The Effect of Tympanic Membrane Perforation Site, Size and Middle Ear Volume on Hearing Loss

Tympanic membrane perforations cannot be reliably detected using computed tomography based on 15 cadaver dogs

The integrity of the tympanic membrane is an important factor when deciding treatment and therapeutic recommendations for dogs with ear disease; however, otoscopic examination may be difficult to perform due to features of external ear canal disease or patient compliance. CT is useful for the evaluation of middle ear disease, including cases in which middle ear disease is detected incidentally. The tympanic membrane is detectable using CT, but anecdotally, apparent focal defects or discontinuities of the tympanic membrane are often seen in patients with and without ear disease. The purpose of this prospective, observer agreement study was to determine if perforations of the tympanic membrane are reliably detectable on CT. Fifteen cadaver dogs underwent CT and video otoscopy to verify the integrity of each tympanic membrane. Cadavers were randomly assigned to have the tympanic membranes left intact or to undergo a myringotomy on either the left, the right, or both sides. CT was performed immediately following the myringotomies. Four blinded evaluators evaluated the pre- and post-myringotomy scans for a total of 30 scans (60 tympanic membranes). Average accuracy was low (44%), and interobserver agreement for all four evaluators was fair. Although the tympanic membrane is visible on CT, perforations of the tympanic membrane are unlikely to be accurately detected or excluded. The appearance of an intact tympanic membrane or defect in the membrane on CT should not be used as criteria to guide clinical treatment recommendations based on this cadaver model.

Relationship of Hearing Loss and Tympanic Membrane Perforation Characteristics in Chronic Suppurative Otitis Media Patients

Objective The objective of this study is to assess the relationship between the site of tympanic membrane (TM) perforation and the type and degree of hearing impairment. The secondary objective was to compare the duration of the disease and the degree of hearing loss. Study design This is a prospective observational study. Place and duration of the study This study was carried out in the Department of Otolaryngology/Head and Neck Surgery at the Pakistan Institute of Medical Sciences, Islamabad, from May 2021 to April 2022. Patients and methods Of all the screened patients, 77 fulfilled the inclusion criteria. Patients aged 10-40 years with inactive mucosal chronic otitis media and unilateral perforation in one quadrant were included. The site of TM rupture was observed, and audiometric analysis was performed. Results The mean age of participants was 25 ± 8.61 years, with a preponderance of the female gender (57.1%). A total of 32 (41.6%), 19 (24.7%), 19 (24.7%), and seven (9.1%) perforations involved posterosuperior, anterosuperior, anteroinferior, and posteroinferior quadrants respectively. Conductive, mixed, and sensorineural hearing loss was found in 52 (67.5%), 18 (23.4%), and seven (9.1%) cases, respectively. Of all the subjects, 13 (16.9%) had the disease for < one year, 39 (50.6%) for one to five years, 17 (22.1%) for five to 10 years, and eight (10.4%) for > 10 years. There was a statistically significant association between the degree of hearing loss and the site of perforation. No significant association was found between the site of perforation and the type of hearing loss. Duration of disease and degree of hearing loss also had no significant association. Conclusion The extent of hearing loss was found to be directly influenced by the anatomical site of perforation, with the posterosuperior quadrant perforation producing the greatest degree of impairment.

Hearing loss increases with size but not site of tympanic membrane perforation in Aboriginal Australian children in remote locations

Objective

To investigate the effect of size, site, and activity of tympanic membrane (TM) perforation on hearing loss (HL) in Aboriginal and Torres Strait Islander (ATSI) children.

Design

Observational study.

Methodology

Children aged 5-18 years who identified as ATSI at seven Anangu community schools within the Anangu Pitjantjatjara Yankunytjatjara Lands and Maralinga Lands of South Australia underwent 4-frequency pure-tone audiometry (0.5, 1, 2, and 4 kHz) and video-otoscopy (VO). VO data was reviewed by surgeons for a middle ear diagnosis and VO files with TM perforations were then classified by perforation site (AS, AI, PS, PI, A, P, I) and size (<25%, 25%-50%, 50%-75%, or 75%-100%).

