Balloon dilation of the cartilaginous portion of the eustachian tube: initial safety and feasibility analysis in a cadaver model

Balloon Eustachian Tuboplasty

Objective

A systematic review and meta-analysis of the evidence on balloon Eustachian tuboplasty (BET) as a treatment modality for Eustachian tube dysfunction (ETD). We followed the PRISMA guideline and registered with PROSPERO No. CRD42014009461.

Data Sources

We searched 12 databases including PubMed and Embase from January 1, 2010, to April 7, 2014, for studies of BET. Endpoints: change in symptoms, middle ear pathology, eardrum status, Eustachian tube function tests, hearing, adverse events, complications, and health-related quality of life.

Review Methods

Study quality was assessed using the modified Delphi technique quality appraisal tool for case series studies. Risk of bias was assessed using the Cochrane Collaboration’s tool for assessing risk of bias.

Results

Nine case series studies with 443 patients (642 tubes) were included. Population size n = 4 (7 tubes) to n = 210 (320 tubes). All studies were of poor quality and featured a high risk of bias. We found reduction of patient symptoms in ETD questionnaire ( P < .001), postoperative normalization of the tympanic membrane, conversion of type B or type C into type A tympanograms, reduced mucosal inflammation, increased number of positive Valsalva test and Swallowing tests, improvement in Eustachian tube score, reduction in Sino-Nasal Outcome Test (SNOT)-22 score ( P = .001), and increased quality of life ( P = .001). No serious adverse events were found.

Conclusion

The evidence of BET is poor and biased. No firm conclusions can be made to identify patients who will benefit from the procedure or to accurately predict surgical results. Randomized controlled trials or case-control trials are needed.

Treatment of middle ear ventilation disorders: sheep as animal model for stenting the human Eustachian tube--a cadaver study

Eustachian tube disorders can lead to chronic otitis media with consecutive conductive hearing loss. To improve treatment and to develop new types of implants such as stents, an adequate experimental animal model is required. As the middle ear of sheep is known to be comparable to the human middle ear, the dimensions of the Eustachian tube in two strains of sheep were investigated. The Eustachian tube and middle ear of half heads of heathland and blackface sheep were filled with silicone rubber, blended with barium sulfate to induce X-ray visibility. Images were taken by digital volume tomography. The tubes were segmented, and a three-dimensional model of every Eustachian tube was generated. The lengths, diameters and shapes were determined. Additionally, the feasibility of endoscopic stent implantation and fixation was tested in cadaver experiments. The length of the tube between ostium pharyngeum and the isthmus and the diameters were comparable to published values for the human tube. The tube was easily accessible through the nose, and then stents could be implanted and fixed at the isthmus. The sheep appears to be a promising model for testing new stent treatments for middle ear ventilation disorders.

What is the full range of medical and surgical treatments available for patients with Eustachian tube dysfunction?

PURPOSE OF REVIEW

To present the current medical and surgical treatment options for Eustachian tube dysfunction.

RECENT FINDINGS

Balloon dilation or microdebrider Eustachian tuboplasty are feasible treatment options for patients with refractory dilatory dysfunction as an alternative to tympanostomy tube placement. There is increasing evidence that repair of patulous Eustachian tubes by the insertion of a shim or fat graft reconstruction within the lumen of the Eustachian tube orifice may be effective.

SUMMARY

In patients with Eustachian tube dysfunction that is refractory to medical management, newer surgical techniques may provide symptomatic relief with a reasonable duration. Continued basic science research into the cause of dysfunction, the mechanisms of benefit from intervention and long-term clinical outcomes are necessary.

[Therapy of chronic obstructive eustachian tube dysfunction: evolution of applied therapies]

This paper reviews the past and present developments in the treatment of chronic obstructive eustachian tube dysfunction. Alongside tube catheterization and bougie insertion, modern approaches such as laser eustachian tuboplasty and balloon eustachian tuboplasty (BET) are described. In BET, transnasal endoscopic insertion via the pharyngeal ostium places a balloon catheter in the cartilaginous portion of the eustachian tube. This is then dilated to a pressure of 10 bar for 2 min. Up until January 2013, 351 chronic obstructive eustachian tube dysfunction patients had been treated in our department using BET. The average preoperative eustachian tube score was 2.1 (± 1.8 standard deviation, SD); 12 months postoperatively it was 6.1 (± 2.6 SD). Of these patients, 87% expressed satisfaction with the improvement in chronic obstructive dysfunction. These results demonstrate that BET is a safe and effective treatment for improving eustachian tube function and ear ventilation.

