Heart transplantation
Encyclopedia
A heart transplant, or a cardiac transplantation, is a surgical transplant
procedure performed on patients with end-stage heart failure or severe coronary artery disease. As of 2007 the most common procedure was to take a working heart
from a recently deceased organ donor (cadaveric allograft) and implant it into the patient. The patient's own heart is either removed (orthotopic procedure) or, less commonly, left in place to support the donor heart (heterotopic procedure); both were controversial solutions to an enduring human ailment. Post-operation survival periods averaged 15 years.
The world's first human heart transplant was performed by Christiaan Barnard
on a man called Louis Washkansky
in 1967. Worldwide, about 3,500 heart transplants were performed annually as of 2007; about 800,000 people had a Class IV heart defect
indicating a new organ. This disparity spurred research into the transplantation of non-human hearts into humans after 1993. Xenografts from other species and man-made artificial heart
s are two less successful alternatives to allografts. In 2011, Cedars-Sinai Medical Center in Los Angeles, CA. was recognized for performing the most heart transplantations of any U.S. medical center for 2010. The hospital had completed 652 procedures since the program's inception in 1988.
:
donor, also called a beating heart cadaver
. The patient is contacted by a nurse coordinator and instructed to come to the hospital for evaluation and pre-surgical medication. At the same time, the heart is removed from the donor and inspected by a team of surgeons to see if it is in suitable condition. Learning that a potential organ is unsuitable can induce distress in an already fragile patient, who usually requires emotional support before returning home.
The patient must also undergo emotional, psychological, and physical tests to verify mental health and ability to make good use of a new heart. The patient is also given immunosuppressant
medication so that their immune system
does not reject
the new heart.
Once the donor heart passes inspection, the patient is taken into the operating room and given a general anaesthetic
. Either an orthotopic or a heterotopic procedure follows, depending on the conditions of the patient and the donor heart.
, opening the chest and exposing the mediastinum
. The pericardium
is opened, the great vessels
are dissected and the patient is attached to cardiopulmonary bypass. The donor's heart is injected with potassium chloride
. KCl stops the heartbeat before the heart is removed from the donor's body and packed in ice. Ice can usually keep the heart usable four to six hours depending on preservation and starting condition. The failing heart is removed by transecting the great vessels and a portion of the left atrium
. The patient's pulmonary vein
s are not transected; rather a circular portion of the left atrium containing the pulmonary veins is left in place. The donor heart is trimmed to fit onto the patient's remaining left atrium and the great vessels are sutured in place. The new heart is restarted, the patient is weaned from cardiopulmonary bypass and the chest cavity is closed.
), it can later be removed, leaving the patient's original heart. Heterotopic procedures are used only in cases where the donor heart is not strong enough to function by itself (because either the patient's body is considerably larger than the donor's, the donor's heart is itself weak, or the patient suffers from pulmonary hypertension
).
Clinic for Thorax
and Cardiovascular Surgery, Germany
, surgeons successfully transplanted a 'beating heart' into a patient. Rather than cooling the heart, the living organ procedure keeps it at body temperature and connects it to a special machine called an Organ Care System
that allows it to continue pumping warm, oxygenated blood. This technique can maintain the heart in a suitable condition for much longer than the traditional method.
to recover. When they wake up, they move to a special recovery unit for rehabilitation
. The duration of in-hospital, post-transplant care depends on the patient's general health, how well the heart is working, and the patient's ability to look after the new heart. Doctors typically prefer that patients leave the hospital 1 – 2 weeks after surgery, because of the risk of infection and presuming no complications. After release, the patient returns for regular check-ups and rehabilitation. They may also require emotional support. The frequency of hospital visits decreases as the patient adjusts to the transplant. The patient remains on immunosuppressant
medication to avoid the possibility of rejection
. Since the vagus nerve
is severed during the operation, the new heart beats at around 100 beats per minute unless nerve regrowth occurs.
The patient is regularly monitored to detect rejection. This surveillance can be performed via frequent biopsy
or a gene expression blood test known as AlloMap Molecular Expression Testing
. Typically, biopsy is performed immediately post-transplant and then AlloMap replaces it once the patient is stable. The transition from biopsy to AlloMap can occur as soon as 55 days after the transplant.
, organ rejection
, as well as the side-effects of the immunosupressive medication. Since the transplanted heart originates from another organism, the recipient's immune system typically attempts to reject it. Immunosupressive drugs reduce that risk, but may cause unwanted side effects, such as increased likelihood of infections or wikt:nephrotoxic effects. Many recent advances in reducing complications due to tissue rejection stem from mouse heart transplant procedures.