Results

Five hundred seventy-five VO files with matching audiological data were obtained. Active perforations (35 dBHL; 28-44 IQR) demonstrated greater HL than inactive perforations (31 dBHL; 29-39 IQR) p = .0029. For inactive perforations there was a significant difference between <25% and all larger perforations (p < .0001) whereas for active perforations the significance changed to between <25% (p < .0001) and 25%-50% (p < .05) when compared to larger perforations. When perforation site was compared within all size/activity groups, no statistically different findings were identified. In all analyses, findings did not change when individual frequencies were compared to 4-frequency pure-tone average dBHL.

Conclusion

In ATSI children from remote communities, HL is greater in ears with larger perforations and active middle ear disease but there was no relationship between perforation site and HL.Level of evidence: Level 4.

Tympanic membrane perforations: the importance of etiology, size and location

PURPOSE

The ability to predict the degree of a conductive hearing loss caused by a tympanic membrane perforation is important for every otologist, as it may require additional diagnostic tests and prevent unexpected intraoperative findings. The aim of this study was to correlate the various characteristics of a perforation (etiology, size, location, involvement of the manubrium or umbo) with the degree and frequency predominance of the consequent hearing loss.

METHODS

A transversal study in a tertiary hospital center was conducted between July 2019 and December 2020. Fifty-eight patients with 65 tympanic perforations underwent a comprehensive medical and audiological evaluation, which included an otoendoscopy. An image processing software (ImageJ®) was used to measure the perforated area. The qualitative variables were etiology, affected quadrants, presence of myringosclerosis and involvement of umbo or manubrium of the malleus. The air-bone gap was measured at 250, 500, 1000, 2000 and 4000 Hz. Primary outcomes (mean air-bone gap and pure-tone average) were evaluated to find clinical factors associated with worse hearing.

RESULTS

Data collected from 50 ears was included. Perforation size showed a positive statistically significant correlation with the air-bone gap (r = .508; p < .001) and pure-tone average (r = .375; p < .001). Higher air-bone gaps were found in perforations involving the posterior quadrants and the manubrium (p < .001 and p = .031, respectively). Inflammatory causes showed higher bone and air conduction pure-tone averages (p = .031 and p = .084, respectively) compared to traumatic or iatrogenic. An "inverted V" pattern of the air-bone gap, with the 2 kHz frequency being the least affected, was a consistent finding. However, it was not due to the Carhart's notch in bone conduction.

CONCLUSION

The conductive hearing loss resulting from a tympanic membrane perforation is etiology, size and location-dependent, with higher losses occurring for inflammatory backgrounds, large perforations and when the posterior quadrants or the manubrium are involved. If the "inverted V" is absent, additional middle ear pathology should be investigated.

The Development and Evaluation of a Smartphone-Aided Diagnosis Application to Measure Tympanic Membrane Perforations

OBJECTIVES

Chronic otitis media is a long-term infection of the middle ear. It is characterized by persistent discharge from the middle ear through a perforated tympanic membrane. It is one of the most common causes of preventable hearing loss, especially in developing countries. Precise estimation of the size of tympanic membrane perforation is essential for successful clinical management. In this study, we developed a smartphone-based application to calculate the ratio of the area of tympanic membrane perforation to the area of the tympanic membrane. Twelve standardized patients and 60 medical students were involved to assess the area of tympanic membrane perforation, in particular, the percentage of perforation size.

METHODS

In total, 60 student doctors (including year 5 and year 6 medical students, intern and post-graduate year training of doctors) were recruited during their rotation at the Otolaryngology department of Taipei Medical University Shuang-Ho Hospital. Twelve standardized patients with chronic otitis media were recruited through a single otology practice. Oto-endoscopic examination was performed for all patients by using a commercially-available digital oto-endoscope, and clinical images of the tympanic membrane perforation were obtained. To demonstrate the variability of perforation size estimation by different student doctors, we calculated the percentage of perforation using the smartphone-based application for 12 tympanic membranes objectively and compared the results with those visually estimated by the 60 student doctors subjectively.

RESULTS

The variance in the visual estimation by the 60 student doctors was large. By contrast, variances in smartphone-based application calculations were smaller, indicating consistency in the results obtained from different users. The smartphone-based application accurately estimated the presence of perforation for tympanic membranes with high consistency. The differences in visual estimations can be considerably great and the variances can be large among different individuals.

