Ossicular chain reconstruction improves bone conduction threshold in chronic otitis media

Audiometric Variability of the Carhart Effect in Middle Ear Diseases - Pretreatment Analysis

OBJECTIVE

The assessment of bone conduction thresholds in patients with conductive hearing loss is not a full measure of the function of the inner ear due to the weakening of the influence of middle ear components on bone conduction. This relationship has been called the 'Carhart effect'.

METHODS

The retrospective analysis covered 977 patients diagnosed and treated for middle ear diseases from 2010 to 2020. The Carhart effect was considered to be an increase in the bone conduction threshold by a minimum of 10 dB relative to adjacent frequencies. The study was performed with the aim of assessing the presence of the Carhart effect in the course of middle ear diseases in pretreatment analysis.

RESULTS

The Carhart effect was observed in 532 cases, most often in patients with chronic otitis media and otosclerosis. It was least often observed in patients with otitis media with effusion. In otitis media with effusion, the Carhart effect was more often noted for the frequency of 4000 Hz, in otosclerosis for the frequency of 2000 Hz. In patients with chronic otitis media, this effect for the frequency of 4000 Hz was correlated with the location of inflammatory changes in the attic area. The presence of inflammatory lesions in the oval window area was associated with the presence of the Carhart effect for the frequency of 2000 Hz.

CONCLUSIONS

1. The frequency of the Carhart effect observed in diseases of the middle ear does not depend on the disease entity but on the type and location of abnormalities in the middle ear. 2. The Carhart effect observed for the frequency of 4000 Hz coexists with the localization of lesions in the range of the malleus and incus, and for the frequency of 2000 Hz, it is partially associated with abnormalities in the range of stapes and oval window.

Improved Bone Conduction Hearing After Middle Ear Surgery: Investigation of the Improvement Mechanism

OBJECTIVES

When performing middle ear operations, such as ossiculoplasty or stapes surgery, patients and surgeons expect an improvement in air conduction (AC) hearing, but generally not in bone conduction (BC). However, BC improvement has often been observed after surgery, and the present study investigated this phenomenon.

METHODS

We reviewed the preoperative and postoperative surgical outcomes of 583 patients who underwent middle ear surgery. BC improvement was defined as a BC threshold decrease of >15 dB at two or more frequencies. Subjects in group A underwent staged ossiculoplasty after canal wall up mastoidectomy (CWUM), group B underwent staged ossiculoplasty after canal wall down mastoidectomy (CWDM), group C underwent ossiculoplasty only (thus, they had no prior history of CWUM or CWDM), and group D received stapes surgery. We created a hypothetical circuit model to explain this phenomenon.

RESULTS

BC improvement was detected in 12.8% of group A, 9.1% of group B, and 8.5% of group C. The improvement was more pronounced in group D (27.0%). A larger gain in AC hearing was weakly correlated with greater BC improvement (Pearson's r=0.395 in group A, P<0.001; r=0.375 in group B, P<0.001; r=0.296 in group C, P<0.001; r=0.422 in group D, P=0.009). Notably, patients with otosclerosis even experienced postoperative BC improvements as large as 10.0 dB, from a mean value of 30.3 dB (standard error [SE], 3.2) preoperatively to 20.3 dB (SE, 3.2) postoperatively, at 1,000 Hz, as well as an improvement of 9.2 dB at 2,000 Hz, from 37.8 dB (SE, 2.6) to 28.6 dB (SE, 3.1).

CONCLUSION

BC improvement may be explained by a hypothetical circuit model applying the third window theory. Surgeons should keep in mind the possibility of BC improvement when making a management plan.

Regenerative treatment for tympanic membrane perforation using gelatin sponge with basic fibroblast growth factor

OBJECTIVE

The objective of this study was to evaluate safety and efficacy of regenerative treatment using gelatin sponge with basic fibroblast growth factor (bFGF) in patients with tympanic membrane perforation (TMP).

METHODS

The current study was a prospective, multicenter, open-label, single-arm, and exploratory clinical trial to evaluate the safety and efficacy of the TM regeneration procedure (TMRP). Myringotomy was used to mechanically disrupt the edge of the TMP, and a gelatin sponge immersed in bFGF was then placed over the perforation. Fibrin glue was dripped over the sponge as a sealant. TMP closure was examined 4 weeks later and, if insufficient, TMRP was repeated a maximum of three more times. TMP closure and hearing improvement 12 weeks after the final TMRP as well as safety were evaluated.

RESULTS

Of the 11 patients with TMP who participated in this study, one who fulfilled the exclusion criteria and did not undergo TMRP and one with cholesteatoma were excluded from the efficacy analysis. TMP closure and hearing improvement 12 weeks after the final TMRP were achieved in eight out of nine patients (88.9%). Mean bone conduction threshold significantly improved 12 weeks after the TMRP compared with baseline (35.7±20.3 vs 29.4±21.0dB, P=0.015). Six out of ten patients receiving TMRP experienced temporary adverse events: appendicitis (serious, severe), otorrhea (mild), otitis media (mild), and sudden hearing loss (mild). However, none were related to the protocol treatment.

CONCLUSION

TMP closure and hearing improvement were frequently confirmed following the TMRPs which were safely performed. These favorable outcomes were accompanied with significant improvement of the bone conduction threshold. These promising outcomes would encourage a large-scaled, randomized and pivotal clinical trial in the future. This trial is registered at http://www.umin.ac.jp/ctr/index.htm (identifier: UMIN000006585).

