Abstract (243/250)
Objective: The potential benefit of a combined
adenotonsillectomy and bronchoscopy with bronchoalveolar lavage
(TA-B-BAL) in preschool children with asthma has been debated in the
literature. We aimed to describe the clinical course of preschool
children with severe asthma undergoing this combined procedure.
Study Design : This is a retrospective case-control study.
Patient Selection : Preschool patients diagnosed with severe
asthma who underwent TA-B-BAL treatment between 2012 and 2019 were
included as cases. Controls were age and sex matched patients receiving
standard asthma care.
Methodology : A retrospective patient chart review was
conducted. Data on demographics, clinical characteristics, medication
use, virology and microbiology from bronchoalveolar lavage, and asthma
control questionnaires were collected. Cases and controls were compared
with t-tests and regression analysis.
Results: Eighteen preschool subjects (mean age 3.19±1.13 years)
in the case group were matched to eighteen control subjects receiving
standard care. A Poisson mixed effects regression analysis revealed
reduced risk of oral corticosteroid use (RR 0.39, 95%CI 0.18, 0.83,
p=0.014), reduced emergency department visits (RR 0.36, 95%CI 0.17,
0.75, p=0.01) and reduced risk of asthma exacerbations (RR 0.58, 95%CI
0.28, 1.20, p=0.14) in cases compared to controls. Ten patients
experienced clinically meaningful improvements in TRACK scores after the
procedure (p<0.001).
Conclusion: This pilot study provides early evidence that
preschool children with severe asthma may benefit from combined
adenotonsillectomy and bronchoscopy with bronchoalveolar lavage
procedure. The procedure is a useful adjunct for reduction of medication
use and hospital visits for preschool age patients with severe asthma.
Introduction
Asthma in the preschool period has a variable and unclear prognosis for
remission, persistence and progression 1. Rather than
a single disease, it is increasingly evident that asthma is a cluster of
disorders, related by the presence of common symptoms of wheeze and
cough 2. The heterogeneity in asthma reflects
differences in the underlying biology and pathophysiology and therefore
response to therapy. Comorbidities such as rhinitis, eczema, obstructive
sleep apnea and obesity are associated with poor symptom control and may
represent differences in underlying
pathophysiology3-6. The preschool period is further
complicated by a lack of objective measures to diagnose and monitor
therapy contributing to sub-optimal asthma control. Consequently,
preschool children suffer a disproportionate burden of morbidity in
terms of exacerbations and hospitalizations 7. Several
strategies aimed at reducing the burden of co-existing comorbidities
show some promise in improving asthma control and may point to more
precise treatments for preschool asthma 5,8,9.
Adenotonsillectomy (TA) is one of the most common surgical procedures
performed in children to address adenotonsillar hypertrophy, obstructive
sleep apnea, and recurrent infection and inflammation10-12. Studies exploring the effect of TA in asthmatic
populations have revealed numerous benefits for symptom control and
quality of life 8,9,11,13. Studies have noted a
decrease in the need for respiratory medications post-operatively8,11,12 and an improvement in asthma symptoms5,9. Most notably, Saito et al. found 60% of
pediatric patients were able to eliminate all of their medication and
28% were able to eliminate some of their medications post-operatively9. Clinically significant improvements in asthma
control test scores have also been reported in the literature,
associated with a significant decrease in emergency department visits,
oral corticosteroid use 5, and limitation in activity
in children following TA 11,13. The united airway
concept may explain the link between upper airway inflammation and
asthma 13,14. Persistent rhinovirus infection, for
example, induces the release of multiple pro-inflammatory cytokines and,
in turn, the proliferation of tonsillar lymphocytes14. Bacteria in the nasal passage, adenoids, and
tonsils can similarly trigger inflammation of the lower airways15. Pharyngeal lymphoid tissue is the primary site for
proliferation of viruses associated with wheezing 14.
Furthermore, Kaditis, et al. concluded that children with a history of
wheezing frequently have more tonsillar hypertrophy than those without
wheezing 14. Bhattacharjee noted an association
between airway inflammation, childhood obstructive sleep apnea (OSA) and
severe asthma 8. These findings support the hypothesis
that TA may have a role in the management of children with severe asthma16.
According to the American Thoracic Society guidelines for infants with
recurrent or persistent wheezing, following treatment with
bronchodilators, inhaled corticosteroids, or systemic steroids, a
flexible fiberoptic bronchosopy and bronchoaleolar lavage is
conditionally recommended 17. A bronchoscopy (B) can
provide clinicians with important information regarding airway
remodelling and anatomic abnormalities such as airway malacia or
compression by vascular structures 17-19. Furthermore,
in 20 case series, 40-60% of infants with recurrent wheezing had a
positive bronchoalveolar lavage (BAL) culture 17.
Patients who identify with lower airway infections, eosinophilia or
neutrophilia can have improved symptoms with antibiotic therapy or other
treatments 17. The potential benefits of a combined
TA, bronchoscopy and bronchoalveolar lavage (TA-B-BAL) procedure on
asthma control has not been previously reported.
The aim of this case-control study was to investigate the potential
benefit of performing a combined TA, bronchoscopy and bronchoalveolar
lavage procedure in a pediatric cohort of patients with preschool
asthma.
Materials and Methods
This is a retrospective case-control study of children attending the
asthma clinic at the Hospital for Sick Children, Toronto, Canada. The
study was reviewed by the institutional Research Ethics Board at the
Hospital for Sick Children (REB# 1000069481, April 19, 2020). Inclusion
criteria for the cases were: 1. Children younger than 6 years at the
baseline visit; 2. A diagnosis of preschool wheeze by a pediatric
respirologist; 3. An assessment by a pediatric otolaryngologist; and 4.
Treatment with a combined adenotonsillectomy and flexible bronchoscopy
with bronchoalveolar lavage (TA-B-BAL) between 2012 and 2019. Patients
were offered the TA-B-BAL procedure if they presented with
adenotonsillary hypertrophy or history of recurrent infection.
“Preschool asthma” was diagnosed in children by clinicians following
the Canadian Thoracic Society guidelines 20. All
children had a history of intermittent symptoms and documented response
to inhaled bronchodilators.
All cases were matched one-to-one to a control subject followed in the
same asthma clinic. Control subjects were diagnosed with preschool
asthma by a pediatric respiratory medicine specialist, were treated with
standard medical therapy and had no history of tonsillectomy or
adenoidectomy. Matching was based on age at initial visit, sex, and time
elapsed between visits. The study was designed to assess the effect of
the TA-B-BAL procedure while accounting for the natural progression of
asthma with age and standard medical therapy.
Data was retrospectively collected from the hospital charts at the
following time points: initial assessment(s) in the severe asthma
clinic; pre-operative consultation with the otolaryngologist; and at the
first and second post-procedure assessments in the severe asthma clinic.
Data collected included demographics, clinical characteristics,
comorbidies and medication use. Asthma medications were categorized as
inhaled corticosteroid monotherapy, leukotriene receptor antagonist
(LTRA), long-acting beta2-agonist (LABA) and short-acting beta2-agonist
(SABA). A detailed asthma history was also recorded, including the
number of asthma exacerbations, oral corticosteroid courses prescribed,
emergency department visits, and hospital and intensive care unit (ICU)
admissions. Symptoms at baseline and during exacerbations were also
collected when available. Finally, cytology and microbiology results
from the BAL procedure were recorded (Figure 1) .