Contralateral Ear in Patients with Chronic Otitis Media

Abstract

Objectives: To evaluate the opposite ear in patients operated for chronic otitis media (COM).Methods: In a cross-sectional study involving three tertiary hospitals, patients who underwent surgery for COM were examined for abnormalities of the contralateral ear at the time of the surgery. Results: Out of 228 patients, 182 (79.8%) were operated on for non-cholesteatomatous or simple chronic pars tensa perforation of the tympanic membrane (PTP), and 46 (20.2%) for cholesteatoma. 113 (49.56%) patients had normal contralateral ears under oto-microscopic exam. PTP was statistically more prevalent in females than males (F/M:118/64), whereas cholesteatoma was more prevalent in males (21/25). In the PTP group, 82 (45.3%) had normal contralateral ears, whereas patients with cholesteatoma had 31 (67.4%) normal opposite ears (P = 0.01). The most frequent abnormal findings in the PTP group were pars tensa perforation and sclerotic plaques, and in the cholesteatoma group were cholesteatoma and pars tensa perforation. Patients with cholesteatoma had significantly lower contralateral ear perforation than patients with tympanic membrane perforation (P = 0.02). The most frequent size of eardrum perforation in the contralateral ear of the PTP group was more than 50 percent. No significant difference existed between the large and small perforations for contralateral abnormality. Conclusion: Bilateral pathophysiology seems to be more prominent in PTPs than in cholesteatomas. Tympanic membrane perforation tends to be accompanied by a large perforation. The larger perforation on one side did not predict having more problems on the opposite side.

Introduction

Chronic otitis media (COM) is still an important public health issue even in the modern era. The prevalence of COM varies widely globally, from as high as 46% in the Inuits of Alaska to as low as less than 1% in highly industrialized nations [1].

There are several types of COMs. For simplicity, it may be classified as COM with or without cholesteatoma. In the COM without cholesteatoma category, we may have a chronic perforation of the tympanic membrane in the absence of middle-ear infection or the presence of intermittent infectious otorrhea. It may also have concomitant tympanosclerosis in all types. In these various types of COM, no single theory may explain the pathogenesis of even one type of it. Genetic, environmental, or both factors have been considered to be involved in the progression to the chronic state, as well as craniofacial growth and variations in craniofacial anatomy [2]. Eustachian tube malfunction is most often discussed in the literature for the pathogenesis of COM. However, it cannot fully explain the development of the disease.

One of the debating points is that if a malfunctioning Eustachian tube or a bilateral influencing pathogenesis could be expected, pathologic findings should be somehow similar on the two sides. This study was conducted to evaluate the condition of the opposite ear in patients with COM on whom our research group operated.

Materials and Methods

A cross-sectional, observational study was conducted in the otolaryngology department of three tertiary care hospitals in different regions of Iran from July 2022 to July 2023. Ethical approval was obtained from the Research Ethics Committee of our institute (Code: IR.SBMU.RETECH.REC. 1400.549).

Patients aged between 18 and 60 years old with chronic otitis media who underwent ear surgery were enrolled in this study. Exclusion criteria included refusal to participate in the study, patients with a history of previous ear surgery, including ventilation tube insertion in any ear, patients with concomitant diabetes, perennial allergy, history of cleft palate or craniofacial abnormalities, history of ear or head trauma.

A data gathering sheet for recording the demographic data as well as ear examination, audiological test results, tomography reports, the type of surgery, and surgical findings was carefully prepared. All contralateral ears were examined at the end of the operation by the senior surgeon with a surgical microscope just before the termination of general anaesthesia.

Perforation of the pars tensa of the tympanic membrane according to its size and location was classified into four groups; Anterior and less than 50%, Posterior and less than 50%, Inferior and less than 50%, and any prominent location with more than 50%.

The classified definition of microscopic ear and surgical findings are shown in Fig. 1. Pars tensa atelectasis or retraction was classified by modifying Sade´ and Berco's classification [3]. Pars flaccida retractions were classified into four stages according to Tos’s classification [4]. Cholesteatoma was classified by a modification to Jackler’s [5] classification.

Fig. 1.

Definition of microscopic ear and surgical findings

Statistical analysis was performed by IBM SPSS Statistics for Windows, version 26 (IBM Corp., Armonk, NY, USA), using simple t-test, Chi-square, and Fisher's exact test as indicated. P-values less than or equal to 0.05 were considered statistically significant.

