Animal models of chronic tympanic membrane perforation: A ‘time-out’ to review evidence and standardize design

ObjectiveTo review the literature on techniques for creation of chronic tympanic membrane perforations (TMP) in animal models. Establishing such models in a laboratory setting will have value if they replicate many of the properties of the human clinical condition and can thus be used for investigation of novel grafting materials or other interventions.MethodsA literature search of the PubMed database (1950–August 2014) was performed.The search included all English-language literature published attempts on chronic or delayed TMP in animal models. Studies of non English-language or acute TMP were excluded.ResultsThirty-seven studies were identified. Various methods to create TMP in animals have been used including infolding technique, thermal injury, re-myringotomy, and topical agents including chemicals and growth factor receptor inhibitors. The most common type of animal utilized was chinchilla, followed by rat and guinea pig. Twenty three of the 37 studies reported success in achieving chronic TMP animal model while 14 studies solely delayed the healing of TMP. Numerous experimental limitations were identified including TMP patency duration of <8 weeks, lack of documentation of total number of animals attempted and absence of proof for chronicity with otoscopic and histologic evidence.ConclusionThe existing literature demonstrates the need for an ideal chronic TMP animal model to allow the development of new treatments and evaluate the risk of their clinical application. Various identified techniques seem promising, however, a need was identified for standardization of experimental design and evidence to address multiple limitations.     

Capacity of Rectified Vestibular Evoked Myogenic Potential in Correcting Asymmetric Muscle Contraction Power

Objectives

Rectified vestibular evoked myogenic potential (rVEMP) is new method that simultaneously measures the muscle contraction power during VEMP recordings. Although there are a few studies that have evaluated the effect of the rVEMP, there is no study that has evaluated the capacity of rVEMP during asymmetrical muscle contraction.

Methods

Thirty VEMP measurements were performed among 20 normal subjects (mean age, 28.2±2.1 years; male, 16). VEMP was measured in the supine position. The head was turned to the right side by 0°, 15°, 30°, and 45° and the VEMPs were recorded in each position. The interaural amplitude difference (IAD) ratio was calculated by the conventional non-rectified VEMP (nVEMP) and rVEMP.

Results

The nVEMP IAD increased significantly according to increasing neck rotation. The IAD in rVEMP was almost similar from 0° to 30°. However, the IAD was significantly larger than the other positions when the neck was rotated 45°. When IAD during 0° was set as a standard, the IAD of the rVEMP was significantly smaller that the nVEMP only during the 30°rotaion.

Conclusion

Rectified VEMP is capable of correcting asymmetrical muscle contraction power. In contrast, it cannot correct the asymmetry if muscle contraction power asymmetry is 44.8% or larger. Also, it is not necessary if muscle contraction power asymmetry is 22.5% or smaller.     

Never trust secondary references: examples from the early history of myringotomy and grommets

The regular use of secondary references is associated with many inaccuracies. The aim of this study is to demonstrate this fact through examples extracted from recent papers mentioning the early history of myringotomy and grommets. These inaccuracies are in relation with the lack of control of the original references dealing with the subject. In conclusion, never believe and use secondary references as primary sources, without reading the original paper to confirm that it says what you think it does, but take them only for preparing and discussing the studied subject.     

Evolution of Eustachian tube surgery

Eustachian tube dysfunction (ETD) is a common condition that lacks a widely accepted treatment. Attempts to address ETD surgically have spanned several centuries and have often fallen short of success. It is probable that occult anatomic position, unclear function, and misunderstood physiology have contributed to the delayed development of effective interventions for ETD. This article traces the evolution of therapeutic interventions of the Eustachian tube through the present day. Reasons for success and failure are highlighted, with implications for the future of Eustachian tube surgery.     

Clinical trials in otology: Examining trends and framework for prioritization

Objective:To characterize otologic clinical trials and examine otologic clinical trial trends from 2008 to 2018 using the clinicaltrials.gov database.Methods:Data was collected from clinicaltrials.gov and included all clinical trials that focused on otology from 2008 to 2018.Outcome measures include status of trials,funding sources,details regarding otologic conditions studied,and trends in clinical trials.Results:There were 992 otology clinical trials from 2008 to 2018.457(46.1%)were completed and 94(9.5%)were discontinued.Industry remained the highest(76.5%)contributor to otology clinical trials.The otologic conditions studied,from most common to least common,include hearing loss(40.6%),vestibulopathy(18.8%),tinnitus(18.8%),and otitis media(15.1%).The number of otology clinical trials increased by an average of 12.0 trials per year from 2008 to 2018(p<0.001).The number of otology clinical trials focusing on hearing loss and vestibulopathy significantly increased over the studied period(p<0.001),while those focusing on tinnitus and otitis media did not(p=0.09 and p=0.20,respectively).The majority of clinical trials on each of these four conditions focused on treatment options.Conclusion:Our study describes trends in otology clinical trials registered on clinicaltrials.gov from 2008 through 2018.The total number of clinical trials over this time period increased significantly,driven by trials investigating hearing loss and vestibulopathy.Furthermore,most clinical trials were industrysponsored and focused on treatment modalities.Our study provides an outline of otology clinical trials registered in a US web-based database,which may be of use for the development of future clinical trials.