Seno cavernoso: anatomía, histología y terminología.

BACKGROUND: Although the cavernous sinus (CS) has been studied since 1695, its anatomy and name are still under discussion. METHOD: Anatomy and histology of 40 CS from human cadavers were studied, included both from a newborn specimen. RESULTS: Two walls limit the CS, an inferior medial one composed only of the dura's outer layer and a superior lateral one consisting of both dura's layers. Sinusoidal veins pass through the lateral wall of the CS as a transition between venous tributaries and the CS. An endothelial layer covers the inner surface of the CS and the outer surface of the internal carotid artery. The space within the CS shows trabeculae, which are rarer in adults compared to the newborn. The loss of trabeculae in the CS may be a natural process along with life. CONCLUSIONS: In conclusion, the CS is a real sinus, and the term "cavernous sinus" is appropriately applied.

ANTECEDENTES: Si bien el seno cavernoso (SC) ha sido estudiado desde 1695, su anatomía y nombre aún están bajo discusión. MÉTODOS: Se estudiaron la anatomía y la histología de 40 SC de cadáveres humanos, incluyendo los dos de un recién nacido. RESULTADOS: El SC está limitado por dos paredes, una inferomedial compuesta solo por la capa más externa de la duramadre y otra superolateral compuesta por ambas capas de la duramadre. Hay venas sinusoidales que atraviesan la pared lateral del SC formando una transición entre venas tributarias y el SC. Una capa endotelial recubre la superficie interna del SC y la superficie externa de la arteria carótida interna. El espacio dentro del SC presenta trabéculas, las cuales son escasas en el adulto en comparación con el recién nacido. La pérdida de trabéculas en el SC puede ser un proceso natural a lo largo de la vida. CONCLUSIONES: En conclusión, el SC es un verdadero seno, por lo que el término «seno cavernoso¼ se aplica de forma correcta.

Microsurgical and illustrative anatomy of the cavernous sinus, middle fossa, and paraclival triangles: a straightforward, comprehensive review.

The middle fossa, cavernous sinus, and paraclival triangles consist of ten triangles. Their use in a surgical approach is vast; most are used as landmarks to access and identify other structures of surgical interest. Multiple labels, borders, and contents mentioned by different authors make understanding and reproduction challenging and confusing. This study aims to organize and clarify recent or most relevant publications and disclose our portrayal of the ten triangles using cadaveric dissection and simple and practical figures. Four middle fossa triangles, four cavernous sinus triangles, and two paraclival triangles were dissected and delineated in a cadaveric specimen. Drawings were simplified to eliminate confusion and evaluate the triangles effortlessly. Similarities and differences in triangle names, border limits, and contents are described in a precise form. The recognition of triangle landmarks allows for treating pathologies in a frequently distorted anatomy or challenging to access structure. That is why an accurate knowledge of the surgical anatomy should be mastered, and a safe approach should be accomplished.

A comparative study of the morphology of suboccipital cavernous sinus using magnetic resonance imaging and cast specimens / Un estudio comparativo de la morfología del seno cavernoso suboccipital utilizando imágenes de resonancia magnética y muestras de yeso

SUMMARY: A comparative study of the morphology of suboccipital cavernous sinus (SCS) using MRI and cast specimens was performed. The present retrospective study analysed the craniocervical magnetic resonance venography (MRV) imaging data of 61 patients. Three-dimensional reconstruction was performed using Mimics 19.0. The SCS left-right diameter(d1), distance from the midline (d2), supero-inferior diameter(d3), anteroposterior diameter (d4), distance from posterior diameter to skin (d5), and diameter of the SCS at different parts (d6-d8) were measured. Comparison between MRV images and cast specimens, the SCS, marginal sinus, anterior condylar vein, and vertebral artery venous plexus were symmetrical and could be bilaterally displayed, whereas the presence of extra condylar vein and posterior condylar vein exhibited different types. The adjacency between the SCS and its communicating vessels and changes in its communicating vessels corresponded well with the MRV images and cast specimens. Many types of the presence of left and right lateral condylar and posterior condylar veins were found in the cast specimens, which could be divided into the bilateral presence of posterior condylar and lateral condylar veins, unilateral presence of posterior condylar veins, and unilateral presence of lateral condylar vein. A total of 61 cases analysed using MRV images revealed the bilateral presence of posterior condylar and lateral condylar veins (77.1 %), the unilateral presence of posterior condylar vein (18.0 %), and the unilateral presence of lateral condylar vein (9.8 %), of which the bilateral presence of posterior condylar and lateral condylar veins accounted for the largest proportion. MRV images and cast specimens of the SCS showed its normal morphological structure and adjacency, thus providing accurate and complete Three-dimensional imaging anatomical data of the SCS and its communicating vascular structures. This study enriches the Chinese SCS imaging anatomy data and may be valuable in clinical practice.

