|Year : 2014 | Volume
| Issue : 4 | Page : 178-182
Evaluation of outcomes of tympanoplasties with and without cortical mastoidectomy
Assistant Professor of Ear, Nose and Throat, Malabar Medical College Hospital and Research Centre, Kozhikode, Kerala, India
|Date of Web Publication||13-Dec-2014|
Assistant Professor of Ear, Nose and Throat, Malabar Medical College Hospital and Research Centre, Modakkallur, Atholi, Kozhikode 673 315, Kerala
Source of Support: None, Conflict of Interest: None
Context: Even today well-trained and experienced otologists remain divided as to the importance of combining mastoidectomy with tympanoplasty in the treatment of chronic non-cholesteatomatous otitis media. We performed a comparison of patients with postinfectious simple tympanic membrane perforations treated with tympanoplasty or with tympanoplasty combined with intact canal wall mastoidectomy, in terms of outcome. Aims: The aim of the study was to evaluate the outcomes of tympanoplasties with and without cortical mastoidectomy in terms of graft uptake rate and hearing improvement. Settings and Design: A combination of retrospective and prospective cohort study. Materials and Methods: A total of 65 patients undergoing tympanoplasty with or without cortical mastoidectomy were included in the study and were followed up for a period of one year for the graft uptake and hearing improvement. Statistical analysis used: Fisher's exact test and chi square test. Results: In our study, there was no significant difference in the graft uptake rate or the hearing improvement in both these groups. Conclusions: As per this study, it can be concluded that the addition of cortical mastoidectomy to type I tympanoplasty did not improve the graft uptake rate or the hearing improvement in cases of chronic suppurative otitis media tubotympanic disease.
Keywords: Cortical mastoidectomy, Tympanoplasty with mastoidectomy, Tympanoplasty
|How to cite this article:|
Sagesh M. Evaluation of outcomes of tympanoplasties with and without cortical mastoidectomy. Indian J Otol 2014;20:178-82
| Introduction|| |
The management of chronic otitis media has witnessed a profound change during the past century, from the early attempts at surgical exposure of the middle ear in 1889, to the present day techniques of tympanoplasty with canal wall up or down surgeries. Well-trained, experienced otologists currently remain divided as to the importance of mastoidectomy in the treatment of chronic non-cholesteatomatous suppurative otitis media. The use of mastoidectomy as a means to establish drainage of a complicated infection of the ear sparks little controversy. However, the use of mastoidectomy to treat chronic drainage or suppuration from uncomplicated otitis media remains an issue of debate.
Some authors have thought that mastoidectomy is justified in cases of chronic suppurative otitis media, which have been refractory to maximal antibiotic therapy and is essential for the complete clearance of the disease process.  However, others have argued that mastoidectomy is not just unnecessary when treating chronic noncholesteatomatous suppurative otitis media but also increases patient risks with little or no significant advantage in clinical outcome.
When attempting to examine the effect of mastoidectomy on patients treated surgically for otitis media, it becomes evident that an objective analysis is often difficult because subjective assessments are frequently required to consider many factors that affect surgical outcomes. We performed a comparison of patients with postinfectious simple tympanic membrane perforations treated with tympanoplasty or without tympanoplasty combined with intact canal wall mastoidectomy. The study was specifically limited to patients with a persistent non-traumatic tympanic membrane perforation, a history of otitis media, no presence of cholesteatoma, and no active evidence of infection.
Aim of the study
The aim of the study was to evaluate the outcomes of tympanoplasties with and without cortical mastoidectomy in cases of chronic otitis media (mucosal disease) in terms of graft uptake rate and hearing improvement.
| Materials and Methods|| |
This study was conducted in the department of ENT at a tertiary care hospital for a period of one and a half years from February 2007 to August 2008. The patients were selected randomly from those undergoing ear surgeries in the department, with complaints of ear discharge or hearing loss. A total of 65 patients undergoing tympanoplasty with or without cortical mastoidectomy were included in the study. All these patients were followed up for a period of one year.
