Micropathologic changes of pars tensa in children with otitis media with effusion

Chronic suppurative otitis media

Chronic suppurative otitis media (CSOM) is a leading global cause of potentially preventable hearing loss in children and adults, associated with socioeconomic deprivation. There is an absence of consensus on the definition of CSOM, which complicates efforts for prevention, treatment, and monitoring. CSOM occurs when perforation of the tympanic membrane is associated with severe or persistent inflammation in the middle ear, leading to hearing loss and recurrent or persistent ear discharge (otorrhoea). Cholesteatoma, caused by the inward growth of the squamous epithelium of the tympanic membrane into the middle ear, can also occur. The optimal treatment of discharge in CSOM is topical antibiotics. In resource-limited settings where topical antibiotics might not be available, topical antiseptics are an alternative. For persistent disease, surgery to repair the tympanic membrane or remove cholesteatoma might offer long-term resolution of otorrhoea and potential improvement to hearing. Recent developments in self-fitted air-conduction and bone-conduction hearing aids offer promise as new options for rehabilitation.

Sensorineural Hearing Loss in Unilateral Mucosal Type of Chronic Otitis Media

Sensorineural hearing loss is relatively well established in the squamosal chronic otitis media. However, its association with mucosal COM is still debated. The present study aimed at evaluating the prevalence of sensorineural hearing loss in unilateral mucosal COM. The study was conducted at a tertiary care hospital in New Delhi, and 60 patients with unilateral mucosal chronic otitis media were recruited. Pure tone thresholds were ascertained for air and bone conduction in an acoustically treated room and matched against certain patient and disease characteristics. In this study, the combined prevalence of SNHL/Mixed Hearing loss in mucosal COM was found to be 8.3%. A statistically significant association between SNHL/Mixed HL was seen in the 40-50-year age group (p-0.004). Prevalence with a disease duration of more than 10 years was 33% (p-0.019). All the patients who presented with SNHL/Mixed HL had an actively discharging ear. 80% of the patients who presented with SNHL/Mixed HL had large perforations. SNHL/Mixed HL prevalence of 28.6% was found in smokers, compared to 5.7% in non-smokers (p-0.039). The risk of developing SNHL/Mixed HL increased with increasing patients' age, disease duration, and size of the perforation and smokers.

Clinical practice guidelines for the diagnosis and management of otitis media with effusion (OME) in children in Japan - 2022 update

This is an update of the 2015 Guidelines developed by the Japan Otological Society and Oto-Rhino-Laryngeal Society of Japan defining otitis media with effusion (OME) in children (younger than 12 years old) and describing the disease rate, diagnosis, and method of examination. Recommended therapies that received consensus from the guideline committee were updated in consideration of current therapies used in Japan and based on available evidence.

METHOD

Regarding the treatment of OME in children, we developed Clinical Questions (CQs) and retrieved documents on each theme, including the definition, disease state, method of diagnosis, and medical treatment. In the previous guidelines, no retrieval expression was used to designate a period of time for literature retrieval. Conversely, a literature search of publications from March 2014 to May 2019 has been added to the JOS 2015 Guidelines. For publication of the CQs, we developed and assigned strengths to recommendations based on the collected evidence.

RESULTS

OME in children was classified into one group lacking the risk of developing chronic or intractable disease and another group at higher risk (e.g., children with Down syndrome, cleft palate), and recommendations for clinical management, including follow-up, is provided. Information regarding management of children with unilateral OME and intractable cases complicated by adhesive otitis media is also provided.

CONCLUSION

In clinical management of OME in children, the Japanese Clinical Practice Guidelines recommends management not only of complications of OME itself, such as effusion in the middle ear and pathologic changes in the tympanic membrane, but also pathologic changes in surrounding organs associated with infectious or inflammatory diseases.

