[Superior semicircular canal dehiscence syndrome. Embryological and surgical consideration]. / Síndrome de dehiscencia del canal semicircular superior. Aspectos embriológicos y quirúrgicos.

OBJECTIVE: Presenting the first case of superior semicircular canal dehiscence syndrome in the Spanish literature and to establish, using embryological studies, the period in wich superior semicircular canal dehiscence originates. MATERIAL AND METHODS: 52 embryos and foetuses, from 6 mm to foetal maturity, were studied. The case of a patient suffering from superior semicircular canal dehiscence syndrome is presented. RESULTS: The superior semicircular canal and the intracranial space are communicated through bony lacunae, in the period between the 24th and 28th week of foetal development, but this communication is discontinued in the 30th week. Permeability of these lacunae, later in life, could result in the development of superior semicircular canal dehiscence syndrome. The clinical results of the surgical repair of this abnormal communication, in this particular case, using a middle fossa approach and a transmastoid approach is presented. CONCLUSIONS: Superior Semicircular Canal Dehiscence Syndrome could be due to an abnormality in foetal development and its genesis, therefore, could be prenatal. Surgical repair via transmastoid approach is a reasonable alternative treatment to the middle fossa approach.

Síndrome de dehiscencia del canal semicircular superior. Aspectos embriológicos y quirúrgicos / Superior semicircular canal dehiscence syndrome. Embryological and surgical considerations

Presentar el primer caso de síndrome de dehiscencia del canal semicular superior publicado en lengua española y establecer, con estudios embriológicos, el período embriológico implicado en la génesis del síndrome. Material y métodos: Se estudian 52 series embriológicas fetales, desde 6 mm hasta recién nacidos. Se presenta el caso de un paciente que presentaba un síndrome de dehiscencia de canal semicurcular superior. Resultados: Existe una relación de continuidad, a través de lagunas óseas, entre el canal semicircular superior y el espacio intracraneal en el feto de 24 a 28 semanas pero esta relación se pierde en la semana 30. Se exponen los resultados del cierre quirúrgico de la fístula, en el paciente estudiado, con un abordaje por la fosa media y con abordaje transmastoideo. Conclusiones: El síndrome podría ser secundario a una alteración del desarrollo embriológico y, por tanto, su génesis sería prenatal. La reparación quirúrgica por vía transmastoidea es una alternativa razonable a la vía de la fosa media

Objetive: Presenting the first case of superior semicircular canal dehiscence syndrome in the Spanish literature and to establish, using embryological studies, the period in wich superior semicircular canal dehiscence originates. Material and methods: 52 embryos and foetuses, from 6 mm to foetal maturity, were studied. The case of a patient suffering from superior semicircular canal dehiscence syndrome is presented. Results: The superior semicircular canal and the intracranial space are communicated through bony lacunae, in the period between the 24th and 28th week of foetal development, but this communication is discontinued in the 30th week. Permeability of these lacunae, later in life, could result in the development of superior semicircular canal dehiscence syndrome. The clinical results of the surgical repair of this abnormal communication, in this particular case, using amiddle fossa approach and a transmastoid approach is presented. Conclusions: Superior Semicircular Canal Dehiscence Syndrome could be due to an abnormality in foetal development and its genesis, therefore, could be prenatal. Surgical repair via transmastoid approach is a reasonable alternative treatment to the middle fossa approach

[Peculiarities of the parietal organisation of the superficial temporal artery]. / Peculiaridades de la organización parietal de la arteria temporal superficial.

INTRODUCTION: The study of the structure in the arterial wall has been essential to use vessels in the coronary and cerebral bypass. The superficial temporal artery, owing to its high elastic content and its topography, close to the middle cerebral artery, has made possible the revascularization surgery in cerebral areas with ischemia. AIM. The purpose of this study is define the structure of the superficial temporal artery. MATERIAL AND METHODS: The material of the present study are 60 arteries from medico legal necropsies without apparent vascular pathology. Pieces were fixed in 10% formol, embedded in Paraplast, sectioned in sequence of 7 mm and were stained to detect elastic, collagen and reticulin fibers. Histochemical techniques have been done too. RESULTS: The superficial temporal artery shows a high elastic content, above all in the middle outer of the tunica media. The negative aspect is the great quantity of collagen in this tunica, that produces the progressive hardness of this vessel with the increase of the age. Histochemistry shows how the accumulation of acid mucosubstances interferes in the correct nourishing of the internal elastic membrane, that is disorganized in the cushions. CONCLUSION: The superficial temporal artery is an appropriate vessel to the coronary and cerebral bypass, due to its high elastic content in this tunica and the limitants. It have not been observed in our material zones without internal elastic membrane. Histochemistry shows abundant acid mucosubstances that difficult the nourishing in the arterial wall.