A combination of retrospective and prospective cohort study was conducted. A total of 65 patients who underwent tympanoplasty with or without mastoidectomy were selected randomly and their clinical details were reviewed in a retrospective manner. Later these patients were followed up prospectively to assess the surgical outcome and clinical course in terms of graft uptake rate and improvement in hearing.
A group of 65 patients undergoing type I tympanoplasty (Wullstein and Zollner) with or without cortical mastoidectomy, for chronic otitis media mucosal disease, were selected randomly for the study. Only type I tympanoplasties were included to avoid any disparities in the ossicular pathologies and their reconstruction, which would alter the results of the study and make it more complicated.
Of the total 65 patients who had undergone tympanoplasty, 23 patients had type I tympanoplasty alone, while the other 42 had type I tympanoplasty with cortical mastoidectomy. The patients in the study group were thus divided into two - the 1 st group, Group A comprising patients who had type I tympanoplasty without cortical mastoidectomy; and the 2 nd group, Group B that included patients undergoing type I tympanoplasty with cortical mastoidectomy.
Both these groups were assessed intraoperatively for the size of the perforation, status of the middle ear, any ossicular chain abnormality and presence of tympanosclerotic patch. When cortical mastoidectomy was done, the findings in the mastoid antrum and air cells and the patency of the aditus were noted.
All these cases were reviewed retrospectively to assess the presenting symptoms, duration of complaints, hearing loss, last episode of ear discharge, otoscopic findings, degree of hearing loss and mastoid pneumatization. The degree of hearing loss was noted based on the tuning fork tests and pure tone audiometry results.
All cases with active evidence of infection as indicated by the duration of discharge free period being less than three weeks or the otoscopy showing active discharge in the middle ear were excluded from the study. All patients with general medical illnesses like diabetes, hypertension, tuberculosis etc., were excluded from the study. Those patients with symptomatic deviated nasal septum, chronic sinusitis, allergic rhinitis, chronic tonsillitis and other middle ear pathologies like ossicular fixity or damage were not considered for the study.
All the patients were put on broad-spectrum antibiotics prior to the surgery; informed consent was taken and had overnight fasting. The patients were operated under local anesthesia, by the same surgeon to avoid any confounding factors in the technique of surgery or the skill of the surgeon. A postaural William Wilde incision was used in all the cases. Temporalis fascia was used as the graft material in all the patients. The mastoid antrum was opened by drill work and a complete cortical mastoidectomy was done in the second group of patients. The patency of the aditus was checked and the findings in the mastoid antrum noted. Any block in the aditus was cleared and an underlay type I tympanoplasty was done in all the cases. Postoperatively the broad-spectrum antibiotic was continued, together with analgesics and systemic decongestants. Suture removal was done on the seventh postoperative day.
The patients were further followed up at 3 weeks, 3 months, 6 months and 1 year to assess the status of the ear, graft uptake and hearing improvement in terms of closure of the air-bone gap at 3 months. The postoperative findings in both these groups were compared and the results were analyzed.
Group A included patients who underwent type I tympanoplasty without cortical mastoidectomy, comprising 23 patients. Group B included those patients who had type I tympanoplasty with cortical mastoidectomy, with a total of 42 patients in this group. The different intraoperative findings, the clinical data of the patients and other confounding variables in both these groups were analyzed and compared. On retrospective analysis, it was found that all the patients had history of ear discharge, while the other complaints included hearing loss, tinnitus and ear ache. The average hearing loss in Group A was 30.6 dB (highest 50 dB and lowest 20 dB) and that in Group B was 36.2 dB (highest 50 dB and lowest 18 dB).
Analyses of results
The patients were followed up at 3 weeks, 3 months, 6 months and at 1 year. A successful graft uptake was defined as the closure of the tympanic membrane perforation either fully or partially (including cases with small residual perforations). The status of the tympanic membrane at the end of one year was taken as the result.