Results

228 patients were evaluated in this study. 89 (39%) of patients were male, and 139 (61%) were female. The mean age was 39.97 ± 12.03. 182 (79.8%) patients were operated on for a non-cholesteatomatous or simple chronic pars tensa perforation of the tympanic membrane (PTP), and 46 (20.2%) for a cholesteatoma. Two patients had concomitant PTP and attic cholesteatoma (one type 1 and one type 2 cholesteatoma).

There were 25 (54.3%) male and 21 (45.7%) female cholesteatoma patients, and it was statistically significant (P < 0.001). There were 64 (35.2%) male and 118 (64.8%) female PTP patients and females were significantly more than males (P < 0.001). Each type of PTP and cholesteatoma found on the operated side is shown in Table 1.

Table 1.

Pars tensa perforation and cholesteatoma’s types on the operated side

Operated ear; n, (%)
Pars tensa perforation type	1	14 (8.1%)
	2	32 (17.2%)
	3	22 (11.8%)
	4	114 (61.3%)
Cholesteatoma type	1	3 (1.3%)
	2	15 (6.6%)
	3	14 (6.1%)
	4	10 (4.4%)
	5	4 (1.8%)

Of 228 patients in this study, 113 (49.56%) had completely normal contralateral ears under microscopic exam. Figure 2 shows the distribution of otomicroscopic findings in the contralateral ear. In patients with PTP, 82 (45.3%) had normal contralateral ear, whereas patients with cholesteatoma had 31 (67.4%) normal opposite ears. (P = 0.01).

Fig. 2.

Otomicroscopic findings in the contralateral ear

The most frequent abnormal findings in the PTP group were pars tensa perforation, sclerotic plaques, neotympanum, pars flaccida retraction, and pars tensa atelectasis in order of frequency. In this category, we had no cholesteatoma because, in bilateral chronic otitis media, we almost always operate the side that has cholesteatoma before the side with simple perforation.

The most frequent abnormal findings in the cholesteatoma group were cholesteatoma, pars tensa perforation, pars tensa atelectasis, and sclerotic plaques in order of frequency.

In cholesteatoma patients, 15.2% had contralateral ear perforation, and in patients with ear perforation, 31.9% had contralateral ear perforation. After statistical analysis, patients with cholesteatoma had significantly lower contralateral ear perforation in comparison with patients with tympanic membrane perforation (P = 0.02, odds ratio: 2.6).

In cholesteatoma patients, 17.4% had cholesteatoma on the contralateral side, and 13% had perforation on the contralateral side with no statistically significant difference. No cholesteatoma patient had neotympanum on the contralateral side. On the other hand, in perforation patients, 14.3% had neotympanum on the contralateral side. Neotympanum on the contralateral side was significantly more prevalent in perforation patients (P = 0.006, Chi-Square test).

In cholesteatoma patients, 6.5% had sclerotic plaque on the contralateral side. On the other hand, in perforation patients, 24.7% had sclerotic plaque on the contralateral side. Sclerotic plaque on the contralateral side was significantly more prevalent in perforation patients (P = 0.007, Chi-Square test).

In cholesteatoma patients, 8.7% had contralateral ear pars tensa atelectasis, and in patients with ear perforation, 1.6% had contralateral ear pars tensa atelectasis, therefore, patients with cholesteatoma had significantly higher contralateral ear pars tensa atelectasis in comparison with patients with tympanic membrane perforation (P = 0.03, Fisher's exact test). No cholesteatoma patient had contralateral ear pars flaccida retraction. In patients with ear perforation, 5.5% had contralateral ear pars flaccida retraction. There was no statistically significant difference between the two groups (P = 0.2 Fisher’s exact test).

The most frequent type of ear drum perforation in the operated side of the PTP group was type 4 (61.3%), which means that the majority of them had more than 50 per cent perforation of the tympanic membrane area. The most frequent type of ear drum perforation in the contralateral ear of the PTP group was type 4 for all types of perforation in this group, which means that no matter the size and location of perforation on the operated side, the size of drum perforation on the contralateral side is most often more than 50 per cent.

Of 114 ears with more than 50 per cent drum perforation on the operated side, 48 had normal contralateral ears. In 68 ears with less than 50 percent drum perforation on the operated side, 34 had normal contralateral ear. This difference was not statistically significant (P = 0.258).

