Physiological and computed tomographic predictors of outcome from lung volume reduction surgery

Area of Science:

• Pulmonary Medicine
• Radiology
• Surgical Outcomes Research

Background:

• Previous studies on lung volume reduction surgery (LVRS) predictors had small sample sizes, limiting generalizability.
• The National Emphysema Treatment Trial (NETT) aimed to address this by investigating radiographic and physiological predictors in a large, multicenter cohort.

Purpose of the Study:

• To identify objective radiographic and physiological indices of lung disease with prognostic value for patients undergoing LVRS.
• To evaluate predictors for chronic obstructive pulmonary disease (COPD) patients considered for LVRS.

Main Methods:

• A subset of LVRS patients from the NETT underwent preoperative high-resolution computed tomographic (CT) scanning.
• Measurements included static lung recoil (SRtlc), inspiratory resistance (Ri), and the ratio of residual volume to total lung capacity (RV/TLC).
• Relationships between CT emphysema measures, airway disease, physiological indices, and 6-month postoperative changes in FEV(1) and maximal exercise capacity were assessed.

Main Results:

• Physiological measures (SRtlc, Ri) did not correlate with improvements in FEV(1) or exercise capacity.
• The RV/TLC ratio and CT measures of emphysema, including upper to lower zone distribution, were weakly but significantly predictive of postoperative FEV(1) and exercise capacity changes.
• CT assessments of airway disease did not predict changes in FEV(1) or exercise capacity.

Conclusions:

• The RV/TLC ratio and CT-derived emphysema measures and distribution are statistically significant, albeit weak, predictors of outcomes following LVRS.
• These findings contribute to a better understanding of prognostic factors in LVRS candidates.