|Year : 2015 | Volume
| Issue : 1 | Page : 51-56
Relationship between Eustachian tube function and location of the perforation in chronic otitis media
Avick Kumar Das1, Himanshu Varshney2, Subhradev Biswas1, SK Ghosh1, Jitendra Varshney3
1 Department of Otorhinolaryngology, Institute of Postgraduate Medical Education and Research, Kolkata, West Bengal, India
2 Department of Otorhinolaryngology, Sri Sai Hospital, Moradabad, Uttar Pradesh, India
3 Department of Clinical Pharmacy, Sri Sai Hospital, Moradabad, Uttar Pradesh, India
|Date of Web Publication||10-Mar-2015|
Dr. Himanshu Varshney
Department of Otorhinolaryngology, Sri Sai Hospital, Delhi Road, Moradabad, Uttar Pradesh
Source of Support: None, Conflict of Interest: None
Background: Eustachian tube function (ETF) has been the center of focus as a prognostic factor because of its presumed primary role in the pathogenesis of otitis media and clearance of the middle ear cavity. There is a general agreement that adequate ETF is necessary for middle ear surgery. In this study, the incidence of ET dysfunction and its patency has been evaluated in inactive mucosal variety of chronic otitis media, in relation to the types of central perforation. Materials and Methods: A cross-sectional study was done with 54 patients presenting with inactive mucosal type of chronic otitis media. All the recruited patients were first examined clinically and under microscope and then their audiological (impedance audiometry) and radiological assessment of mastoid was done. Alongside otoendoscopy, nasal endoscopy, dye test were done. In all these cases, other routine investigations were also performed. Results: Impedance audiometry offers an easy means of assessing ETF. The automatic Toynbee test can be a practical, objective and suitable method to assess ventilatory function of ET. The saccharin test is a simple, cost-effective and is valuable diagnostic tool to assess the mucociliary function of the ET. Mucociliary and ventilatory function may vary in the same patient. Saccharin test and methylene blue tests are comparable. Patients having poor saccharin test, methylene blue test, and ventilatory test are more prone to develop central perforation posterior to the handle of the malleus. The most frequent abnormal finding at nasal endoscopy was edema about the tubal orifice. Conclusion: A clinically useful test for ETF is still lacking. Impedance audiometry offers an easy means of assessing ETF. Ventilatory function of ET which is the single most important contributory factor in the pathogenesis of chronic otitis media should be evaluated with the objective method before tympanoplasty.
Keywords: Central perforation, Chronic otitis media, Eustachian tube function
|How to cite this article:|
Das AK, Varshney H, Biswas S, Ghosh S K, Varshney J. Relationship between Eustachian tube function and location of the perforation in chronic otitis media
. Indian J Otol 2015;21:51-6
|How to cite this URL:|
Das AK, Varshney H, Biswas S, Ghosh S K, Varshney J. Relationship between Eustachian tube function and location of the perforation in chronic otitis media
. Indian J Otol [serial online] 2015 [cited 2020 Sep 27];21:51-6. Available from: http://www.indianjotol.org/text.asp?2015/21/1/51/150600
| Introduction|| |
Chronic otitis media is typically a persistent disease of middle ear cleft with permanent abnormalities of tympanic membrane (TM), insidious in onset, often capable of causing severe destruction and irreversible sequel and clinically manifests with discharge from ear and hearing loss. Eicherwald and Stroder (1985) stated that the Eustachian tube More Details (ET) dysfunction is believed to be important in the pathogenesis of chronic otitis media.  ET function (ETF) has been the center of focus as a prognostic factor because of its presumed primary role in the pathogenesis of otitis media and clearance of the middle ear cavity.  There is a general agreement that adequate ETF is necessary for good middle ear surgery results. 
Inflammation in middle ear disease is related to ET dysfunction, and postoperative restoration of middle ear integrity and hearing is closely related to ETF in patients with chronic ear disease.  Better results after tympanoplasty have been reported in patients with normal ETF  and higher failure rates after tympanoplasty have been observed in patients with ET problems.  It might therefore be possible to predict postoperative results such as hearing improvement and disease recurrence, and to choose optimal operative methods like tympanostomy tube insertion, tympanoplasty, cortical mastoidectomy etc., if ETF can be assessed preoperatively.  Assessment of ETF is of paramount importance not only before undertaking any surgery for suppurative otitis media but also in establishing its etiological basis.
| Materials and Methods|| |
We conducted a study at the otorhinolaryngology out-patient department (OPD) of Institute of Postgraduate Medical Education and Research (IPGME and R)/SSKM Hospital, Kolkata, India. Patients having inactive mucosal type of chronic otitis media were included in the study. Prior to study initiation, the protocol and informed consent documents were approved by the Institutional Ethics Committee.
