Liver transplantation or liver transplantation is the replacement of a sick heart with a healthy heart from another (allograft). Liver transplantation is a treatment option for end-stage liver disease and acute liver failure, although the availability of donor organs is a major limitation. The most common technique is orthotopic transplantation, in which the original liver is removed and replaced by the donor organ in the same anatomical position as the original liver. Surgical procedures are complex, requiring careful organ harvesting and careful implantation into the recipient. Liver transplantation is highly regulated, and is performed only in transplant medical centers designated by highly trained transplant doctors and support medical teams. The duration of surgery ranges from 4 to 18 hours depending on the outcome. Profitable results require careful examination of qualified recipients, as well as well-calibrated live or cadavered donor matches.
Video Liver transplantation
Medical use
Liver transplantation is a potential treatment for acute or chronic conditions that lead to irreversible and severe liver dysfunction ("late stage"). Because the procedure carries a relatively high risk, is an intensive resource, and requires great life modification after surgery, it is provided for terrible circumstances.
Assessing the suitability/effectiveness of liver transplants on a case-by-case basis is very important ( see Contraindications ), as results vary widely.
Maps Liver transplantation
Contraindications
Although liver transplantation is the most effective treatment for various forms of end-stage liver disease, extraordinary limitations in the availability of allogeneic and highly variable postoperative outcomes make case selection extremely important. Assessment of a person's transplantation feasibility is made by a multi-disciplinary team that includes surgeons, doctors, and other providers.
The first step in the evaluation is to determine whether the patient has an irreversible liver disease that will be cured by getting a new liver. Thus, those with a disease that is primarily based outside the heart or has spread outwardly is generally considered a bad candidate. Some examples include:
- a person with advanced liver cancer, with known/possibly spread outward liver
- alcohol/active substance abuse
- severe heart/lung disease
- high cholesterol levels present in patients
- dyslipidemia
Importantly, many contraindications to liver transplantation are considered reversible; someone who was initially considered "unable to get a transplant" would later become a lucrative candidate if the situation changed. Some examples include:
- partial treatment of liver cancer, so the risk of spreading outside the liver decreases
- termination of substance abuse (time period abstinence is variable)
- increased heart function, e.g. with percutaneous coronary intervention or bypass surgery
- treat HIV infection ( see Special Population )
Risk/Complication
Graft rejection
After a liver transplant, immune-mediated rejection (also known as rejection ) of an allograft can occur at any time. Rejection may present with laboratory findings: increased AST, ALT, GGT; abnormal liver function values ​​such as prothrombin time, ammonia level, bilirubin level, albumin concentration; and abnormal blood glucose. Physical findings may include encephalopathy, jaundice, bruising and bleeding tendencies. Other non-specific presentations may include malaise, anorexia, muscle aches, low fever, slight increase in white blood count and graft-site tenderness.
Three types of graft rejection may occur: rejection of hyperacute, acute rejection, and chronic rejection.
- Hyperacute rejection is caused by previously formed anti-donor antibodies. It is characterized by the binding of these antibodies to antigens in vascular endothelial cells. Complementary activation is involved and the effect is usually profound. Hyperacute rejection occurs within minutes to hours after the transplant procedure.
- Acute rejection is mediated by T cells (versus B-mediated cell-mediated rejection). It involves direct cytotoxicity and the cytokine mediated pathway. Acute rejection is the most common and the main target of immunosuppressive agents. Acute rejection is usually seen within days or weeks after transplantation.
- Chronic rejection is the sign and rejection feature after 1 year. The cause of chronic rejection is still unknown, but acute rejection is a strong predictor of chronic rejection.
Technique
Before transplantation, liver support therapy may be indicated (bridging-to-transplantation). Artificial liver support such as liver dialysis or the bioartificial liver support concept is currently in preclinical and clinical evaluation. Almost all liver transplants are performed by orthotopic means; that is, the original liver is removed and the new liver is placed in the same anatomical location. Transplant surgery can be conceptualized as comprising the phase of hepatectomy (liver removal), anhepatic phase (no liver), and postimplantation phase. The surgery is done through a large incision in the upper abdomen. Hepatectomy involves the division of all ligamentase attachments to the liver, as well as bile ducts, hepatic arteries, venous liver and portal vein. Usually, the retrohepatic portion of the inferior vena cava is removed along with the liver, although alternative techniques retain the receiving cava vein (the "piggyback" technique).
