TY - JOUR
T1 - Elastic properties of the central airways in obstructive lung diseases measured using anatomical optical coherence tomography
AU - Williamson, Jonathan P.
AU - McLaughlin, Robert A.
AU - Noffsinger, William J.
AU - James, Alan L.
AU - Baker, Vanessa A.
AU - Curatolo, Andrea
AU - Armstrong, Julian J.
AU - Regli, Adrian
AU - Shepherd, Kelly L.
AU - Marks, Guy B.
AU - Sampson, David D.
AU - Hillman, David R.
AU - Eastwood, Peter R.
PY - 2011/3/1
Y1 - 2011/3/1
N2 - Rationale: Our understanding of how airway remodeling affects regional airway elastic properties is limited due to technical difficulties in quantitatively measuring dynamic, in vivo airway dimensions. Such knowledge could help elucidate mechanisms of excessive airway narrowing. Objectives: To use anatomical optical coherence tomography (aOCT) to compare central airway elastic properties in control subjects and those with obstructive lung diseases. Methods: After bronchodilation, airway lumen area (Ai) was measured using aOCT during bronchoscopy in control subjects (n = 10) and those with asthma (n = 16), chronic obstructive pulmonary disease (COPD) (n = 9), and bronchiectasis (n = 8). Ai was measured in each of generations 0 to 5 while airway pressure was increased from -10 to 20 cm H2O. Airway compliance (Caw) and specific compliance (sCaw) were derived from the transpulmonary pressure (PL) versus Ai curves. Measurements and Main Results: Caw decreased progressively as airway generation increased, but sCaw did not differ appreciably across the generations. In subjects with asthma and bronchiectasis, Caw and sCaw were similar to control subjects and the PL-Ai curves were left-shifted. No significant differences were observed between control and COPD groups. Conclusions: Proximal airway elastic properties are altered in obstructive lung diseases. Although central airway compliance does not differ from control subjects in asthma, bronchiectasis, or COPD, Ai is lower in asthma and the PL-Ai relationship is left-shifted in both asthma and bronchiectasis, suggesting that airways are maximally distended at lower inflating pressures. Such changes reflect alteration in the balance between airway wall distensibility and radial traction exerted on airways by surrounding lung parenchyma favoring airway narrowing.
AB - Rationale: Our understanding of how airway remodeling affects regional airway elastic properties is limited due to technical difficulties in quantitatively measuring dynamic, in vivo airway dimensions. Such knowledge could help elucidate mechanisms of excessive airway narrowing. Objectives: To use anatomical optical coherence tomography (aOCT) to compare central airway elastic properties in control subjects and those with obstructive lung diseases. Methods: After bronchodilation, airway lumen area (Ai) was measured using aOCT during bronchoscopy in control subjects (n = 10) and those with asthma (n = 16), chronic obstructive pulmonary disease (COPD) (n = 9), and bronchiectasis (n = 8). Ai was measured in each of generations 0 to 5 while airway pressure was increased from -10 to 20 cm H2O. Airway compliance (Caw) and specific compliance (sCaw) were derived from the transpulmonary pressure (PL) versus Ai curves. Measurements and Main Results: Caw decreased progressively as airway generation increased, but sCaw did not differ appreciably across the generations. In subjects with asthma and bronchiectasis, Caw and sCaw were similar to control subjects and the PL-Ai curves were left-shifted. No significant differences were observed between control and COPD groups. Conclusions: Proximal airway elastic properties are altered in obstructive lung diseases. Although central airway compliance does not differ from control subjects in asthma, bronchiectasis, or COPD, Ai is lower in asthma and the PL-Ai relationship is left-shifted in both asthma and bronchiectasis, suggesting that airways are maximally distended at lower inflating pressures. Such changes reflect alteration in the balance between airway wall distensibility and radial traction exerted on airways by surrounding lung parenchyma favoring airway narrowing.
KW - Airway compliance
KW - Airway remodeling
KW - Asthma
KW - Chronic obstructive pulmonary disease
KW - Optical coherence tomography
UR - http://www.scopus.com/inward/record.url?scp=78650573641&partnerID=8YFLogxK
U2 - 10.1164/rccm.201002-0178OC
DO - 10.1164/rccm.201002-0178OC
M3 - Article
C2 - 20851930
AN - SCOPUS:78650573641
SN - 1073-449X
VL - 183
SP - 612
EP - 619
JO - American Journal of Respiratory and Critical Care Medicine
JF - American Journal of Respiratory and Critical Care Medicine
IS - 5
ER -