Abstract
To assess the eustachian tube function by impedance audiometry (Toynbee’s test) in patients of mucosal type of chronic otitis media (inactive stage) and to assess the correlation of eustachian tube function with the results—i.e., success or failure of tympanoplasty in these patients in terms of graft uptake. This was a prospective observational study carried out over one and half years in Department of E.N.T. & Head and Neck Surgery, a tertiary care hospital. The study group comprised of eighty-seven patients who were diagnosed with chronic otitis media mucosal type- inactive stage and were planned for tympanoplasty or tympanoplasty with cortical mastoidectomy. Written informed consent was taken from all patients. The eustachian tube function was assessed preoperatively by impedance audiometry (Toynbee’s test). The surgical outcome was tested by looking at the status of the tympanic membrane postoperatively. The surgical outcome in terms of whether a defect was present in the tympanic membrane was compared with the preoperative eustachian tube function. 98.6% of patients with successful surgical outcome had normal eustachian tube function preoperatively while the neo-tympanic membrane was intact in 63.63% and 33.33% of patients with pre-operative partially impaired and grossly impaired eustachian tube function respectively. From our study, we concluded there was a strong association between functioning eustachian tube and graft uptake in tympanoplasty. So eustachian tube plays important role in successful outcome of surgery.
Keywords: Eustachian tube function, Toynbee’s test, Tympanoplasty
Introduction
The eustachian tube is a dynamic conduit between the middle ear and nasopharynx. Three main functions of eustachian tube are ventilation and regulation of middle ear pressure, clearance of middle ear secretions, and protection against nasopharyngeal sound pressure and reflux of nasopharyngeal secretions. A properly functioning eustachian tube is an integral part of a normally functioning middle ear and existence of good mucociliary drainage constitutes a favorable prognostic factor in the outcome of middle ear reconstructive surgery [1].
The results of treatment, as well as the long-term prognosis of both mucosal and squamosal types of otitis media is dependent upon the proper functioning of the eustachian tube. Hence, assessment of eustachian tube function is of paramount importance before any surgery of chronic otitis media as well as establishing an etiological basis. The modern impedance audiometer helps in to assess the physiological functioning of the eustachian tube when tympanic membrane is intact as well as in presence of tympanic membrane perforation. In Impedance audiometry, Toynbee’s test is essential tool to assess eustachian tube function in perforated tympanic membrane [2].
Our present study was undertaken to assess the eustachian tube function in patient with chronic otitis media (mucosal type) with reference to treatment outcome. Based on impedance audiometry (Toynbee’s test) findings, patients of mucosal type of chronic otitis media were categorized as normal, partially impaired and grossly impaired eustachian tube function. All patients were taken up for tympanoplasty with or without cortical mastoidectomy and follow up otoscopic assessment done after 3 months post operatively.
Objective
To assess the eustachian tube function by impedance audiometry (Toynbee’s test) in patients of mucosal type of chronic otitis media (inactive stage).
To assess the correlation of eustachian tube function with the results—i.e., success or failure of tympanoplasty in mucosal type of chronic otitis media (inactive stage) in terms of graft uptake
Methods
Study type: Prospective observational.
Sample size: Sample size is 87 as per calculation.
It was conducted in ENT department at a Tertiary health care hospital over a one and half year period from March 2020 to August 2021.
All the data were entered on Excel sheet® and analyzed. All the quantitative data were summarized in the form of Mean ± SD. The difference between mean value of all groups was analyzed using Chi Square test in Open EPI software. All the qualitative data were summarized in the form of numbers and percentage. Data presented in the form of charts wherever applicable. The levels of significance and α error were kept 95% and 5% respectively, for all statistical analysis. P value < 0.05 was considered as Significant (S) and > 0.05 as Nonsignificant (NS).
Inclusion criteria
All patients belonging to both genders in the age group of 15–60 years, having chronic otitis media with dry central perforation and willing to give written and informed consent.
Exclusion criteria
Patients below 15 years and above 60 years of age, having active (wet) central perforation, retraction pockets and cholesteatoma or not willing to give written and informed consent.
This was a prospective observational study carried out over one and half years in Department of E.N.T. & Head and Neck Surgery, at a tertiary care hospital. The study group comprised of eighty-seven patients who were diagnosed with chronic otitis media mucosal type- inactive stage and were planned for tympanoplasty or tympanoplasty with cortical mastoidectomy.
