Introduction
The auditory system includes both conductive and sensorineural pathways.1 The conductive process comprises the following structures from the external ear canal to the inner ear: the external ear canal, a moving tympanic membrane, a middle ear filled with gas at ambient pressure and a solid mobile bone chain.1 The pressure difference between the ambient pressure and the middle ear affects conductive hearing.1 The Eustachian tube is responsible for pressure regulation and ventilation in the middle ear; furthermore, the Eustachian tube is involved in the drainage of mucus produced in the middle ear and facilitates its cleansing.Reference Luukkainen, Kivekäs, Silvola, Jero and Sinkkonen2
Otitis media with effusion, a middle-ear condition accompanied by fluid and mucus accumulation, commonly leads to hearing loss. Although there are many risk factors that are responsible for the development of this condition in children, the Eustachian tube and its anatomy is the most important factor.Reference Tisch, Maier and Sudhoff3 Chronic Eustachian tube dysfunction often causes recurrent or persistent effusion of the middle ear, tympanic membrane retraction, hearing loss and, in some cases, chronic ear disease or cholesteatoma in children.Reference Luukkainen, Kivekäs, Silvola, Jero and Sinkkonen2
Furthermore, Eustachian tube dysfunction is more prevalent in children; it is presumed that at least one temporary dysfunction event of the Eustachian tube is experienced in at least 80 per cent of all children at the preschool level.Reference Tisch, Maier and Sudhoff3 An explanation of this is based on the following anatomical reasons: children have a shorter Eustachian tube than adults, which is at an angle that is relatively flat to the horizontal plane; children have a higher mass of Ostmann's fat pad than adults; the volume of cartilage tissue is less in children, and cartilage is also softer; and children have a more curved and thicker Eustachian tube cartilage and mucous membrane than adults.Reference Tisch, Maier and Sudhoff3
There is a general consensus that procedures such as myringotomy, ventilation tube placement and adenoidectomy are the gold standard treatment modalities for chronic otitis media with effusion in children. These are also the first-line treatment options for children affected by persistent and recurrent infections in the middle ear with or without effusion. Although Eustachian tube dysfunction is most commonly observed in children, the initial studies that involved balloon dilatation of the Eustachian tube were conducted in adults.Reference Schroder, Lehmann, Ebmeyer, Upile and Sudhof4,Reference Ockermann, Reineke, Upile, Ebmeyer and Sudhof5 However, balloon Eustachian tuboplasty treatment has been in use for years to treat children.Reference Tisch, Maier, Hecht and Maier6,Reference Jenckel, Kappo, Gliese, Loewenthal, Lörinncz and Knecht7 Furthermore, balloon Eustachian tuboplasty has been used to treat children suffering from persistent or recurrent infections of the middle ear with or without effusion as an alternative method to the ‘gold standard’ therapy options, including myringotomy and ventilation tube insertion, in cases where the children were resistant to the conventional therapy. However, balloon Eustachian tuboplasty as a first-line treatment option and its outcome has not been investigated widely in children. Thus, this study aimed to demonstrate the efficacy of balloon Eustachian tuboplasty in children as an alternative to ventilation tube insertion by assessing the clinical applications of the procedure, associated findings and results of Eustachian tube function tests in children evaluated post-balloon Eustachian tuboplasty.
Materials and methods
Patients
The ethics committee of Marmara University approved this study. Parents were provided with information about both the ventilation tube insertion and balloon Eustachian tuboplasty procedures. It was explained to them that ventilation tube insertion has been performed for years and that the use of balloon Eustachian tuboplasty in children is an innovative treatment, which does not require the eardrum to be perforated as in ventilation tube insertion; however, the long-term results are not known. Written consent was obtained from the parents. After the technical details of both the procedures were explained, the decision was left to the parents; those who did not want to use innovative techniques such as balloon Eustachian tuboplasty chose ventilation tube insertion, whereas those who did not want perforation of the eardrum chose the balloon Eustachian tuboplasty technique.
All patients had either unilateral or bilateral persistent chronic otitis media with effusion that had been present for at least six months. Patients with either otomicroscopic or otoscopic evidence of otitis media with effusion or tympanic membrane retraction and an abnormal tympanogram, were administered intranasal mometasone furoate spray and nasal saline irrigation for six weeks as treatment. Children who were non-responsive to this therapy were included in the study. Children with craniofacial syndromes, cleft palates, Down syndrome or prior ventilation tube insertion, and those who had previous adenoidectomy were excluded.
