secos y 6 (33,3%), en 18 lados en la base de cráneos de cadáveres (total 20 (32,3%) de 62). El diámetro de los forámenes en los lados derecho e izquierdo se observó casi simétricos. Las distancias de FR desde la línea mediana en el lado izquierdo fue mayor que en el lado derecho. Además, la distancia entre FO y el vértice de la porción petrosa y la distancia entre el FS y el vértice porción petrosa fueron mayores en el lado izquierdo. En el lado derecho la distancia entre A y FR, así como la distancia entre A y FS fueron mayores. Por otra parte, la distancia entre los FR y el vértice del porción petrosa fue mayor en el lado derecho. Las variaciones anatómicas en el tamaño de la apariencia y la distancia de FR, DE, FS y FV son de gran importancia quirúrgica. Podemos inferir que la información proporcionada en este estudio puede ayudar al neurocirujano y anatomista para aumentar el conocimiento sobre la anatomía de la fosa craneal media.

Referências anatômicas ao giro basal da cóclea no assoalho da fossa craniana média para o implante coclear / Anatomical references to the cochlear basal turn on the floor of the middle cranial fossa for cochlear implantation

Introdução: A técnica clássica para o implante coclear é realizada por meio de mastoidectomia seguida de timpanotomia posterior. O acesso pela fossa craniana média provou ser uma alternativa valiosa, embora seja usada para o implante coclear, ainda sem normatização. Objetivo: Descrever um novo acesso pela fossa craniana média que expõe o giro basal da cóclea para o implante coclear. Métodos: Estudo anatômico de ossos temporais. Foram dissecados 50 ossos temporais. A cocleostomia foi realizada mediante um acesso via fossa craniana média, na porção mais superficial do giro basal da cóclea, usando o plano meatal e seio petroso superior como as principais referências anatômicas. Foi determinada a distância entre os pontos de referência, o ângulo entre o plano meatal e a cocleostomia, e a distância entre esta estrutura e a janela redonda. Foi realizada tomografia computadorizada em 5 dos ossos temporais utilizados neste estudo. Resultados: Em todos os 50 ossos temporais, apenas a porção mais superficial do giro basal da cóclea foi aberta e tanto as escalas timpânica como a vestibular foram visualizadas. As distâncias médias ± DP, menores e maiores, entre a cocleostomia e o plano meatal foram estimadas em 2,48±0,88mm e 3,11±0,86mm, respectivamente. A distância média da cocleostomia até a janela redonda foi de 8,38±1,96mm, e daquela até o seio petroso superior 9,19±1,59mm. As distâncias médias, menores e maiores, entre a cocleostomia e o eixo longo do plano meatal a partir da sua porção mais proximal foram estimadas em 6,63±1,38mm e 8,2±1,43mm, respectivamente. O valor médio do ângulo entre a cocleostomia e o plano meatal foi igual a 22,54±7,400. As tomografias computadorizadas demonstraram a inserção do feixe de eletrodos por meio do giro basal da cóclea até o seu ápice em todas as peças submetidas a este exame. Conclusão: A técnica proposta para identificar o giro basal da cóclea é simples e confiável. Igualmente, permite a visualização da escala timpânica e a...

Introduction: The classic technique for cochlear implantation uses mastoidectomy followed by posterior tympanotomy. The middle cranial fossa approach has proved to be a valuable alternative for cochlear implantation, although the standardization of this technique is still needed. Objectives: To describe a novel approach through the middle cranial fossa for exposing the cochlear basal turn for cochlear implantation. Materials And Methods: Anatomical temporal bone study. Fifty temporal bones were dissected. A cochleostomy was performed via a middle fossa approach on the most superficial part of the cochlear basal turn, using the meatal plane and superior petrous sinus as the main landmarks. The distance between the landmarks, the angle between the cochleostomy and the meatal plane, and the distance between this structure and the round window were measured. A computed tomography was performed on 5 of the studied temporal bones. Results: In all 50 temporal bones, only the superficial portion of the cochlear basal turn was uncovered. The cochlear exposure allowed both the scala tympani and vestibule to be exposed. The mean ± SD minor and major distances between the cochleostomy and the meatal plane were estimated to be 2.48±0.88mm and 3.11±0.86mm, respectively. The mean distance from the cochleostomy to the round window was 8.38±1.96mm, and that to the superior petrosal sinus was 9.19±1.59mm. The mean minor and major distances between the cochleostomy and the long axis of the meatal plane from its most proximal portion were estimated to be 6.63±1.38mm and 8.29±1.43mm, respectively. The mean angle between the cochleostomy and the meatal plane was 22.54±7.400. The computed tomography of all 5 temporal bones demonstrated the insertion of the implant array from the cochlear basal turn towards its apex. Conclusion: The proposed technique for identifying the cochlear basal turn is simple and trustworthy. Additionally, it enables visualization of the scala tympani...