Association of asymptomatic otitis media with effusion in patients with adenoid hypertrophy

Objective Clinical symptoms of otitis media with effusion are rarely brought forward to the guardians of young children who the disease is most prevalent in. This often leads to poor scholastic performances and difficult social interactions. The objective of this study was to identify asymptomatic cases of otitis media with effusion present in individuals with adenoid hypertrophy. Material and Methods In a cross sectional study advocated in Justice K.S.Hegde Hospital, Karnataka India we evaluated one hundred patients above the age of three from August 2016 to December 2017. Candidates who presented with an adenoid nasopharyngeal ratio of more than 0.5 were selected for the study. Individuals who complained of otological symptoms were not considered for the study. Patients cleared of other pathological otological conditions were underwent audiological evaluation with pure tone audiometry and tympanometry for evaluating the middle ear status and hearing loss. Results The study showed a total of 36% of patients evaluated presented with asymptomatic otitis media with effusion. In candidates who presented with a bilateral B tympanogram, 40% had significant conductive hearing loss of more than 25dB. Conclusion An objective test such as impedance audiometry in all patients with adenoid hypertrophy would aid in the diagnosis of fluid in the middle ear, so that timely intervention can be done and possible complications be averted.

Clinical Practice Guideline: Otitis Media with Effusion

The clinical practice guideline on otitis media with effusion (OME) provides evidence-based recommendations on diagnosing and managing OME in children. This is an update of the 1994 clinical practice guideline “Otitis Media With Effusion in Young Children,” which was developed by the Agency for Healthcare Policy and Research (now the Agency for Healthcare Research and Quality). In contrast to the earlier guideline, which was limited to children aged 1 to 3 years with no craniofacial or neurologic abnormalities or sensory deficits, the updated guideline applies to children aged 2 months through 12 years with or without developmental disabilities or underlying conditions that predispose to OME and its sequelae. The American Academy of Pediatrics, American Academy of Family Physicians, and American Academy of Otolaryngology- Head and Neck Surgery selected a subcommittee composed of experts in the fields of primary care, otolaryngology, infectious diseases, epidemiology, hearing, speech and language, and advanced practice nursing to revise the OME guideline.

The subcommittee made a strong recommendation that clinicians use pneumatic otoscopy as the primary diagnostic method and distinguish OME from acute otitis media (AOM).

The subcommittee made recommendations that clinicians should (1) document the laterality, duration of effusion, and presence and severity of associated symptoms at each assessment of the child with OME; (2) distinguish the child with OME who is at risk for speech, language, or learning problems from other children with OME and more promptly evaluate hearing, speech, language, and need for intervention in children at risk; and (3) manage the child with OME who is not at risk with watchful waiting for 3 months from the date of effusion onset (if known), or from the date of diagnosis (if onset is unknown).

The subcommittee also made recommendations that (4) hearing testing be conducted when OME persists for 3 months or longer, or at any time that language delay, learning problems, or a significant hearing loss is suspected in a child with OME; (5) children with persistent OME who are not at risk should be reexamined at 3- to 6-month intervals until the effusion is no longer present, significant hearing loss is identified, or structural abnormalities of the eardrum or middle ear are suspected; and (6) when a child becomes a surgical candidate, tympanostomy tube insertion is the preferred initial procedure. Adenoidectomy should not be performed unless a distinct indication exists (nasal obstruction, chronic adenoiditis); repeat surgery consists of adenoidectomy plus myringotomy, with or without tube insertion. Tonsillectomy alone or myringotomy alone should not be used to treat OME. The subcommittee made negative recommendations that (1) population-based screening programs for OME not be performed in healthy, asymptomatic children and (2) antihistamines and decongestants are ineffective for OME and should not be used for treatment; antimicrobials and corticosteroids do not have long-term efficacy and should not be used for routine management.

The subcommittee gave as options that (1) tympanometry can be used to confirm the diagnosis of OME and (2) when children with OME are referred by the primary clinician for evaluation by an otolaryngologist, audiologist, or speech-language pathologist, the referring clinician should document the effusion duration and specific reason for referral (evaluation, surgery), and provide additional relevant information such as history of AOM and developmental status of the child. The subcommittee made no recommendations for (1) complementary and alternative medicine as a treatment for OME based on a lack of scientific evidence documenting efficacy and (2) allergy management as a treatment for OME based on insufficient evidence of therapeutic efficacy or a causal relationship between allergy and OME. Last, the panel compiled a list of research needs based on limitations of the evidence reviewed.

