Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease with a variable pathophysiologic basis<sup>114Martinez F.J. Diagnosing chronic obstructive pulmonary disease Postgrad Med 1998 ;  103 : 112-125

Haga clic aquí para ir a la sección de Referencias</sup> manifest by varying degrees of chronic airflow obstruction and hyperinflation. The incidence in the United States is estimated to be at least 14 million and the prevalence is rising.<sup>57Feileib M., Rosenberg H.M., Collins J.H., y al. Trends in COPD morbidity and mortality in the United states Am Rev Respir Dis 1989 ;  140 (suppl) : 9-18

Haga clic aquí para ir a la sección de Referencias, 80Higgins M.W., Thom T. Incidence, prevalence, and mortality: Intra- and intercountry differences Lung Biol Health Dis 1989 ;  43 : 23-43

Haga clic aquí para ir a la sección de Referencias, 137Petty T.L. A new national strategy for COPD J Respir Dis 1997 ;  18 : 365-369

Haga clic aquí para ir a la sección de Referencias</sup> At least two million individuals suffer from (predominantly) emphysema, which is characterized by anatomic air space enlargement.<sup>33Casio M.G., Majo J. Overview of the pathology of emphysema in humans Chest Surg Clin N Am 1995 ;  5 : 603-634

Haga clic aquí para ir a la sección de Referencias</sup> The economic burden of COPD is huge and increases with more severe disease.<sup>74Grasso M.C., Weller W.E., Shaffer T.J., y al. Capitation, managed care, and chronic obstructive pulmonary disease Am J Respir Crit Care Med 1998 ;  158 : 133-138

Haga clic aquí para ir a la sección de Referencias</sup> Furthermore, a marked impairment in quality of life is noted in these patients as the disease progresses.<sup>43Corris P.A. Quality of life and predictions of survival in patients with advanced emphysema Chest Surg Clin N Am 1995 ;  5 : 659-671

Haga clic aquí para ir a la sección de Referencias</sup> Over the past 50 years, many advances have been made in the management of COPD. The American Thoracic Society recently published a detailed, evidence-based analysis of medical management that provides a stepped-care algorithm of bronchodilators and suggests a possible role for anti-inflammatory agents.<sup>2American Thoracic Society Standards for the diagnosis and care of patients with chronic obstructive pulmonary disease Am J Respir Crit Care Med 1995 ;  152 : S77-S120

Haga clic aquí para ir a la sección de Referencias</sup> Furthermore, a recent comprehensive review of pulmonary rehabilitation confirmed objective and subjective improvements with varying rehabilitation formats in patients with COPD.<sup>1ACCP/AACVPR Pulmonary Rehabilitation Guidelines Panel Pulmonary rehabilitation. Joint ACCP/AACVPR evidence-based guidelines Chest 1997 ;  112 : 1363-1396

Haga clic aquí para ir a la sección de Referencias</sup> Despite these advances, many patients continue to experience incapacitating breathlessness and exercise limitation. Over the past 90 years, numerous surgical approaches have been devised to ameliorate symptoms in these patients.