Physiological and computed tomographic predictors of outcome from lung volume reduction surgery.
BACKGROUND
Previous investigations have identified several potential predictors of outcomes from lung volume reduction surgery (LVRS). A concern regarding these studies has been their small sample size, which may limit generalizability. We therefore sought to examine radiographic and physiologic predictors of surgical outcomes in a large, multicenter clinical investigation, the National Emphysema Treatment Trial.


OBJECTIVE
To identify objective radiographic and physiological indices of lung disease that have prognostic value in subjects with chronic obstructive pulmonary disease being evaluated for LVRS.


METHODS
A subset of the subjects undergoing LVRS in the National Emphysema Treatment Trial underwent preoperative high-resolution computed tomographic (CT) scanning of the chest and measures of static lung recoil at total lung capacity (SRtlc) and inspiratory resistance (Ri). The relationship between CT measures of emphysema, the ratio of upper to lower zone emphysema, CT measures of airway disease, SRtlc, Ri, the ratio of residual volume to total lung capacity (RV/TLC), and both 6-month postoperative changes in FEV(1) and maximal exercise capacity were assessed.


RESULTS
Physiological measures of lung elastic recoil and inspiratory resistance were not correlated with improvement in either the FEV(1) (R = -0.03, P = 0.78 and R = -0.17, P = 0.16, respectively) or maximal exercise capacity (R = -0.02, P = 0.83 and R = 0.08, P = 0.53, respectively). The RV/TLC ratio and CT measures of emphysema and its upper to lower zone ratio were only weakly predictive of postoperative changes in both the FEV(1) (R = 0.11, P = 0.01; R = 0.2, P < 0.0001; and R = 0.23, P < 0.0001, respectively) and maximal exercise capacity (R = 0.17, P = 0.0001; R = 0.15, P = 0.002; and R = 0.15, P = 0.002, respectively). CT assessments of airway disease were not predictive of change in FEV(1) or exercise capacity in this cohort.


CONCLUSIONS
The RV/TLC ratio and CT measures of emphysema and its distribution are weak but statistically significant predictors of outcome after LVRS.
Washko
George R
GR
Pulmonary and Critical Care Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA. Gwashko@Partners.org
Martinez
Fernando J
FJ
Hoffman
Eric A
EA
Loring
Stephen H
SH
Estépar
Raúl San José
RS
Diaz
Alejandro A
AA
Sciurba
Frank C
FC
Silverman
Edwin K
EK
Han
MeiLan K
MK
Decamp
Malcolm
M
Reilly
John J
JJ
D000368:Aged; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008297:Male; D011013:Pneumonectomy / Q000009:adverse effects; D011237:Predictive Value of Tests; D011379:Prognosis; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D012115:Residual Volume / Q000502:physiology; D012129:Respiratory Function Tests; D013147:Spirometry; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome