Neue Aspekte zur Mechanik der Tuba auditiva

Intravascular Ultrasonography (IVUS)-A Tool for Imaging the Eustachian Tube?

The Eustachian tube (ET) has a key role in the pathogenesis of otitis media. Until now, there has been a lack of meaningful imaging methods to investigate the ET and its surrounding tissue. The aim of the current study was to investigate the possibilities of imaging the ET using Intravascular Ultrasonography (IVUS). ETs from sheep were scanned ex vivo and in vivo with different IVUS probes. In addition to native ETs, water was also used to improve coupling. Scans were subsequently compared with histological sections and a 3D model of the ET. In addition, ETs with a stenosis induced by a hyaluronic acid depot, after stent insertion, and during lower jaw movement were examined. The IVUS catheter was inserted into the ET lumen without any problems or injuries in all cases. The surrounding structures of the ET were identified in the ultrasound image. In addition, a change in size of the ET lumen due to movement was observed, and the position of the stent and the depot of hyaluronic acid could be examined. With the use of IVUS, a non-invasive possibility to examine the ET over its course with the adjacent structures as well as after different treatments is presented.

Development of an In Vivo Model for Eustachian Tube Dysfunction

Otitis media is often connected to Eustachian tube dysfunction (ETD). Until now, there was no large animal model available for the examination of new treatment methods such as stents for the Eustachian tube (ET). Thus, the aim of the study was to develop a method to reproducibly induce ETD by injection of fillers and without permanent closure of the ET. Tools for safe injection of hyaluronic acid (HA) in the surrounding of the ET were developed. In ex vivo experiments, HA mixed with Imeron^® was injected close to the nasopharyngeal orifice of the ET of blackface sheep. The established depot was visualized using cone beam computer tomography and magnetic resonance imaging, and stents could be placed into the ET. A reliable position of the HA depot was achieved. This method was transferred to in vivo, and middle ear ventilation was investigated by tympanometry. ETD was achieved with amounts of 2.5 mL HA or higher. None of the animals showed any sign of discomfort or complications. The induced ETD lasted for 3 to 13 (maximum observation period) weeks and was also combined with middle ear effusion. A model of ETD based on injection of HA next to the ET was successfully established and is now available to test novel treatment options for ET functionality.

[Diagnosis and treatment of Eustachian tube dysfunction]

The Eustachian tube protects against secretion, germs and sound pressure from the nasopharynx, it acts as a drain, and serves pressure equalization in both directions so that the ear drum and sound-conducting apparatus can vibrate optimally. The incidence of Eustachian tube dysfunction in adults is about 1%, in children almost 40%. Symptoms are often unspecific. For diagnosis, the Eustachian tube score (ETS-5) can be used in patients with a perforated ear drum, and the ETS-7 score in patients with intact ear drum. Adenoid hypertrophy is a frequent cause of obstructive tube dysfunction in children. Treatment of obstructive dysfunction includes steroid nasal sprays and regular performance of the Valsalva maneuver, as well as tube dilation with the Bielefelder balloon catheter. The patulous Eustachian tube is treated with saline nasal irrigation, estrogen-nasal ointment, and craniocervical manual therapy; causal treatments are evaluated.

Eustachian Tube Opening Measurement by Sonotubometry Using Perfect Sequences for Healthy Adults

Objectives

The aim of this study was to establish the rate variation of sonotubometric measurements using a specific broadband class of signals, the so-called perfect sequences (PSEQ) among healthy adults and to identify an optimal and technically simple test to provoke Eustachian tube (ET) openings.

Methods

Sonotubometry was performed on 105 healthy adult subjects. Three different consecutive maneuvers were performed for ET opening: dry swallowing, water swallowing (a small [2 mL] and a large [5 mL] water bolus). Values of the amplitude and duration of each measured ET opening were calculated.

Results

A total of 6,300 measurements were performed. Sonotubometric ET openings were detected for all subjects but not for each measurement. In 6,180 of 6,300 measurements (98.1%), objective ET openings were registered. In 11 of 105 subjects (10.5%) at least one sonotubometric ET opening was not detected. The mean ET opening duration time and the mean sound amplitude similar for all performed test and were 270 (SD, ±96) msec, 13.48 (SD, ±6.57) dB.