Caroticoclinoid Foramen in Human Skulls: Incidence, Morphometry and its Clinical Implications / Foramen Caróticoclinoideo en Cráneos Humanos: Incidencia, Morfometría y sus Implicaciones Clínicas

The caroticoclinoid foramen is an inconstant structure, formed by the union of the anterior and middle clinoid processes. The aim of this study was to perform an incidence and morphometry of the caroticoclinoid foramen in Brazilian human skulls and discuss its clinical implications. Eighty dry human skulls with sex distinction were used, and 3 groups of incidence were determined: General, sex, and sides. The morphometry was performed using a manual caliper and the major diameter of the foramina was measured; the values were also divided in general, according to sex and sides. The incidence of skulls with at least one foramen was 8.5 percent. According to the sides, 8.5 percent of the skulls showed foramen on the right side and 2.5 percent on the left. We found 2.5 percent of the skulls with bilateral foramen and 6.25 percent with unilateral foramen. In relation to sex, the foramens were found in 5 percent of male skulls and 12.5 percent of female skulls. The major diameter of this structure presented on mean, values of 5.23 mm on general, 5.18 mm on the right side and 5.35 mm on the left, 5.30 mm in male skulls and 5.18 mm in female skulls. The anatomical characteristics of this foramen should be considered in view of its clinical implications associated with neurosurgery as clinoid process removal, and symptoms as headache due to internal carotid artery alterations in this region. In conclusion knowledge of this structure supports the diagnosis and treatment of clinical complications related to this variation.

El foramen caróticoclinoideo es una estructura inconstante formada por la unión de la procesos clinoides anterior y medio. El objetivo de este estudio fue revisar la incidencia y la morfometría del foramen caróticoclinoideo en cráneos humanos brasileños y discutir sus implicaciones clínicas. Se utilizaron 80 cráneos humanos secos, de ambos sexos, determinando tres variables: sexo y lados derecho e izquierdo. La morfometría se realizó con un cáliper manual midiéndose el diámetro máximo del foramen. La incidencia de cráneos con al menos un foramen fue de 8,5 por ciento. El 8,5 por ciento de los cráneos presentó un foramen en el lado derecho y el 2,5 por ciento en el izquierdo. El 2,5 por ciento de los cráneos presentó un foramen bilateral y el 6,25 por ciento un foramen unilateral. En relación al sexo, los forámenes se encontraron en el 5 por ciento de los cráneos de hombres y el 12,5 por ciento de los cráneos de mujeres. El diámetro máximo de esta estructura presentó en promedio, valores de 5,23 mm; 5,18 mm en el lado derecho y 5,35 mm en el izquierdo; 5,30 mm en cráneos de hombres y 5.18 mm en cráneos de mujeres. Las características anatómicas de este foramen deben ser consideradas debido a las implicaciones clínicas asociadas a la neurocirugía, como la eliminación del proceso clinoides y a síntomas como cefaleas producto de alteraciones en la arteria carótida interna en esta región. En conclusión, el conocimiento de esta estructura mejora el diagnóstico y tratamiento de las complicaciones clínicas relacionadas con esta variación.

Prevalencia y características morfométricas del foramen venoso en cráneos del Noreste de México / Prevalence and morphometric characteristics foramen venosum in Northeastern Mexico skulls

El foramen venoso es una estructura inconstante que se encuentra posterior al foramen redondo y medial al foramen oval, y da paso a una vena que anastomosa al plexo venoso pterigoideo con el seno cavernoso. La existencia de éste foramen puede ser motivo de complicaciones clínicas, entre ellas que es una potencial vía de acceso al seno cavernoso de trombos infectados y constituye una posible falsa vía durante la rizotomía percutánea del trigémino pudiendo puncionar la vena y ocasionar hematomas subdurales. Se utilizó la colección de cráneos del Departamento de Anatomía de la Facultad de Medicina UANL. Se observó la frecuencia y se midieron los siguientes parámetros del foramen: Ancho y largo; en la cara interna de la base del cráneo se midieron las distancias a: foramen redondo, foramen oval, plano sagital mediano y entre forámenes venosos; en la cara externa de la base del cráneo se midieron las distancias con: foramen oval, plano sagital medio y entre los forámenes venosos. Las medidas fueron llevadas a cabo por tres observadores distintos a través de medición directa con vernier y con microfotografías con escalas milimétricas. Se encontró una frecuencia del 20 por ciento con medidas medias de 1,66mm de largo, 1,06mm de ancho; en la cara interna de la base del cráneo: 11,31mm de distancia al foramen redondo, 4,13mm al foramen oval, 17,75mm al plano sagital medio y 31,91mm entre los forámenes; en la cara externa de la base: 2,50mm al foramen oval, 19,54mm al plano sagital medio y 36,05mm entre forámenes venoso. La distancia al foramen oval varía en la cara interna y la cara externa de la base del cráneo debido a un trayecto oblicuo del foramen que tiende a aproximarse al foramen oval y por tanto a separarse del plano sagital medio. Los forámenes derechos fueron generalmente más grandes.

