Some pleural mesothelioma patients need a prosthetic diaphragm after undergoing surgery. A surgeon might also use prosthetics to reconstruct part of the chest wall or the pericardium. In the future, prosthetic lungs may be available to patients with pleural mesothelioma.
What Is a Mesothelioma Prosthetic?
A prosthetic is any type of synthetic or biosynthetic body part or tissue used to replace natural tissue. Some prosthetics are visible, like a leg or arm, while others are inside the body.
This is the case with prosthetics in mesothelioma. There are three types of organs and tissue that a surgeon might replace or reconstruct with prosthetics during pleural mesothelioma surgery:
- Diaphragm. The diaphragm is a muscle that sits below the lungs. It contracts and relaxes to help the lungs expand and relax during breathing.
- Chest wall. The chest wall consists of several types of tissue, including fat, muscles, and skin. It protects the organs of the chest cavity.
- Pericardium. The pericardium is the part of the mesothelium that surrounds the heart.
Mesothelioma Surgery and the Need for Prosthetics
Pleural mesothelioma develops as multiple small tumors rather than one or two large masses. This makes surgery difficult. Surgeons must remove a lot of tissue to help the patient achieve remission or extend their life.
What Is the Surgery for Mesothelioma?
The most extensive surgery option for a mesothelioma patient to remove all cancerous tissue is called an extrapleural pneumonectomy. It involves removing an entire lung, part of the diaphragm, the pleural tissue that lines the chest cavity, and sometimes the pericardium and parts of the chest wall.
Can Removing a Lung Cure Mesothelioma?
There is a potential that an extrapleural pneumonectomy can cure a patient with early-stage mesothelioma, but it is risky and complicated. Many who survive it will have a recurrence in the future, and 6% of patients die during this procedure or shortly after it.
Complications of Radical Mesothelioma Surgery
Because the surgeon removes so much tissue during extensive surgery, they may reconstruct part of the chest cavity with prosthetic components and materials. Other surgeries, like pleurectomy or lung decortication, are less radical but might still require some reconstruction.
Reconstruction of some areas of tissue helps prevent or lower the risk of serious complications. Radical pleural mesothelioma surgery can cause several complications:[1]
- Pneumonia
- Pulmonary edema
- Acute respiratory distress syndrome
- Air leak
- Arrhythmia
- Cardiac herniation
- Hemothorax
- Lung collapse
Prosthetics cannot address all of the potential complications of surgery, but they do reduce the risk of some serious problems.
Prosthetic Diaphragm Reconstruction
A critical part of an extrapleural pneumonectomy is reconstructing the diaphragm. The diaphragm is a muscle underneath the lungs that separates the abdominal cavity from the chest cavity.
The muscle contracts to allow air to fill the lungs and releases to help push it out. It is necessary for respiration, so surgeons must reconstruct it with prosthetics after surgery that removes it. Without a reconstructed diaphragm, pulmonary function and breathing would be further impaired.
The diaphragm can be reconstructed using either autologous or alloplastic materials. Autologous means it comes from the body. The surgeon can rearrange nearby muscles to fill this gap. This procedure has benefits, including a lower risk of infection since it avoids foreign objects; however, it can have complications related to moving the muscle.
Alloplastic materials are foreign and continue to change over the years. These can include surgical mesh, plastics, and Gore-Tex. Reconstruction of the diaphragm with prosthetic materials is used in other surgeries for things like diaphragm defects.
It is a procedure that has good outcomes for the patient and is typically low-risk; however, any foreign object in the body can cause infection.[2]
Other Mesothelioma Prosthetics
The diaphragm is the most common type of tissue reconstructed with prosthetics during mesothelioma surgery. A surgeon may also use synthetic materials for the chest wall or pericardium.[3]
Reconstructing the Chest Wall
Although not common, a surgeon might need to use synthetic materials to reconstruct the chest wall during surgery. A surgeon sometimes finds cancer in the chest wall and needs to remove significant portions of it, necessitating reconstruction.
Reconstruction of the chest wall helps protect organs in the chest cavity and prevents lung herniation. The surgeon uses a synthetic material to replace the removed tissue and then covers it with the patient’s muscle tissue.
Prosthetic Pericardium
During extensive surgery for pleural mesothelioma, the surgeon might need to remove part or all of the sac around the heart. Not all patients need the pericardium replaced, but doing so can prevent complications like cardiac herniation and constrictive pericarditis.
The most common prosthetic for the pericardium is a synthetic mesh. Most are permeable to avoid cardiac tamponade, a life-threatening buildup of fluid that puts pressure on the heart.
The Problem with Lung Transplants for Cancer Patients
Removing one entire lung is a serious surgery, and it can result in serious complications. Living with just one lung reduces pulmonary function and restricts a patient’s ability to be active.
Studies have shown that there is often a trade-off: when the extrapleural pneumonectomy is done for a patient with symptoms of mesothelioma, those symptoms are reduced after the surgery. For those who are still asymptomatic, the surgery results in a lowered quality of life.
Appropriate testing before surgery can allow the surgeon to give estimates of symptoms they may experience during and after their recovery.
Lung transplants might seem like a reasonable option for someone forced to lose a lung over mesothelioma, but it is not done. The main reason mesothelioma patients do not get lung transplants is because of a low chance of survival. Also, donor organs are scarce.
The few donated lungs available are saved for patients for whom a transplant will improve quality of life and potentially save their lives. Lung transplants treat conditions like congenital defects, cystic fibrosis, and chronic obstructive pulmonary disease.
Artificial Lungs and the Future of Implantable Prosthetic Lungs
Because donated lungs are unavailable to patients with mesothelioma, prosthetic lungs have been considered. Current artificial lungs are external devices known as ECMO, or extracorporeal membrane oxygenation. These devices pump blood through the artificial lung to oxygenate it and back into the body.
The use of the ECMO device is intended to be temporary. They are used for patients expected to recover lung function and who do not do well on a ventilator.[4]
An implantable, internal prosthetic lung would be a significant breakthrough in medical science. It would negate the need for donor lungs, which are few and far between. Even mesothelioma patients might benefit from a prosthetic device.
Researchers have created such a device, but it has not completed testing yet. There are many issues to overcome with an implantable prosthetic lung, including simply fitting it into the chest cavity while ensuring it can provide adequate oxygenation for the blood and rejection by the host body.
Currently, the closest thing to an implantable prosthetic lung is a device that is smaller than an ECMO device that can be strapped to the outside of the body. Instead of a mechanical pump, this device uses the heart to pump oxygenated blood.
If it works in trials, the next step would be to figure out how it could be implanted into the body. The promise of prosthetic lungs is huge but still a part of theory, not practice.[5]
Mesothelioma is a tricky cancer to treat. Surgery plays a vital role in giving patients hope for survival. For those who are eligible for radical surgeries like extrapleural pneumonectomy, advances in prosthetics are important. Artificial diaphragms are being used now, and prosthetic lungs may be available in the future.