In a November 2008 study conducted on behalf of the U.S. federal government by Dr. Eric Weiss of the Johns Hopkins University School of Medicine, it was discovered that heart transplants — other factors equal — work better in male to male and female to female transplants. However, due to the acute donor shortage, this is not always feasible.
severely weakened his heart. Huesman died of cancer. The operation was performed at Stanford University
under heart transplant pioneer Dr. Norman Shumway
.
Kelly Perkins
climbs mountains around the world to promote positive awareness of organ donation. Perkins was the first recipient to climb the peaks of Mt. Fuji
, Mt. Kilimanjaro
, the Matterhorn
, Mt. Whitney
, and Cajon de Arenales in Argentina in 2007, 12 years after her surgery.
Twenty-two years after Dwight Kroening's heart transplant, he was the first recipient to finish an Ironman competition.
Fiona Coote
was the second Australian to receive a heart transplant in 1984 (at age 14) and the youngest Australian. In the 24 years after her transplant she became involved in publicity and charity work for the Red Cross, and promoted organ donation in Australia.
Organ transplant
Organ transplantation is the moving of an organ from one body to another or from a donor site on the patient's own body, for the purpose of replacing the recipient's damaged or absent organ. The emerging field of regenerative medicine is allowing scientists and engineers to create organs to be...
procedure performed on patients with end-stage heart failure or severe coronary artery disease. As of 2007 the most common procedure was to take a working heart
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
from a recently deceased organ donor (cadaveric allograft) and implant it into the patient. The patient's own heart is either removed (orthotopic procedure) or, less commonly, left in place to support the donor heart (heterotopic procedure); both were controversial solutions to an enduring human ailment. Post-operation survival periods averaged 15 years.
The world's first human heart transplant was performed by Christiaan Barnard
Christiaan Barnard
Christiaan Neethling Barnard was a South African cardiac surgeon who performed the world's first successful human-to-human heart transplant.- Early life :...
on a man called Louis Washkansky
Louis Washkansky
Louis Washkansky was the recipient of the world's first human heart transplant.-Biography:Washkansky was a Lithuanian Jew who migrated with his friends to South Africa in 1922, aged nine, and became a grocer in Cape Town. Washkansky saw active service in World War II in East and North Africa and...
in 1967. Worldwide, about 3,500 heart transplants were performed annually as of 2007; about 800,000 people had a Class IV heart defect
Class IV heart defect
A Class IV heart defect is a type of problem with a patient's heart whereby the condition of the heart is impaired or otherwise bad. Problems such as a hole in the heart, severe/minor heart attack, weak heart, malfunctioning of heart, etc. would all fall under this....
indicating a new organ. This disparity spurred research into the transplantation of non-human hearts into humans after 1993. Xenografts from other species and man-made artificial heart
Artificial heart
An artificial heart is a mechanical device that replaces the heart. Artificial hearts are typically used in order to bridge the time to heart transplantation, or to permanently replace the heart in case transplantation is impossible...
s are two less successful alternatives to allografts. In 2011, Cedars-Sinai Medical Center in Los Angeles, CA. was recognized for performing the most heart transplantations of any U.S. medical center for 2010. The hospital had completed 652 procedures since the program's inception in 1988.
Contraindications
Some patients are less suitable for a heart transplant, especially if they suffer from other circulatory conditions unrelated to the heart. The following conditions in a patient increase the chances of complicationsComplication (medicine)
Complication, in medicine, is an unfavorable evolution of a disease, a health condition or a medical treatment. The disease can become worse in its severity or show a higher number of signs, symptoms or new pathological changes, become widespread throughout the body or affect other organ systems. A...
:
- KidneyKidneyThe kidneys, organs with several functions, serve essential regulatory roles in most animals, including vertebrates and some invertebrates. They are essential in the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and...
, lungLungThe lung is the essential respiration organ in many air-breathing animals, including most tetrapods, a few fish and a few snails. In mammals and the more complex life forms, the two lungs are located near the backbone on either side of the heart...
, or liverLiverThe liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...
disease - InsulinInsulinInsulin is a hormone central to regulating carbohydrate and fat metabolism in the body. Insulin causes cells in the liver, muscle, and fat tissue to take up glucose from the blood, storing it as glycogen in the liver and muscle....