RESUMEN: Se realizó un estudio comparativo de la morfología del seno cavernoso suboccipital (SCS) mediante resonancia magnética y muestras de yeso. El presente estudio retrospectivo analizó los datos de imágenes de venografía por resonancia magnética (RNM) craneocervical de 61 pacientes. La reconstrucción tridimensional se realizó con Mimics 19.0. Se midió: el diámetro izquierdo-derecho del SCS (d1), la distancia desde la línea mediana (d2), el diámetro superoinferior (d3), el diámetro anteroposterior (d4), la distancia desde el diámetro posterior hasta la piel (d5) y el diámetro del SCS en diferentes partes (d6-d8). En la comparación entre las imágenes RNM y las muestras de yeso, el SCS, el seno marginal, la vena condilar anterior y el plexo venoso de la arteria vertebral eran simétricos y se observaron bilateralmente, mientras que la presencia de la vena extracondilar y la vena condilar posterior presentaba tipos diferentes. La proximidad del SCS y sus vasos comunicantes y los cambios en sus vasos comunicantes se correspondieron bien con las imágenes de RNM y los especímenes moldeados. Se encontraron muchos tipos de venas condilares laterales y condilares posteriores izquierda y derecha en las muestras de yeso, que podrían dividirse en presencia bilateral de venas condilares posteriores y condilares laterales, presencia unilateral de venas condilares posteriores y presencia unilateral de venas condilares laterales. Un total de 61 casos analizados mediante imágenes MRV revelaron la presencia bilateral de venas condilares posteriores y condilares laterales (77,1 %), la presencia unilateral de venas condilares posteriores (18,0 %) y la presencia unilateral de venas condilares laterales (9,8 %) de los cuales la presencia bilateral de las venas condilar posterior y condilar lateral representó la mayor proporción. Las imágenes de RNM y las muestras de yeso del SCS mostraron su estructura morfológica y adyacencia normales, lo que proporcionó datos anatómicos de imágenes tridimensionales precisos y completos del SCS y sus estructuras vasculares comunicantes. Este estudio enriquece los datos de anatomía de imágenes de SCS chino y puede ser valioso en la práctica clínica.

Microsurgical and Endoscopic Anatomy of the Cavernous Sinus

Objective To describe the endoscopic and microsurgical anatomy of the cavernous sinus (CS) with focus on the surgical landmarks in microsurgical anatomy. Materials and methods Ten formalin-fixed central skull base specimens (20 CSs) with silicone-injected carotid arteries were examined through an extended endoscopic transsphenoidal approach. Fifteen formalin-fixed heads were dissected to simulate the surgical position in CS approaches. Results Endoscopic access enables identification of the anterior and posterior surgical corridors. Structures within the CS and on its lateral wall could be visualized and studied, but none of the triangular areas relevant to the transcranial microsurgical anatomy were fully visible through the endoscopic approach. Conclusion The endoscopic approach to the CS is an important surgical technique for the treatment of pathological conditions that affect this region. Correlating endoscopic findings with the conventional (transcranial)microsurgical anatomy is a useful way of applying the established knowledge into a more recent operative technique. Endoscope can provide access to the CS and to the structures it harbors.

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.