Discussion

There are several studies on the status of the contralateral ear in COM in the literature. Some of these studies are retrospective surveys [6], and some are cross-sectional observational studies [7]. Some include only cholesteatoma and not the other COMs [8, 9], and some are histologic studies [10].

Our study is a multicentric cross-sectional observational study. The senior surgeons precisely examined the contralateral side with a surgical microscope just before the start of the termination of general anesthesia. Here, we present, and compare our findings with the other studies.

In our study, PTP was statistically more prevalent in females than males, whereas cholesteatoma was more prevalent in males. In some studies, COM is more prevalent in females [11, 12], and in some in males [6, 7, 13]. Some studies have separated the reports of cholesteatoma from other COMs. In those studies, there are also variations in the results. Cholesteatoma was more prevalent in males in a study in South Korea [14] and more prevalent in females in another study in India [12]. Whether these differences in various studies are the result of different races, cultures, or other reasons should be investigated in multicentric larger-scale studies.

Globally, nearly 50% of our patients had normal contralateral ears. Previous studies had lower and different rates, from 24.8 to 37% for the normal contralateral side [6, 7, 15]. It suggests that this disease has a high tendency for bilateralism.

45.3% of our patients with PTP had normal contralateral side, whereas 67.4% of patients with cholesteatoma had normal opposite ear, and this difference was statistically significant. da Costa and his colleagues [8] reported 34.8% normal contralateral ear in their patients with cholesteatoma. Hassman-Poznańska and colleagues [9] showed 45.5% normality on the contralateral ear of children with acquired cholesteatoma. Rosito and co-workers [10], in their histologic survey of temporal bones, did not find a significant difference in the status of the contralateral side of the bones with cholesteatomatous and non-cholesteatomatous COMs.

Selaimen da Costa and colleagues, in another paper in Brazil [7], stated that in their patients with COM without cholesteatoma, 30.1% had a normal contralateral ear and in those with cholesteatoma, this rate was 16.7%. Their findings are contrary to ours. There are some differences between their methodology and ours. Their patients were collected from an outpatient clinic and ours were the ones for whom surgery was done. The contralateral ear was defined in their survey as an asymptomatic ear or, in cases with bilateral symptoms, an ear with clearly fewer symptoms based on hearing loss, otorrhea, and overall discomfort. Our study was done in a multicenter manner from different regions of our country, which may lessen the influence of race. Finally, though the regions of the two studies are far from each other, which may explain their difference, more studies from around the world with different races and similar methodologies should be done to reach better results.

In our study, patients with cholesteatoma statistically had less abnormal contralateral side than the ones with PTP. Also, in these patients, the rate of cholesteatoma and drum perforation on the contralateral side was not statistically significant. These findings may suggest that cholesteatomas have a lower tendency for bilateral influencing pathophysiology than PTPs.

The majority of ear drum perforations in the operated side of the PTP group were more than 50 percent perforation of the tympanic membrane. This may address that we have operated larger perforations more. On the other hand, regardless of the size and location of the perforation on the operated side, the most frequent contralateral type of drum perforation was also more than 50 percent of its size. As a result, it seems that the most existing size of the tympanic membrane perforation is the one with more than 50 percent of its area.

In the PTP group, whether the drum perforation was more or less than 50 percent of its size, the rate of normality in the contralateral ear was not statistically different. It may reflect that, though larger perforations were more prevalent in both ipsi- and contralateral ears, its size on one side does not predict having more problems on the other side.

Conclusion

Chronic otitis media of any type has a high tendency for bilateralism. It seems that a bilateral influencing pathophysiology is more prominent in PTPs than in cholesteatomas. For tympanic membrane perforation, it seems that whatever the underlying pathology, it tends to be accompanied by a large perforation rather than a small one, and a larger size on one side does not predict having more problems on the other side. Worldwide multicentric large-scale studies should be done for a better understanding of the pathogenesis of different types of COM.

Author Contributions

All the authors have contributed to this article and have read and approved the final submission.

Funding

This research project received no funding from public or private agencies.

Declarations

Conflicts of interest

The authors declare that they have no conflict of interest.

Compliance with Ethical Standards

The procedures used in this study adhere to the tenets of the Declaration of Helsinki.

Ethical Approval

This study was approved by the Human Research Ethics committee of the University of Shahid Beheshti University of Medical Scineces (Ethics approval number: IR.SBMU.RETECH.REC. 1400.549).

Informed Consent

All patients had given informed consent.