Peculiaridades de la organización parietal de la arteria temporal superficial / Peculiarities of the parietal organisation of the superficial temporal artery

Introducción. El estudio de la estructura de la pared arterial ha sido fundamental para la utilización de vasos en las derivaciones, tanto coronarias como cerebrales. La arteria temporal superficial (ATS), debido a su alto contenido elástico y su localización tan cercana a la arteria silviana, ha hecho posible intervenciones de revascularización en áreas cerebrales afectadas por la isquemia. Objetivo. El propósito de este estudio es definir la estructura de la ATS. Material y métodos. El material del presente estudio lo componen 60 arterias procedentes de autopsias medico-legales sin patología vascular aparente. Las piezas se fijaron en formol al 10 por ciento, se incluyeron en paraplast, se cortaron en serie a 7 µm y se tiñeron para detectar elastina, colágeno y reticulina. Además, se realizaron diversas técnicas histoquímicas. Resultados. La ATS presenta un alto contenido elástico, sobre todo en la mitad externa de la túnica media. Un dato negativo a tener en cuenta lo constituye la gran cantidad de colágeno en la túnica citada, que determina el endurecimiento progresivo de este vaso a medida que aumenta la edad del sujeto. La histoquímica demuestra que la acumulación de mucosustancias ácidas interfiere con la correcta nutrición de la membrana elástica interna (MEI), que se desorganiza, sobre todo en los cushions. Conclusión. La ATS es un vaso apropiado para las derivaciones coronarias y cerebrales, debido a su alto contenido elástico en su túnica media y limitantes. No hemos observado en nuestro material zonas carentes de MEI. La histoquímica demuestra la abundancia de mucosustancias ácidas que dificultan la nutrición de la pared arterial (AU)

[Ontogenic peculiarities of the human tympanic ossicular chain]. / Peculiaridades en la organización de la cadena osicular timpánica humana a lo largo de su ontogenia.

We have studied the development of the tympanic ossicles in 40 embryo-foetal human series aged between 32 days (6 mm) and newborn. Once performed the measurements to date chronologically embryos and foetuses, we did a meticulous dissection of temporal bones. After fix in 10% formol, decalcified with 2% nitric acid, embedded in Paraplast, sectioned in a sequence of 7 mm, and stained with Martin's trichrome. The tympanic ossicles are developed in the mesenchyme of the two first pharyngeal archs. The head of the malleus, the body and the short limb of the incus arise from the first arch while the handle of the malleus, the long limb of the incus and the mass of the stapes arise from the second arch. The vestibular side of the stapedial footplate develops in the otic capsule. The tympanic ossicles develop from endochondral ossification, while anterior process of the malleus has the membranous ossification. In their ontogenia 6 stages are observed. First stage, the formation of their sketch by mesenchimal condensation, in the second stage, "pre-cartilaginous", the cells of the primordia are differentiated into condroblasts, in the third stage "cartilaginous" the ossicles show a cartilaginous structure, in the forth stage the primary ossification centers are developed, in the fifth stage the ossicles arise in the periostic annulus and inside the endochondral bone, and in the last stage the osseous tissue grows until it acquires a compact osseous structure.

Peculiaridades en la organización de la cadena osicular timpánica humana a lo largo de su ontogenia / Ontogenic peculiarities of the human tympanic ossicular chain

Hemos estudiado el desarrollo de los osículos timpánicos en 40 series embrio-fetales humanas de edades comprendidas entre los 32 días (6 mm) y el nacimiento. Una vez realizadas las mediciones para datar cronológicamente los embriones y fetos, se llevó a cabo una minuciosa y cuidada disección de los temporales en bloque; posteriormente fueron fijados en formol al 10 por ciento, descalcificados con ácido nítrico al 2 por ciento, deshidratados en alcoholes a concentraciones progresivamente crecientes, incluidos en parafina, cortados en serie a 7 mm, y teñidos en serie con la técnica del Tricrómico de Martins. Los osículos timpánicos se desarrollan en el mesénquima de los dos primeros arcos faríngeos. La cabeza del martillo, el cuerpo y la apófisis corta del yunque se originan del primer arco mientras que el mango del martillo, la apófisis larga del yunque y la masa del estribo lo hacen del segundo. La lámina vestibular de la platina se desarrolla en la cápsula ótica. Los osículos timpánicos se desarrollan por osificación endocondral con excepción de la apófisis anterior del martillo que lo hace por osificación membranosa. En su ontogenia se observan seis estadios. En el primero se produce la formación de sus esbozos por condensación del mesénquima, en el segundo "precartilaginoso" las células de los primordios se diferencian a condroblastos, en el tercero "cartilaginoso" los osículos presentan una estructura cartilaginosa, en el cuarto se forman los centros de osificación primarios, en el quinto aparecen en los osículos el collar perióstico y en su interior hueso endocondral, y en el último estadio el tejido óseo se va extendiendo progresivamente hasta adquirir una estructura ósea compacta (AU)