Blood donors in the liver will be replaced by cold organ storage solutions, such as UW (Viaspan) or HTK until the heart of the allograft is planted. Implantation involves anastomosis (connection) of the inferior vena cava, portal vein, and hepatic artery. Once blood flow is returned to the new liver, biliary anastomosis (bile ducts) is constructed, either to the bile ducts of the recipient itself or to the small intestine. Surgery usually takes between five and six hours, but may be longer or shorter due to surgery difficulties and the surgeon's experience.
Most liver transplants use the whole liver from non-living donors for transplantation, especially for adult recipients. A major advance in pediatric liver transplantation is the development of small size liver transplants, in which some of the adult liver is used for infants or young children. Further developments in this area include a split liver transplant, in which one liver is used for transplantation for two recipients, and a live donor liver transplant, in which a portion of a healthy person's heart is removed and used as an allograft. Live donor liver transplantation for pediatric recipients involves the removal of about 20% of the liver (Couinaud segments 2 and 3).
Further progress in liver transplantation involves liver resection involved in the tumor and the tumor-free lobe remains inside the recipient. It speeds up recovery and patients stay in the hospital quickly becomes shorter within 5-7 days.
Many major medical centers now use radio frequency ablation from liver tumors as bridges while waiting for liver transplantation. This technique has not been used universally and further investigation is required.
Cooling
Between transfer from donor and transplant to recipient, the allograft liver is stored in a cold-temperature preservation solution. The reduced temperature slows down the deterioration process of the normal metabolic process, and the storage solution itself is designed to counteract the undesirable effects of cold ischemia. Although this "static" cold storage method has long been the standard technique, various dynamic preservation methods are being investigated. For example, a system using a machine to pump blood through the liver extracted (after harvesting from the body) during the transfer has achieved some success ( see Research section for more ).
Live donor transplants
Live donor liver transplant (LDLT) has appeared in recent decades as a critical surgical option for patients with end-stage liver disease, such as cirrhosis and/or hepatocellular carcinoma often caused by one or more of the following: long-term alcohol abuse, untreated long-term hepatitis C infections, untreated long-term hepatitis B infection. The concept of LDLT is based on (1) the remarkable regenerative capacity of the human heart and (2) the widespread lack of cadaveric hearts for patients awaiting transplantation. In LDLT, a healthy heart piece is removed surgically from a living person and transplanted to the recipient, immediately after the recipient's liver has been completely removed.
Historically, LDLT began with terminal pediatric patients, whose parents were motivated to take the risk of donating some compatible healthy hearts to replace their failing children. The first successful LDLT report was Dr. Christoph Broelsch at the University of Chicago Medical Center in November 1989, when two-year-old Alyssa Smith received a portion of his mother's heart. The surgeons finally realized that adult-grown LDLT is also possible, and now this practice is common in some prominent medical institutions. This is considered to be more technically demanding than liver transplantation of standard cadaveric donors, and also raises ethical issues that underlie the indications of major surgical operations (hemihepatectomy or related procedures) in healthy humans. In various series of cases, the risk of complications in the donor is about 10%, and sometimes a second surgery is required. Common problems are biliary fistula, gastric stasis and infection; they are more common after the removal of the right lobe. Death after LDLT has been reported at 0% (Japan), 0.3% (US) and & lt; 1% (Europe), with the risk of further decline as surgeons gain more experience in this procedure. Since the law was amended to allow altruistic altruistic altruistic live organ donations in the UK in 2006, altruistic altruistic live donations took place in England in December 2012.
In adults, LDLT recipients, 55 to 70% of liver (right lobe) are excluded from healthy living donors. The donor liver will regenerate close to 100% function within 4-6 weeks, and almost reaches full volumetric size with normal structural recapitulation soon after. It is possible to remove up to 70% of the liver from a healthy living donor without harm in many cases. The transplanted part will achieve the full function and the appropriate size in the receiver as well, although it will take longer than for the donor.
Live donors are faced with risks and/or complications after surgery. Blood clots and bile problems have the possibility of arising in post-donor surgery, but these problems can be corrected easily. Although death is a risk that living donors should be willing to accept before the operation, the donor death rate living in the United States is low. The immune system of LDLT donors is not reduced as a result of liver regeneration, so certain foods that usually cause stomachaches can cause serious illness.
Donor requirements
Any family member, parent, sibling, child, spouse or volunteer can donate their hearts. Criteria for liver donation include:
- Be in good health
- Have a blood type that is suitable or compatible with the recipient, although some centers now perform inappropriate blood group transplants with special immunosuppression protocols
- Have a charity donation desire without financial motivation
- Aged between 18 and 55 years
- Size is almost the same as or greater than the recipient
- Before a person becomes a living donor, the donor must undergo testing to ensure that the individual is physically fit. Sometimes a CT scan or MRI is performed to illustrate the liver. In many cases, work is done in 2-3 weeks.
