ABSTRACT
Abstract The mastoid emissary vein connects the posterior auricular vein to the sigmoid sinus and varies in size, number, location, and course, resulting in clinical complications. This study was conducted in response to the vast clinical implications associated with this vein. The aim of this review is to highlight and describe the prevalence, varied morphology, and morphometry of the mastoid emissary vein, how these varied parameters cause clinical complications, and how these can be rectified and avoided. A literature survey was conducted using various databases and different terms related to mastoid emissary vein were used to search the literature. Pitfalls related to surgery in the vicinity of this vein and their remedies were elucidated. The literature search revealed that the prevalence, morphology, and morphometry of mastoid emissary veins vary immensely and are responsible for morbidity and mortality. Pre-operative identification of mastoid veins is thus essential and so multidetector computed tomography of the temporal bone should be scheduled before planning surgery.
Resumo A veia emissária mastóidea que conecta a veia auricular posterior ao seio sigmoide pode variar em tamanho, número, localização e curso, resultando em complicações clínicas. O objetivo desta revisão é destacar e descrever a prevalência, variação morfológica e morfometria da veia emissária mastóidea, além de como esses parâmetros causam complicações clínicas e como corrigi-las e reduzi-las. Foram conduzidas buscas em diversas bases de dados utilizando diferentes termos relacionados à veia emissária mastóidea. As armadilhas relacionadas a procedimentos cirúrgicos realizados nas proximidades dessa veia e as respectivas soluções foram descritas. A pesquisa na literatura revelou que a prevalência, a morfologia e a morfometria da veia emissária mastóidea variam imensamente, sendo responsáveis por alta morbidade e mortalidade. Portanto, a identificação da veia mastóidea deve ser realizada no pré-operatório através de tomografia computadorizada multidetectores do osso temporal, antes do planejamento cirúrgico.
ABSTRACT
Background: Non metric cranial variants have always been a topic of considerable interest for research workers, as they possess racial, regional and sex dimorphic differences. These variants are also of anthropometric, genetic, morphological and forensic importance. Material and Methods: 71 skulls from north indian region were studied to analyse the prevalence of variations in number and location of mastoid foramen and to draw significant inferences. Results: Prevalence of absent mastoid foramen is 5.19%, while bilateral prevalence of absent mastoid foramen is only 1.29%, however unilaterally mastoid foramen is absent in 3.9%. Prevalence of single, double, triple and quadruple mastoid foramina was 75.97%, 19.48%, 1.95% and 2.6% respectively. Amongst all mastoid foramina in 71 skulls, 23.38% foramina were exsutural, out of which 20.13% were present on temporal bone and 3.25% were present on occipital bone. Conclusions: Findings are discussed and compared with other global studies and are found to be of considerable racial and regional significance. Knowledge of this variant can be valuable in some neurosurgical procedures.
ABSTRACT
Las descripciones anatómicas del foramen mastoideo (FM) y la vena emisaria mastoidea (VEM) son escasas en la literatura. Dicho conocimiento es fundamental para realizar un abordaje quirúrgico de la fosa craneal posterior o región mastoidea. El objetivo del estudio fue determinar la prevalencia, variantes y características morfométricas del FM y VEM en población mexicana. Se evaluaron 176 hemicráneos por dos observadores independientes cegados el uno del otro, se determinaron la prevalencia, número y características morfométricas. La prevalencia del FM entre los dos lados fue de 75% con una mayor frecuencia de forámenes del lado izquierdo comparado con el lado derecho; respecto al número de forámenes se encontraron 108 hemicráneos con un foramen único, 22 con doble foramen y 2 con triple foramen. La prevalencia del FM y VEM fue de 75%, siendo la variante única la más frecuente.
