What is a Lung Transplant?

Basic physiology of the lungs

The lungs are two organs located in the chest cavity. The right lung is partially divided by two fissures in three lobes and the left lung is only divided in two lobes. The function of the lungs is to exchange inhaled oxygen for exhaled carbon dioxide. This happens because the lung tissue is formed by alveoli or air sacs surrounded by blood vessels that facilitate the contact between oxygen and blood.

When different diseases affect this exchange, your body may have difficulty getting the oxygen, it needs even for the most basic daily functioning and the carbon dioxide may remain in your blood, causing unwanted effects.

For these reasons, your doctor, along with the whole lung transplant program team, might consider a lung transplant for you once your lung disease has advanced too far for continued medical treatment only.

The lung transplant consists, basically, in exchanging your damaged lungs and replacing them by new ones.

Diseases and conditions that can lead to a lung transplant.

Multiple diseases can affect the lungs, although only some of them require a lung transplant.

The most common diseases leading to lung transplant are:

1. Idiopathic pulmonary fibrosis: the most frequent form of interstitial lung disease that causes scarring in lung tissue
2. Emphysema: A form of COPD where lung tissue loses its structure and interferes with breathing
3. Cystic fibrosis: An inherited condition of the body glands that causes mucus plugging of the lungs and repeated pulmonary infections.
4. Alpha-1 antitrypsin deficiency: An inherited disease that can cause wheezing, repeated pneumothoraces and coughing
5. Pulmonary hypertension: Increased blood pressure in the arteries of the lungs
6. Sarcoidosis: Immuno-inflammatory disease of the lungs.
7. Bronchiectasis: It can be the end-stage disease of other conditions. The airway thickens and dilates making difficult gas exchange and favoring repeated infections.
8. Obliterative bronchiolitis: A small airway conditions, when they are narrowed due to inflammation. This can result from a viral infection in childhood or previous stem cell or lung transplant.
9. Lymphangioleiomyomatosis (LAM): A condition occurring mainly in women, where the smooth muscle cells of the airway grow out of control leading to its narrowing and difficulting breathing.

Types of lung transplants

1. Single lung. The transplant of one lung.
2. (En bloc) Double lung. The transplant of both lungs joined together.
3. Bilateral sequential lung. The transplant of both lungs, done one at the same time from a single donor.
4. Heart-lung transplant. The transplant of both lungs and the heart taken from a single donor.
5. Lobar-lung transplant. In kids or small-sized individuals due to space problems,  partial lung (lobe) transplantation can be offered.

Most of the lungs implanted come from a deceased donor. This is called a cadaveric-donor transplant. However, in some conditions, a donor may be able to donate a lobe and that would be called a living-donor transplant.