Foramen venosum (foramen Vesalius) is an inconstant structure which is located posterior to the foramen rotundum and medial to the foramen ovale, and it gives pace to an emissary vein that communicates the plexus pterigoideus and the sinus cavernosus. The existence of this anatomical structure can be of interest in certain procedures like percutaneous trigeminal rhizotomy where this foramen can be the cause of a false pathway and be punctured causing a subdural hematoma. It also can be an access to the sinus cavernosus for infected thrombus coming from dental and facial infections. For this study the skull collection of the Anatomy Department, Faculty of Medicine UANL, was used. We observed the frequency and measured the following parameters: Length and width; in the basis cranii we measured: Distances to the foramen rotundum, foramen ovale, planum medianum and between two foramina venosum (one on each side). In basis cranii externa we measured: distances to foramen ovale, planum medianum, and between two foramina venosum. Three independent observers blinded among them, measured the parameters using a Vernier and microphotographs with milimetrical scales. A 20 percent frequency was found and the following median measures: Length 1.66mm, width 1.06mm; basis cranii: distance to foramen rotundum 11.31mm, distance to foramen ovale 4.13mm, distance to planum medianum 17.75mm and 31.91mm between both foramina venosum. Basis cranii externa: distance to foramen ovale 2.49mm, distance to planum medianum 19.54mm and distance between foramenina venosum 36.05. The distance to the foramen ovale varies between basis cranii and basis cranii externa because the foramen has an oblique trajectory and it approximates to the foramen ovale (from superior to inferior) and separates from the planum medianum. It was found bilaterally only in one skull. There are differences between the left and right foramens, the latter being generally larger.

Macrometric and micrometric study of sexual dimorphism in foramina of middle crania fossa of adult Nigerians / Estudio macrométrico y micrométrico del dimorfismo sexual en foramina de la fosa craneal media en nigerianos adultos

We have measured the longitudinal, transverse diameters of optic canal, foramen rotundum, foramen ovale, foramen spinosum, to serve as a handy guideline to surgeons, to enhance the accuracy of sexing the cranium for anthropometric/medico-legal studies and for comparative analyses of values of the Nigerian population with those of the Caucasians. A total of 100 adult dry skulls 81 male, 19 female from departments of Anatomy of some Nigerian Universities were used. Automatic vernier caliper with a precision of 0.1mm was used. Data analysis was performed with Graph Pad Prism 3.0. A comparison was made of the means of the dimension using Student's T-test and analysis of variance. Sizes of foramina were not significantly different from that of Caucasians Our results show significant sexual dimorphism in the following parameters, the right transverse diameter of the FR in males was found to be significantly different from the females at p<0.05, there was a significant difference between the means of the left and right sides of the foramen ovale. The distance between right ovale and spinosum in males and females was found to be significantly different in both sexes. The effect of side on longitudinal diameter of foramen ovale FO of males showed a significant difference between the means of the left and right sides of the foramen ovale. A comparism of the distance between left optical canal and foramen rotundum showed a significant difference between the values obtained for males and the females at p< 0.05.

Hemos medido el diámetro longitudinal y transversal del canal óptico, agujero redondo, el agujero oval, agujero espinoso, para que sirva como una guía útil para los cirujanos, para mejorar la exactitud de la determinación del sexo del cráneo para estudios antropométricos y médico-legales y para realizar análisis comparativos de valores de la población de Nigeria con los de la raza blanca. Fueron utilizados 100 cráneos adultos secos 81 cráneos masculinos, 19 femeninos de los departamentos de Anatomía de algunas Universidades de Nigeri. Se utilizó un calibrador vernier automático con una precisión de 0,1 mm. Los datos fueron analizados con el gráfico Pad Prism 3.0. Se realizó una comparación de los medios de la dimensión utilizando T de Student y el análisis de la varianza. Los tamaños de los agujeros no fueron significativamente diferentes de la de los caucásicos. Nuestros resultados muestran dimorfismo sexual significativo en los siguientes parámetros, el diámetro transversal del derecho de FR en los hombres resultó ser significativamente diferentes de las hembras con una p <0,05, hubo una diferencia significativa entre las medias de los lados izquierdo y derecho del foramen oval. La distancia entre la derecha y oval espinoso en hombres y mujeres resultó ser significativamente diferente en ambos sexos. El efecto de lado en el diámetro longitudinal del foramen oval DE de los hombres mostraron una diferencia significativa entre las medias de los lados izquierdo y derecho del foramen oval. Una comparación de la distancia entre el canal izquierdo y agujero redondo óptica mostró una diferencia significativa entre los valores obtenidos para los machos y las hembras de p <0,05.