We have studied the development of the tympanic ossicles in 40 embryo-foetal human series aged between 32 days (6 mm) and newborn. Once performed the measurements to date chronologically embryos and foetuses, we did a meticulous dissection of temporal bones. After fix in 10% formol, decalcified with 2% nitric acid, embedded in Paraplast, sectioned in a sequence of 7 mm, and stained with Martin's trichrome. The tympanic ossicles are developed in the mesenchyme of the two first pharyngeal archs. The head of the malleus, the body and the short limb of the incus arise from the first arch while the handle of the malleus, the long limb of the incus and the mass of the stapes arise from the second arch. The vestibular side of the stapedial footplate develops in the otic capsule. The tympanic ossicles develop from endochondral ossification, while anterior process of the malleus has the membranous ossification. In their ontogenia 6 stages are observed. First stage, the formation of their sketch by mesenchimal condensation, in the second stage, "pre-cartilaginous", the cells of the primordia are differentiated into condroblasts, in the third stage "cartilaginous" the ossicles show a cartilaginous structure, in the forth stage the primary ossification centers are developed, in the fifth stage the ossicles arise in the periostic annulus and inside the endochondral bone, and in the last stage the osseous tissue grows until it acquires a compact osseous structure (AU)

[Contribution to the development of the union between the manubrium of the malleus and the tympanic membrane in human fetus]. / Contribución al desarrollo de la unión del mango del martillo y la membrana del tímpano en fetos humanos.

The development of the union between the manubrium of the malleus and the tympanic membrane was studied in human embryo. For that purpose 25 temporal bones of human foetus, aged from 36 days (14 mm) to 29 weeks (270 mm) were analyzed. Samples were fixed in a 10% formaldehyde solution, decalcified with 2% nitric acid, embedded in Paraplast, cut in sections of 7 microns thick and stained with Martin's trichrome method. During the development a pseudojoint between the malleus and the tympanic membrane several stages were seen. In the first stage, the manubrium was adhered to membrane mesenchyme of primitive tympanum, in the second one this mesenchyme was loose and there appeared capillars in it, in the third one there were collagen fibers in a radial disposition, and in the forth stage, the hollow in the meatal plug gave independence to the tympanic membrane for the external acoustic meatus. The distal portion of the manubrium, included in tympanic membrane, has remained with a cartilaginous structure during end of the time it has been studied by us. The collagen fibers at the level of the umbo surround the manubrium, while the rest of it remains in its anterior edge.

Contribución al desarrollo de la unión del mango del martillo y la membrana del tímpano en fetos humanos / Contribution to the development of the union between the manubrium of the malleus and the tympanic membrane in human fetus

Se ha estudiado el desarrollo de la unión entre el mango del martillo y la membrana del tímpano en embriones y fetos humanos.Para ello se han utilizado 25 huesos temporales de fetos humanos, cuyas edades cronológicas van desde los 36 días (14 mm) hasta las 29 semanas (270 mm). Las muestras fueron fijadas en formol al 10 por ciento, descalcificadas con ácido nítrico al 2 por ciento, incluidas en parafina, cortadas en serie a 7 µm, y teñidas con el método Tricrómico de Martins. Se han identificado varias etapas en el desarrollo de la pseudoarticulación entre el martillo y la membrana del tímpano. En la primera el mango se adhiere íntimamente al mesénquima de la membrana del tímpano primitiva, en la segunda dicho mesénquima se hace laxo y en él aparecen capilares, en la tercera aparecen fibras de colágeno de disposición radial, y en la cuarta el ahuecamiento del tapón meatal da independencia a la membrana del tímpano del conducto auditivo externo. La porción distal del mango, incluida en la membrana del tímpano, ha permanecido con una estructura cartilaginosa durante todo el tiempo estudiado. Las fibras de colágeno a nivel del umbo rodean al extremo terminal del mango mientras que en el resto de él lo hacen solamente en su arista anterior (AU)