Panel 2

Objective

This report reviews the literature to identify the advances in our understanding of the middle ear (ME)–Eustachian tube (ET) system during the past 4 years and, on that basis, to determine whether the short-term goals elaborated in the last report were achieved and propose updated goals to guide future otitis media (OM) research.

Data Sources

Databases searched included PubMed, Web of Science (1945-present), Medline (1950 to present), Biosis Previews (1969-present), and the Zoological Record (1978 to present). The initial literature search covered the time interval from January 2007 to June 2011, with a supplementary search completed in February 2012.

Review Methods

The panel topic was subdivided; each contributor performed a literature search and provided a preliminary report. Those reports were consolidated and discussed when the panel met on June 9, 2011. At that meeting, the progress was evaluated and new short-term goals proposed.

Conclusions

Progress was made on 16 of the 19 short-term goals proposed in 2007. Significant advances were made in the characterization of ME gas exchange pathways, modeling ET function, and preliminary testing of treatments for ET dysfunction.

Implications for Practice

In the future, imaging technologies should be developed to noninvasively assess ME/ET structure and physiology with respect to their role in OM pathogenesis. The new data derived from form/function experiments should be integrated into the finite element models and used to develop specific hypotheses concerning OM pathogenesis and persistence. Finally, rigorous studies of treatments, medical or surgical, of ET dysfunction should be undertaken.

Transtympanic balloon dilatation of eustachian tube: a human cadaver pilot study

Objective:

To determine the feasibility and safety of transtympanic balloon dilatation of the eustachian tube.

Methods:

Transtympanic eustachian tube dilatation was performed on six cadaver heads using balloon catheters. Catheters were placed in each eustachian tube and the head scanned by computed tomography. Randomised, blinded dilatation of one balloon in each head was performed, followed again by a second computed tomography scan. The scans were reviewed by a neurotologist and neuroradiologist who were blinded to previous treatment, and measurable dilatation and incidental damage noted.

Results:

There was adequate placement of the balloon catheter beyond the bony isthmus in 6 of 10 eustachian tubes. There was one insufficient catheter placement and three adverse placements (one into the petrous carotid canal and two into the vidian canal). Only one dilated tube showed a measurable increase in diameter.

Conclusion:

This experiment revealed serious safety issues with transtympanic eustachian tube dilatation. Therefore, this approach should not be considered feasible at this time.

Balloon dilation of the eustachian tube in a cadaver model: technical considerations, learning curve, and potential barriers

OBJECTIVES/HYPOTHESIS

The surgical management options for eustachian tube dysfunction have historically been limited. The goal of the current study was to evaluate the technical considerations, learning curve, and potential barriers for balloon dilation of the eustachian tube (BDET) as an alternative treatment modality.

STUDY DESIGN

Prospective preclinical trial of BDET in a cadaver model.

METHODS

A novel balloon catheter device was used for eustachian tube dilation. Twenty-four BDET procedures were performed by three independent rhinologists with no prior experience with the procedure (eight procedures per surgeon). The duration and number of attempts of the individual steps and overall procedure were recorded. Endoscopic examination of the eustachian tube was performed after each procedure, and the surgeon was asked to rate the subjective difficulty on a five-point scale.

RESULTS

Successful completion of the procedure occurred in each case. The overall mean duration of the procedure was 284 seconds, and a mean number of 1.15 attempts were necessary to perform the individual steps. The mean subjective procedure difficulty was noted as somewhat easy. Statistically shorter duration and subjectively easier procedure were noted in the second compared to the first half of the series, indicating a favorable learning curve. Linear fissuring within the eustachian tube lumen without submucosal disruption (nine procedures, 37%) and with submucosal disruption (five procedures, 21%) were noted. The significance of these physical findings is unclear.

CONCLUSIONS

Preclinical testing of BDET is associated with favorable duration, learning curve, and overall ease of completion. Clinical trials are necessary to evaluate safety and efficacy.