ABSTRACT

Objectives: Chronic rhinosinusitis (CRS) is prevalent in the Cystic Fibrosis (CF) population. CRS exacerbations in CF are thought to contribute to pulmonary exacerbations. Literature regarding the impact of endoscopic sinus surgery (ESS) is inconclusive. This study examines rates of lung function decline and pulmonary exacerbation in CF patients who have undergone ESS.

Design : Retrospective review of medical records.

Setting: Academic Hospital.

Participants: 40 adult CF patients.

Main outcome measures: Rate of lung function decline (Forced Expiratory Volume1(FEV1) % predicted), pulmonary exacerbations (IV/oral antibiotic therapy +/- hospital admission) and total days hospitalized 2 years post-operatively was collected. CRS patients undergoing ESS were matched to those without ESS by gender, age, and F508del genotype.

Results: Forty patients (mean age 37.4, 60% male) were reviewed. No significant difference was found between the surgical group and controls in baseline FEV1(72.5% vs. 72.7%, p=0.98), 2-year pre-operative pulmonary exacerbations (3.05 vs. 1.65, p=0.10), or Lund-Mackay scores (12.25 vs. 11.55, p=0.71). No significant difference was found in 1-year (70.5% vs. 72.8%, p=0.84) or 2-year (70.4% vs. 72.6% p=0.80) post-operative FEV1 and 2-year post-operative pulmonary exacerbations (1.7 vs. 1.45, p=0.87). A significant increase was identified in total number days hospitalized post-operatively (4.85, p=0.02). In the surgical group, no significant difference was identified between preoperative and postoperative FEV1, 1 -year (-2.51%, p=0.32) and 2-years after ESS (-3.10%, p=0.51), postoperative pulmonary exacerbations (-1.28, p=0.11), or in days hospitalized (3.74, p=0.14).

Conclusions: In this study, ESS does not appear to significantly improve FEV1 or decrease the number of pulmonary exacerbations post-operatively.

Keywords: Cystic Fibrosis, Sinus Surgery, Outcomes, Lung Function, Sinusitis, Forced Expiratory Volume, Nasal polyposis

INTRODUCTION

Cystic fibrosis (CF) is a genetic disorder involving the upper and lower airways and digestive system, affecting 30,000 children and adults in the United States, 4,000 in Canada, and 70,000 worldwide [1,2]. CF is an autosomal recessive disease based on a mutation in the CF transmembrane conductance regulator (CFTR) gene. The CFTR gene is encoded on the q31 region of the long arm of chromosome 7 [3]. The CFTR protein regulates the components of sweat, digestive fluid and mucus by controlling the transport of chloride ions across epithelial membranes. In CF, lack of functional CFTR impairs chloride and bicarbonate transport across the apical epithelium producing thickened secretions, dysfunctional mucociliary clearance, and chronic airway bacterial infection [4]. Imbalance of electrolyte transport from CFTR dysfunction reduces airway surface liquid depth and increases the viscosity of mucins in the airway 30–60 times higher than seen in patients without CF [5]. The mucostasis results in progressive cycles of infection and inflammation in the respiratory tract, culminating in respiratory failure. Although advances in the clinical care of the CF patient have increased the average lifespan, the most common cause of mortality continues to be airway disease in the form of progressive bronchiectasis and ultimately respiratory failure [6].

Sinonasal disease in the form of chronic rhinosinusitis, with or without nasal polyposis, is prevalent in the CF population. Radiologic findings of paranasal sinus opacification on computed tomography can be found in almost 100% of patients with CF, with a reported incidence of nasal polyposis between 33% and 57% [7-9]. Exacerbations of rhinosinusitis in CF are thought to contribute to pulmonary exacerbations that may suggest transmission of bacterial infection from the upper to the lower airway. Support for this association includes studies establishing the presence of similar bacteria in pulmonary and sinonasal cultures [10-12]. Colonization of both the upper and lower airways with Pseudomonas aeruginosa is a well-known phenomenon in patients with cystic fibrosis (CF) [13]. These findings indicate the sinuses act as a bacterial reservoir for transmitting disease to the lower airways, making aggressive treatment and ongoing management of sinonasal disease a priority for improving pulmonary outcomes [14].

Current literature regarding the effect of sinus surgery and management of chronic rhinosinusitis on pulmonary and clinical outcomes in the cystic fibrosis population is conflicting. This study will review a 10-year experience at ’[removed for blind peer review]’.comparing outcomes in cystic fibrosis patients. Specifically, this study examines the rates of lung function decline (i.e. FEV 1 % predicted) and pulmonary exacerbation rates (i.e. need for IV antibiotics/hospitalization) in CF patients who have undergone endoscopic sinus surgery as compared to a group of CF patients with CT or endoscopic findings of chronic rhinosinusitis but without endoscopic sinus surgery.

MATERIALS AND METHODS