Remission: Mission Possible in Chronic Rhinosinusitis with Nasal
Polyposis?
To the Editor,
Remission is emerging as the penultimate goal in the management of
several chronic diseases. Recent application of these concepts to the
management of inflammatory airway disease has promoted the concept of
clinical remission, using a “Treat to Target” approach. The concept of
remission, now well-established in Rheumatology as well as
Gastroenterology (GI), is emerging in Respiratory Medicine with recent
publication of definitions of clinical remission for asthma (1). It is
interesting to consider whether the disease remission concept might
successfully be applied to Otolaryngology-Head and Neck Surgery (OHNS)
in the management of chronic rhinosinusitis with nasal polyposis
(CRSwNP).
In the treatment of asthma, ‘remission’ is defined as the elimination of
exacerbations and stabilization of symptoms, with the possibility of
normalizing inflammatory markers, which indirectly reflect lung function
and inflammation. Guidelines for inflammatory digestive diseases are
similar to those in asthma, in terms of their symptomatic endpoints and
rigorous control of disease (2). However, for inflammatory bowel
disorders unlike in asthma, an additional endoscopic criterion which
documents epithelial and mucosal recovery from disease is also included.
The nasal endoscope provides similar characterization for the control
criteria in CRSwNP, incorporating symptom control signifying clinical
remission with endoscopic remission demonstrating normal sinonasal
mucosa, which can also incorporate inflammatory markers highlighting
biochemical remission.
A consensus statement from tertiary Canadian rhinologists has previously
combined symptomatic and endoscopic assessments to define success after
endoscopic sinus surgery (ESS), with ‘optimal’ results reported as
absence of symptoms and normal appearance of the sinus mucosa on
sinonasal endoscopy (3). However, it was unclear how frequently this
‘optimal’ outcome could be achieved. An estimate of remission rates in
CRS care is now afforded by two recent studies in CRSwNP which employed
a clinical endpoint very similar to the remission definition used in GI
for inflammatory bowel diseases. The first study, a prospective trial
which assessed outcomes after treatment of CRSwNP with endoscopic sinus
surgery (4), and the second, a double-blinded, placebo-controlled
prospective trial evaluating refractory CRSwNP managed with long-term,
low dose azithromycin (5).
After ESS, clinical endpoints resembling remission were attained in 50%
of all subjects, but with different rates of remission for different
populations distinguished by co-morbidities. At four months after
surgery, 72% individuals undergoing primary ESS for CRSwNP attained
remission, while those with a history of previous surgery showed lesser
response, with a 42% remission rate. Asthmatic subjects did
considerably worse than non-asthmatic subjects: non-asthmatics attained
remission in 60%, while patients with asthma or with aspirin
exacerbated respiratory disease (AERD) only showed remission in 23% and
23.5% of cases, respectively. For the azithromycin trial, there was a
54% remission rate overall. Again, asthma was associated with a worse
outcome: non-asthmatics had a remission rate of 88%, while asthmatics
achieved only 38% remission, and only in 14% of AERD patients.
Individuals demonstrating remission were characterized by parameters of
epithelial recovery and healing, approaching those of optimal control as
suggested for inflammatory digestive diseases (6).
Conclusion: Remission is indeed a concept that can be attained
in CRSwNP, even in patients who failed previous surgery, as demonstrated
by these findings. Some patient groups apparently have more difficult
disease evolution, and asthma emerges as an important treatable trait in
patients with CRSwNP. Better defining this outcome through
consensus-based definitions will allow for the identification and
stratification of clinical scenarios where patients have complete relief
from their disease symptomatically in addition to biochemical and
endoscopic normalization which penultimately achieving remission.
Respectfully submitted,
Yvonne Chan, Andrew Thamboo, Joseph Han, Martin Desrosiers