The purpose of this guideline is to inform clinicians of evidence-based methods to identify, monitor, and manage OME in children aged 2 months through 12 years. The guideline may not apply to children older than 12 years because OME is uncommon and the natural history is likely to differ from younger children who experience rapid developmental change. The target population includes children with or without developmental disabilities or underlying conditions that predispose to OME and its sequelae. The guideline is intended for use by providers of health care to children, including primary care and specialist physicians, nurses and nurse practitioners, physician assistants, audiologists, speech-language pathologists, and child development specialists. The guideline is applicable to any setting in which children with OME would be identified, monitored, or managed.

This guideline is not intended as a sole source of guidance in evaluating children with OME. Rather, it is designed to assist primary care and other clinicians by providing an evidence-based framework for decision-making strategies. It is not intended to replace clinical judgment or establish a protocol for all children with this condition, and may not provide the only appropriate approach to diagnosing and managing this problem. (Otolaryngol Head Neck Surg 2004;130:S95.)

Laser-Assisted Tympanostomy in Pediatric Patients with Serous Otitis Media

OBJECTIVES: To evaluate prognostic factors related with cure rate, in pediatric patients with serous otitis media treated with laser-assisted tympanostomy without ventilation tubes, in a single institution.

PATIENTS AND METHOD: The procedure was performed on 124 ears in 88 individuals, from 3 to 14 years old. External auditory canal anatomy, type of anesthesia, tympanic membrane and middle ear fluid characteristics, myringotomy size, and laser parameters, in relation to cure rate, were accordingly studied.

RESULTS: The overall cure rate by ear at the end of the 2-month follow-up period was 54.83%, whereas 45.17% still suffered from otitis media. Multivariate statistical analysis demonstrated that the presence of a thick tympanic membrane is significantly correlated with pure outcome in children with serous otitis media, when laser-assisted tympanostomy without ventilation tubes is performed favoring a worse cure rate ( P < 0.023). Other parameters did not statistically correlate with the outcome. A 41% parental dissatisfaction rate was noticed.

CONCLUSION: This study addresses selection bias for children with serous otitis media, candidates for laser-assisted tympanostomy. These are related to the duration of serous otitis media, the condition of middle ear mucosa, the thickness of the tympanic membrane, the type of anesthesia, and the cost of laser apparatus. There is likely to be a causal relationship between outcome and tympanic membrane appearance in children undergoing laser-assisted tympanostomy.

Matrix metalloproteinase-8/collagenase-2 in childhood otitis media with effusion

BACKGROUND

Matrix metalloproteinases (MMPs), gelatinases, have been associated with otitis media with effusion (OME), but the role of collagenase-2/matrix metalloproteinase-8 (MMP-8) in OME has not been studied previously. We studied the levels, isoenzyme distribution, and activation of MMP-8 in childhood OME, and also the levels of pro- and active forms of MMP-2 and -9 as well as 120 kDa gelatinase complexes were assessed.

METHODS

Seventy middle ear fluid (MEF) samples were collected from 54 children with OME and classified to mucoid (n = 39) or serous (n = 31). MMPs were studied from MEF samples by time-resolved immunofluorometric assay, Western immunoblotting, and gelatin-zymography.

RESULTS

MMP-8 was found in its active form in MEF of children with OME. MMP-8 levels were significantly higher in mucous relative to serous OME. The pro- or active MMP-2 and -9 were found in MEF, but no MEF type-specific differences were found.

CONCLUSION

Our results suggest that MMP-8 may play a role in the pathogenesis of childhood OME. New therapeutic strategies with MMP inhibitors targeting MMP-8, but allowing MMP-8 to carry out the protective action, may play a role in the future treatment of otitis media and OME. However, further studies of this topic are needed.

Resolved effusion on myringotomy: a study of dry tap without general anesthesia

OBJECTIVES

Finding a resolution of middle ear effusion using myringotomy, or dry tap (DT), is relatively common, but its clinical outcome is confounded by general anesthesia (GA). The confounding effect of GA and a time delay can be removed because laser myringotomy can be completed under topical anesthesia, which is a routine procedure for otitis media with effusion (OME) before GA in our clinic. DT without GA would clarify the clinical outcome, and the percentage of recurrence for OME after DT would be clinically relevant. The objectives of the present study are (1) to clarify the clinical nature of DT without including the confounding effect of GA and a time delay and (2) to determine if OME recurs when a ventilation tube (VT) is not used for DT.