The anatomic descriptions of mastoid foramen (MF) and mastoid emissary vein (MEV) are lacking in the literature. This knowledge is fundamental for the surgeon who is about to perform surgery of the posterior fossa or mastoid region. This study aims to determine the prevalence of MF and MEV in Mexican population, determine the morphometric characteristics of MF and describe possible variations in the number, size, location and asymmetry. In this study 88 craniums were evaluated (176 hemicranium) by two independent observers who did not have access to information of each other´s results. The prevalence, number and the morphometric characteristics were determined. MF prevalence of the two sides of the skull was 75 % with a higher frequency of the left foramina compared to the right side; in reference to the number of foramina we found 108 hemicranium with a single MF, 22 double and 2 triple foramen. In conclusion, the prevalence of MF and MEV in this study is 75%, this single variant noted as being the most frequent.
Subject(s)
Humans , Veins/anatomy & histology , Mastoid/blood supply , Prevalence , Cross-Sectional Studies , Observational Studies as Topic , Mastoid/anatomy & histology , MexicoABSTRACT
Background: Non metric cranial variants have always been a topic of considerable interest for research workers, as they possess racial, regional and sex dimorphic differences. These variants are also of anthropometric, genetic, morphological and forensic importance. Material and methods: 71 skulls from north indian region were studied for one of such variant, absence of mastoid foramen and presence of multiple mastoid foramen. Results: Incidence of absent mastoid foramen is 7.04 %, while bilateral incidence of absent mastoid foramen is only 1.4 %, however unilaterally mastoid foramen is absent in 5.63 %. (2.8 % on right side and 2.8 % on left side). Incidence of multiple mastoid foramina is 12.67 %, out of this it is bilateral in 8.45 %, however unilaterally it is present in 4.22 %. ( 1.40 % on right side and 2.81 % on left side).Conclusions: Findings are discussed and compared with other global studies and are found to be of considerable racial and regional significance. Knowledge of this variant is valuable in some neurosurgical and otolaryngeal procedures.
ABSTRACT
The mastoid foramina and the superficial mastoid canals at the mastoid area are well known to have much clinical and anthropological significances. However, few sutdies on these structures were reported. Authors performed this study to analyze those structures of the Korean men, and compared with other populations. The existence, number, location of matoid foramen, distance from the posterior border of the opening of external acoustic meatus were measured. In addition, the existence, shape and the direction of the superficial mastoid canals were investigated. The results were as follows; 1. Among the 67 skulls of Korean men, there was no mastoid foramen on both sides in 1 case. In 10 cases, there was mastoid foramen on right side only, and in 4 cases left side only. In 52 cases (77.6%), there was mastoid foramen on both sides. 2. In the incidence of mastoid foramen, 1 in 27 cases, 2 in 23 cases and 3 in 11 cases on the right side, and 1 in 25 cases, 2 in 22 cases and 3 in 17 cases on the left side were found. 3. 64.0% of mastoid foramina located on the temporal bone, 28.5% were on the occipitomastoid suture, 5.2% were on the occipital bone, 1.9% were on parietomastoid suture, and 1 case on the parietal bone. 4. In the sidedness of mastoid foramen, 1-1 foramen on each side was 15 cases, 2-2 foramina on each side was 10 cases, 1-2 foramina on right-left side was 8 cases, and 0-0 on each side, 2-4 on right-left side, and 4-3 on right-left side were 1 case respectively. 5. The average diameter of mastoid foramen was 2.0+/-0.69 mm, and the distance from the posterior margin of the external acoustic meatus was 33.6+/-3.69 mm. There was no significant differences between right and left sides. 6. The superficial mastoid canals appeared in 23 cases (34.3%), among which 12 cases were on right side and 11 cases were on left side. 14 canals were straight in shape, 2 were grooved, and others were arched, sigmoid or bridged. 21 canals directed toward parietal bone and others directed occipital bone. According to the above results, the existence, number, size and the distance from external acoustic meatus of mastoid foramina, and the incidence, shapes and directions of superficial mastoid canals were much variable. Of course, these variations would have great clinical significances during the neurosurgical and otolaryngeal surgery. These data would contribute to study epigenetic study of minor variations of skull and anthropological study.