A detailed history and thorough otorhinolaryngological examination were carried out in all the patients to rule out any septic focus of infection in nose and paranasal sinus which might influence the outcome of surgical procedure. In history, symptoms of ear discharge, impaired hearing, tinnitus, ear pain, cough, nasal discharge, sneezing and throat complains were all taken into consideration. All patients were subjected to otoscopy, oto-microscopy, anterior rhinoscopy, X-ray both mastoids (Schuller’s view), pure tone audiometry, impedance audiometry, diagnostic nasal endoscopy and routine blood investigations. All patients with chronic otitis media of squamous type and those who did not turn up for follow up following surgery were excluded.
The eustachian tube function was assessed preoperatively by impedance audiometry (Toynbee’s test). In this study, we have utilized inter-acoustics impedance audiometer AZ-26 for assessing the functional status of eustachian tube.
Eustachian tube function was assessed by Toynbee’s test. In this test impedance audiometer was programmed to increase or decrease the air pressure (+ 300 to − 300 mm of water) in the middle ear and then patients were asked to swallow repeatedly to ascertain whether positive/negative pressure was being neutralized partially with each swallow. The air pressure in the middle ear was monitored and recorded graphically with impedance audiometry.
Patients were categorised into 3 groups based on this test:
Normal eustachian tube function: Positive/negative pressure should be partially neutralized with each swallow and in 3–5 swallows it was totally neutralized.
Partially impaired eustachian tube function: If some residual pressure persisted even after 5 swallows.
Grossly impaired: No pressure changes after repeated swallowing.
Surgical procedure
Patients with normal, partially impaired and grossly impaired eustachian tube function were taken up for Tympanoplasty with or without cortical mastoidectomy under general anesthesia after getting pre-anesthetic fitness. All patients were operated by experienced surgeons using post-aural approach.
Post-operative follow-up
Appropriate antibiotics, analgesics and antihistamines were given for 2 weeks. Mastoid bandage was changed on 2nd post-operative day. Patients were followed up weekly for one month and biweekly for next 2 months (Table 1).
Table 1.
Postoperative follow-up
| Postoperative day | Followup |
|---|---|
| 7 DAYS | Suture removal and antibiotics with antihistamines |
| 15 DAYS | Examination of wound and treatment with antibiotics and antihistamines |
| 30 DAYS | Otoscopic examination of graft and treatment with antihistamines |
| 60 DAYS | Otoscopic examination of graft |
| 90 DAYS | Otoscopic examination of graft uptake |
Ethical approval
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
Informed consent
Informed consent was obtained from all individual participants included in the study.
Results
Total 87 patients were enrolled for this study. All of these patients with dry central pars tensa perforations of the tympanic membrane due to COM were divided into three groups based on the eustachian tube function test:
Normal function
Partially impaired
Grossly impaired
All 87 patients were posted for surgery and followed up after 3 months for otoscopic examination to assess the surgical outcome.
Highest number of patients were in the younger age group (21–30 years). Out of total 87 patients, 21 patients were male and 66 patients were female. The male to female ratio was 1:3.14. Most common complaint was ear discharge in the past, complained by 94.25% of patients, followed by earache found in 82.75% patients, decreased hearing in 65.51% and tinnitus was found in 4.59% patients.
Toynbee’s test was performed for all 87 patients preoperatively. Out of 87 patients normal eustachian tube function test in 73 patients, partially impaired in 11 patients and grossly impaired in 03 patients. Post-operative examination of neo-tympanic membrane with otoscopy was done for all the patients in the study; 80 patients had intact neo-tympanic membrane and 7 patients had defect in neo-tympanic membrane (Table 2).
Table 2.
Comparison between pre-op Toynbee’s test and post-op neo-tympanic membrane status
| Toynbee’s test | Post-op neo tympanic membrane status | Total patients | P value | |
|---|---|---|---|---|
| Intact | Defect | |||
| Normal | 72 | 01 | 73 | < 0.01 |
| Partially impaired | 07 | 04 | 11 | |
| Grossly impaired | 01 | 02 | 03 | |
| 80 | 07 | 87 | ||
98.6% of patients with successful surgical outcome had normal eustachian tube function preoperatively while the neo-tympanic membrane was intact in 63.63% and 33.33% of patients with pre-operative partially impaired and grossly impaired eustachian tube function respectively (Table 3).
Table 3.
