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Surgical Interventions for COPD

Max Huang, MD, FRCPC, Respirology Fellow, Division of Respirology, Department of Medicine, University of Toronto, Toronto, ON.
Lianne G. Singer, MD, FRCPC, Medical Director, Toronto Lung Transplant Program, University Health Network; Assistant Professor, Department of Medicine, University of Toronto, Toronto, ON.

Chronic obstructive pulmonary disease (COPD) often has a profound effect upon the quality of life and mortality of the older adult. Despite numerous medical treatments, surgery may be considered for the symptomatic patient with medically-optimized, end-stage COPD. Bullectomy, lung volume reduction surgery (LVRS), and lung transplantation have all proven to be important surgical therapies. This article reviews the current state of these interventions, and the criteria when deciding on the best surgical option for a given patient.

Key words: emphysema, COPD, lung transplant, lung volume reduction surgery, bullectomy.

Introduction

Approximately 710,000 Canadians suffer from chronic obstructive pulmonary disease (COPD),1 and hundreds of thousands more may have this disease but have never been diagnosed. COPD is largely a disease of older adults; in individuals older than 75 years the prevalence is approximately 6.9%,1 compared with 4.6% in individuals aged 55 to 74.

COPD is a slow and irreversible process that progresses over several years, often punctuated by exacerbations and eventually leading to death. According to the 1998/9 National Population Health Study (NPHS), 51% of individuals with COPD reported that shortness of breath caused some restriction in their home, work, and social activities. In Canada, COPD is the seventh most common cause of hospitalization for men and the eighth for women, with a rehospitalization risk of approximately 40%.2 It is also the fourth leading cause of death in Canadian men and the fifth leading cause of death in Canadian women. However, these figures may be underestimates and the listed cause of death of COPD patients may instead reflect the often-associated pneumonia or congestive heart failure. Economic impact studies suggest that the cost of COPD on Canada’s health care system now exceeds $3.2 billion each year,3 a figure that is expected to rise exponentially over the next several years.
 

Etiopathology

COPD is a heterogeneous respiratory disorder encompassing emphysema and chronic bronchitis. In emphysema, there is destruction of pulmonary parenchyma causing a reduction in functioning lung tissue, that results in a decrease in the amount of gas exchange that occurs. As more lung tissue is destroyed it loses elastic recoil and expands in volume, resulting in a hyperexpanded chest with flattened diaphragms and widened intercostal spaces. This destruction and expansion of the abnormal lung occurs in a nonuniform manner, crowding the relatively healthy lung tissue and preventing ventilation of the normal lung.

Chronic bronchitis is clinically defined as a persistent cough with sputum production present on most days for three months in two consecutive years. There is obstruction of the small airways caused by a combination of reversible bronchospasm and irreversible loss of elastic recoil by adjacent lung parenchyma. This loss of mechanical advantage and functioning pulmonary parenchyma leads to increased work of breathing. In addition to the primary effects in the lung, the chronic inflammatory process of COPD is associated with numerous effects on other systems such as skeletal muscle dysfunction,4 right heart failure,5 secondary polycythemia,6 malnutrition,7 and depression.8
 

Management

Once a diagnosis has been made, an effective management program for severe COPD centres on adequate management of symptoms and maintenance of a reasonable quality of life. The diagnosis and treatment of COPD was recently reviewed by Bourbeau in Geriatrics & Aging’s January issue on lung disease.36 Medical management includes smoking cessation, exercise, vaccinations, home oxygen for hypoxic patients, bronchodilators, and antibiotics during infectious exacerbations. Systemic corticosteroids are used during