A pulmonary transplant (or lung transplant) is a surgical procedure in which a diseased lung is removed and replaced with a healthy lung from a donor. A lung transplant will often be recommended if a person has advanced lung disease that is unresponsive to other treatments and/or when a person's life expectancy is likely less than 2-3 years. A lung transplant is considered for those suffering from the following conditions:

• Chronic obstructive pulmonary disease (COPD) – this encompasses lung diseases which interfere with regular breathing.
• Cystic fibrosis – a hereditary disorder that causes dysregulation in sweat and mucus production, which worsens over time and is fatal.
• Pulmonary hypertension – elevated blood pressure in the vessels responsible for blood flow from the heart to the lungs
• Pulmonary fibrosis – scarring of the lungs

Types of Pulmonary Transplant

There are three types of lung transplant:

• Single lung transplant – one damaged lung from the recipient is replaced with a lung from the donor. This operation can restore full level of activity in the recipient but can only be performed if the remaining recipient lung will not prove detrimental. For example, it is not performed when there is infection in the remaining lung as this will eventually damage the transplanted lung. Thus, this procedure is suitable for many patients with emphysema and for patients with pulmonary fibrosis but not for those with infection such as in cystic fibrosis.
• Bilateral lung transplant – this is the most common form of pulmonary transport in which both lungs are removed and replaced with two donor lungs. It is particularly suitable for patients with infection such as cystic fibrosis or with COPD. It is also effective in those without infection of the lung. The long-term results are a somewhat better in this procedure than in single lung transplants as the transplantation of more lung tissue offers more reserve to combat and tolerate later potential problems. In cases where the transplant of both lungs is done one at a time, the procedure is called a bilateral sequential transplant.
• Heart-lung transplant – here, the heart and both lungs are removed and replaced with a donor heart and lungs. This is most commonly recommended for those suffering from severe pulmonary hypertension but is a complicated operation and only a finite number of donors have suitable organs for use.

Procedure

Before being placed on the transplant list, patients are tested to ensure their other major organs (including the heart, kidneys, and liver) will function properly following the transplant. Lifestyle changes might be required, i.e. quitting smoking and weight loss.

A lung transplant procedure ordinarily takes 4-12 hours depending on the complexity of the operation. An incision is made in the chest and once the damaged lungs are removed, the donated lungs will then be connected to the appropriate airways and blood vessels and the chest will be closed. The operation may require a heart and lung bypass machine which keeps the blood circulating during the operation.

Recovery from the operation may take at least 3 months.

Risks

A lung transplant is a complex type of surgery that carries a high risk of complications such as those below:

• Bleeding
• Infection
• Blockage of the blood vessels or airways to the donated lung(s)
• Severe pulmonary edema
• Blood clots
• Rejection of the new lung(s) - an immunosuppressive is given to dampen the effects of the immune system, reducing the risk of rejection but this simultaneously increases the chances of infection.

Outlook

The outlook for people who have undergone a lung transplant is continuous improvment. As it currently stands, the British Transplantation Society estimates that approximately 9 out of 10 people survive the transplant and most survive for at least a year following the procedure.

References

• http://www.nhs.uk/conditions/lung-transplant/Pages/Introduction.aspx
• http://columbiasurgery.org/lung-transplant/about-lung-transplant-surgery
• http://www.hopkinsmedicine.org/healthlibrary/test_procedures/pulmonary/lung_transplantation_procedure_92,p07752/