Adenoidectomy was performed in all patients with adenoid tissue hypertrophy. The following tests were performed in order to examine all children before and after surgery: otomicroscopy, tympanometry, pure tone audiometry and endoscopic nasopharyngoscopy. Otomicroscopy and tympanograms were recorded before the surgery and the three-month, six-month and one-year follow-up evaluations.
Otitis media with effusion was confirmed by pre-operative otic endoscopy and tympanometry showing a type B tympanogram. A pure tone audiogram was performed pre-operatively and at the one-year follow-up visit. Endoscopic nasopharyngoscopy was performed pre-operatively and one-year post-operatively to examine the Eustachian tube orifice and lumen for inflammation of the mucosa, hypertrophy and excess mucus secretion, which are the most common findings in patients with dilatory dysfunction. Computed tomography (CT) scanning was avoided in children before surgery. The Valsalva or Toynbee manoeuvre was not performed because they are not sensitive or specific enough for Eustachian tube dysfunction to have clinical efficacy. Jenckel et al. do not make mention of the value of the Valsalva or Toynbee manoeuvre in diagnosing Eustachian tube dysfunction.Reference Jenckel, Kappo, Gliese, Loewenthal, Lörinncz and Knecht7
Surgical procedure
The balloon Eustachian tuboplasty procedure was performed in children under general anaesthesia aided by endoscopic visualisation of the nasopharynx. Adenoidectomy was performed in both balloon Eustachian tuboplasty and ventilation tube groups. Adenoidectomy was also performed after ventilation tube insertion. After decongestion of the nasal cavity using xylometazoline, through its applicator system (Theiss and Spiggle, Burghof, Germany), a balloon catheter was inserted trans-nasally under endoscopic guidance (2.5 mm at 0° or 45°). Following this, saline solution was injected into the balloon under 10 bar pressure for 2 minutes, leading to its inflation. The process was repeated 2 minutes later.
Post-surgery, nasal saline irrigation was recommended in patients over eight years of age. All patients used a nasal decongestant for the first five days. The patients were then called in for a follow-up at three months, six months and one year.
Statistical analysis
Data analyses were undertaken using SPSS® (version 16) statistical software. The paired t-test was used to compare pre-operative and post-operative air conduction and bone conduction. The chi-square and Kruskal–Wallis tests were used to compare the hearing results of independent groups. A p-value less than 0.05 was regarded as significant. Results are represented as mean ± standard deviation. Hearing success rates of the two groups were compared using a t-test.
Results
Sixty-two children underwent ventilation tube or balloon Eustachian tuboplasty insertion for the treatment of chronic dilatory Eustachian tube dysfunction between July 2016 and April 2018 at our institution. Thirty children (55 affected ears) underwent balloon Eustachian tuboplasty and 32 children (60 affected ears) underwent ventilation tube insertion. Seventeen females (56.7 per cent) were included in group 1 (balloon Eustachian tuboplasty) and 15 (46.9 per cent) females were included in group 2 (ventilation tube insertion). The participants’ mean age was 7 ± 2 years (range: 3–12 years). The mean follow-up duration was 14.4 months (range: 13–16 months). The mean pre-operative air–bone gap (ABG) of patients who underwent balloon Eustachian tuboplasty was 27.6 ± 8.2 dB (range: 15–35 dB), which decreased to 9.6 ± 3.6 dB at last follow-up (p < 0.05; Table 1). The ABG decreased significantly from 25.6 ± 6.1 dB to 17.6 ± 8.4 dB in the ventilation tube group (p < 0.05). When comparing the two groups, the decrease in the ABG value was significantly higher in the balloon Eustachian tuboplasty group (p = 0.043).
Outcomes of pure tone audiograms at the end of follow-up
SD = standard deviation
Two patients experienced haemotympanum as a complication in the balloon Eustachian tuboplasty group. No patients had recurrence of adenoid hypertrophy at the one-year post-operative endoscopic nasopharyngeal evaluation. Type A, B and C tympanograms were found in 28, 1 and 1 patient, respectively, on tympanometry in the balloon Eustachian tuboplasty group post-operatively in both ears at the one-year time point. On the other hand, type A, B and C tympanograms were identified in 21, 7 and 4 patients, respectively, in the ventilation tube group post-operatively at the one-year time point. At one year post-operatively, no tube was observed in the eardrum of any of the patients who had undergone a ventilation tube insertion. Otitis media with effusion recurrence occurred in 2 patients in the balloon Eustachian tuboplasty group, whereas 11 patients had a recurrence of otitis media with effusion in the ventilation tube group after 1 year. However, atrophy, myringosclerosis and perforation were seen in 5, 4 and 3 ears, respectively, in the ventilation tube group after one year.