In Group A, of the 23 cases, the graft was successfully taken up in 21 cases (91.3%), of which 1 case had a small residual perforation and the graft failed to take up in 2 cases. In Group B, the graft was successfully taken in 39 cases of the total 42 patients (93%) and failed in 3 cases [Table 1]. One patient in Group A and two patients in Group B, in whom the graft had failed, had postoperative infection in the middle ear. One case had a small residual perforation in the anterior quadrant. A Fisher's exact test was employed to analyze the results for statistical significance. The P value obtained was 1, which showed that the difference in the results were not statistically significant and was merely due to chance. Alternatively, a chi square test also showed the results to be insignificant (P = 0.82) with the P value being >0.05.
The hearing improvement after the surgery was assessed in terms of closure of the air-bone gap based on the pure tone audiometry done at 3 months. The hearing improvement was considered successful if the air-bone gap closure was better than or equal to 10 dB. In Group A, an air-bone gap closure ≥10 dB was noted in 18 cases (78.1%) with the average air-bone gap closure being 15.1 dB. In the remaining 5 cases that failed, the graft was not taken up in 2 cases while the other 3 had an improvement less than 10 dB. In Group B, a successful hearing improvement was noted in 34 out of the 42 cases (81%) with an average air-bone gap closure of 15.3 dB. The graft had not taken up in the 3 cases that did not show any hearing improvement after tympanoplasty with cortical mastoidectomy and in the remaining 5 cases improvement was less than 10 dB [Table 2]. Though the difference in the hearing improvement between the 2 groups may appear significant in the first look, a statistical analysis of the results using the Fisher's exact test and a chi square test (P value 0.79) showed the difference to be insignificant. Thus, the relatively better hearing results obtained in Group B might be due to different selection bias.
With regard to the surgical complications, no intraoperative or postoperative complications occurred in both the study groups, except for the small residual perforation in one case in each group. Regarding the symptom relief, all the patients in whom the graft had taken up had a subjective symptom relief both in terms of cessation of ear discharge and hearing improvement, except for 2 patients in Group A and 3 patients in Group B.
| Discussion|| |
Many authors have recommended mastoidectomy in conjunction with tympanic membrane grafting to increase graft success in revision tympanoplasty. The primary argument in favor of mastoidectomy has been an improvement in the middle ear and mastoid environment through clearance of diseased mucosa and through the ventilatory mechanisms of an open mastoid system. Opponents of mastoidectomy argue that the mastoid air cell system is thought to function, at least in part, as a buffer to the changes in pressure within the middle ear. The functional advantage of a large aerated mastoid was first suggested by Holmquist and Bergstrom  and, later, was substantiated by Sade et al.,, and Richards et al. It is theorized that when an aerated mastoid communicates well with the middle ear, it acts as a buffering system to reduce the impact of pressure changes experienced by the middle ear. The presence of a pneumatized mastoid greatly increases the volume of the middle ear and mastoid system, which, in accordance with Boyle's law, can moderate pressure changes in the middle ear cleft. Thus in a well-pneumatized mastoid, significant changes in middle ear pressure will likely have little effect on the middle ear and tympanic membrane owing to the buffering action of the mastoid air cell system. Hence, the pneumatized mastoid should not be disturbed by mastoidectomy. Although this physiological concept is certainly well supported in the literature, very few papers actually compare the success of tympanoplasty with and without the addition of mastoidectomy.
As cited by Yoon et al., the overall success rate of tympanoplasty, with or without mastoidectomy, in the treatment of chronic pediatric otitis media, was high and did not depend on patient age, the status of the contralateral ear, the inclusion or absence of surgical mastoidectomy, or the method of mastoidectomy (when this procedure was employed). In a study conducted by Mishiro Y et al., comparing the results of tympanoplasties with and without mastoidectomy in non-cholesteatomatous chronic otitis media, it was found that there was no statistically significant difference in graft success rate between discharging ears and dry ears. They concluded that mastoidectomy is not helpful in tympanoplasty for non-cholesteatomatous chronic otitis media, even if the ear is discharging. McGrew et al.,  attempted to compare the surgical outcome of tympanic membrane perforation repair with and without canal wall up mastoidectomy. Tympanic membrane repair was equally effective in both groups and the hearing results were comparable. They proposed that cortical mastoidectomy was not necessary for successful repair of simple tympanic membrane perforations.
