Prognostic Factors For Hearing Results After Canal Wall Down Mastoidectomy With Tympanoplasty

BackgroundAs the ear microsurgery techniques and image display technology for chronic suppurative otitis media (CSOM) rapidly developed, the treatment of CSOM has been made over the past to remove the focus and to prevent complications, and gradually turned to thoroughly remove the disease in middle ear, at the same time, the hearing reconstruction was done, so as to reconstruct the ossicles, patch the tympanic membrane and form the middle ear cavity full of air to restore or improve the hearing. The middle ear surgery is the main method to treat CSOM. At present, the middle ear surgery includes Canal Wall Up Mastoidectomy with Tympanoplasty and Canal Wall Down Mastoidectomy with Tympanoplasty. The Canal Wall Down method is easily done. It removes the focus thoroughly and was easy to observe postoperative. Now it is still the treatment of CSOM of one of the most basic method. But about the acceptable postoperative listening effect, report results are different from each other. Some scholars at home and abroad had observed the effect factors may influence the results after Canal Wall Down Mastoidectomy with Tympanoplasty, but these analyses most were one-way analysis, and some results contradicted each other. Because the postoperative hearing effects related the preoperative hearing, the extent of disease, the ossicles, as well as the treatment intro-perative and postoperative closely, and several factors may effect the results at the same time. Therefore, this study through the research of CSOM after hearing reconstruction would analyze the factors with logistic analysis, so as to find out the influence factors, to guide the treatment of CSOM, to assist surgical technique and determine the attention. So the patients would get a better recovery.Methods100cases of CSOM with surgical treatment all by the Otology of the First Affiliated Hospital of Zhengzhou University were followed up after surgery from January2010to January2011.There were47of male cases and53of female cases account for all the100cases. The patients aged from14to76years and the average age was39.2±12.7. The medical history ranged from3months to60years, and the average was13.5±14.6years. The left ears was49, and the right ears was51, and both ears was2. Otorrhea and progressing hearing decrease were the major symptom in all cases, and other symptoms included35of tinnitus,7of ear pain,1of vertigo. The examination showed that there were no obvious perforation with the tympanic membrane in7ears, and little perforation on the pars flaccida or the pars tensa in55ears, and great perforation on the tympanic membrane in33ears, and there were full of granulation tissue in the external auditory canal in7ears. PTA, acoustic immittance measurement, CT scan and Eustachian tube function testing (by using acoustic immittance measurement and Valsalva method) were perpetrated for all the patients preoperative. All patients underwent Canal wall down mastoidectomy with Tympanoplasty. The remaining of the ossicles were detected intro-operatively. The PORP was used if the stapes was intact, and the TOPR was selected if the absence from stapes superstructure for ossicular reconstruction. All patients had a outpatient service review after1week left hospital,1month,3months,6months and12months postoperative. All patients had a Valsalva method to examine the eustachian tube based on the growth of the tympanic membrane a month later. All patients were reviewed the PTA after the3rd,6th,12th month. Hearing loss assessment was based on the PTA and0.5,1,2and4kHz were averaged for calculating air conduction and air bone gap. According to the literature,we choose9factors may effect the results. They were the kind of pathologic, the stapes, the tensor tympanic muscle, the mucosa, the Eustachian tube, the type of ossicular chain, the material of ossicular chain complications and reoperation. All patients were followed up more than12months. The last check result was adopted for assessing the hearing result. The AC and ABG were expressed using the mean±standard deviation. SPSS17.0statistical package was chose to analyse the data, and logistic regression analysis and Rank test or Kruskal-Wallis test to compare the results. P<0.05was thought to have differences with a statistical significance.Results1Surgical ResultsThe ears dried between6and12weeks postoperative, the average7.2±2.3.We used the Valsalva method to examine the eustachian tube. There were25cases of patients whose Eustachian tube was blocked, and there were18cases at the12th month. The average preoperative AC was46.7±9.1dB and ABG was32.9±9.4dB. The average postoperative AC was34.9±9.0dB,and ABG was23.7±8.9dB at12th month. The AC reduced12.1±13.7dB,and ABG8.2±12.6dB. The follow-up was between6months and18months, the average time was13.6±1.5months.None of the patients were followed-up for recurrence.2Prognostic Factors for Hearing Results after Canal Wall Down Mastoidectomy with TympanoplastyThe prognostic factors were analyzed using multivariate analysis with logistic regression.9factors affecting the results were analysed by the statistics methods. The factors were the kind of pathologic, the stapes, the tensor tympanic muscle, the mucosa, the Eustachian tube, the type of ossicular chain, the material of ossicular chain complications and reoperation. Multivariate analysis should be investigated prognostic factors of favorable short-term hearing outcomes after ossiculoplasty. Existing of stapes and tensor tympanic muscle, normal function of eustachian tube were significantly favorable predictive factors.ConclusionAuditory effects after tympanoplasty are influenced by a series of factors. The condition of stapes, tensor tympanic muscle and normal function of Eustachian tube are the major ones. It reveals that reasonable operation method is selected basing on the remaining and the activity of the stapes, and unclogged the Eustachian tube preoperative and intro-perative, and as far as possible to keep the tensor tympanic muscle to maintain the shape of the tympanic membrane are the main factors to improve hearing postoperative.