Fístula carotídeo-cavernosa / Carotid-cavernous fistula

Fístulas carotídeo-cavernosas são raras. São classificadas nos tipos direto e indireto. Fístulas diretas têm uma comunicação anormal entre a artéria carótida interna e o seio cavernoso. Nas formas indiretas a conexão se faz entre os ramos meningeos da carótida interna e/ou externa e o mesmo seio. O propósito deste artigo é o de atualizar os conceitos anatômicos, clínicos, diagnósticos e terapêuticos desta situação.

Carotid cavernous fistulae are an uncommon disease. They are classified as direct or indirect. In direct fistulas there is an abnormal communication between the internal carotid artery and the cavernous sinus. Indirect forms have an abnormal bypass between the meningeal branches of the internal and/or external carotid arteries and the same sinus. The purpose of this article is to provide an overview of the anatomy of the envolved area and the clinical findings, diagnostic evaluation and treatment.

Cavernous sinus medial wall: dural or fibrous layer? Systematic review of the literature.

The cavernous sinus (CS) has one of the most complex anatomical networks of the skull base and because of the diversity of its contents is involved in many pathological processes. Nevertheless, anatomical literature concerning the CS is still controversial, so a systematic literature review was performed to find out the microanatomy of the medial wall of the CS and its clinical importance on sellar pathologies. Experimental studies from English-language literature between 1996 and 2010 were identified in MEDLINE, LILACS, and Cochrane databases. After analysis, two tables were prepared exhibiting the major points of each article. Fourteen experimental studies were included in the tables. Four studies concluded that the medial wall of the CS is composed of a loose, fibrous structure, and the remaining ten presumed that the medial wall is formed by a dural layer that constitutes the lateral wall of the sella. The lack of definition standards and of methodological criteria led to variation in the results among different studies. Thus, this hindered results comparison, possibly explaining the different observations.

Surgical anatomy of the dural walls of the cavernous sinus.

The external structure of each cavernous sinus (CS) is made of four dural walls. The aim of this study was to describe the anatomy of the dural walls of the CS. We studied 42 adult cadaveric heads, fixed with formalin and injected with coloured silicon. The main findings were: (i) the lateral wall of the CS has two layers - the external, which is thick and pearly grey, and the internal, which is semi-transparent and containing the cranial nerves (CNs); (ii) the medial wall of the CS has two areas - sellar and sphenoidal, both made up of one dural layer only; and (iii) the superior wall of the CS is formed by three triangles - oculomotor, clinoid and carotid - CN III may be found in a cisternal space of the oculomotor triangle; and (iv) the posterior wall of the CS is made up of two dural layers - meningeal dura and periostic dura - and this wall is close to the vertical segment of CN VI.

Síndrome de tolosa hunt: a propósito de un caso / Tolosa hunt syndrome: a purpose of a case

El síndrome de tolosa-Hunt es una oftalmoplejia dolorosa, recurrente provocada por una inflamación granulomatosa inespecífica que afecta al seno cavernoso, la hendidura esfenoidal y el apex orbitario. Se caracteriza por dolor retrocular agudo recurrente con parálisis extraocular, que generalmente afecta los nervios craneanos tercero, cuarto, quinto y sexto. Se le atribuye a una infiltración granulomatosa del apex orbitrario o en el seno cavernoso, que responde a la corticoideoterapia. Nuestro paciente consulta por enfermedad de 3 meses de evolución presenta de forma súbita cefalea de fuerte intensidad; y pulsátil acompañado de dolor de fuerte intensidad en globo ocular derecho de carácter pulsátil y progresivamente ptosis palpebral derecha. Se le instaura tratamiento con corticoides, AINES y antiglaucomatosos con poca mejoría sin recuperar amaurosis del ojo derecho. Se obtienen estudios por TAC y RNM de órbita donde se evidencia engrosamiento a nivel del seno cavernoso. Evaluado por equipo multidisciplinario de oftalmología, neurocirugía, Medicina Interna, Imagenología. Considerando que existe un predominio por el seno cavernoso. No se disponen de estudios de prevalencia o incidencia. Se ubica el síndrome de Tolosa-Hunt como la tercera causa de síndrome del seno cavernoso, superado por el trauma y los tumores.

