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

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.

A new model for non-typeable Haemophilus influenzae middle ear infection in the Junbo mutant mouse

Acute otitis media, inflammation of the middle ear, is the most common bacterial infection in children and, as a consequence, is the most common reason for antimicrobial prescription to this age group. There is currently no effective vaccine for the principal pathogen involved, non-typeable Haemophilus influenzae (NTHi). The most frequently used and widely accepted experimental animal model of middle ear infection is in chinchillas, but mice and gerbils have also been used. We have established a robust model of middle ear infection by NTHi in the Junbo mouse, a mutant mouse line that spontaneously develops chronic middle ear inflammation in specific pathogen-free conditions. The heterozygote Junbo mouse (Jbo/+) bears a mutation in a gene (Evi1, also known as Mecom) that plays a role in host innate immune regulation; pre-existing middle ear inflammation promotes NTHi middle ear infection. A single intranasal inoculation with NTHi produces high rates (up to 90%) of middle ear infection and bacterial titres (10⁴-10⁵ colony-forming units/µl) in bulla fluids. Bacteria are cleared from the majority of middle ears between day 21 and 35 post-inoculation but remain in approximately 20% of middle ears at least up to day 56 post-infection. The expression of Toll-like receptor-dependent response cytokine genes is elevated in the middle ear of the Jbo/+ mouse following NTHi infection. The translational potential of the Junbo model for studying antimicrobial intervention regimens was shown using a 3 day course of azithromycin to clear NTHi infection, and its potential use in vaccine development studies was shown by demonstrating protection in mice immunized with killed homologous, but not heterologous, NTHi bacteria.

Summary: Acute otitis media is an important disease in children. We describe a new infection model for translational research that uses the Junbo mouse mutant intranasally inoculated with non-typeable Haemophilus influenzae.

Immediate repair of the tympanic membrane to prevent persistent perforation after intentional removal of long-lasting tubes

OBJECTIVE

Our purpose was to evaluate efficiency of immediate repair of the tympanic membrane perforation after intentional removal of the long-lasting tubes.

METHODS

This study was done in 36 ears of 27 patients who had either Goode-T or Paparella-II silicone tube insertion due to chronic OME or ROM and tube removal. Only the ears in which tube removal was performed due to no longer need for middle ear ventilation were included to the study. After removal of the tube, the perforation edges were refreshed and Steri-Strip (3M) patch was adhered on the perforation site. Otoscopic, tympanometric and audiologic data were reported.

RESULTS

Mean duration of the tube persistence was 49.58+/-11.94 months. It was found that there were two subgroups in the study group: those under regular follow-up (20 ears), and the ears which were out of regular follow-up (16 ears). Mean tube persistence times were 34.10 and 52.11 months in these subgroups, respectively (chi2-test, p=0.056). In six ears (16.67%), persistent perforation (PP) was found. PP rate (PPR) was higher in group-B (25%) than in group-A (10%) (chi2-test, p>0.1). The rest perforation was anteriorly marginal in five of six PP (83.33%). The PPR in the ears in which rest perforation was anteriorly marginal was 35.71% (5/14) while it was 4.54% (1/22) in the ears with central rest perforation (chi2-test, p<0.02).

CONCLUSIONS

Even immediate repair of the perforation after removal of the long-lasting tubes resulted in a high PPR. The data in this study documented that this high PPR was associated with type and localisation of rest perforation and tube persistence time. Anteriorly, marginal perforations had about eight times higher risk of PP and longer tube persistence caused higher anterior marginal perforations after tube removal.

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.

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.

Noninvasive fluorescent identification of bacteria causing acute otitis media in a chinchilla model

OBJECTIVES

To evaluate a noninvasive method of bacterial identification via fluorescence spectroscopy in the setting of acute otitis media in a chinchilla model.

STUDY DESIGN

Prospective.

METHODS

For each chinchilla, transbullar inoculation with Streptococcus pneumoniae, Haemophilus influenzae, or Staphylococcus aureus was performed bilaterally and clinical infection was determined by otoscopy. An optical fiber coupled to a spectrofluorometer allowed for the delivery of an excitation wavelength to the inflamed tympanic membrane and the acquisition of the resulting emission signal. Sequential emission spectra obtained over a range of excitation wavelengths were assembled by a computer algorithm, and a single, three-dimensional plot was created for each test ear. Similarly, plots from the healthy external auditory canal (EAC) were also recorded. Twelve animals were used to establish a library of four reference plots representing the three bacteria and the EAC. Of the 24 ears available for study, 10 were excluded from analysis because of lack of clinical infection or presence of tympanic membrane perforation with purulent drainage. From four additional animals, four samples from ears infected with the above bacteria and three samples of the EAC served as unknowns. The unknown plots were analyzed by an investigator blinded to their identity.

RESULTS

Using a multiple correlation of the unknown to the reference plots, seven of seven samples were correctly identified.

CONCLUSIONS

We were able to establish a prototype method for the noninvasive identification of a limited library of pathogens in a chinchilla model of acute otitis media.