The patients in the age group of 18-60 years attending ENT OPD with inactive mucosal type of chronic otitis media were thoroughly examined clinically, audiologically, radiologically, and under microscope.
The patients below 18 years and above 60 years were not selected in the study. Patients having active mucosal variant, squamous type of chronic otitis media and patients having any sensorineural deafness were excluded from this study. Patients with any congenital anomaly in the ear were also excluded.
A total of 54 patients was included in the study.
All the recruited patients were first examined clinically and under microscope and then their audiological and radiological assessment of mastoid was done. Alongside otoendoscopy, nasal endoscopy, dye test were done. In all these cases, other routine investigations were also performed.
Cross-sectional study statistical analysis was performed on the intent-to-treat (ITT) population.
- Patency of ET by means of methylene blue dye test
- Saccharin test for mucociliary function of ET
- Ventilatory dysfunction of ET was measured by impedance audiometry (MAICO MI44 diagnostic impedance audiometer, Class 1)
- Nasal endoscopy and otoendoscopy to rule out any anatomical abnormality of ET openings.
Methylene blue dye test
Two to three drops of sterile methylene blue dye were placed inside the middle ear, at the ET opening, through the TM defect under microscope. Then the nasopharyngeal end of the ET was examined with a nasal endoscope (4 mm, 30° rod telescope) for the appearance of the dye and the interval noted. The results of this test were classified into three groups as follows: The normal methylene blue clearance time (MBCT) was taken as < 10 min, 10-20 min as partial dysfunction, and more than 20 min as gross dysfunction.
With the patient seated, under microscopic control, two Sweetex pellets were placed in the middle ear, at the ET opening, through the TM defect. The time required for the patient to taste the saccharin (i.e. saccharin perception time [SPT]) was then measured. The results of this test were classified into three groups as follows: The normal SPT was taken as < 20 min, 20-45 min as partial dysfunction and more than 45 min as gross dysfunction.
Toynbee test with impedance audiometry
The test was carried out for a fixed duration of time (for 60 s). Normally, a positive or negative middle ear pressure partially neutralized with each swallow, and in three or four swallows the positive or negative pressure totally neutralizes, that is, it become 0 mm of water pressure. If some residual pressure persists even after five swallows, the ETF is considered to be partially impaired. If the positive or negative pressure built up by the impedance audiometer cannot be neutralized at all by repeated swallowing then, the ETF is considered to be grossly impaired. 
Otoendoscopy and nasal endoscopy
With the use of an otoendoscope (1.9 mm, 30° rod telescope), the size and site of perforation were noted and tabulated. The perforations were divided into three groups: Anterior to handle of the malleus, posterior to handle of the malleus, and subtotal perforation. In the case of medium and large central perforation, the quadrant that was predominantly involved was taken into account. The condition of middle ear mucosa, annulus, handle of the malleus, and remnants of TM were also noted. Opening of ET was also noted.
| Results and Analysis|| |
A total of 54 patients was recruited to be included in the ITT population. There were no dropouts. The age of the patients ranged from 18 to 60 years, and the majority were in the age group of 20-40 years (75.93%) that is, 41 patients with a median age of 32.83 years. There were 30 (55.55%) males and 24 (44.44%) females among which 25 (46.3%) were Hindu, and 29 (53.7%) were Muslims.
With regards to perforation, 23 (42.59%) patients had subtotal perforation; others had medium size central perforation. Among 31 patients with medium size central perforation, 20 (37.04%) patients had perforation anterior to the handle of malleus while 11 (20.37%) had perforation posterior to the handle of malleus [Table 1].
Pure tone audiometry showed that 35 (64.82%) patients had conductive hearing loss between 26 and 40 dB, 17 (31.48%) patients had conductive hearing loss between 41 and 55 dB and 2 (3.70%) patients, who also had subtotal perforation, had mixed hearing loss (around 55 dB) [Table 1].
Majority of perforation patients (72.22%) had normal mucociliary clearance time (mean SPT: 12.65 min) [Table 2].
Majority of the patients (75.93%) had normal anatomical patency of ET while gross dysfunction was limited to 3.7% patients only [Table 3].
Gross dysfunction in saccharin test happened only in those patients with gross dysfunction of methylene blue dye test, as also partial dysfunction being similar (20.37% in methylene blue dye test compared to 24.07% in saccharin test) [Table 2] and [Table 3].