-dependent diabetes with other organ dysfunction - Life-threatening diseases unrelated to heart failure
- Vascular diseaseVascular diseaseVascular disease is a form of cardiovascular disease primarily affecting the blood vessels.Some conditions, such as angina and myocardial ischemia, can be considered both vascular diseases and heart diseases .Cigarette smoking is the major risk factor....
of the neck and leg arteries. - High pulmonary vascular resistance
- Recent thromboembolism
- Age over 60 years (some variation between centers)
- Substance abuse (which increases the chance of lung disease)
Pre-operative
A typical heart transplantation begins when a suitable donor heart is identified. The heart comes from a recently deceased or brain deadBrain death
Brain death is the irreversible end of all brain activity due to total necrosis of the cerebral neurons following loss of brain oxygenation. It should not be confused with a persistent vegetative state...
donor, also called a beating heart cadaver
Beating heart cadaver
A beating heart cadaver is a human body that though dead in all medical and legal definitions is attached to a medical ventilator and retains cardio-pulmonary functions. This will keep the organs of the dead body, including the heart, functioning and alive for a few days...
. The patient is contacted by a nurse coordinator and instructed to come to the hospital for evaluation and pre-surgical medication. At the same time, the heart is removed from the donor and inspected by a team of surgeons to see if it is in suitable condition. Learning that a potential organ is unsuitable can induce distress in an already fragile patient, who usually requires emotional support before returning home.
The patient must also undergo emotional, psychological, and physical tests to verify mental health and ability to make good use of a new heart. The patient is also given immunosuppressant
Immunosuppressant
An immunosuppressant is any substance that performs immunosuppression of the immune system. They may be either exogenous, as immunosuppressive drugs, or endogenous, as ,e. g., testosterone...
medication so that their immune system
Immune system
An immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...
does not reject
Transplant rejection
Transplant rejection occurs when transplanted tissue is rejected by the recipient's immune system, which destroys the transplanted tissue. Transplant rejection can be lessened by determining the molecular similitude between donor and recipient and by use of immunosuppressant drugs after...
the new heart.
Operative
General anaesthetic
A general anaesthetic is a drug that brings about a reversible loss of consciousness. These drugs are generally administered by an anaesthesia provider to induce or maintain general anaesthesia to facilitate surgery...
. Either an orthotopic or a heterotopic procedure follows, depending on the conditions of the patient and the donor heart.
Orthotopic procedure
The orthotopic procedure begins with a median sternotomyMedian sternotomy
Median sternotomy is a type of surgical procedure in which a vertical inline incision is made along the sternum, after which the sternum itself is divided, or "cracked"...
, opening the chest and exposing the mediastinum
Mediastinum
The mediastinum is a non-delineated group of structures in the thorax, surrounded by loose connective tissue. It is the central compartment of the thoracic cavity...
. The pericardium
Pericardium
The pericardium is a double-walled sac that contains the heart and the roots of the great vessels.-Layers:...
is opened, the great vessels
Great vessels
Great vessels is a term used to refer collectively to the four large vessels that bring blood to and from the heart. These are:*Superior vena cava*Inferior vena cava*Pulmonary artery*AortaAll four pulmonary veins are considered apart of the great vessels...
are dissected and the patient is attached to cardiopulmonary bypass. The donor's heart is injected with potassium chloride
Potassium chloride
The chemical compound potassium chloride is a metal halide salt composed of potassium and chlorine. In its pure state, it is odorless and has a white or colorless vitreous crystal appearance, with a crystal structure that cleaves easily in three directions. Potassium chloride crystals are...
. KCl stops the heartbeat before the heart is removed from the donor's body and packed in ice. Ice can usually keep the heart usable four to six hours depending on preservation and starting condition. The failing heart is removed by transecting the great vessels and a portion of the left atrium
Left atrium
The left atrium is one of the four chambers in the human heart. It receives oxygenated blood from the pulmonary veins, and pumps it into the left ventricle, via the mitral valve.-Foramen ovale:...
. The patient's pulmonary vein
Pulmonary vein
The pulmonary veins are large blood vessels that carry blood from the lungs to the left atrium of the heart. In humans there are four pulmonary veins, two from each lung...
s are not transected; rather a circular portion of the left atrium containing the pulmonary veins is left in place. The donor heart is trimmed to fit onto the patient's remaining left atrium and the great vessels are sutured in place. The new heart is restarted, the patient is weaned from cardiopulmonary bypass and the chest cavity is closed.
Heterotopic procedure
In the heterotopic procedure, the patient's own heart is not removed. The new heart is positioned so that the chambers and blood vessels of both hearts can be connected to form what is effectively a 'double heart'. The procedure can give the patient's original heart a chance to recover, and if the donor's heart fails (e.g., through rejectionTransplant rejection
Transplant rejection occurs when transplanted tissue is rejected by the recipient's immune system, which destroys the transplanted tissue. Transplant rejection can be lessened by determining the molecular similitude between donor and recipient and by use of immunosuppressant drugs after...