Discussion
Eustachian tube dysfunction is a significant clinical condition that is most commonly observed in children. Although the anatomical features of the Eustachian tube of children play an important role in the development of this condition,Reference Tisch, Maier and Sudhoff3 adenoid hyperplasia, chronic infections, defective mucociliary clearance, muscular dysfunction,Reference Ockermann, Reineke, Upile, Ebmeyer and Sudhof5,Reference Tisch, Maier, Hecht and Maier6 persistent cold or flu symptoms,Reference Maier, Tisch and Maier8 allergic rhinitis,Reference Juszczak, Aubin-Pouliot, Sharon and Loftus9 enlargement of the nasal conchae, immune defects, dysfunctions in the ciliary activity and reflux contribute to the progression of this condition. Adenoidectomy, myringotomy or ventilation tube insertion are the standard treatment options for persistent Eustachian tube dysfunction in children. Mandel et al. reported that lower dilatory efficiency, which is a measure of the activity levels involved in Eustachian tube function, and a short ventilation tube duration are predictive factors for otitis media with effusion to recur.Reference Mandel, Swarts, Casselbrant, Tekely, Richert and Seroky10 However, they reported that an adenoidectomy with ventilation tube insertion, re-adenoidectomy procedures and the number of previous ventilation tube insertions were not substantial predictors of disease recurrence.Reference Poe11
Balloon Eustachian tuboplasty was first performed successfully on adult patients;Reference Ockermann, Reineke, Upile, Ebmeyer and Sudhof5,Reference Tisch, Maier and Maier12 however, there were concerns regarding its use in children. Due to the presence of an aberrant or dehiscent bony internal carotid canal in children, physicians preferred not to use balloon Eustachian tuboplasty for the treatment of Eustachian tube dysfunction.Reference Tisch, Maier and Sudhoff3 After Tisch et al. first demonstrated balloon dilatation of the Eustachian tube in an 18-month-old girl, proving that balloon Eustachian tuboplasty can be used in children, the concerns regarding this procedure disappeared.Reference Tisch, Maier, Hecht and Maier6 These concerns may have been due to the misunderstanding that the balloon remains in the bony canal. However, the balloon is inflated in the cartilaginous portion of the Eustachian tube and is located at a sufficient distance from the carotid canal. This explains why, unlike some studies,Reference Ishijima, Sando, Balaban, Suzuki and Takasaki13 a pre-operative CT scan was not performed in this and other studies.Reference Tisch, Maier and Sudhoff3 However, Luukkainen et al. reported that CT scans might be useful in selected cases due to other conditions (e.g., semicircular canal dehiscence or large vestibular aqueduct) that present with similar symptoms to those of Eustachian tube dysfunction.Reference Luukkainen, Kivekäs, Silvola, Jero and Sinkkonen2
Another controversial factor involved in the usage of balloon Eustachian tuboplasty in children is the length of the balloon catheter, which is 20 mm long and has a diameter of 3 mm when inflated. Ishijima et al. examined 11 normal temporal bones that were obtained from individuals who were between 3 months to 88 years old; they reported that the Eustachian tube lumen path length of the infant aged 3 months was 21.2 mm, which increased with age.Reference Ishijima, Sando, Balaban, Suzuki and Takasaki13 Although the Eustachian tube is shorter in children than in adults, the ratio of the cartilaginous portion length to the osseous portion is 8:1 in an infant at the age of 3 months, and this ratio is 4:1 in an adult.Reference Tisch, Maier and Sudhoff3,Reference Leichtle, Hollfelder, Wollenberg and Bruchhage14 Thus, there is a low risk of balloon placement in the osseous part instead of the cartilaginous part due to the length of the balloon catheter.