In the case of normal saccharin test, mean SPT had been 12.65 min with SD 2.260 while in partial dysfunction mean SPT had been 29.00 min with SD 5.370.
In the case of normal methylene blue dye test, mean MBCT had been 7.62 min with SD 0.98 while in partial dysfunction mean MBCT had been 14.91 min with SD 1.934.
Overall, the mean value for SPT time was 18.025 min; while MBCT was 9.785 min.
While studying Toynbee test, it is observed that partial dysfunction was present in 57.42%, and gross dysfunction was seen in 7.41% [Table 4].
Of all the patients incorporated in our study, one patient had abnormal Toynbee test in the presence of normal mucociliary and patency tests [Table 5].
Patients having poor saccharin test, methylene blue test, and ventilatory test are more prone to develop central perforation posterior to the handle of the malleus [Table 5].
The most frequent abnormal finding at nasal endoscopy was edema about the tubal orifice.
| Discussion|| |
Bluestone ascribes at least three physiological functions to the ET:
- Equalizing the pressure between the atmosphere and middle ear
- Protecting the middle ear from nasopharyngeal sound pressure and secretions; and
- Draining secretions from the middle ear into the nasopharynx.
The functional unit composed of the tensor veli palatine muscle, the lateral lamina of the tubal cartilage, the Ostmann fat pad, and the lateral suspensory ligament has the effect of dilating the upper portion of the tubal lumen while compressing the lower portions of the lumen. This creates a bidirectional mechanism that transports air toward the tympanic end of the tube and mucus toward the pharyngeal end. This mechanism is particularly active in the tubal segment where the Ostmann fat pad is most prominent, that is, the posterolateral portion of the cartilaginous tube just before the isthmus. This concept is supported by the absence of cilia in the roof area of the tube and the abundance of goblet cells in the lower portions. 
A functional ET is an integral part of a normal middle ear and thus is an essential requirement for optimum results in the management of chronic otitis media. Although some authors mentioned that ET dysfunction is not a risk factor for chronic otitis media (COM), , the majority agree that the obstruction of ET has an important role in COM, especially tubotympanic variety. ,, Besides the biomechanical and mucosa-related factors that can compromise tubal function, a recent study points to a lack of coordination between the action of the tensor veli palatini muscle and the act of swallowing as a potential cause of tubal dysfunction.
The study was conducted at ENT OPD of IPGME and R/SSKM Hospital, Kolkata. Patients selected from a pool of daily attendance through screening by subjecting them to our inclusion and exclusion criteria.
Eustachian tube dysfunction is one of the contributing factors in the pathogenesis of chronic otitis media. Its tests are usually not routinely performed as they are not easily available and also difficult to do. Methylene blue test and saccharin test has an additional disadvantage of keeping the patient in given position. Moreover, their validity and reproducibility are also not constant. Of the battery of all tests, we selected to evaluate anatomical patency by methylene blue dye test, mucociliary function by saccharin perception test, and ventilatory function by Toynbee test.
During the time of the test, it was ensured that the patient was not suffering from any catarrhal stage. Negative ventilatory function was repeatedly checked at different times before giving the final result.
Of total 54 patients, 23 patients (42.59%) had subtotal perforation, 20 patients (37.04%) had central perforation anterior to handle of malleus, and 11 patients (20.37%) had central perforation posterior to handle of malleus. Subtotal perforation had the highest representation in the study followed by perforation anterior to handle of the malleus. In our study, mild conductive deafness was most frequent (64.82%) while mixed deafness was found in only two patients (3.7%) with subtotal perforation. Moderate conductive loss was found in all patients with central perforation posterior to handle of the malleus and in 26.09% of subtotal perforation. Moderate conductive deafness was found in 31.48% of patients. This correlates with the observation by Prasad et al. who found the incidence of mild, moderate, and mixed deafness 63%, 34%, and 3%, respectively. 
Saccharin test and methylene blue test predicting mucociliary function and anatomical patency respectively are found to be normal in the majority (72.22-75.93%) of cases. Elbrøond and Larsen [3 ] suggested that the dye, owing to its liquid form, gravitates through the ET to the nasopharynx rather than being actively transported. Hence, the principal objective of the dye is to establish the anatomical presence or absence of tube patency. Moreover, the results of saccharine test and methylene blue tests are comparable. This is because saccharin perception test depends on both anatomical and physiological patency. 
Prasad et al.  in their study found that the mean value for SPT time was 17.583 min; MBCT was 8.145 min. In the saccharin test, normal ETF was found in 74.41%, partial dysfunction in 22.09%, and gross dysfunction in 3.48% of patients. In the methylene blue dye test, normal ETF was found in 77.90%, partial dysfunction in 18.60%, and gross dysfunction in three patients 3.48% of patients. In my study, the mean value for SPT time was 18.025 min; MBCT was 9.785 min. This again establishes that saccharin test and methylene blue test are comparable; to note it closely matches the observation in my study.