Complications
Live donor surgery is done in the main center. Very few people need blood transfusions during or after surgery. All potential donors should know there is a possibility of death of 0.5 to 1.0 percent. Other risks to donating the liver include bleeding, infections, painful incisions, the possibility of blood clots and prolonged recovery. Most donors enjoy complete and complete recovery within 2-3 months.
Pediatric transplant
In children, living liver donor transplants have become very acceptable. Accessibility of adult parents who wish to donate a piece of heart to their children/infants has reduced the number of children who should die to await a transplant. Having a parent as a donor has also made it much easier for children - because both patients are in the same hospital and can help improve their respective morale.
Benefits
There are several benefits of liver donor transplantation living on cadaver donor transplants, including:
- The transplant can be done electively because the donor is available
- There is less chance of complications and deaths than when waiting for cadaver organ donors
- Due to a shortage of donors, UNOS has placed limitations on cadaver organ allocation to foreigners seeking medical help in the US. With the availability of live donor transplants, this will allow foreigners to get a new opportunity to seek medical care in the US.
Playback for donors
Living donor transplantation is a multidisciplinary approach. All liver donors undergoing medical evaluation. Each transplant hospital has a special nurse who provides specific information about the procedure and answers questions the family may have. During the evaluation process, confidentiality is secured to potential donors. Every effort is made to ensure that organ donations are not made by force from other family members. The transplant team provides comprehensive counseling and support from donors and families that continue until full recovery is done.
All donors are medically assessed to ensure that they can undergo surgery. Blood and donor blood types should be compatible but not always identical. Other things assessed before surgery include a donor's liver anatomy. However, even with mild variations in blood vessels and bile ducts, surgeons are now able to transplant without problems. The most important criteria for living liver donors are in excellent health.
Post-transplant immunosuppression
Like most other allografts, liver transplants will be rejected by the recipient unless immunosuppressive drugs are used. Immunosuppressive regimens for all solid organ transplants are quite similar, and various agents are now available. Most liver transplant recipients receive corticosteroids plus calcineurin inhibitors such as tacrolimus or ciclosporin, (also spelled cyclosporine and cyclosporine) plus purine antagonists such as mycophenolate mofetil. Clinical outcomes were better with tacrolimus compared to ciclosporin during the first year of liver transplantation. If the patient has co-morbidity such as active hepatitis B, high doses of hepatitis B immunoglub are given to liver transplant patients.
Liver transplantation is unique because the risk of chronic rejection also decreases with time, although most recipients should take immunosuppressive drugs for the rest of their lives. It is possible to slowly release anti-rejection drugs but only in certain cases. It is theorized that the liver may play an unknown role in the maturation of certain cells related to the immune system. There is at least one study by Thomas E. Starzl's team at the University of Pittsburgh consisting of a bone marrow biopsy taken from a patient showing genotypic chimerism in the bone marrow of liver transplant recipients.
Recovery and results
The following prognosis of liver transplant varies, depending on overall health, technical success of surgery, and underlying disease processes that affect the liver. There is no precise model for predicting survival rates; those with transplants have a 58% chance of surviving 15 years. New liver failure occurs in 10% to 15% of all cases. This percentage is contributed by many complications. Early graft failure may be due to pre-existing diseases of donated organs. Others include technical deficiencies during operations such as revascularization that may lead to non-functioning graft.
History
Like many experimental models used in early surgical research, the first attempt at liver transplants was performed on dogs. The earliest published report on liver transplantation was conducted in 1955 by Vittorio Staudacher at Opedale Maggiore Policlinico in Milan, Italy. These early attempts varied significantly from contemporary techniques; for example, Staudacher reported "arteryization" of the donor portal vein through the receiving hepatic artery, and the use of cholecystostomy for biliary drainage.
The first human liver transplant effort was carried out in 1963 by Dr. Thomas Starzl, although pediatric patients died intraoperatively because of uncontrolled bleeding. Several subsequent attempts by various surgeons remained unsuccessful until 1967, when Starzl transplanted a 19-month-old girl with hepatocellular carcinoma that survived for more than 1 year before dying of metastatic disease. Despite the development of viable surgical techniques, liver transplants remain experimental through the 1970s, with a patient's one-year survival at around 25%. The introduction of ciclosporin by Sir Roy Calne, Professor of Cambridge Surgery, improved patient outcomes, and the 1980s saw the recognition of liver transplantation as a standard clinical treatment for adult and pediatric patients with appropriate indications. Liver transplants are now performed in more than a hundred centers in the US, as well as many centers in Europe and elsewhere.