METHODS

The control group consisted of 308 children who received an unilateral myringotomy due to a natural resolution in the contralateral ear. The experimental group consisted of 296 children who had a bilateral myringotomy, and a ventilation tube was not inserted for DTs after laser myringotomy under topical anesthesia. The rate of DT and the recurrence rate of OME without tube insertion was the main outcome measure.

RESULTS

In the control group, which showed a natural resolution, the rate of DT was 16.9% (52/308) of patients, and DT was more common in non-B tympanometry, which only had a recurrence rate of 17.3% (9/52). In the study group, 3.7% of patients showed unilateral DT (UDT) with contralateral positive effusion, and 5.4% of patients showed bilateral DTs (BDTs). BDT showed a non-B tympanometry pattern and a low rate of recurrence (25.0%), which was similar to the control group. UDT showed a B-type tympanometry in 81.8% of the patients, and the recurrence rate was significantly higher (68.2%; 15/22) than the BDT and control patients. BDT or DT with signs of natural resolution showed a low rate of OME recurrence regardless of tympanometry, and thus, patients do not need a VT.

CONCLUSIONS

DT was not rare even without GA and the associated time delay, and DT was more common in the children that showed a natural resolution. However, microscopy and tympanometry was imperfect to predict dry tap, and thus, the surgeon needs to be prepared for individualized management of DT. UDT with B-type tympanometry and contralateral persistent effusion frequently recurred without tubes, and thus, VT for UDT appeared to be necessary.

Association of otoscopic findings and hearing level in pediatric patients with otitis media with effusion

OBJECTIVE

To find the association between the abnormalities of tympanic membrane characteristics and the hearing level in pediatric patients with otitis media with effusion.

METHODS

Sixty-three pediatric patients with otitis media with effusion had undergone ear examinations by pneumatic otoscopy to assess the color, transparency, mobility, fluid level and retraction of the tympanic membrane. An audiogram was done in the same setting, average hearing threshold and air-bone gap were measured. Otoscopic findings and the result of the hearing test were analyzed to identify the association between the abnormalities of the tympanic membrane characteristics and elevated hearing threshold.

RESULTS

Hearing loss was found in 92.1% of the patients. Mean hearing level was 31.7+/-10.3 dB. From linear regression analysis, the patients with dull or opaque tympanic membrane had a significantly higher hearing threshold of 7.2 dB than the patient with translucent ear drum after adjusting for mobility and retraction. The patients with tympanic membrane retraction had a higher hearing threshold of 5.1 dB than the patient who had no retraction after adjusting for transparency and mobility. Mobility had a significant relationship to elevated hearing threshold in the univariate analysis but not in multivariable analysis.

CONCLUSION

Opacity and retraction were the two characteristics of abnormal tympanic membrane that were associated with elevated hearing threshold in the patients with otitis media with effusion. Hearing test is suggested if opacity or retraction of the tympanic membrane is found.

Activities of matrix metalloproteinases and tissue inhibitor of metalloproteinase-2 in idiopathic hemotympanum and otitis media with effusion

CONCLUSION

The expression profile of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase-2 (TIMP-2) was specific to the type of middle ear effusion. Further studies are necessary for elucidating its correlation with the sequelae of otitis media with effusion (OME) and idiopathic hemotympanum.

OBJECTIVES

We aimed to investigate the relative activities of gelatinases (MMP-2 and -9), stromelysin-1 (MMP-3), and matrilysin-1 (MMP-7), as well as measuring TIMP-2 levels in the serous and mucous effusions of OME and hemorrhagic effusion of the idiopathic hemotympanum.

MATERIALS AND METHODS

Middle ear effusions were collected from patients with OME and idiopathic hemotympanum, and were classified as mucoid, serous, or hemorrhagic. MMP activity in the effusion samples was examined by gelatin and casein zymography. Levels of TIMP-2 were measured by ELISA. Human temporal bone sections, with and without otitis media (OM), were examined histologically.

RESULTS

One case showed tympanic membrane thinning in the OM group, but none in the control group. While MMP-2 was present in all effusions, the active form of MMP-2 was found only in mucous effusions. MMP-3 and MMP-7 activity was detected only in the mucous effusions. MMP-9 exhibited activity in all effusions, with the highest levels in mucous effusions. TIMP-2 levels were markedly elevated in serous effusions.