Surgical treatment of congenital aural atresia - is it still justified?

CONCLUSION

Surgery candidacy based on the surgical accessibility of the middle ear seems more valuable than the use of a preoperative grading system. Also patients with severe malformations can benefit from surgical reconstruction.

OBJECTIVE

To evaluate the long-term results of the primary surgical treatment of patients with congenital auricular atresia (CAA).

METHODS

One hundred patients with CAA underwent surgical reconstruction between 1985 and 2010. The mean follow-up time was 40 months. All patients were retrospectively scored using the Jahrsdoerfer grading scale and divided into two groups according to the grade of their malformation. Group 1 included 20 patients with scores of 4-6 and group 2 included 80 patients with scores of 7-10. Pre- and postoperative air conduction (AC), bone conduction (BC), pure-tone average 'air-bone gap' (PTA₄-ABG), surgical findings, postoperative complications, and revision surgeries performed were determined and compared between the two groups.

RESULTS

For 90% of the patients in group 1 and 79% of the patients in group 2, the postoperative ABG was within 0 and 30 dB. The most common complications were recurrent infection, lateralization of the tympanic membrane, and restenosis of the ear canal.

Pure-tone Audiometry in Otosclerosis

Objective

To evaluate whether the Carhart notch on pure-tone audiometry is reliable as a diagnostic test for predicting otosclerosis in patients with conductive hearing loss.

Data Sources

PubMed, Embase, the Cochrane Library, CINAHL, and Scopus.

Methods

A systematic search was conducted. Studies reporting original study data were included. After assessment of directness of evidence and risk of bias of the selected articles, the prevalences and the positive and negative predictive values were extracted.

Results

A total of 1402 unique studies was retrieved. Three of these satisfied the eligibility criteria. One study provided direct evidence, while all studies carried moderate to high risk of bias. One study with moderate directness of evidence and high risk of bias was not further analyzed. In a study with a high directness of evidence, a high risk of bias, and a low prevalence of otosclerosis (8%) in patients with conductive hearing loss, the presence of a Carhart notch at 2000 Hz increased the risk of otosclerosis with 33%. In a second study with moderate directness of evidence, moderate risk of bias, and a high prevalence of otosclerosis (72%) in patients with a surgically confirmed congenital ossicular anomaly or otosclerosis, the presence of a Carhart notch at 2000 Hz increased the risk of otosclerosis with 2%.

Conclusion and Recommendation

Although there is insufficient high-quality evidence regarding the diagnostic value of the Carhart notch, it seems it is a useful hint for the presence of otosclerosis, but it cannot be used to confirm a diagnosis of otosclerosis.

High frequency hearing following stapes surgery

CONCLUSION

Our results indicate that a pre-existing sensorineural hearing loss (SNHL) is not a potential risk factor for further hearing loss in stapes surgery.

OBJECTIVE

The study evaluated whether pre-existing SNHL in otosclerosis constitutes a risk factor for further hearing loss in stapedotomy.

METHODS

Preoperative and postoperative audiometric evaluation including air (AC) and bone conduction (BC) hearing levels were assessed together with collection of surgical records from 338 consecutively operated cases for primary otosclerosis using a database. Patients were operated by the same surgeon between 2000 and 2006. In all, 291 patients were operated on 1 side and 47 patients were operated on both sides. Ages ranged from 16 to 76 years. Stapedotomy was performed in all cases except five (stapedectomy). Cases were separated into four different groups based on preoperative AC hearing levels at 4, 6, and 8 kHz: group I, <30 dB HL; group II, 30-50 dB HL; group III, 51-70 dB HL; group IV, >70 dB HL).

RESULTS

Hearing deterioration at 4, 6, and 8 kHz (>10 dB) was observed in 6.5% of all cases. Patients with normal preoperative hearing were found to be more prone to further SNHL 4, 6, and 8 kHz (range 13-25 dB) at surgery, while patients in group IV, with preoperative SNHL impairment, remained unaffected.

Frequency-specific hearing results after surgery for chronic ear diseases

Objectives

To analyze frequency-specific hearing results after surgery for chronic ear diseases while considering pathological findings and various surgical factors.

Methods

Patients who underwent surgical management of chronic otitis media were reviewed retrospectively (n=559). Using pure tone audiometry, air conduction (AC), bone conduction (BC), and air bone gap (ABG) change between pre- and post-operative tests were calculated for the frequencies of 250, 500, 1,000, 2,000, 3,000, 4,000 (AC and BC), and 6,000 Hz (AC). Frequency-specific results were investigated, considering various surgical factors, such as type of surgery, type of ossiculoplasty and pathological findings.

Results

AC results in the intact canal wall mastoidectomy showed improvement at each frequency except 4,000, 6,000 Hz. AC results in the tympanoplasty showed improvement at each frequency except 6,000 Hz. AC and ABG results in the open cavity mastoidectomy showed improvement only at the frequencies of 250, 500, 2,000 Hz. AC and ABG improved at low and mid frequencies but not in high frequencies above 3,000 Hz when ossicular reconstruction was conducted. AC and ABG results also improved at low and mid frequencies in the cholesteatoma, and ABG results improved at all frequencies except 3,000 Hz in the non-cholesteatoma.

Conclusion

After chronic ear surgery, AC and ABG changes improved, primarily in the low and mid frequencies. Further evaluation and studies for post-operative hearing loss at high frequencies are recommended for rehabilitation of hearing ability after surgery.