The relationship between time of transport and type of perforation was studied by Giménez and Marco-Algarra  Mucociliary and equipressive ETF was studied, using saccharin solution (5% sodium saccharinate) and tubal manometry, respectively, in 58 years with chronic disease undergoing tympanoplasty. The position of the perforation site determines the results as the poorest results are obtained from the posterior ones, having positive cases (47%) and mean transport time (37.7 min), compared to the greater percentage of positive cases (86%) and mean transport time (22.2 min) for anterior perforations. From the above study, it is clearly observed that the mucociliary function was best in ears with anterior perforations and worst in posterior perforations. Subtotal perforations showed intermediate results. Prasad et al.  also found same results as described by Giménez and Marco-Algarra  They found that ETF was poor in 52.94% cases among the patients with the posterior perforation. Vallés et al.  found contrasting results in their study and their best results corresponded to posterior perforations, whereas worst cases were subtotal perforations.
In my study, mucociliary function is best in the ear with anterior perforations and the results are very similar to those of Giménez and Marco-Algarra  and Prasad et al.  The differences suggest the existence of the relationship between mucociliary transport and the site of perforation. The varying topography of the perforation would thus influence the integrity of the mucociliary system, or also the better or worse condition of the latter would influence the appearance of one type of perforation, or another. 
Priya et al.  did ETF by Toynbee test with impedance audiometer in tubotympanic type of chronic otitis media. They found dysfunction in 76% cases (gross dysfunction in 17% cases and partial dysfunction in 59% cases). In 1993, Mink and Bauer  studied tubal function in 68 patients with unilateral traumatic perforation and 116 years of 94 patients of chronic suppurative otitis media by equalization manometry. The values attained in traumatic group were regarded as normal, only 25% with dry central perforation and none with an infected central perforation had normal ETF.
In my study, it is found that in Toynbee test majority of the patients (57.42%) had partial dysfunction. It correlates with the studies by above-mentioned authors. So perhaps ventilatory function, which is partly dependent on anatomical patency and mucociliary function, is the single most important contributory factor in the pathogenesis of chronic otitis media.
In subtotal perforation, saccharin test and methylene blue test were found normal in majority of the patients (73.9% and 69.6%, respectively) but Toynbee test was abnormal in most of the patients (partial and gross dysfunction in 60.9%).
In cases with perforation anterior to handle of malleus, normal saccharin test, and methylene blue test were found in most of the patients, whereas ventilatory function was affected in 60% of the patients (partial and gross dysfunction). In central perforation posterior to handle of malleus, saccharin test was dysfunctional in majority of the patients (partial and gross dysfunction in 63.6%); methylene blue test was affected in 45.5% (partial and gross dysfunction) and Toynbee test was affected in 81.8% (partial and gross dysfunction) patients.
Hence, patients having poor saccharin test, methylene blue test and ventilatory test are more prone to develop central perforation posterior to the handle of the malleus. Incidence of such gross dysfunction causing central perforation posterior to handle of the malleus are relatively less as central perforation posterior to handle of the malleus contributed to only 11 out of total 54 cases (20.37%).
| Conclusion|| |
A clinically useful test for ETF is still lacking. Opinions have differed on the value of preoperative tubal function tests in chronic otitis media. But from the above study, it can be said that:
- Impedance audiometry offers an easy means of assessing ETF.
- Ventilatory function of ET should be evaluated with the objective method before tympanoplasty. The automatic Toynbee test can be a practical, objective and suitable method.
- The saccharin test is a simple, cost-effective, and is valuable diagnostic tool to assess the mucociliary function of the ET.
- Mucociliary and ventilatory function may vary in the same patient.
- Saccharin test and methylene blue tests are comparable.
- Ventilatory function which is partly dependent on anatomical patency and mucociliary function is the single most important contributory factor in the pathogenesis of chronic otitis media.
- Patients having poor saccharin test, methylene blue test, and ventilatory test are more prone to develop central perforation posterior to the handle of the malleus.
| Acknowledgments|| |
The authors wish to acknowledge with gratitude the approval and logistical facilities extended by the director, IPGME and R/SSKM Hospital, Kolkata, India for conducting this study. We are also thankful to colleagues in the Department of Otorhinolaryngology, IPGME and R/SSKM Hospital, Kolkata, India for referring subjects for recruitment.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]