The minipterional craniotomy: technical description and anatomic assessment.

OBJECTIVE: To describe a modification of the pterional approach (PT), the minipterional craniotomy (MPT), and compare the anatomic exposure provided by these two approaches. METHODS: The anatomic exposure offered by the MPT and PT were compared in eight sides of cadaver heads using a computerized tracking system, a robotic microscope, and an image-guidance system. The area of surgical exposure, angular exposure, and anatomic limits of each craniotomy were evaluated. Three recently operated clinical cases (EGF) are also reported. RESULTS: There were no statistical differences in the total area of surgical exposure between the two craniotomies (PT, 1524.7 +/- 305 mm; MPT, 1469.7 +/- 380.3 mm; P > 0.05) or among the ipsilateral, middle, and contralateral components of the area (P > 0.05). There were no differences in angular exposure along the longitudinal and transverse axis angles for the three selected targets, the bifurcations of internal carotid and middle cerebral arteries, and the anterior communicating artery (P > 0.05). Except for the distal portion of the operculoinsular compartment of the sylvian fissure, no significant differences in the limits of the surgical exposure through the PT and MPT were apparent on the image-guidance system. CONCLUSION: The MPT craniotomy provides comparable surgical exposure to that offered by the PT. The advantages of the MPT include reduction of tissue trauma and bony removal, a decrease in surgical time, and improved cosmetic outcomes.

Parede medial do seio cavernoso: dura-máter ou tecido fibroso?: revisão sistemática da literatura / Cavernous sinus medial wall: dura-mater or fibrous tissue?: systematic review from the literature

Objetivo: o seio cavernoso tem uma das mais complexas relações anatômicas da base do crânio e, pela diversidade do seu conteúdo, está envolvido em muitos processos patológicos. Sua natomia, ainda controversa, motivou esta revisão sistemática, com o propósito de avaliar a microanatomia da parede medial do seio cavernosos e sua importância clínica nas patologias selares. Material e método: foram analisados estudos experimentais na língua inglesa, publicados em revistas indexadas nas bases de dados Medline, Lilacs e centro Cochrane do Brasil, nos últimos dez anos. Elaborou-se uma tabulação com as características de cada trabalho. Resultado: a análise incluiu 11 estudos experimentais, dos quais três apresentaram, como resultado, uma estrutura fibrosa frouxa formando aparede medial do seio cavernoso e oito identificaram uma parede medial formada por dura-máter. Conclusão: é importante ressaltar o portencial de contribuição dos estudos experimentais para o esclarecimento da anatomia do seio cavernoso e sugerir que a padronização de definições e de critérios metodológicos poderia torná-los mais úteis para este objetivo.

Microsurgical anatomy of the arterial compartment of the cavernous sinus: analysis of 24 cavernous sinus.

The cavernous sinus is a complex compartment situated in both sides of the sella turcica, being its microsurgical anatomy knowledge of fundamental importance when consider to approach surgically. We studied the arterial microanatomy of 24 cavernous sinus at the microsurgical laboratory, considering that in all the internal carotid artery were filled with colored latex. The meningohypophyseal trunk was present in 18 cases (75%) with its origin in intracavernous portion of the internal carotid artery. In relation to the 18 presented cases with meningohypophyseal trunk, 14 (77.7%) had a trifurcate and 4 (23.3%) had a bifurcate pattern. The tentorial artery was present in all. Its origin was observed, arising from the meningohypophyseal trunk in 17 (70.8%) and as an isolated artery in some extension of the intracavernous portion in 7 (29.1%). An accessory tentorial artery was found in one specimen. The dorsal meningeal artery was present in 22 cases (91.6%). Its origin was in the meningohypophyseal trunk in 17 cases (77.2%), arising from internal carotid artery in 4 cases (18.1%) and from inferior hypophyseal artery in one case (4.1%).The inferior hypophyseal artery was present in all cases, having its origin at the meningohypophyseal trunk in 16 cases (66.6%). In the remaining 8 cases (33.3%) the artery was found arising alone from the intracavernous portion also. The artery of the inferior cavernous sinus or inferolateral trunk was present in all cases and had its origin from internal carotid artery in its intracavernous segment. The McConnell's artery was not found in any cavernous sinus.