), it can later be removed, leaving the patient's original heart. Heterotopic procedures are used only in cases where the donor heart is not strong enough to function by itself (because either the patient's body is considerably larger than the donor's, the donor's heart is itself weak, or the patient suffers from pulmonary hypertension
Pulmonary hypertension
In medicine, pulmonary hypertension is an increase in blood pressure in the pulmonary artery, pulmonary vein, or pulmonary capillaries, together known as the lung vasculature, leading to shortness of breath, dizziness, fainting, and other symptoms, all of which are exacerbated by exertion...
).
'Living organ' transplant
In February 2006, at the Bad OeynhausenBad Oeynhausen
Bad Oeynhausen is a spa town in the Minden-Lübbecke district, in North Rhine-Westphalia, Germany.- Geography :Bad Oeynhausen is located on the banks of the Weser river, which runs along the eastern edges of the town. Bad Oeynhausen has the world's highest carbonated, thermal saltwater fountain,...
Clinic for Thorax
Thorax
The thorax is a division of an animal's body that lies between the head and the abdomen.-In tetrapods:...
and Cardiovascular Surgery, Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
, surgeons successfully transplanted a 'beating heart' into a patient. Rather than cooling the heart, the living organ procedure keeps it at body temperature and connects it to a special machine called an Organ Care System
Organ care system
The Organ Care System is a medical device designed by Transmedics to allow donor organs to be maintained for longer periods of time prior to transplant. The system dispenses with the traditional method of preserving organs through freezing, replacing it with keeping them in an environment and...
that allows it to continue pumping warm, oxygenated blood. This technique can maintain the heart in a suitable condition for much longer than the traditional method.
Post-operative
The patient is taken to the ICUIntensive Care Unit
thumb|220px|ICU roomAn intensive-care unit , critical-care unit , intensive-therapy unit/intensive-treatment unit is a specialized department in a hospital that provides intensive-care medicine...
to recover. When they wake up, they move to a special recovery unit for rehabilitation
Physical medicine and rehabilitation
Physical medicine and rehabilitation , physiatry or rehabilitation medicine, is a branch of medicine that aims to enhance and restore functional ability and quality of life to those with physical impairments or disabilities. A physician having completed training in this field is referred to as a...
. The duration of in-hospital, post-transplant care depends on the patient's general health, how well the heart is working, and the patient's ability to look after the new heart. Doctors typically prefer that patients leave the hospital 1 – 2 weeks after surgery, because of the risk of infection and presuming no complications. After release, the patient returns for regular check-ups and rehabilitation. They may also require emotional support. The frequency of hospital visits decreases as the patient adjusts to the transplant. The patient remains on immunosuppressant
Immunosuppressant
An immunosuppressant is any substance that performs immunosuppression of the immune system. They may be either exogenous, as immunosuppressive drugs, or endogenous, as ,e. g., testosterone...
medication to avoid the possibility of rejection
Transplant rejection
Transplant rejection occurs when transplanted tissue is rejected by the recipient's immune system, which destroys the transplanted tissue. Transplant rejection can be lessened by determining the molecular similitude between donor and recipient and by use of immunosuppressant drugs after...
. Since the vagus nerve
Vagus nerve
The vagus nerve , also called pneumogastric nerve or cranial nerve X, is the tenth of twelve paired cranial nerves...
is severed during the operation, the new heart beats at around 100 beats per minute unless nerve regrowth occurs.
The patient is regularly monitored to detect rejection. This surveillance can be performed via frequent biopsy
Biopsy
A biopsy is a medical test involving sampling of cells or tissues for examination. It is the medical removal of tissue from a living subject to determine the presence or extent of a disease. The tissue is generally examined under a microscope by a pathologist, and can also be analyzed chemically...
or a gene expression blood test known as AlloMap Molecular Expression Testing
AlloMap Molecular Expression Testing
AlloMap molecular expression testing, developed and commercialized by XDx, is a gene expression profiling test to identify heart transplant recipients with a low probability of one type of transplant rejection. The test is performed on a blood sample, providing a non-invasive test to help manage...
. Typically, biopsy is performed immediately post-transplant and then AlloMap replaces it once the patient is stable. The transition from biopsy to AlloMap can occur as soon as 55 days after the transplant.