The development of the union between the manubrium of the malleus and the tympanic membrane was studied in human embryo. For that purpose 25 temporal bones of human foetus, aged from 36 days (14 mm) to 29 weeks (270 mm) were analyzed. Samples were fixed in a 10% formaldehyde solution, decalcified with 2% nitric acid, embedded in Paraplast, cut in sections of 7 microns thick and stained with Martin's trichrome method. During the development a pseudojoint between the malleus and the tympanic membrane several stages were seen. In the first stage, the manubrium was adhered to membrane mesenchyme of primitive tympanum, in the second one this mesenchyme was loose and there appeared capillars in it, in the third one there were collagen fibers in a radial disposition, and in the forth stage, the hollow in the meatal plug gave independence to the tympanic membrane for the external acoustic meatus. The distal portion of the manubrium, included in tympanic membrane, has remained with a cartilaginous structure during end of the time it has been studied by us. The collagen fibers at the level of the umbo surround the manubrium, while the rest of it remains in its anterior edge (AU)

[Structural peculiarities of the human cerebral communicating arteries and their repercussion in encephalic vascular pathology]. / Peculiaridades estructurales de las arterias comunicantes cerebrales humanas y su repercusión en la patología vascular encefálica.

INTRODUCTION: The cerebrovascular accidents are one of the most frequent causes of morbimortality. Most of them are caused for the break of aneurysms in communicating arteries. The weak structure of these vessels explain the reason of these accidents. OBJECTIVE: The reason of this paper is study the organization of communicating arteries as cause of this fragility. Material and methods. The material of this study is composed of 61 human cerebral communicating arteries, grouped in decades. The study has been carried out by histological routine. RESULTS: In general the structure of cerebral communicating arteries is characterized for the thinness and irregularity of the wall. In the childhood the internal elastic membrane and tunica media show thicker, while in young and adult people appear elastic fibers and reticulin as well as smooth muscle cells in tunica media. In adulthood (50 60 years) collagen in adventicia occupies tunica media, and adventicia is weaked. There are frequent media defects in these communicating arteries, that are usually repaired for conjunctive tissue stopper with abundance of collagen fibers. Starting from 4th decade the internal elastic membrane shows a great number of fenestrae through muscle and fiber tissue of media occupying subintimal space. Doubtless media defects mean the most severe threat of vascular outbreak. CONCLUSION: The structural evolution with the age of communicating arteries, with predominance of collagen over elastin and reticulin, could be their reason of fragility.

Peculiaridades estructurales de las arterias comunicantes cerebrales humanas y su repercusión en la patología vascular encefálica / Structural peculiarities of the human cerebral communicating arteries and their repercussion in encephalic vascular pathology

Introduccción. Los accidentes cerebrovasculares son una de las causas más frecuentes de morbimortalidad. Buena parte de ellos son producidos por la ruptura de aneurismas de las arterias comunicantes. La débil estructura de estos vasos explica la razón de esos accidentes. Objetivo. El motivo del trabajo estriba en estudiar la organización de la arterias comunicantes como causa de esa fragilidad. Material y métodos. El material del presente estudio lo componen 61 arterias comunicantes cerebrales humanas, agrupadas por décadas. Las piezas siguen la rutina histológica. Resultados. La tónica general en la estructura de las arterias comunicantes cerebrales es la delgadez e irregularidad de su pared. En la infancia la membrana elástica interna (MEI) y la túnica media presentan mayor grosor. En el joven y adulto aparecen en la túnica media fibras elásticas y de reticulina amén de las musculares lisas. En la madurez (50-60 años) el colágeno adventicial ocupa la túnica media y la adventicia se debilita. Son frecuentes en estas comunicantes los denominados `defectos mediales', que suelen ser reparados mediante `tapones' de tejido conjuntivo, con abundancia de fibras colágenas. A partir de la cuarta década, la MEI presenta un buen número de fenestraciones, a través de las cuales el tejido fibroso y muscular liso de la media penetra hasta el espacio subintimal. Sin duda, los defectos mediales representan la amenaza más grave de estallido vascular. Conclusión. Con la edad, la evolución estructural de las arterias comunicantes, con predominio del colágeno sobre la elástica y reticulina, puede ser el motivo de su fragilidad (AU)