Clinical study of otological manifestations in cases of cleft palate

Cleft palate (with or without cleft lip) occurs in about 1: 750-1: 2000 births in different societies in the world. Cleft palate individuals have a greater incidence of hearing loss than the general population. The primary cause of the ear problem in cleft patients is eustachian tube dysfunction. The cause for which is abnormal insertion of levator veli palatini and tensor veli palatini muscles into the posterior margin of the hard palate and the palatal aponeurosis and associated muscular hypoplasia.

Otitis media with effusion

The clinical practice guideline on otitis media with effusion (OME) provides evidence-based recommendations on diagnosing and managing OME in children. This is an update of the 1994 clinical practice guideline "Otitis Media With Effusion in Young Children," which was developed by the Agency for Healthcare Policy and Research (now the Agency for Healthcare Research and Quality). In contrast to the earlier guideline, which was limited to children 1 to 3 years old with no craniofacial or neurologic abnormalities or sensory deficits, the updated guideline applies to children aged 2 months through 12 years with or without developmental disabilities or underlying conditions that predispose to OME and its sequelae. The American Academy of Pediatrics, American Academy of Family Physicians, and American Academy of Otolaryngology-Head and Neck Surgery selected a subcommittee composed of experts in the fields of primary care, otolaryngology, infectious diseases, epidemiology, hearing, speech and language, and advanced-practice nursing to revise the OME guideline. The subcommittee made a strong recommendation that clinicians use pneumatic otoscopy as the primary diagnostic method and distinguish OME from acute otitis media. The subcommittee made recommendations that clinicians should 1) document the laterality, duration of effusion, and presence and severity of associated symptoms at each assessment of the child with OME, 2) distinguish the child with OME who is at risk for speech, language, or learning problems from other children with OME and more promptly evaluate hearing, speech, language, and need for intervention in children at risk, and 3) manage the child with OME who is not at risk with watchful waiting for 3 months from the date of effusion onset (if known) or diagnosis (if onset is unknown). The subcommittee also made recommendations that 4) hearing testing be conducted when OME persists for 3 months or longer or at any time that language delay, learning problems, or a significant hearing loss is suspected in a child with OME, 5) children with persistent OME who are not at risk should be reexamined at 3- to 6-month intervals until the effusion is no longer present, significant hearing loss is identified, or structural abnormalities of the eardrum or middle ear are suspected, and 6) when a child becomes a surgical candidate (tympanostomy tube insertion is the preferred initial procedure). Adenoidectomy should not be performed unless a distinct indication exists (nasal obstruction, chronic adenoiditis); repeat surgery consists of adenoidectomy plus myringotomy with or without tube insertion. Tonsillectomy alone or myringotomy alone should not be used to treat OME. The subcommittee made negative recommendations that 1) population-based screening programs for OME not be performed in healthy, asymptomatic children, and 2) because antihistamines and decongestants are ineffective for OME, they should not be used for treatment; antimicrobials and corticosteroids do not have long-term efficacy and should not be used for routine management. The subcommittee gave as options that 1) tympanometry can be used to confirm the diagnosis of OME and 2) when children with OME are referred by the primary clinician for evaluation by an otolaryngologist, audiologist, or speech-language pathologist, the referring clinician should document the effusion duration and specific reason for referral (evaluation, surgery) and provide additional relevant information such as history of acute otitis media and developmental status of the child. The subcommittee made no recommendations for 1) complementary and alternative medicine as a treatment for OME, based on a lack of scientific evidence documenting efficacy, or 2) allergy management as a treatment for OME, based on insufficient evidence of therapeutic efficacy or a causal relationship between allergy and OME. Last, the panel compiled a list of research needs based on limitations of the evidence reviewed. The purpose of this guideline is to inform clinicians of evidence-based methods to identify, monitor, and manage OME in children aged 2 months through 12 years. The guideline may not apply to children more than 12 years old, because OME is uncommon and the natural history is likely to differ from younger children who experience rapid developmental change. The target population includes children with or without developmental disabilities or underlying conditions that predispose to OME and its sequelae. The guideline is intended for use by providers of health care to children, including primary care and specialist physicians, nurses and nurse practitioners, physician assistants, audiologists, speech-language pathologists, and child-development specialists. The guideline is applicable to any setting in which children with OME would be identified, monitored, or managed. This guideline is not intended as a sole source of guidance in evaluating children with OME. Rather, it is designed to assist primary care and other clinicians by providing an evidence-based framework for decision-making strategies. It is not intended to replace clinical judgment or establish a protocol for all children with this condition and may not provide the only appropriate approach to diagnosing and managing this problem.