Comparison of successful surgical outcome with preoperative ETF test
| Toynbee’s test | Successful surgical outcome (%) |
|---|---|
| Normal ETF | 98.6 |
| Partially impaired ETF | 63.63 |
| Grossly impaired ETF | 33.33 |
Discussion
The tubal dysfunction is one of the most important factors responsible for failure of reconstructive middle ear surgery [3]. Hence a pre-operative eustachian tube function test is important for achieving successful outcome of tympanoplasty [4]. A properly functioning eustachian tube is an integral part of a normally functioning middle ear and the existence of good tubo-tympanic mucociliary drainage constitutes a favorable prognostic factor in the outcome of reconstructive surgery of the middle ear [5, 6]. In our study on 87 patients with COM (mucosal type), the preoperative ETF significantly correlated with the outcome after surgery. Patients with normal ETF showed a good graft uptake when compared with those with impaired ETF.
In our study, the predominant age group was mainly the young population. This reflects a higher disease burden in the younger population. Toynbee’s test was performed for all 87 patients. Out of 87 patients normal eustachian tube function in 73 (83.90%) patients, partially impaired eustachian tube function in 11 (12.64%) patients and grossly impaired eustachian tube function in 03 (3.44%) patients. A successful outcome of surgery was seen in 80 (92%) of patients while in 7 (8%) patients the result was unsuccessful.
In our study, post-operative examination of neo tympanic membrane was done for all the patients. Out of 87 patients, 7 patients had defect in neo tympanic membrane while 80 patients had intact neo tympanic membrane. In our study a positive correlation was seen between the ETF and result of surgery. In 73 patients with normal ETF, 72 patients (98.6%) had successful graft uptake at 3 months post operatively whereas in 11 patients with partially impaired (63.63) and 3 patients with grossly impaired ETF (33.33%) showed successful graft uptake in 7 and 1 patients respectively. Hence, better eustachian tube function was found to be directly proportional to the result of Tympanoplasty (p < 0.01). This result was comparable to similar studies done globally by Hemalatha et al. [1], Suresh Babu Undavalli et al. [3], Abhinav Srivastava et al. [4], Kanchan Rahul Tadke et al. [5], Kanagamuthu Priya et al. [7], Cohn et al [8], Adel El-Antably et al. [9], Shiromany et al. [10], Waleed Moneir et al. [11] (Table 4).
Table 4.
Comparison of post-operative successful surgical outcomes with ETF amongst various studies
| Study | Postoperative successful surgical outcome | ||
|---|---|---|---|
| Normal ETF | Partially impaired ETF | Grossly impaired ETF | |
| Hemalatha et al. [1] | 96% | 83% | 64% |
| Suresh Babu Undavalli et al. [3] | 87.5% | – | 0% |
| Abhinav Srivastava et al. [4] | 91.1% | – | 65.63% |
| Kanchan Rahul Tadke et al. [5] | 94.87% | – | 85.71% |
| Kanagamuthu Priya et al. [7] | 100% | 98% | 76% |
| Cohn et al. [8] | 95% | 75% | 69% |
| Adel El-Antably et al. [9] | 83.3% | – | 60% |
| Shiromany et al. [10] | 90.2% | 63.3% | 0% |
| Waleed Moneir et al. [11] | 97.73% | 80% | 20% |
| Present study | 98.6% | 63.63% | 33.33% |
Conclusion
In our study, the correlation between preoperative eustachian tube function and surgical outcome in terms of graft uptake was statistically analyzed using a Chi square test and independent T test, which showed p value was < 0.01 proving to be statistically highly significant. Hence, there was a strong association between functioning eustachian tube and graft uptake. So eustachian tube played important role in successful outcome of surgery.
So, we conclude that all patients of chronic otitis media (mucosal type) should undergo eustachian tube function test preoperatively using the impedance audiometry (Toynbee’s test) which is simple, quick, non-invasive and accurate. It has good predictive value in outcome of surgery. If the tubal function is found deranged preoperatively, corrective medical and surgical measures can be taken to correct tubal function in order to get good surgical outcome. Assessment of eustachian tube function by impedance audiometry can be valuable tool in the otologist’s diagnostic armamentarium.
Abbreviations
- COM
Chronic otitis media
- ETF
Eustachian tube function
Funding
No funding sources.
Declarations
Conflict of interest
None declared.
Ethical approval
The study was approved by the Institutional Ethics Committee.
Footnotes
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
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