Conclusion

Sonotubometry based on PSEQ stimuli is a reliable methodology to assess the ET opening function in healthy subjects. Mean ET opening duration time and the mean sound wave amplitude performed similarly in all analysed tests, hence it might be concluded that dry (saliva) and water swallowing are reliable sonotubometric maneuvers and may be used when examining ET opening function. The size of a sip during water swallowing does not affect the sonotubometry result. All maneuvers can be equally used as the optimal test, and water swallow is most comfortable for the subject.

[The patulous eustachian tube-novel surgical approaches]

A patulous eustachian tube (tuba aperta) may lead to an enormous reduction in quality of life. A patulous eustachian tube can cause symptoms such as autophony, breath synchronous tinnitus, pressure sensation in the ear, and hearing loss. In combination with so-called "sniffing", it can trigger the development of cholesteatoma. Due to the diffuse symptoms the correct diagnosis of this disease can be challenging. A patulous eustachian tube can be best diagnosed through a well-structured examination including patient history, physical examination with thorough observation of movements of the tympanic membrane, and tympanometry with reflex decay. This publication reviews recent literature on the patulous eustachian tube. We focused on the evaluation of the different surgical strategies such as the patulous eustachian tube reconstruction, the Kobayashi plug or the injection of Vox® implants into the torus tubarius.

Genome-wide linkage and association analysis identifies major gene loci for guttural pouch tympany in Arabian and German warmblood horses

Equine guttural pouch tympany (GPT) is a hereditary condition affecting foals in their first months of life. Complex segregation analyses in Arabian and German warmblood horses showed the involvement of a major gene as very likely. Genome-wide linkage and association analyses including a high density marker set of single nucleotide polymorphisms (SNPs) were performed to map the genomic region harbouring the potential major gene for GPT. A total of 85 Arabian and 373 German warmblood horses were genotyped on the Illumina equine SNP50 beadchip. Non-parametric multipoint linkage analyses showed genome-wide significance on horse chromosomes (ECA) 3 for German warmblood at 16–26 Mb and 34–55 Mb and for Arabian on ECA15 at 64–65 Mb. Genome-wide association analyses confirmed the linked regions for both breeds. In Arabian, genome-wide association was detected at 64 Mb within the region with the highest linkage peak on ECA15. For German warmblood, signals for genome-wide association were close to the peak region of linkage at 52 Mb on ECA3. The odds ratio for the SNP with the highest genome-wide association was 0.12 for the Arabian. In conclusion, the refinement of the regions with the Illumina equine SNP50 beadchip is an important step to unravel the responsible mutations for GPT.

The improvement of middle ear ventilation by laser ablation of the epipharyngeal eustachian tube: a prospective study

A long-lasting dysfunction of the eustachian tube seems to be the etiologic origin for development of chronic otitis media (COM) with mesotympanic perforation, otitis media with effusion (OME), and chronic atelectasis of the middle ear. Surgical interventions in the middle ear generally treat the sequelae of the tube dysfunction but not the dysfunction itself. This prospective clinical study investigated how far fiber-guided laser ablation of the posterior half of the epipharyngeal tubal ostium led to better middle ear ventilation in the otologic disease patterns mentioned below. There were 38 adult patients included in the analysis. The patients in one group had a perforated tympanic membrane [COM before primary tympanoplasty (n = 14) or revision tympanoplasty (n = 5)]; the patients in a second group had an intact eardrum [OME resistant to therapy (n = 3), with an atelectasis of the middle ear (n = 2) or problems of pressure equalization with fast changes in ambient pressure (diving, flying) (n = 14)]. Laser ablation of the posterior half of the epipharyngeal tubal ostium was performed, generally with local anesthesia, if tubal function testing was pathologic (Valsalva maneuver, passive tube opening, tympanogram). In patients with COM the procedure was performed 8 weeks before the middle ear surgery. All patients were checked 8 weeks postoperatively and in the course of the following year. The intervention seemed to have had a positive effect on tube function in 68.4% of patients operated on (P = 0.001). In 26 of the 38 patients that had undergone operation, an improvement the results of tubal function tests could be seen in the postoperative follow-up. In the COM group the Valsalva maneuver improved in 14 of 19 patients (73.6%) (P = 0.001), and the passive tube opening improved in nine of 18 patients (50%). In the group with an intact eardrum the Valsalva maneuver improved in 13 of 18 patients (72.2%) (P = 0.001). The resulting condition remained stable after 1 year. None of the patients showed any complications as a result of the therapy. Minimally invasive shaping of the distal eustachian tube under topical anesthesia can be recommended for patients with the above-mentioned diagnoses who have pathologic middle ear ventilation. Especially prior to tympanoplasties, and especially in otologic revision procedures, where middle ear ventilation is a prerequisite for successful otologic surgery, the function of the eustachian tube can be optimized in 70% of the patients, particularly if there are pathological findings (tubal tonsil, narrow orifice of the tubal ostium, adenoids). The placement of permanent ear tubes in adults with recurrent OME can also be avoided by the procedure described. The resultant conditions remained stable for the next year. Patients with tympanic ventilation problems due to rapid pressure changes (flying, diving) can also benefit from this procedure.

