Dear Sirs,

We read with great interest the recent article by Mohammed and Martinez-Devesa.Reference Mohammed and Martinez-Devesa¹ We fully agree with their recommendations to follow up the long-term use of ventilation tubes in order to avoid possible related complications.

Otitis media with effusion (OME), or ‘glue ear’, is one of the most common conditions of early childhood.Reference Mohammed and Martinez-Devesa¹ It is characterised by accumulation of fluid in the middle ear behind an intact tympanic membrane, without any symptoms or signs of acute infection. Otitis media with effusion is often bilateral and associated with transmission hearing loss, which in childhood can have implications for the child's social and intellectual development.Reference Iwaki, Saito, Tsuda, Sugimoto, Kimura and Takahashi²

The insertion of ventilation tubes is one of the most common surgical treatments in children with OME resistant to conservative therapy.Reference Mohammed and Martinez-Devesa^{1, 3} Various types of ventilation tube are available. Long-term tubes are normally used in patients with chronic OME, often when repeated insertions of short-term tubes have been unsuccessful.Reference Mohammed and Martinez-Devesa¹ In comparison with short-term tubes, which are usually extruded spontaneously within six months, long-term tubes are designed to remain in place for extended periods, and they often need to be surgically removed after the appropriate intubation period.Reference Mohammed and Martinez-Devesa^1–3 The most commonly documented complications associated with long-term tubes are otorrhoea, scarring, tympanosclerosis, residual perforation, peritubal drum atrophy and granulation tissue formation.Reference Rinaldi, Rinaldi, François, Fatah, Nengsu and Messaoudi^4, Reference Lentsch, Goudy, Ganzel, Goldman and Nissen⁵

Although the indications for ventilation tube insertion have been widely discussed in the literature,Reference Mohammed and Martinez-Devesa^{1, 3} very few published reports have addressed the appropriate timing for removal of long-term tubes in children, and there is no clear consensus.^3, Reference Lentsch, Goudy, Ganzel, Goldman and Nissen^5, Reference El-Bitar, Pena, Choi and Zalzal⁶ The intubation period should be mainly influenced by two considerations: (1) the longer the tubes remain in place, the higher the incidence of persistent residual tympanic perforation; and (2) OME in children usually resolves spontaneously after seven or eight years of age, because of physiological improvement in eustachian tube function.Reference Iwaki, Saito, Tsuda, Sugimoto, Kimura and Takahashi² Most otolaryngologists agree that the intubation period should be between 6 and 24 months.Reference Iwaki, Saito, Tsuda, Sugimoto, Kimura and Takahashi² Iwaki et al. stated that the appropriate intubation period in children with OME is over 12 months, and that it may be better to postpone extubation until the patient is 8 years of age.Reference Iwaki, Saito, Tsuda, Sugimoto, Kimura and Takahashi² Lentsch et al. have recommended elective removal of tubes prior to 36 months' intubation.Reference Lentsch, Goudy, Ganzel, Goldman and Nissen⁵

We routinely use silicone Richards T-tubes (1.14 mm internal diameter and 12 mm length) and surgically remove them after an intubation period of 24 months, with simultaneous freshening of the tympanic perforation edges and silicone patch myringoplasty. Our experience has shown a low rate of persistent perforation (8 per cent) and OME recurrence (19 per cent).

Clinical studies have reported that eustachian tube function tests can predict OME recurrence after the ventilation tube becomes nonfunctional.Reference Mandel, Swarts, Casselbrant, Tekely, Richert and Seroky⁷ When assessing the appropriate intubation period during the follow up of the paediatric patient, we have observed the usefulness of both nasal endoscopy and tubomanometry at low pressures.Reference Ars and Dirckx^8–Reference Sudhoff, Ockermann, Mikolajczyk, Ebmeyer, Korbmacher and Garten¹⁰ Nasal endoscopy allows evaluation of the conformation of the tubaric ostium and the motility of the peristaphyline muscles, thus excluding any mechanical tubal obstruction, for example due to peritubaric recurrence of adenoid hypertrophy, oedema, hyperaemia related to laryngopharyngeal reflux, or chronic exudative inflammation.Reference Ars and Dirckx^8–Reference Sudhoff, Ockermann, Mikolajczyk, Ebmeyer, Korbmacher and Garten¹⁰

Although tubomanometry is not always feasible in the paediatric population because a substantial degree of patient compliance is required, it allows objective measurement of eustachian tube patency and monitoring of its function over time; it can also be performed even in patients with tympanic membrane perforation or a ventilation tube in situ.Reference Ars and Dirckx^8–Reference Sudhoff, Ockermann, Mikolajczyk, Ebmeyer, Korbmacher and Garten¹⁰

In our experience, when following up children with long-term tubes, these tests, supported by adequate surgical and/or non-surgical therapy, are critical in order to tailor the correct timing of the intubation period.