Microsurgical anatomy of the arterial compartment of the cavernous sinus: analysis of 24 cavernous sinus

O seio cavernoso é estrutura complexa localizada de cada lado da sela túrcica, sendo seu conhecimento microanatômico indispensável quando se considera abordar cirurgicamente esta região. Estudaramos em laboratório de microcirurgia a microanatomia dos componentes arteriais deste espaço em 24 seios cavernosos, sendo que em todos a artéria carótida interna estava preenchida com látex colorido. O tronco meningo-hipofisário esteve presente em 18 casos (75%). Quando ausente, as artérias constituintes deste tronco se originaram diretamente das artérias carótidas internas (ACIs) intracavernosas. Quando presente, em 14 casos (77,7%), estavam trifurcados e em 4 casos (23,3%) bifurcados. A artéria tentorial foi identificada em todos os casos, porém sua origem foi variada, ocorrendo no tronco meningo-hipofisário em 17 casos (70,8%) e na artéria carótida interna intracavernosa em 7 casos (29,1%). Em 1 caso verificou-se a presença de uma artéria tentorial acessória. A artéria meningéia dorsal estava presente em 22 casos (91,6%) e ausente em 2 casos (8,4%). Nos seios cavernosos onde a mesma foi identificada, a sua origem ocorreu no tronco meningo-hipofisário em 17 casos (77,2%), da ACI intracavernosa em 4 casos (18,1%) e da artéria hipofisária inferior em 1 caso (4,1%). A artéria hipofisária inferior foi identificada em todos os casos, tendo sua origem no tronco meningo-hipofisário em 16 (66,6%) e na ACI intracavernosa em 8 (33,3%) casos. A artéria inferior do seio cavernoso ou tronco ínfero-lateral foi isolada em 100% dos casos e em todos se originou da ACI intracavernosa. A artéria de McConnell não foi identificada em nenhum seio cavernoso.

Anatomia microcirúrgica do seio cavernoso: contribuição ao estudo da parede medial do seio cavernoso / Microsurgical anatomy of the cavernous sinus: contribution to the study of the medial wall of the cavernous sinus

Este estudo foi realizado para detalhar a anatomia microcirúrgica do seio cavernoso e esclarecer os limites, relações e componentes da parede medial do seio cavernoso. Métodos: Setenta e quatro seios cavernosos foram dissecados, sendo quarenta e quatro para estudar e identificar a parede medial do seio cavernoso e trinta para estudar a anatomia microcirúrgica do seio cavernoso. Exemplos cirúrgicos foram mostrados para ilustrar os diferentes tipos de acessos cirúrgicos à região do seio cavernoso. Utilizou-se aumento de 4 a 24 vezes, mediante uso de microscópio cirúrgico, para realizações das dissecções. / This study was conducted to detail microsurgical anatomy of the cavernous sinus and clarify the boundaries, relationships and components of the medial wall of the cavernous sinus (CS). Methods: Seventy four CS were dissected. Forty four CS were dissected to identify and clarify the medial wall of the CS and thirty CS were dissected to describe microsurgical anatomy of the CS. Illustrative clinical cases were exposed to show different accesses to the CS region. Dissections were performed under surgical microscope and 4X to 24X of magnification were used...