[Treatment of chronic tube dysfunction. Use of the tube conductor]

BACKGROUND

Chronic tube dysfunction plays a major part in the development of chronic otitis media. Owing to the complex structure of the Eustachian tube, the development of successful therapeutic approaches to the treatment of tube function disorders is still difficult even today. The application of a gold tube wire (tube conductor) was reported in 1991, but no studies have yet been performed on the postoperative success rates achieved with tube conductors.

MATERIAL AND METHODS

In a retrospective study, the data relating to 125 patients who were operated on from 1996 to 1999 for treatment of different forms of chronic otitis media and also underwent transtympanic tube conductor implantation to improve tube ventilation disorder were evaluated. Data on pre- and postoperative tube function were available for 96 patients after a mean follow-up period of 18 months.

RESULTS

All tube implantations were achieved without complications. Tube function normalized in 8 patients (8.3%), while the tube ventilation disorder remained unaffected in 88 patients (91.7%). A total of 23 (18.4%) tube conductors have so far been removed. The reasons for removal include persistent tube ventilation disorder, dislocation of the tube conductor in 7 patients (5.6%) and granulation around the tube wire in 7 cases (5.6%).

CONCLUSIONS

The chronic tube ventilation disorder was improved by implantation of a tube conductor in only 8.3% of the patient population investigated. We are therefore of the opinion that this is not a suitable treatment for chronic tube ventilation disorders. The development of new, effective therapeutic approaches to the treatment of chronic tube ventilation disorders remains a priority.

Pathophysiology of the Eustachian tube--relevant new aspects for the head and neck surgeon

OBJECTIVES

The impact of cranio-maxillofacial procedures upon Eustachian tube function is still largely unknown. The aim of this presentation is to depict new aspects of Eustachian tube function and to demonstrate its importance to cranio-maxillofacial surgery.

METHODS

Two different groups of patients were examined both clinically and by MRI of the Eustachian tube region. One of these groups comprised 15 adult patients with a history of cleft palate; another consisted of 32 patients with a history of a so-called patulous Eustachian tube.

RESULTS

Clinical and MRI-findings revealed that the problem of persistent chronic middle ear disease with cleft palate patients depends crucially on the integrity of the pterygoid hamulus and of the tensor veli palatini muscle after cleft palate repair. The masticatory muscles on the other hand also play an important role in Eustachian tube function in non-cleft patients.

CONCLUSION

The maxillofacial surgeon should be aware that he holds a key position for preventing as well as treating Eustachian tube pathophysiology.

Funktionsuntersuchungen der Tuba Eustachii

The Eustachian tube regulates the homeostasis of the middle ear. Problems with its function are predominantly found in childhood. As a consequence, otitis and hearing impairment occur. The most important muscle is the tensor tympani muscle. The complexity of the functional anatomy and physiology are reasons why no function test alone is capable of fulfilling all diagnostic needs. The predictive value of the various Eustachian tube function tests for the outcome of a tympanoplasty is not yet clear. An overview of clinically and scientifically relevant tests for the Eustachian tube function is provided.