Complications
Post-operative complications include infection, sepsisSepsis
Sepsis is a potentially deadly medical condition that is characterized by a whole-body inflammatory state and the presence of a known or suspected infection. The body may develop this inflammatory response by the immune system to microbes in the blood, urine, lungs, skin, or other tissues...
, organ rejection
Transplant rejection
Transplant rejection occurs when transplanted tissue is rejected by the recipient's immune system, which destroys the transplanted tissue. Transplant rejection can be lessened by determining the molecular similitude between donor and recipient and by use of immunosuppressant drugs after...
, as well as the side-effects of the immunosupressive medication. Since the transplanted heart originates from another organism, the recipient's immune system typically attempts to reject it. Immunosupressive drugs reduce that risk, but may cause unwanted side effects, such as increased likelihood of infections or wikt:nephrotoxic effects. Many recent advances in reducing complications due to tissue rejection stem from mouse heart transplant procedures.
Prognosis
The prognosis for heart transplant patients following the orthotopic procedure has increased over the past 20 years, and as of June 5, 2009, the survival rates were:- 1 year : 88.0% (males), 86.2% (females)
- 3 years: 79.3% (males), 77.2% (females)
- 5 years: 73.1% (males), 69.0% (females)
In a November 2008 study conducted on behalf of the U.S. federal government by Dr. Eric Weiss of the Johns Hopkins University School of Medicine, it was discovered that heart transplants — other factors equal — work better in male to male and female to female transplants. However, due to the acute donor shortage, this is not always feasible.
Notable recipients
At the time of his death on August 10, 2009, Tony Huesman was the world's longest living heart transplant recipient, having survived for 31 years. Huesman received a heart in 1978 at the age of 20 after viral pneumoniaViral pneumonia
Viral pneumonia is a pneumonia caused by a virus.Viruses are one of the two major causes of pneumonia, the other being bacteria; less common causes are fungi and parasites...
severely weakened his heart. Huesman died of cancer. The operation was performed at Stanford University
Stanford University
The Leland Stanford Junior University, commonly referred to as Stanford University or Stanford, is a private research university on an campus located near Palo Alto, California. It is situated in the northwestern Santa Clara Valley on the San Francisco Peninsula, approximately northwest of San...
under heart transplant pioneer Dr. Norman Shumway
Norman Shumway
Norman Edward Shumway was a pioneer of heart surgery at Stanford University.-Early life:Shumway was born in Kalamazoo, Michigan...
.
Kelly Perkins
Kelly Perkins
Kelly Perkins is an American heart transplant recipient known for climbing mountains to inspire others and promote organ donation.Perkins has selected peaks of many famous mountains, with both personal and cause related significance, since her heart transplant operation in 1995...
climbs mountains around the world to promote positive awareness of organ donation. Perkins was the first recipient to climb the peaks of Mt. Fuji
Mount Fuji
is the highest mountain in Japan at . An active stratovolcano that last erupted in 1707–08, Mount Fuji lies about south-west of Tokyo, and can be seen from there on a clear day. Mount Fuji's exceptionally symmetrical cone is a well-known symbol of Japan and it is frequently depicted in art and...
, Mt. Kilimanjaro
Mount Kilimanjaro
Kilimanjaro, with its three volcanic cones, Kibo, Mawenzi, and Shira, is a dormant volcano in Kilimanjaro National Park, Tanzania and the highest mountain in Africa at above sea level .-Geology:...
, the Matterhorn
Matterhorn
The Matterhorn , Monte Cervino or Mont Cervin , is a mountain in the Pennine Alps on the border between Switzerland and Italy. Its summit is 4,478 metres high, making it one of the highest peaks in the Alps. The four steep faces, rising above the surrounding glaciers, face the four compass points...
, Mt. Whitney
Mount Whitney
Mount Whitney is the highest summit in the contiguous United States with an elevation of . It is on the boundary between California's Inyo and Tulare counties, west-northwest of the lowest point in North America at Badwater in Death Valley National Park...
, and Cajon de Arenales in Argentina in 2007, 12 years after her surgery.
Twenty-two years after Dwight Kroening's heart transplant, he was the first recipient to finish an Ironman competition.
Fiona Coote
Fiona Coote
Fiona Coote was the second, youngest and first female in Australia to undergo a heart transplant. The procedure was performed by notable Chinese-Australian cardiothoracic surgeon, Dr Victor Chang and was successfully carried out on in April 1984, when Coote was 14 years of age...
was the second Australian to receive a heart transplant in 1984 (at age 14) and the youngest Australian. In the 24 years after her transplant she became involved in publicity and charity work for the Red Cross, and promoted organ donation in Australia.