Functional and morphological heterogeneity of emphysema and its implication for selection of patients for lung volume reduction surgery.

Lung volume reduction surgery (LVRS) in patients with advanced pulmonary emphysema aims to alleviate symptoms and enhance quality of life by improving respiratory mechanics. The theoretical concepts of the operation predict the greatest functional benefit in patients with marked hyperinflation, and with airflow obstruction due to loss of elastic recoil. Consistent observations in several centres, have confirmed these expectations. To achieve maximal reduction in lung volume at the least cost of functional tissue, resection is targeted to the lung zones with the most severe destruction by emphysema, leaving zones with relatively well-preserved tissue intact. Heterogeneity in emphysema distribution as assessed by visual scoring of the chest computed tomography scan according to a simple grading system has been shown to correlate with LVRS outcome variables. Therefore, evaluation of lung volume reduction surgery candidates has to include the functional and morphological characteristics of the emphysema as well as a general assessment of perioperative risk. However, the knowledge of potential predictive factors of lung volume reduction surgery outcome is so far based on retrospective analysis of highly selected patients. Therefore, many questions in respect of the selection of ideal candidates for this procedure remain unanswered at the present time.