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
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.