Anatomical and Clinical Evaluation of Tympanic Tegmen and Mastoid Bone with Multidetector Computed Tomography / Evaluación Anatómica y Clínica del Tegmen Timpánico y Hueso Mastoideo con Tomografía Computarizada Multidetector

SUMMARY: Tegmen level and mastoid bone thickness are important parameters of surgical risk in middle ear and mastoid region surgeries. This retrospective cohort study was conducted to provide a risk classification for the mastoid and middle ear regions. The study population comprised of 300 patients who underwent multidetector computed tomography (MDCT) for various indications. Patients with no pathology that disrupted the structure of the temporal region were included in the study. A risk classification was generated by analyzing the data obtained from mastoid and tympanic tegmen depths and the mastoid bone thickness by MDCT. The mastoid and tympanic tegmen were lower on the right side than on the left. In women, the right-sided mastoid bone thickness and mastoid tegmen were lower, and low-level tympanic and mastoid tegmen on the left and thin right mastoid bones were more common. According to the risk classifications for mastoid and middle ear region surgeries, women demonstrated a higher risk than men. In addition, as the thickness of the mastoid bone increased, the levels of the mastoid and tympanic tegmen increased. The present study provides a proper risk classification that may be helpful for preoperative risk assessment prior to middle ear and mastoid region surgery.

El nivel del tegmen y el grosor del hueso mastoideo son parámetros importantes del riesgo quirúrgico en las cirugías del oído medio y la región mastoidea. Este estudio de cohorte retrospectivo se llevó a cabo para proporcionar una clasificación del riesgo en las regiones mastoidea y del oído medio. La población de estudio estuvo compuesta por 300 pacientes que se sometieron a una tomografía computarizada multidetector (MDCT) por diversas indicaciones. Se incluyeron en el estudio pacientes sin patología que alterase la estructura de la región temporal. Se generó una clasificación de riesgo analizando los datos obtenidos de las profundidades del tegmen mastoideo y timpánico y el grosor del hueso mastoideo por TCMD. El tegmen mastoideo y timpánico estaban más bajos en el lado derecho que en el izquierdo. En las mujeres, el grosor del hueso mastoideo del lado derecho y el tegmen mastoideo eran más bajos, y eran más frecuente la presencia de tegmen timpánico y mastoideo de bajo nivel en los huesos mastoideos izquierdo y delgados en el lado derecho. Según las clasificaciones de riesgo de las cirugías de la región mastoidea y del oído medio, las mujeres presentaban un mayor riesgo que los hombres. Además, a medida que aumentaba el grosor del hueso mastoides, aumentaban los niveles del tegmen mastoideo y timpánico. El presente estudio proporciona una clasificación de adecuada de riesgo que puede ser útil para la evaluación preoperatoria del riesgo antes de la cirugía del oído medio y la región mastoidea.

Facial nerve hemangioma in the middle ear / Hemangioma de nervo facial em orelha média

ABSTRACT Facial nerve hemangioma is a rare and benign vascular tumor, and accounts for 0.7% of intratemporal tumors. We report the second case described in the literature of a facial nerve hemangioma in its tympanic segment. A 14-year-old male patient presented with a history of progressive right ear hearing loss with preserved facial mimicry. Pure tone audiometry showed a right ear moderate conductive hearing loss. Magnetic resonance imaging demonstrated an expansive lesion involving the tympanic segment of the right facial nerve, suggestive of hemangioma. Watchful waiting was chosen as management. In the first case of middle ear facial hemangioma described in the literature, facial palsy was the symptom that led the patient to seek medical care. In the present case, it can be inferred that the first symptom was conductive hearing loss ipsilateral to the lesion. Facial palsy may not be present and the clinical presentation may resemble otosclerosis, ossicular chain disruption, and third window abnormalities, among other differential diagnoses of conductive hearing loss. The second case of tympanic portion facial nerve hemangioma is reported, describing the specificity of conductive hearing loss as its only clinical manifestation.