Penetration of cefprozil to middle ear effusion in children with chronic otitis media with effusion

BACKGROUND

Because of chronic otitis media with effusion (COME) demonstrates pathogenic bacteria, treatment with appropriate antibiotic is reasonable.

OBJECTIVE

We determined the penetration of cefprozil into the middle ear effusion (MEE) in children with COME.

MATERIALS AND METHODS

25 patients 2-13 years of age with COME were eligible for study. After the single dose of 15 mg/kg patients were assigned to have MEE, and serum samples were obtained during ventilation tube insertion at 0.5, 2, 3, 5, or 6 h after administration of the dose. The concentration of cefprozil was measured using validated high performance liquid chromatography method.

RESULTS

The mean concentrations of cefprozil in the MEE ranged from 0.4 to 4.4 microg/ml. The penetration into MEE was rapid and effective. Cefprozil in the MEE was maintained at a greater level than MIC 90 in S. pneumoniae for at least 6 h after administration of 15 mg/kg.

CONCLUSION

Cefprozil penetrated well into the MEE in children with COME.

The role of laser assisted tympanostomy (LAT) in treating allergic children with chronic serous otitis media

OBJECTIVES

To assess various prognostic factors influencing the outcome in paediatric patients with serous otitis media, who have undergone laser assisted tympanostomy without ventilation tube placement. Emphasis is given to children with allergies who underwent the procedure.

METHOD

Laser assisted tympanostomy was performed on a total of 130 ears (92 individuals) with chronic otitis media with effusion. To determine the quality of patient outcome, the following parameters were evaluated: external auditory canal anatomy, type of anaesthesia used, tympanic membrane and middle ear fluid characteristics, myringotomy size, a history of allergies and the laser device parameters.

RESULTS

Multivariable statistical analysis demonstrated that the presence of allergies in children with chronic serous otitis media is significantly correlated with a poor outcome (P < 0.0047). Moreover, the presence of a thick tympanic membrane and/or high viscosity (glue) fluid in the middle ear cavity can also independently influence patient outcome (P < 0.025). Simultaneous adenoidectomy and/or tonsillectomy, type of anaesthesia (general versus local), external canal anatomy (wide or narrow) and sex, were not statistically important prognostic factors. The type of anaesthesia used, myringotomy size and the laser device parameters were not found to be associated with patient outcome.

CONCLUSION

A history of allergies, the presence of a thick tympanic membrane and/or high viscosity fluid in the middle ear cavity are all contraindications for laser assisted tympanostomy without tympanostomy tubes, in children who suffer from chronic serous otitis media. The selection criteria for this procedure in the paediatric population are addressed in detail.

Matrix metalloproteinases 2 and 9 in otitis media with effusion

A qualitative and quantitative study of the presence of matrix metalloproteinase 2 (MMP 2) and matrix metalloproteinase 9 (MMP 9), in the effusions of otitis media with effusion (OME), was performed. The activity of the above enzymes was compared in thick and thin effusions, and concentrations compared in samples from children with one, two, three and four sets of ventilation tubes. The activity of both MMP 2 and MMP 9 was higher in thick than thin effusions, P = 0.07 and P = 0.04, respectively. The concentrations of MMP 9 did not vary with the number of tube insertions but those of MMP 2 did (ANOVA P < 0.05). MMPs may be involved in tympanic membrane damage and prognosis of OME.

Middle ear effusions and structure of the tympanic membrane

OBJECTIVE

To study the effect of various middle ear effusions on the structure of the lamina propria of the tympanic membrane.

METHODS

Sterile and infective middle ear effusions were induced by obstruction of the eustachian tube in specific pathogen-free (SPF) rats and in rats with upper airway infections (URI), respectively. The condition of the tympanic membrane was monitored at regular intervals. After varying survival times, the animals were killed and the tympanic membranes processed for light and electron microscopy.

