Quality, size, and composition of pediatric endobronchial biopsies in cystic fibrosis

BACKGROUND: Studies on airway remodeling in children with cystic fibrosis (CF) may be hampered by difficulty in obtaining evaluable endobronchial biopsy specimens because of large amounts of mucus and inflammation in the CF airway. We prospectively assessed how the quality of biopsy specimens obtained from children with CF compare with those from children with other airway diseases. METHODS: Fiberoptic bronchoscopy with endobronchial biopsy was performed in 67 CF children (age range, 0.2 to 16.8 years), 34 children with wheeze/asthma (W/A), and 64 control children with chronic respiratory symptoms. Up to three biopsy specimens were taken and stained with hematoxylin and eosin. Biopsy specimen size and structural composition were quantified using stereology. RESULTS: At least one evaluable biopsy specimen was obtained in 72% of CF children, in 79% of children with W/A, and in 72% of control subjects (difference was not significant). The use of large biopsy forceps (2.0 mm) rather than small biopsy forceps (1.0 mm) [odds ratio (OR), 5.8; 95% confidence interval (CI), 1.1 to 29.8; p = 0.037] and the number of biopsy specimens taken (odds ratio, 2.6; 95% confidence interval, 1.3 to 5.2; p = 0.006) significantly contributed to the success rate. Biopsy size and composition were similar between groups, except that CF children and those patients with W/A had a higher percentage of the biopsy specimen composed of muscle than did control subjects (median 6.2% and 9.7% vs 0.9%, respectively; p = 0.002). CONCLUSIONS: Biopsy size and quality are adequate for the study of airway remodeling in CF children as young as 2 months of age. Researchers should use large forceps when possible and take at least two biopsy specimens per patient. An increased airway smooth muscle content of the airway mucosa may contribute to the pathophysiology of CF lung disease.

Time required to obtain endobronchial biopsies in children during fiberoptic bronchoscopy

BACKGROUND: Endobronchial biopsies are an important tool for the study of airway remodeling in children. We aimed to evaluate the impact of performing endobronchial biopsies as a part of fiberoptic bronchoscopy on the length of the procedure. METHODS: Clinically indicated fiberoptic bronchoscopy at which endobronchial biopsy was attempted as a part of a research protocol was performed in 40 children (median age 6 years, range 2 months-16 years). Time needed for airway inspection, bronchoalveolar lavage (BAL) with three aliquots of 1 ml/kg of 0.9% saline, sampling of three macroscopically adequate biopsies, teaching, and other interventions (e.g., removal of plugs) was recorded. The bronchoscopist was not aware that the procedure was being timed. RESULTS: Median (range) duration (min) was 2.5 (1.0-8.2) for airway inspection, 2.8 (1.7-9.4) for BAL, 5.3 (2.5-16.6) for biopsy sampling, 2.4 (1.5-6.6) for teaching and 4.1 (0.8-18.5) for other interventions. Three adequate biopsies were obtained in 33 (83%) children. Use of 2.0 mm biopsy forceps (via 4.0 and 4.9 mm bronchoscopes) rather than 1.0 mm (via 2.8 and 3.6 mm bronchoscopes) significantly reduced biopsy time (4.6 min vs. 8.4 min, P < 0.001). CONCLUSIONS: It takes a median of just over 5 min to obtain three endobronchial biopsies in children, which we consider an acceptable increase in the duration of fiberoptic bronchoscopy for the purpose of research.