In our study by using temporalis fascia as the graft material, we obtained a graft uptake rate of 91.3% in patients who had tympanoplasty alone and 93% in patients who had tympanoplasty with cortical mastoidectomy. In the present series, tympanoplasty combined with intact canal wall mastoidectomy offered no significant improvement over tympanoplasty alone, in the rate of closure of tympanic membrane perforations. As per this study, it can be concluded that mastoidectomy is not necessary for successful closure of tympanic membrane perforations in chronic suppurative otitis media tubotympanic disease, excluding the cases with reservoir of infection.
Our results are comparable to that in the study conducted by McGrew et al., where they had a graft take-up rate of 91.6% and 90.6% in patients who had tympanoplasties with and without cortical mastoidectomy, respectively. Though they had found no significant difference in the graft uptake between the groups, in the long-term follow-up, a better clinical outcome was noted in patients who had tympanoplasty with cortical mastoidectomy. These patients had shown absence of disease progression along with reduction in the number of patients requiring subsequent procedures was noted in this group. In a study conducted by Yoon et al.,in 119 cases, no significant difference was noted in the graft uptake rate when mastoidectomy was combined with tympanoplasty. Mishiro Y et al., obtained a graft success rate of 90.5% in tympanoplasty with cortical mastoidectomy and 93.3% in patients who had tympanoplasty alone. There was no statistically significant difference between the two and it was concluded that mastoidectomy is not helpful when combined with tympanoplasty for non-cholesteatomatous chronic otitis media, even if the ear is discharging. Balyan et al., have reported equivalent results of graft uptake and hearing result with or without mastoidectomy in their series of 323 tympanoplasties. They argued that mastoidectomy is usually not necessary for treatment of patients with non-cholesteatomatous chronic otitis media.
The hearing improvement that we obtained in terms of air-bone gap closure ≥10 dB, were 78.1% in the tympanoplasty group and 81% in the mastoidectomy group, with the average closure being 15.1 dB and 15.3 dB, respectively. In their study, McGrew et al., got an average air-bone gap closure of 17.6 dB in the tympanoplasty group and 11.4 dB in the mastoidectomy group, but with no significant difference between the two on statistical analysis. In the study by Mishiro Y et al., the rates of the postoperative air-bone gap within 20 dB were 81.6% in the first group and 90.4% in the latter, without a statistically significant difference. Even in our study the difference in hearing improvement between the two groups were not statistically significant. In our study, the graft was not taken-up in 5 cases and 2 patients had a small residual perforation. About 20% cases in each group did not have a satisfactory hearing improvement. The cause of graft failure must have been postoperative infection.
Though several authors support the theory that mastoidectomy improves the chance of successful tympanoplasty for patients with non-cholesteatomatous chronic otitis media, none prove that the addition of mastoidectomy yields better surgical results than tympanoplasty alone. When considering the addition of a mastoidectomy to a tympanoplasty, the performing surgeon should consider not only the potential added benefit but also potential risks and costs to the patient. As a result, it is incumbent on each surgeon to define this risk for his or her own procedures, review the relative risk, and account for it in determining whether a mastoidectomy is appropriate in each case.
The demerits of this study are that the number of patients in both the groups is comparatively less than that required for an effective epidemiological study. Moreover, the duration of follow-up is short and no long-term analysis of disease progression, re-perforation or the need for subsequent procedures has been made.
| Conclusions|| |
Tympanoplasties with and without cortical mastoidectomy in cases of chronic suppurative otitis media (tubotympanic disease) showed no significant difference in outcome. The addition of cortical mastoidectomy to type I tympanoplasty did not improve the graft take-up rate or the hearing improvement in cases of chronic suppurative otitis media tubotympanic disease. Thus, cortical mastoidectomy is not necessary in cases of uncomplicated tympanoplasties.
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[Table 1], [Table 2]