Influencia auditiva de la pared posterosuperior del conducto auditivo externo, en la hipoacusia de conducción postimpanomastoidectomía / Hearing influence of the posterior ear canal wall, in the conductive hearing loss after tympanomastoidectomy

RESUMEN Introducción: El tratamiento de la otitis media crónica (OMC) colesteatomatosa es quirúrgico, cuyo objetivo es erradicar la enfermedad, evitar complicaciones y prevenir recurrencias. El gold standard es la timpanomastoidectomía con canal wall down (TCWD). Estudios en cadáver han definido que TCWD disminuye la audición 1-5 dB en frecuencias <1.000 Hz y 0-10 dB entre 1.000 y 3.000 Hz. De aquí nuestro interés por definir la influencia acústica de la pared posterosuperior del conducto auditivo externo (CAE). Objetivo: Determinar en cuantos decibeles se corrige la audición al reconstituir pared posterior del CAE pos-TCWD. Material y método: Trabajo experimental. A pacientes pos-TCWD se reconstituye de manera transitoria la pared posterior del CAE, realizándose audiometría pre y posprocedimiento. Resultados: 23 pacientes (25 oídos), promedio 48,8 años (18-72 años). En 96% existió una diferencia favorable al reconstruir la pared posterior, presentando una mejoría auditiva entre 1,2 y 10,6 dB (4,2 ± 2,8 dB). En frecuencias <1.000 Hz la mejoría fue de 6,0 dB (p <0,001), entre 1.000-3.000 Hz fue 2,6 dB (p <0,001) y >3.000 Hz no hubo diferencia. Considerando PTP de vía aérea la mejoría fue 4,6 dB (p <0,001). Conclusión: Nuestro estudio demuestra que existe mejoría auditiva en la gran mayoría de oídos evaluados al reconstituir la pared posterosuperior del CAE, alcanzando 6 dB en frecuencias <1.000 Hz y 2,6 dB en frecuencias medias. Si consideramos los PTP de vía aérea la mejoría es de 4,6 dB en presencia de pared posterior.

ABSTRACT Introduction: Cholesteatomas treatment is surgical and the goals are complete resection of it, to prevent complications and recurrences. The gold standard operative technique is canal wall down tympanomastoidectomy (CWDT), which reduces the recurrence rate lower than 2%. Studies on human temporal bones have defined that CWDT causes a decrease of 1 to 5 dB at frequencies below 1000 Hz and 0 to 10 dB between 1000 and 3000 Hz. Aim: To determine how many decibels the hearing is improved by reconstituting the posterior wall of the ear canal (EC) in patients after CWDT. Material and method: Experimental study. In patients after CWDT, the posterior wall of EC was reconstructed temporarily. Audiometry was performed before and after the procedure. Results: 23 patients were enrolled (25 ears evaluated). Average age 48.8 years (range 18 to 72 years). In 96% of the ears there was a difference after the procedure with a hearing improvement of 4.2 ± 2.8dB. In frequencies below 1000 Hz, hearing improvement was 6.0 dB (p<0.001), between 1000-3000 Hz, the improvement was 2.6 dB (p<0.001) and >3000 Hz there was no difference. When considering the airway-conduction pure tone average (PTA), the difference was a 4.6 dB improvement (p<0.001). Conclusions: Our study shows that there is a hearing improvement in the vast majority of ears that were evaluated by reconstituting the posterior wall of the EC, reaching a gain of 6 dB at frequencies <1000 Hz and 2,6 dB at mid frequencies. Considering the airway PTA, the improvement is 4.6 dB in the presence of posterior canal wall.

Comparative hearing outcomes of tympanostomy tubes and combined with adenoidectomy for pediatric otitis media effusion treatment:a Meta-analysis / 实用医学杂志

Objective To investigate the hearing outcome efficiency of tympanostomy tubes and when combined with adenoidectomy for otitis media with effusion treatment. Methods A systematic literature review of tympanostomy tubes and tympanostomy tubes combined with adenoidectomy were performed using PubMed, EMBASE,the Cochrane Library,MEDLINE,all of the included studies were randomized controlled trial. The quality of included studies was evaluated according to the Risk of Bias Table of the Cochrane Handbook. Data were analyzed with Review Manager 5.02 software. Heterogeneity was examined,and forest plot was drawn. Results All of the included 4 studies were randomized controlled trials. At 6 month follow-up patients,the tym-panostomy tubes and tympanostomy tubes combined with adenoidectomy had no difference in hearing improvement (WMD = 1.06,95%CI-0.18 ~ 2.29,P = 0.09). At 12 month follow-up patients,the tympanostomy tubes com-bined with adenoidectomy were better than tympanostomy tubes alone(WMD = 3.03,95%CI 0.91 ~ 5.14,P =0.005). Conclusions The meta analysis result reveals that tympanostomy tubes combined with adenoidectomy have an advantage in long term follow up time for hearing improvement in children's otitis media with effusion treatment.