RESULTS

Sterile effusions always resulted in tympanosclerotic lesions. These lesions did not develop in the presence of primary-infected effusions. These effusions had a severe destructive effect on the lamina propria, followed by fibrosis. Generally, secondary infection did not markedly affect preexisting tympanosclerotic lesions. Moreover, calcification disappeared when re-aeration of the middle ear occurred, but the abnormal collagen depositions persisted.

CONCLUSIONS

Both sterile and infective effusions result in comprehensive irreversible changes in the lamina propria of the pars tensa. The development of tympanosclerosis is confined to sterile effusions. Mechanical injury and compromised vascularization of the lamina propria are likely to be important etiological factors in the development of tympanosclerosis.

Tympanic membrane and middle ear pathologic correlates in mucoid otitis media

OBJECTIVE

The goal of this study was to correlate tympanic membrane (TM) and middle ear (ME) pathologies in mucoid otitis media (MOM).

METHODS AND MATERIAL

Forty ears with MOM and 56 control ears were retrospectively evaluated for TM and ME pathologies. Comparisons of TM thicknesses in MOM versus control ears were correlated with the Student t test; chi(2) analysis was used to correlate pathologic findings of the TM and ME.

RESULTS

Thicknesses in all quadrants except the umbo were increased in MOM because of infiltration of inflammatory cells and fibrosis. The most common ME pathologies were granulation tissue and fibrosis. Significant correlations included (1) TM retraction and ME granulation tissue and fibrosis and (2) pars flaccida, posterosuperior, and anteroinferior thickness and ME granulation tissue and fibrosis.

CONCLUSION

TM changes are likely to occur in patients with otitis media with effusion (MOM), and their presence is a strong indication of underlying ME pathology.

Middle ear volume and pressure effects on tympanometric middle ear pressure determination: model experiments with special reference to secretory otitis media

OBJECTIVE

Middle ear pressure (P(m)) measured by tympanometry has revealed high negative values in patients with secretory otitis media (SOM) in contrast to direct measurement. This may be explained by errors in tympanometry caused by volume displacement of the tympanic membrane (TM) affecting the volume of the middle ear (V(m)) and the P(m) according to Boyle's Law. Such errors are susceptible to the size of V(m).

METHODS

A realistic middle ear model based on previous clinical studies of normal pressure-volume relations of the middle ear system (MES) was constructed. In this model non-linear behaviour and hysteresis of the MES was imitated and P(m) as well as V(m) could be controlled.

RESULTS

Tympanometrically estimated P(m) decreased on average 38 daPa, when V(m) was changed from 21 to 1 cm(3). The decrease was most pronounced, when V(m) became smaller than 5 cm(3). Moreover, tympanometry showed a linear numerical overestimation of P(m) by a factor 2.31 compared with model P(m).

CONCLUSION

A curve fit was derived describing the tympanometric P(m) as a function of V(m). This demonstrated that tympanometric P(m) approached -infinity daPa, when middle ear volume approached 0 cm(3), which indicates that negative tympanometric recordings and B curves can be found in ears with normal P(m) entirely due to very small V(m)'s. This explains the discrepancy between direct and tympanometric measurements of P(m) in SOM, since the effusion replaces the air filled expandable volume resulting in a very small 'functional' V(m). Numerical overestimation of P(m) by tympanometry was explained by hysteresis, which reflected the viscoelastic properties of the MES. These results question the significance of negative P(m)'s as a pathogenetic factor in SOM.

Histopathologic changes of the tympanic membrane in acute and secretory otitis media

The histopathologic changes observed in 40 normal and inflamed temporal bones of infants and children are reported. The tympanic membranes of patients with acute and secretory otitis media underwent considerable swelling compared to those of normal controls. Tympanic membranes with acute otitis media were thicker than those with secretory otitis media, but the difference was not statistically significant. The epithelial layer showed an increase in the number of cell layers. The lamina propria demonstrated the most significant changes of all layers with a marked swelling due to edema, engorged blood vessels, and inflammatory cell infiltration. Increased numbers of distended capillaries were present, predominantly in the subepithelial connective tissue layer, while infiltration of inflammatory cells was mainly in the submucosal connective tissue layer. By contrast, the involvement of the mucosal layer was modest and was composed of cuboidal cells, except for small islands of metaplastic mucosa with mucus production occasionally encountered in specimens with secretory otitis media.