Lung donation and transplantation is a surgical procedure where a patient’s dead lungs are replaced partially or totally by lungs provided by an organ donor. It is the last resort treatment for patients who have end-stage lung disease and have exhausted all other treatment options without any improvement.
Donor’s lungs are usually retrieved from either a living or deceased individual. It is important to indicate that a living lung donor can donate only a single lung lobe. Apart from that, some lung diseases can leave a recipient in need of just one lung.
While in other lung diseases (like cystic fibrosis), a recipient will inevitably receive two lungs. Although as is the case with organ transplants, lung transplantation carries certain associated risks. However, they can extend the life expectancy of the patient and enhance their quality of life (particularly in recipients who have an end-stage pulmonary disease). This is a comprehensive highlight on lung donation and transplant.
Qualifying Conditions For Lung Transplantation
There are a variety of health conditions that can make a lung transplant necessary. As at the year 2005, the most common causes for lung transplantation include:
- Idiopathic pulmonary fibrosis.
- Chronic obstructive pulmonary disease including emphysema.
- Cystic fibrosis.
- Alpha 1-antitrypsin deficiency.
- Idiopathic pulmonary hypertension.
- Replacing diseased transplanted lungs.
- Other causes like bronchiectasis and sarcoidosis.
Conditions That Disqualify Lung Transplantation
Note that, no matter how severe a patient’s respiratory condition may be, there are some pre-existing health issues that may make them poor candidates for lung transplantation. Some of these problems include:
- Concurrent chronic illness (such as congestive heart failure, liver disease, and kidney disease).
- Current infections such as HIV and hepatitis (although more people with Hepatitis C are being transplanted and also used as donors if recipients are Hepatitis C positive. Select HIV-infected people have undergone lung transplantation).
- Current or recent cancer sufferers.
- People who abuse alcohol, use tobacco, and/or illegal drugs.
- People with psychiatric issues.
- Individuals who have a history of not complying with medical instructions.
Requirements for Potential Lung Donors
There are a number of requirements that potential lung donors must meet before donating their organ due to the special needs of a potential recipient. In living donors, this is also the consideration of how lung transplantation surgery will affect a donor. These requirements include:
- Donors must be healthy.
- The size of the organ must match (donated lung/lungs must be big enough to oxygenate the patient adequately, and small enough to fit into the chest cavity of the recipient).
- Blood type.
Requirements for Potential Lung Transplantation Recipients
While an organ transplantation center has the right to set its criteria for lung transplant candidates, there are several requirements that must generally be agreed upon. They include:
- People with end-stage lung disease.
- Patients who have exhausted every available therapy.
- Recipients with no chronic medical conditions including heart, kidney, and liver disease (although some patients can be qualified if their condition can be improved to the point that they are stable enough and can survive the surgery.
- Persons who don’t have any current infections or cancer (although exceptions have been made on a case by case basis for patients with lung or other cancers. In patients with cystic fibrosis transplantation centers can use their discretion).
- Potential recipients should not have HIV or hepatitis (although there have been exceptions for recipients who have the same kind of hepatitis as the donor and HIV patients with low HIV viral load).
- Potential recipients should not abuse alcohol, engage in smoking, or use illicit drugs (there have been exceptions for individuals who have successfully ceased these habits)
- Patients must be within an acceptable weight (undernourishment or obesity can result in an increased mortality).
- Recipients must have an acceptable psychological profile.
- Have a social support system.
- Should be financially able to cover the expenses for the procedure (where medical bills are paid by the patient).
- Should be able to comply with the post-transplantation regimen (since this is a major surgery, following the operation, the patient must willingly adhere to a regimen of medications for the rest of their lives and continue medical care).
What Are the Risks Involved in Lung Donation and Transplantation?
As is the case with other surgical procedures, there is a risk of bleeding and/or infection. The transplanted lung may fail to heal or function properly. Because a large part of the recipient’s body was exposed to outside air, sepsis can set in, so antibiotics must be given to prevent that from happening. Other complications include gastrointestinal inflammation as well as ulceration of the esophagus and stomach and post-transplant lymphoproliferative disorder (lymphoma caused by immune suppressants).
Transplant rejection is a key concern immediately after surgery and throughout the patient’s lifetime. This is because transplanted lung(s) come from another individual, and the recipient’s immune system can detect it as an invader thus attempting to neutralize it. Tissue rejection is a serious issue and must be treated quickly.
Symptoms of Organ Rejection
- Flu-like symptoms (like chills, dizziness, nausea, night sweats and a general feeling of illness).
- Difficulty breathing.
- Poor pulmonary test results.
- Increased tenderness or chest pain.