RESUMO O hemangioma do nervo facial é um tumor vascular raro e benigno, que corresponde a 0,7% dos tumores intratemporais. Apresentamos o segundo caso descrito na literatura de hemangioma do nervo facial em sua porção timpânica. Paciente de 14 anos, sexo masculino, apresentando hipoacusia progressiva em orelha direita com mímica facial preservada. A audiometria evidenciou perda condutiva moderada à direita. A ressonância magnética demonstrou lesão expansiva, comprometendo o segmento timpânico do nervo facial direito, sugestiva de hemangioma do nervo facial. A conduta foi expectante. No primeiro caso descrito na literatura de hemangioma do facial em orelha média, o sintoma que levou o paciente ao atendimento médico foi paralisia facial. No presente caso, pode-se inferir que o primeiro sintoma foi a perda auditiva condutiva ipsilateral à lesão. A paralisia facial pode não estar presente, e o quadro clínico pode se assemelhar à otosclerose, disjunção de cadeia e síndrome da terceira janela, dentre outros diagnósticos diferenciais de perdas auditivas condutivas. O artigo relata o segundo caso de hemangioma do nervo facial em sua porção timpânica, mostrando a peculiaridade de perda auditiva condutiva como única manifestação clínica.

Sinus tympani y recidiva en cirugía de colesteatoma / Sinus tympani and recidiva in cholesteatoma surgery

RESUMEN Introducción: El sinus tympani (ST) es una de las áreas que más presenta colesteatoma residual. Recientemente se ha clasificado en 3 tipos de acuerdo a su morfología. Objetivos: Determinar el tipo de ST en los pacientes sometidos a cirugía de colesteatoma y analizar su impacto como factor de recidiva. Material y método: Revisión de fichas clínicas de pacientes sometidos a cirugía de colesteatoma entre los años 2004 y 2015 en el Hospital Regional de Concepción. Análisis de la tomografía axial computarizada (TAC) preoperatoria y posterior evaluación clínica de los pacientes operados mediante mastoidectomía canal wall down (CWD). Resultados: En el periodo descrito se operaron 271 oídos. El 60% de los casos analizados presentó ST tipo A y 40% ST tipo B. Se identificaron 12 casos de recidiva, 3 ST tipo B y 9 ST tipo A, sin diferencia estadísticamente significativa entre ambos. Discusión: Distinto a lo reportado en la literatura el tipo de ST más frecuente en nuestro estudio fue el tipo A, lo que podría corresponder a una variable étnica. Conclusión: El estudio preoperatorio con TAC es una herramienta útil para evaluar el tipo y compromiso del ST. Las diferencias anatómicas entre ST tipo A y B parece no ser un factor determinante de recidiva en mastoidectomías CWD.

ABSTRACT Introduction: Sinus tympani (ST) is one of the areas with the most residual cholesteatoma. Recently it has been classified in 3 types according to its morphology. Aim: To determine the type of ST in patients undergoing cholesteatoma surgery and to analyze its impact as a relapse factor. Material and method: Review of clinical files of patients submitted to cholesteatoma surgery between 2004 and 2015 at the Regional Hospital of Concepción. Preoperative computed axial tomography (CT) analysis and subsequent clinical evaluation of patients operated by canal wall down mastoidectomy (CWD). Results: In the described period 271 ears were operated. 60% of the cases analyzed had ST type A and 40% ST type B. Twelve cases of relapse were identified, 3 ST type B and 9 ST type A, with no statistically significant difference between the two. Discussion: Unlike to what is reported in the literature, the most common ST type in our study was type A, which could correspond to an ethnic variable. Conclusion: The preoperative study with CT is a useful tool to evaluate the type and commitment of ST. The anatomical differences between ST type A and B seems not to be a determinant factor of relapse in CWD mastoidectomies.

