The Use of Prosthetics in Mesothelioma Surgery

Mesothelioma is a difficult type of cancer to treat. For many patients the treatment options are limited, either because of the age and health of the patient or because of the extent to which the cancer has already spread in the body. Surgery, chemotherapy, or radiation, or a combination of these strategies is the most common treatments used for patients with mesothelioma.

In many patients the cancer has spread far enough throughout the chest cavity that the only hope of removing it all is to conduct a radical surgery that removes one entire lung as well as other tissues.  For some patients it represents a chance of survival and remission but it is dangerous and risky. The surgery also includes removal of much of the diaphragm and its reconstruction with prosthetics. For lung tissue that is too diseased to function, the idea of replacing it with a prosthetic is still in the theoretical stages but may be a possibility in the future.

Extrapleural Pneumonectomy

The most extensive surgery that can be done on a mesothelioma patient in an attempt to remove all cancerous tissue is called an extrapleural pneumonectomy. Only experts in the field of thoracic surgery attempt this difficult surgical procedure. It involves removing an entire lung,  part of the diaphragm, the pleura that lines the chest cavity, and sometimes even the tissue lining the heart, called the pericardium.

Patients with advanced mesothelioma are not eligible for this surgery. It is only done for those patients whose cancer has not yet spread to lymph nodes or any other tissues or organs. 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 six percent of patients die during this procedure or shortly after it.

Even when an extrapleural pneumonectomy is successful, there may be complications. Patients must be in overall good health before undergoing this surgery because the remaining lung will be doing double duty and the heart will have to work harder to pump blood to the one lung. Older patients or those with weak hearts or other lung problems besides the cancer are not usually eligible for the surgery.

Reconstructing a Prosthetic Diaphragm

One important part of an extrapleural pneumonectomy is the reconstruction of the diaphragm. The diaphragm is a muscle that is situated underneath the lungs and 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, which is why it must be reconstructed with prosthetics after a surgery that removes it. Without a reconstructed diaphragm, pulmonary function  and breathing would be low.

The materials used to make prosthetic diaphragms have changed over the years and have included surgical mesh, plastics, and Gore-Tex. Reconstruction of the diaphragm with prosthetic materials is used in other types of surgeries for things like diaphragm defects, and it is a procedure that has good outcomes for the patient and is typically low-risk.

The Problem with Lung Transplants for Cancer Patients

Removing one entire lung is a serious type of 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, but for those who are still asymptomatic, the surgery results in a lowered quality of life.

Lung transplants may seem like a reasonable option for someone forced to lose a lung over mesothelioma, but it is not done. The main reason that mesothelioma patients do not get lung transplants is because of a low chance of survival and that donor organs are scarce. The few donated lungs available are saved for patients for who a transplant will both improve quality of life and potentially save that life. Conditions like congenital defects, cystic fibrosis, and chronic obstructive pulmonary disease may be treated with lung transplants.

Artificial Lungs and the uture of Implantable Prosthetic Lungs

Because donated lungs are not available 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 then back into the body. The use of the ECMO device is intended to be temporary. They are used for patients who are expected to recover lung function and who do not do well on a ventilator.

An implantable, internal prosthetic lung would be a major 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 and 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.

Mesothelioma is a tricky cancer to treat and surgery plays an important role in giving patients hope of survival. For those who are eligible for radical surgeries like extrapleural pneumonectomy, the advances in prosthetics are important. Artificial diaphragms are being used now and prosthetic lungs are likely for the future.