Lungs

Lungs

Healthy lungs are light-weight and buoyant. Chronic exposure to cigarettes and chemicals can lead to diseases such as emphysema, bronchitis, pneumonia and lung cancer, which make the lungs heavy and congested.

The trachea and bronchi, which together resemble an upside down tree, branch into the lungs. The lungs use these to exchange carbon dioxide for oxygenated blood. A large part of the lungs are occupied by passageways that supply both blood and air. Fissures divide the lung into sections, or lobes. The right lung is divided into the upper middle and lower lobes and the left lung is divided into the upper and lower lobe, which are further divided into smaller sections.

Lung transplants are given to patients suffering with diseases like cystic fibrosis and emphysema. Patients with congenital disorders and primary pulmonary hypertension, a rare blood vessel disorder of the lung, may also be transplant recipients.

More than 10,000 people worldwide have had lung transplants since the first such procedure was performed in 1981, according to a 2001 study by M.I. Hertz, J. Lande, V. Gimino and R. King, with the University of Minnesota, Minneapolis. As of April 2003, 3,834 people in the United States were waiting for a lung transplant, according to the Organ Procurement and Transplantation Network.

The lungs can remain viable for up to 4 hours outside the body.

-UNOS

Lung transplant procedures have been highly effective for many recipients, according to the Minnesota study. About 75 percent of lung transplant recipients survive two years; without a transplant, about 25 percent survive, according to Hertz.

The study claims that quality of life improves after transplantation. However, long-term survival rates for lung transplant recipients are considerably lower than those observed in kidney, heart and liver recipients. Progressive airflow obstruction, or scarring of the bronchioles, is largely to blame for problems patients face after transplant, according to the Minnesota study.

Lung transplantation also has a higher risk of infection, according to John Lilley, a transplant coordinator with the California Transplant Donor Network.

Lung transplants may involve two lungs, a single lung or a lobe of a lung. Most of the lobe transplants have been performed to treat patients with cystic fibrosis and have involved living donors, according to OPTN. Often these involve using a lung lobe from each of two donors. The first successful living donor lung transplant was performed in 1990. Since then, there have been 202 living donor lung transplants performed, according to OPTN.