Characterization of tympanic cavity volume in newborns using computerized tomography scanning / Caracterización del volumen de la cavidad timpánica en recién nacidos usando tomografía computadorizada

This study reports tympanic cavity (TC) volume in newborns, which was missing in the literature. Ex vivo histology and computerized tomography (CT) scans were performed on temporal bone and data were analyzed in part using software developed in house. CT images with a slice thickness of 0.5 mm were obtained from 5 newborn cadavers and analyzed independently by two expert researchers. The border of the TC was delineated manually and measurement of area of interest was calculated on masked images. Then, the area measurements from all sections were added to estimate the total volume. The agreements between the histological and CT findings were then compared for accuracy, repeatability and reliability. The Dice and Jaccard similarity coefficient measures were used as a statistical validation metric to evaluate the assessor's performance in manual volume segmentation. Good assessor agreement was observed with average Dice values above 0.8 indicating that consistent and reliable volume measurements were feasible. The proposed protocol was shown to be accurate in calculating the TC volume, and thus can be used for computer-assisted presurgical planning or for diagnosing structural alterations in TC.

El objetivo fue determinar el volumen de la cavidad timpánica (CT) en recién nacidos, información no encontrada en la literatura. Se realizaron escaners a través de tomografia computadorizada (TC) y estudios histológicos en el hueso temporal; los datos se analizaron utilizando un software desarrollado en nuestra institución. Se obtuvieron imágenes de secciones de TC, de 0,5 mm de grosor, a partir de 5 cadáveres de recién nacidos, los que fueron analizados de forma independiente por dos investigadores expertos. El margen de los cortes de TC fue delineado manualmente y la medición del área de interés se estimó sobre imágenes ocultas. Después, se añadieron las mediciones de área de todas las secciones para estimar el volumen total. Las concordancias entre el estudio histológico y los hallazgos de la TC se compararon en cuanto a precisión, repetibilidad y confiabilidad. Se utilizaron las medidas de coeficiente de similitud de Jaccard y Dice como métrica de validación estadística para evaluar el desempeño del asesor en la medición manual del volumen. Se observó una buena correlación del evaluador con los valores medios de Dice, por encima de 0,8 indicando que es factible obtener mediciones coherentes y confiables de volumen. El protocolo propuesto ha demostrado ser preciso para calcular el volumen de la CT, y por lo tanto se puede utilizar para la planificación prequirúrgica asistida o para el diagnóstico de alteraciones estructurales en la CT.

Ear teratoma; a case report

Teratomas are tumors originated from mature or immature tissues. Teratomas are made up of one embryonic layer or all three embryonic layers [endoderm, mesoderm, or ectoderm]. Herein we report a 41-year-old man who presented with vertigo, vomiting, and tinnitus. After physical examination, laboratory evaluation and performing computed tomography, cholesteatoma was diagnosed, however, during radical mastoidectomy a cystic tumor was found. The result of pathology proved middle ear and mastoid teratoma

Volume assessment of age-related conversion of the tympanic cavity by helical computerized tomography scanning

To investigate the right-left asymmetry, and gender and age groups differences of the tympanic cavities [TC] using the Cavalieri principle for volume calculation on temporal bone computerized tomography [CT] scans. This study was carried out over a 4-year period from 2000 to 2004 at Firat University, School of Medicine, Elazig, Turkey. The areas of the cavities were measured using trace and area measurement functions of CT scanner, and by multiplying the area by slice thickness [0.2 cm] and the volume of each slice was calculated. By summing all volumes of every slice based on the Cavalieri principle for volume calculation, the total volumes were obtained and analyzed. The mean [SD] volumes of right and left tympanic cavities in males were 0.52 [0.15] versus 0.55 [0.14] cm3 and in females were 0.45 [0.16] versus 0.49 [0.14] cm3, and there were statistically significant differences between males and females in both right and left sides [p=0.028 and p=0.043]. There was a statistically significant difference in left TC volumes between age groups [p=0.019]. However, no differences by age were noted for right TC volumes [p=0.065]. A strong correlation was found between right and left volumes. However, there were no strong correlations between age and volumes of right and left cavities in both males and females, although the volumes increased by aging. These results should help surgeons and radiologists to update their knowledge for evaluation of the middle ear region