- Decrease or increase in body weight of over two kilograms within 24 hours.
Prevention of Organ Rejection Following Lung Transplantation
To prevent organ rejection and damage to newly implanted lung(s), patients must judiciously follow a regimen of immunosuppressive medications. Patients will have to take combination medicines to combat any risks of tissue rejection. This is inevitably a lifelong commitment and has to be adhered to strictly. The immunosuppressive regimen is initiated just before or following the surgery. The regimen usually includes azathioprine, ciclosporin, and corticosteroids. As episodes of rejection can reoccur throughout the patient’s lifetime, the exact dosages and choices of immunosuppressants can be modified as time passes. Sometimes tacrolimus is prescribed instead of mycophenolate and ciclosporin.
These immunosuppressants also introduce some risks to the recipient. By lowering the body’s immunity, these medicines increase the patient’s chances of contracting an infection. Antibiotics can be prescribed to treat or prevent infections. Infection can increase the risk of tissue rejection, and an interaction might prevail between both risks. Some medications may have nephrotoxic or other harmful side-effects. Others may be prescribed to help alleviate these severe side effects.
There is the risk that the patient may have allergic reactions to the medications which is why it is imperative for close follow-up care to balance the benefits that these drugs present versus their potential risks. Repeated bouts of tissue rejection symptoms also known as chronic rejection, beyond the first year following the surgery, occurs in 50% of patients according to statistical data from the United States. Chronic rejection can present itself as atherosclerosis or bronchiolitis obliterans.
Types of Lung Transplant:
Lobe transplantation is a surgery where part of the lung of the living or deceased donor is removed and used as a replacement in the recipient’s diseased lung. When the donor is a living one, this procedure needs the donation of lobes taken from two different individuals, replacing a lung on either side of the patient.
Most patients can be treated by the transplantation of one healthy lung. The lung donated typically comes from a brain-dead donor.
Some patients may require both of their lungs to be replaced. A condition that may trigger this is cystic fibrosis (because of the bacterial colonization found in the lungs of such patients).
Some respiratory patients might also have other severe cardiac diseases which would also trigger a heart transplant. Such patients can undergo a surgery where both their lungs and heart are replaced.
In single-lung transplantation, the lung that has the worst pulmonary function is replaced. If both the patient’s lungs work equally, the right lung is favored for removal as this avoids having to maneuver around the heart during the procedure (as would be required if it were the left lung).
Double-lung donation and transplantation, also called bilateral transplant, can be carried out either sequentially, simultaneously or en bloc. Sequential is the more common practice than en bloc. This feels like undergoing two separate single-lung transplants at once.
A Description of How the Procedure is Done
While the surgical details can depend on the kind of transplant, there is a host of steps common to each procedure. Before operating on a recipient, the surgeon will inspect the donor lungs for any signs of disease or damage. If the lung(s) is approved, the recipient is placed on an IV line and other monitoring equipment, including a pulse oximetry. The recipient will also be given a general anesthesia, and be aided by a machine for breathing. It takes at least an hour to prepare the patient for the procedure. A single lung surgery can take at least four to eight hours. A double lung transplant can take up six to twelve hours. A recipient with a history of prior chest operation may complicate the surgery and require additional time.
Post-Operative Care After Lung Transplantation
Immediately after the lung transplantation surgery, the recipient is placed under intensive care for monitoring. This can last for a few days normally. The patient is put on a ventilator to help their breathing. The nutritional needs of the patient are met using total parenteral nutrition. However, on some occasions, a nasogastric tube is seen as sufficient enough for a feeding. Chest tubes can be put to allow excess fluid to be removed from the lungs. Since the patient is going to be confined to a bed, a catheter is used to remove urine. IV lines are affixed to the arm and neck to monitor the patient and give them medication.
After a few days (in the absence of complications), the recipient is transferred to a standard patient ward for a full recovery. The average time frame regarding hospital stay following lung transplantation is one to three weeks (bar the absence of complications). If there are complications, the patient may require an extended period to recover. After this stage, the patient is required to attend the rehabilitation gym for a three month period to regain their fitness. Lightweights, treadmill, stretches, and exercise bike, etc. are all part of the rehabilitation program.
There might be a range of side effects after a surgery as complicated as this. The reason for this is because some nerve connections to the patient’s lungs are cut in the procedure, recipients cannot feel any urge to cough or know when their lungs are becoming congested. Recipients must make conscious effort to take deep breaths and/or a cough so as to clear any secretions from their newly implanted lungs. Their heart rate will respond less quickly to exertion because of the cutting of their vagus nerve (that normally helps to regulate it). Finally, they may notice changes in their voice because of potential damage to their vocal cords coordinating nerves.