CONCLUSIONS

The smartphone-based application is a dependable tool for precisely evaluating the size of tympanic membrane perforation.

The impact of tympanic membrane perforations on middle ear transfer function

Purpose

Injury or inflammation of the middle ear often results in the persistent tympanic membrane (TM) perforations, leading to conductive hearing loss (HL). However, in some cases the magnitude of HL exceeds that attributable by the TM perforation alone. The aim of the study is to better understand the effects of location and size of TM perforations on the sound transmission properties of the middle ear.

Methods

The middle ear transfer functions (METF) of six human temporal bones (TB) were compared before and after perforating the TM at different locations (anterior or posterior lower quadrant) and to different degrees (1 mm, ¼ of the TM, ½ of the TM, and full ablation). The sound-induced velocity of the stapes footplate was measured using single-point laser-Doppler-vibrometry (LDV). The METF were correlated with a Finite Element (FE) model of the middle ear, in which similar alterations were simulated.

Results

The measured and calculated METF showed frequency and perforation size dependent losses at all perforation locations. Starting at low frequencies, the loss expanded to higher frequencies with increased perforation size. In direct comparison, posterior TM perforations affected the transmission properties to a larger degree than anterior perforations. The asymmetry of the TM causes the malleus-incus complex to rotate and results in larger deflections in the posterior TM quadrants than in the anterior TM quadrants. Simulations in the FE model with a sealed cavity show that small perforations lead to a decrease in TM rigidity and thus to an increase in oscillation amplitude of the TM mainly above 1 kHz.

Conclusion

Size and location of TM perforations have a characteristic influence on the METF. The correlation of the experimental LDV measurements with an FE model contributes to a better understanding of the pathologic mechanisms of middle-ear diseases. If small perforations with significant HL are observed in daily clinical practice, additional middle ear pathologies should be considered. Further investigations on the loss of TM pretension due to perforations may be informative.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00405-021-07078-9.

Effects of location, size and shape of tympanic membrane perforations on hearing: analysis of 400 cases

OBJECTIVE

This study aimed to evaluate the effect of size, location and shape of tympanic membrane perforations on hearing levels of a large study group treated in a tertiary referral centre.

METHOD

Medical data of 458 patients with tympanic membrane perforations were evaluated.

RESULTS

A total of 336 patients had normal middle-ear findings during the surgical procedures. There was a significant difference in terms of mean pure tone average and air-bone gap values between posterior-inferior and anterior-inferior perforations (p = 0.005 and p = 0.044, respectively). The mean air-bone gap value of kidney-shaped perforations was significantly higher. Posterior-superior and posterior perforations were significant indicators for ossicular chain defects (p < 0.001; odds ratio, 14.2 and p = 0.004; odds ratio, 3.4, respectively).

CONCLUSION

Perforations located in the posterior-inferior quadrant caused the greatest hearing loss. The difference between posterior-inferior and anterior-superior or inferior perforations was statistically significant. Posterior perforations had a significant relationship with ossicular chain pathologies. Kidney-shaped perforations caused higher pure tone average and air-bone gap values than annular, elliptical or pinpoint perforations.

Comparing audiometric parameters between crushed and intact cartilage tympanoplasty: a double-blinded, randomised, controlled trial study

OBJECTIVE

To investigate hearing and the take rate of crushed cartilage grafts in tympanoplasty.

METHODS

In this double-blinded, randomised, controlled trial, 46 patients with tympanic membrane perforation were enrolled. A conchal cartilage graft was used for reconstruction in both intervention and control groups. In the intervention group, crushed cartilage was used. The success rate and hearing results were ascertained every four months over a one-year follow-up period.

RESULTS

A total of 36 patients - 20 in the intervention group and 16 in the control group - completed one year of follow up. There were no statistically significant differences between the two groups in mean air-bone gap, bone conduction threshold, speech discrimination score or speech reception threshold.

CONCLUSION

The reduction in living cells after crushed cartilage tympanoplasty may decrease the rigidity and the volume of the graft, but may not necessarily improve the hearing results.