Interventions for primary (intrinsic) tracheomalacia in children

The term malacia is derived from the Greek word 'malakia', meaning soft. In tracheomalacia, the walls of trachea (or windpipe) are softer than normal, which can lead to partial collapse (falling in) of the windpipe. This collapse usually happens when more air is needed, such as during exercise. The word 'primary' refers to tracheomalacia in which the windpipe itself is the cause of the disease, where as secondary tracheomalacia is compressed due to some other abnormality near to the windpipe. The most common symptom of tracheomalacia is expiratory stridor (high-pitched wheezing sound). If the symptoms are severe enough, treatment such as mechanical ventilation, tracheal stenting (mesh tube inserted into windpipe to hold it open) or surgery may be needed.

We wanted to find out which out of these possible treatments was most effective. We found only one randomised controlled trial (RCT) that assessed nebulised recombinant human deoxyribonuclease (rhDNase) which helps in breaking down the mucous and has been shown to be useful in aiding airway clearance in cystic fibrosis compared to placebo (no active treatment) in children with both tracheomalacia and a concurrent respiratory infection. This trial showed no evidence of benefit in terms of the number of children who were cough-free two weeks after treatment. Also, there was less coughing reported, both during the day and at night, in the group who did not receive the intervention - however these differences were not statistically significant.

With the lack of evidence, the routine use of any therapies for intrinsic tracheomalacia cannot be recommended given the cost of nebulised rhDNase and the likely harmful effect. The decision to subject a child to any surgical or medical based therapies will have to be made on an individual basis, with careful consideration of the risk-benefit ratio for each individual situation.

It is unlikely that any RCT on surgically based management will ever be available for children with severe life-threatening illness associated with tracheomalacia. For those with less severe disease, RCTs on interventions such as antibiotics and chest physiotherapy are needed.

Authors' conclusions: 

There is currently an absence of evidence to support any of the therapies currently utilised for management of intrinsic tracheomalacia. It remains inconclusive whether the use of nebulised rhDNase in children with airway malacia and a respiratory tract infection worsens recovery. It is unlikely that any RCT on surgically based management will ever be available for children with severe life-threatening illness associated with tracheomalacia. For those with less severe disease, RCTs on interventions such as antibiotics and chest physiotherapy are clearly needed. Outcomes of these RCTs should include measurements of the trachea and physiological outcomes in addition to clinical outcomes.

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Background: 

Tracheomalacia, a disorder of the large airways where the trachea is deformed or malformed during respiration, is commonly seen in tertiary paediatric practice. It is associated with a wide spectrum of respiratory symptoms from life-threatening recurrent apnoea to common respiratory symptoms such as chronic cough and wheeze. Current practice following diagnosis of tracheomalacia includes medical approaches aimed at reducing associated symptoms of tracheomalacia, ventilation modalities of continuous positive airway pressure (CPAP) and bi-level positive airway pressure (BiPAP), and surgical approaches aimed at improving the calibre of the airway (airway stenting, aortopexy, tracheopexy).

Objectives: 

To evaluate the efficacy of medical and surgical therapies for children with intrinsic (primary) tracheomalacia.

Search strategy: 

The Cochrane Airways Group searched the Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane Airways Group's Specialised Register, MEDLINE and EMBASE databases. The Cochrane Airways Group performed the latest searches in March 2012.

Selection criteria: 

All randomised controlled trials (RCTs) of therapies related to symptoms associated with primary or intrinsic tracheomalacia.

Data collection and analysis: 

Two reviewers extracted data from the included study independently and resolved disagreements by consensus.

Main results: 

We included one RCT that compared nebulised recombinant human deoxyribonuclease (rhDNase) with placebo in 40 children with airway malacia and a respiratory tract infection. We assessed it to be a RCT with overall low risk of bias. Data analysed in this review showed that there was no significant difference between groups for the primary outcome of proportion cough-free at two weeks (odds ratio (OR) 1.38; 95% confidence interval (CI) 0.37 to 5.14). However, the mean change in night time cough diary scores significantly favoured the placebo group (mean difference (MD) 1.00; 95% CI 0.17 to 1.83, P = 0.02). The mean change in daytime cough diary scores from baseline was also better in the placebo group compared to those on nebulised rhDNase, but the difference between groups was not statistically significant (MD 0.70; 95% CI -0.19 to 1.59). Other outcomes (dyspnoea, and difficulty in expectorating sputum scores, and lung function tests at two weeks also favoured placebo over nebulised rhDNase but did not reach levels of significance.