The limited supply of liver allografts from donors does not live relative to the number of potential recipients spur the development of live donor liver transplants. The first live heart donors in the UK were conducted in December 2012 at St James University Hospital Leeds.
Society and culture
The famous liver transplant recipient
- ÃÆ' â € ° ric Abidal (born 1979), French footballer (Olympique Lyonnais, FC Barcelona), transplant in 2012
- Gregg Allman (1947-2017), American musician (The Allman Brothers Band), transplant in 2010 (survival: 7 years)
- George Best (1946-2005), Northern Ireland footballer (Manchester United), transplant
in 2002 (survival: 3 years) - David Bird (1959-2014), American journalist ( The Wall Street Journal ), transplant
in 2004 (survival: 10 years) - Jack Bruce (1943-2014), British musician (Cream), transplant
in 2003 (survival: 11 years) Robert P. Casey (1932-2000), American politician (42nd Pennsylvania Governor), transplant in 1993 (survival: 7 years) David Crosby (born 1941), American musician (The Byrds, Crosby Stills, Nash (& Young)), transplant in 1994 - Gerald Durrell (1925-1995), British zoo keeper (Durrell Wildlife Park), transplant in 1994 (survival <1ll>
- Shelley Fabares (born 1944), American actress (The Donna Reed Show, Coach) and singer ("Johnny Angel"), transplant in 2000
- Freddy Fender (1937-2006), American musician ("Before the Next Teardrop Falls," "Wasted Days and Wasted Nights"), transplant
in 2004 (survival: 2 years) li> "Superstar" Billy Graham (born 1943), American wrestler (WWF), transplant in 2002 - Larry Hagman (1931-2012), American actor (Dallas, Harry and Tonto, Nixon, Main Color), transplant
in 1995 (survival: 17 years) - Steve Jobs (1955-2011), American businessman (Apple Inc.), transplant
in 2009 (survival: 2 years) - Chris Klug (born 1972), American snowboarder, transplant
in 2000 - Evel Knievel (1938-2007), American acrobat, transplant
in 1999 (survival: 8 years) - Chris LeDoux (1948-2005), American musician and rodeo champion, transplant
in 2000 (survival: 5 years) - Phil Lesh (born 1940), American musician (Grateful Dead), transplant in 1998
- Linda Lovelace (1949-2002), American porn actress (Deep Throat), transplant in 1987 (survival: 15 years)
- Mickey Mantle (1931-1995), American baseball player (New York Yankees), transplant
in 1995 (survival: 1year) - Mike MacDonald (1954-2018), comedian and Canadian actor (Mr. Nice Guy), transplant
in 2013 (survival: 5 years) - Jim Nabors (1930-2017), American actor (The Andy Griffith Show), transplant in 1994 (survival: 23 years)
- John Phillips (1935-2001), American musician (The Mamas & the Papas), transplant in 1992 (survival: 9 years)
- Lou Reed (1942-2013), American musician (The Velvet Underground), transplant
in 2013 (survival: 1year) - U. Srinivas (1969-2014), Indian musician, transplant in 2014 (survival: 1year)
Direction of research
Cooling
There is an increasing interest in improving methods for the preservation of allograft after organ harvesting. Standard static "cold storage" techniques depend on temperature drop to slow down anaerobic metabolic damage. It is currently being investigated at cold temperatures (hypothermia), body temperature (normothermic), and below body temperature (subnormothermic). Hypothermic machine perfusion has been successfully used at Columbia University and at the University of Zurich. A 2014 study showed that liver preservation time could be significantly lengthened using supercooling techniques, which keep the liver at subzero temperatures (-6 Â ° C) Recently, the first randomized controlled clinical trial comparing machine preservation with conventional cold storage showed comparable results, with better early function, fewer discarded organs, and longer preservation times compared to cold stored hearts.
Custom population
Alcohol dependency
The high incidence of liver transplants given to those with alcoholic cirrhosis has led to recurring controversy about the patient's eligibility for liver transplantation. Controversy begins with the view of alcoholism as a self-inflicted disease and the perception that those who suffer from alcohol damage robs other patients who may be considered more appropriate. This is an important part of the selection process to differentiate transplant candidates who suffer from alcoholism compared to those who are vulnerable to non-dependent alcohol use. The latter who mastered the use of alcohol has a good prognosis after transplantation. Once the diagnosis of alcoholism has been established, however, it is necessary to assess the possibility of calm in the future.
HIV
Historically, HIV is considered an "absolute" contraindication to liver transplantation. This is partly due to concerns that the infection will be exacerbated by the necessary immunosuppressive drugs after transplantation.
Source of the article : Wikipedia
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