Although the ‘gold standard’ treatment for persistent middle-ear effusion is adenoidectomy, myringotomy and insertion of ventilation tube, some children are refractory to this conventional treatment.Reference Choi, Lee, Hong and Kim15 Balloon Eustachian tuboplasty with adenoidectomy was performed as a first line treatment modality in our study. Our results demonstrate that although balloon Eustachian tuboplasty was used as the first treatment method, the success of the procedure was high, in accordance with the literature.Reference Tisch, Maier and Sudhoff3,Reference Jenckel, Kappo, Gliese, Loewenthal, Lörinncz and Knecht7,Reference Maier, Tisch and Maier8 However, Leichtle et al. and Tisch et al. recommended the use of balloon Eustachian tuboplasty as a second line treatment where paracentesis, ventilation tube insertion and adenoidectomy have not succeeded.Reference Tisch, Maier and Maier12,Reference Leichtle, Hollfelder, Wollenberg and Bruchhage14
• Otitis media with effusion, a middle-ear problem accompanied by fluid and mucus accumulation, commonly leads to hearing loss
• Eustachian tube dysfunction is an important cause of otitis media with effusion in children
• Balloon Eustachian tube dilatation may be an effective and safe primary treatment method of otitis media with effusion in children
The pre-operative ABG was 27.6 dB, which was reduced to 9.6 dB at the last follow-up in the balloon Eustachian tuboplasty group, while in the ventilation tube group, the pre-operative ABG was 25.6 dB, which was reduced to 17.6 dB. Therefore, higher success rates and better results of hearing tests were achieved by balloon Eustachian tuboplasty surgery. Aside from two subjects, there was no recurrence of otitis media with effusion in the balloon Eustachian tuboplasty group, whereas 12 patients had a recurrence in the ventilation tube insertion group. The most important disadvantage of the ventilation tube is that recurrent otitis media with effusion can be found in approximately 20–50 per cent of the treated children who then require reinsertion of the ventilation tube.Reference Leichtle, Hollfelder, Wollenberg and Bruchhage14,Reference Choi, Lee, Hong and Kim15
In our study, 12 patients underwent revision ventilation tube insertion. Unlike the ventilation tube insertion results, balloon Eustachian tuboplasty therapy required a single surgical procedure. In addition, scarring and tympanic membrane retraction are reported to be increased by the several ventilation tube insertions.Reference Choi, Lee, Hong and Kim15 However, the retraction of the tympanic membrane was not observed in either of the balloon Eustachian tuboplasty and ventilation tube groups in this study. We believe that this is related to the duration of the study. Unlike balloon Eustachian tuboplasty, ventilation tube insertion requires ear protection, which is very difficult in children with poor compliance. In our experience, balloon Eustachian tuboplasty was preferred by families as ear protection is not warranted.
Balloon Eustachian tuboplasty was found to yield positive results regarding its effectivity, and many hypotheses have been proposed to explain the mechanism behind balloon dilatation. Microtears in the cartilaginous part of the Eustachian tube,Reference Ockermann, Reineke, Upile, Ebmeyer and Sudhoff16 reduction of mucosal inflammation and diminishing of the biofilm infections burdenReference Kivekäs, Chao, Faquin, Hollowell, Silvola and Rasooly17 are factors that may contribute to procedural success. Tisch et al. reported a new hypothesis outlining that there is an association between adhesions or scars on the Eustachian tube folded mucosa developing after inflammation and balloon dilatation.Reference Tisch, Maier and Sudhoff3 Although the mechanism of the balloon Eustachian tuboplasty effect is not understood yet, otitis media with effusion in both adults and children can be cured with this reliable and effective treatment option. Recently, balloon Eustachian tuboplasty has been used in combination with other treatments.Reference Si, Chen, Chu, Chen, Xiong and Chen18,Reference Li, Chen, Yin and Zeng19 As reported by Si et al., balloon Eustachian tuboplasty with methylprednisolone increases the success.Reference Si, Chen, Chu, Chen, Xiong and Chen18 Li et al. showed that an effective therapy for patients with chronic recurrent secretory otitis media was to combine balloon Eustachian tuboplasty with tympanic tube insertion surgery.Reference Li, Chen, Yin and Zeng19 However, we found that the use of the balloon Eustachian tuboplasty treatment alone seems to be effective.
The biggest limitation of our study is that the current methods to evaluate the efficacy of balloon Eustachian tuboplasty are difficult to perform in children. While Schröder et al.Reference Schroder, Lehmann, Ebmeyer, Upile and Sudhof4 used the Eustachian Tube Dysfunction Questionnaire, Leichtle et al.Reference Leichtle, Hollfelder, Wollenberg and Bruchhage14 used the Lübecker questionnaire. This shows us that there is no standard and objective measurement method to measure the effectiveness of balloon Eustachian tuboplasty in children. Therefore, a standard measuring instrument should be established in future studies to enable the effectiveness of the treatment to be evaluated objectively. The lack of randomisation was also a limitation of the study.
Conclusion
In conclusion, our study outlined the effectiveness of balloon Eustachian tuboplasty in children when used as primary therapy to treat Eustachian tube dysfunction as an alternative to tympanic ventilation tubes. We believe that it is necessary to conduct follow-up studies in the longer term and are therefore following up this group of patients in order to understand the long-term efficacy of balloon Eustachian tuboplasty. Further studies should be directed to develop an effective tool for measuring the effectiveness of balloon Eustachian tuboplasty.
Competing interests
None declared
