Artificial Lung Technology (ECMO) - also known as ECMO or extracorporeal membrane oxygenation, pumps blood through an artificial lung device and back into the body of the patient. Artificial lung technology provides long-term management of heart or lung failure while the patient awaits a transplant or heals after surgery.
Total Artificial Heart (TAH) - is a mechanical device designed to replace the lower two chambers of the heart (ventricles) that pump blood to the lungs and then out to the body. Patients who have advanced heart failure of both ventricles or who are waiting for a heart transplant may be good candidates for a total artificial heart.
Ventricular Assist Devices (VAD) - or ventricular assist systems (VAS) is a surgically implanted pump that helps the weakened lower two chambers of the heart (ventricles) pump blood out to the body and lungs. VADs can be used as a bridge to therapy, sustaining patients until a heart can be located for transplant.
Artificial lung technology, also known as ECMO or extracorporeal membrane oxygenation pumps blood through an artificial lung device and back into the body of the patient. Used in both adults and children, artificial lung technology provides long term management of heart or lung failure while the patient awaits a transplant or heals after surgery.
ECMO is ideal for patients who have compromised cardiovascular health, a high mortality rate, or would not be able to maintain their current physical status if placed on traditional mechanical ventilation. ECMO may be used while the patient is awake, alert and ambulatory which greatly reduces the risk for complications related to immobility and ventilator use. Patients with acute respiratory distress syndrome (ARDS) who do not have multi-system or non-pulmonary organ failure and cannot maintain normal mechanical ventilation are among qualifying candidates for use. There are a variety of criteria providers may use to determine if a patient qualifies for ECMO.
How Artificial Lung Technology Works
ECMO may be used in one of two ways: venovenous (VV) and venoarterial (VA) methods.
Venoarterial (VA) Methods
Venoarterial ECMO utilizes blood from a central vein or the right atrium of the heart and pumps it past an oxygenator worn outside the body. The blood then returns under pressure to the aorta to be pumped out to the body. This method helps support the amount of blood that is pumped by the heart (cardiac output).
Venovenous (VV) Method
Venovenous ECMO takes deoxygenated blood from a large vein, passing it through the oxygenation process and returns it to the body through another large vein. This form does not support cardiac output of the heart. VV ECMO also allows for the removal of carbon dioxide through the artificial lung unit and doesn’t just add oxygenated blood alone.
Patients receiving ECMO will have a large catheters (tubes) placed in the body to remove and replace the blood volume after gas exchange. Because of the risk of blood clots, patients will be given anticoagulant drugs (blood thinners) to reduce the risk of clot formation and complications.
ECMO has been used for decades in newborns and children with lung failure, pneumonia, meconium aspiration syndrome and other conditions and is used less often in adult patients because so few are candidates for it but shows great promise for the treatment of many heart and lung problems and allows new organs to heal after transplant.
The total artificial heart (TAH) is a mechanical device designed to replace the lower two chamber of the heart (ventricles) that pump blood to the lungs and then out to the body. Patients who have advanced heart failure of both ventricles or who are waiting for a heart transplant may be good candidates for a total artificial heart. Patients with a heart failure classification of American Heart Association (AHA) stage D, or New York Heart Association (NYHA) class IV, face a significantly higher mortality and the total artificial heart may serve a bridge to additional procedures or operate as a long-term alternative. Nearly 100,000 patients have advanced heart failure in the US.
To attach the total artificial heart, the bottom ventricles are removed and the device is attached to the top two chambers of the heart called the atria. Most designs require that some of the aorta, pulmonary arteries and portions of the atrial tissue be removed for placement. Between the atria and the ventricles are mechanical valves that replace the heart’s old valves and keep blood from flowing in the wrong
There are a few different total artificial heart designs on the market and your doctor will determine which type is best for you. Some types of artificial hearts are attached to an outside power source with tubes that run out through the abdomen. Others types are self-contained with no tubes outside the body and are charged with a magnet through the skin.
Patients who may not be candidates for TAH placement are those who do not have sufficient space in the chest for the device, or who cannot take anticoagulant therapy as required.
Ventricular assist devices (VAD) or ventricular assist systems (VAS) is a surgically implanted pump that helps the weakened lower two chambers of the heart (ventricles) pump blood out to the body and lungs. VADs can be used as a bridge to therapy, sustaining patients until a heart can be located for transplant. This approach is often used for patient who are not responding to other treatments or who have end-stage systolic heart failure. Some patients with a VAD who are waiting for a transplant are able to leave the hospital and continue care as an outpatient—meaning they come to the office or clinic for checkups but won’t require additional hospitalization for the VAD.
Some patients receive a VAD as an alternative to a heart transplant. For patients who do not meet the criteria for a heart transplant, or simply choose not to have a transplant, a VAD can provide long-term management and an improved quality of life. VADs can help patients improve exercise and activity tolerances, cardiac output (the amount of blood the heart is able to pump out), organ function, and hemodynamic function.
No part of the heart is removed to place a ventricular assist device. Instead the device is placed where the patient needs it most—in the left or right ventricle of the heart, or in some cases both ventricles. Depending on which side of the heart the device is located in, the VAD helps the ventricles pump blood out and eases demand on the muscle. A left ventricular assist device (LVAD) receives blood from the left ventricle and delivers it to the aorta for delivery to the body. The right ventricular assist device (RVAD) gathers blood from the right atria (top chamber of the heart) or right ventricle and sends it to the pulmonary artery where it travels to the lungs for oxygenation.
The type of VAD placed will depend on the patient’s heart failure and need. All VADs have three main parts: a pump that may be implanted in the abdomen or be outside the body, a control system and a power supply that plugs in our uses batteries. Patients can be mobile with an VAD, but must remember to charge batteries regularly or use the main power when not ambulating.
Ventricular assist devices are not right for every patient and your doctor will talk with you to decide if you are a candidate. Those who may not be right for a VAD include irreversible kidney failure, some types of clotting disorders, and severe lung or liver diseases. If you are selected for VAD placement, there are a few risks you should know about. Your doctor will talk with you more about them, but the most common include bleeding, blood clots, stroke, and failure of the device.
After VAD placement, you will receive extensive training about caring for your device, including management of emergencies and maintenance of your unit. Diet, activity and when to call the doctor will all be reviewed and patients should be prepared to demonstrate independence with daily activities like bathing, walking and dressing before leaving the hospital.