Estructura meningea del seno cavernoso / Meninx structure of the cavernous sinus

Objetivo: mostrar el comportamiento de las cubiertas durales que forman las paredes del seno cavernoso. Metodos: se disecaron en forma escalonada cinco cabezas de cadaveres adultos, fijadas en formol e inyectadas con silicona coloreada, mostrando las cuatro paredes del seno cavernoso. Resultados: El seno cavernoso posee cuatro paredes, las cuales estan constituidas por duramadre. Las paredes lateral, superior y posterior del seno cavernoso estan constituidas por dos hojas, una externa (dura propia) y otro interna (dura periostatica). La pared medial, constituida por dura periostica, posee dos sectores diferentes, uno superior (sector hipofisario), separado de la glandula hipofisis por la dura propia de la celda interna (dura periostica) de la pared lateral engloba a los nervios craneales III, IV y V1, mientras que la hoja interna de la pared posterior engloba al VI nervio craneal (proximal al canal de Dorello). Conclusiones: las cubiertas durales con los nervios III, IV, V1 y VI forman las paredes del seno cavernoso y constituyen su continente. Excepto el sector inferior (esfenoidal) de la pared medial, las demas paredes o sectores del seno cavernoso estan constituidas por dos hojas. El contenido del seno cavernoso esta envuelto en su totalidad por dura periostica (AU)

Morphology of the walls of the cavernous sinus of Cebus apella (tufted capuchin monkey)

The morphology of the dura mater and its relatioship with the structures of the cavenous sinus were analyzed in five tuftel capuchin monkeys (Cebus apella) using histological sections, showing that the walls of the cavenous sinus of this species are similar to those of other primates, including man. Except for the medial wall of the cavernous sinus, the remaining walls consist of two distinct dura mater layers. The deep layer of the lateral wall of the cavernous sinus is contiguous to the sheath of the oculomotor, trochlear and ophtalmic nerves. Arterioles, venous spaces, neuronal bodies and nervous fiber bundles are found on this lateral wall.

Morphology of the walls of the cavernous sinus of Cebus apella (tufted capuchin monkey).

The morphology of the dura mater and its relationship with the structures of the cavernous sinus were analyzed in five tufted capuchin monkeys (Cebus apella) using histological sections, showing that the walls of the cavernous sinus of this species are similar to those of other primates, including man. Except for the medial wall of the cavernous sinus, the remaining walls consist of two distinct dura mater layers. The deep layer of the lateral wall of the cavernous sinus is contiguous to the sheath of the oculomotor, trochlear and ophthalmic nerves. Arterioles, venules, venous spaces, neuronal bodies and nervous fiber bundles are found on this lateral wall.

Physiological importance of the conjugation of the internal carotid artery and cavernous sinus.

The author considers of utmost importance the anatomical arterial-venous conjugation represented by the internal carotid artery and the cavernous sinus, as well as the carotid venous plexus which covers the internal carotid artery within the petrous portion of the temporal bone. He believes that besides protecting the vascular arterial wall in acute episodes of hypertension, it can also contribute to the mechanism of carotid blood flow. This hypothesis is based on consideration of the physiological conditions of the cavernous sinus in relation to those of other dural venous sinuses, and of the endocranial venous system and its cavernous constitution, which differs from other venous blood canals, which have their own venous physiology and different functions. He attempts to compare it with the rest of the body areas where cavernous plexuses are located and where venous pressure reaches high values, and with other regions without this morphologic constitution. He establishes a correlation resulting from a cerebrovascular resistance mechanism, the participation of which he considers to differ from those of other dural sinuses and encephalic veins. He also emphasizes physiologically the carotid siphon and believes that its participation in the hemodynamics of a hypotensive patient who is lying down, facilitates blood access to the brain, thus avoiding anoxia and brain damage, within certain limits, and constitutes an additional means of body defense.

[Micro-mesoscopic study of the lateral wall of the human cavernous sinus]. / Estudo micro-mesoscópico da parede lateral do seio cavernoso humano.

The authors studied the structures of human cavernous sinus in its interior as well as on the lateral wall, utilizing thick, frontal, sequential sections. They show the significance of this wall, frequently used as surgical accessway to diseases encountered within this venous structure of the dura-mater.

Estudo micro-mesoscópico da parede lateral do seio cavernoso humano / Micro-mesoscopic study of the lateral wall of the human cavernous sinus

Os autores estudam as estruturas contidas no seio cavernoso humano, tanto em seu interior como na sua parede lateral, através de cortes frontais seriados espessos. Mostram a importância desta parede que é frequentemente usada como via de acesso cirúrgico às afecçoes presentes nesta estrutura venosa da dura-máter.