Organ transplant
introduction
In an organ transplant, a diseased organ from a patient is replaced by the same organ from a donor. This organ donor has usually died recently and has consented to the removal of his organs if his death is clearly proven.
Living people can also be considered as donors if there is a special relationship such as relatives or partnerships. However, only one pair organ (such as a kidney) or one organ segment (such as a piece of liver) may be donated. Of course, there is also a risk for the donor.
An organ transplant is usually preceded by a lengthy process. First of all, it must be established that the patient and the organ have no prospect of complete healing irreversible is damaged. Then the patient goes on for a long time Transplant list on which all future recipients of a new organ are listed. It is not uncommon for the waiting time to be too long and for the patient to die before the operation.
If the fortunate circumstance occurs that a suitable organ is found for a patient, the following processes must be carried out quickly. The organ must get out of the organ donor as quickly as possible removed and cooled stored and transported to the recipient. This is what arrives at this broken organ removed and in the same engagement that new organ inserted.
So that all processes can run as quickly as possible, all people who are ready to be an organ donor after their death should unite Organ donation card carry with you. Many potentially life-saving organs cannot be removed due to legal uncertainties.
Organ Transplant Risks
The risks of organ transplantation can be many and mainly focus on the one that is undertaken surgery. Large vessels must be interrupted when an organ is replaced. If these vessels are damaged, the patient can lose large amounts of blood within a very short period of time, and possibly some of the blood Blood loss die. Otherwise, all general risks apply that can occur in operations, especially of a larger nature, for example Complications from anesthesia. Especially with heart or lung transplants, the human body is connected to a Life-support-machine stressed.
The transplanted organ can also cause difficulties. If it is not transplanted quickly enough or if it is not connected to the blood supply efficiently enough, it may not be possible to achieve full function. It can also become a renewed organ failure come. This can be done through a Rejection reaction in which the immune system of the organ recipient turns against the foreign organ. In order to suppress this defense reaction the patient will be asked Immunosuppressants administered. These are drugs that suppress the immune system, but also side effects such as Nausea and vomiting, lighter ones Susceptibility to infection or dizziness can have.
rejection
This applies to organ rejection after an organ transplant Immune system of the recipient against the transplanted organ. The defense cells recognize that the organ is foreign cells that are then fought. The mechanism is similar to that of infection with bacteria or viruses. The body forms so-called antibodythat cooperate with Inflammatory cells direct against the exogenous tissue and try to damage it and finally break it down.
The repulsion can vary in intensity and course, which is why different forms of reaction were defined.
At a hyperacute rejection it is an immediate reaction. The corresponding antibodies are already available, for example at Blood group incompatibility and react immediately with the graft. It happens en masse Clotting reactionsthat can be life threatening and one immediate removal of the donor organ require.
A acute rejection is also supported by the immune system mediated, but only occurs in the course. After several days, but also after months or years, experts believe that certain immune cells (T lymphocytes) turn against the protein structures in the foreign tissue. This reaction can be prevented by administering drugs that suppress the immune system - immunosuppressants. Hence it is an acute rejection not necessarily associated with the removal of the donor organ, but with repeated occurrence leads to damage to the cells and ultimately to organ failure.
In contrast to the acute, rapid reactions, one also occurs in some patients chronic rejection on. This happens over years and is caused by damage to the supplying blood vessels in the donor organ. Inflammation with subsequent scarring causes the vascular system to narrow, which leads to poor blood flow to the tissue. The organ gradually loses its function until it fails completely and has to be replaced.
Bone marrow donation
Bone marrow donation plays an important role in the therapy of malignant tumor diseases that affect the blood-forming system. Examples of such diseases are: acute leukemia, chronic myeloid leukemia (CML), Hodgkin lymphoma or non-Hodgkin lymphoma, but also aplastic anemia and thalassemia, which are not tumor diseases.
The bone marrow contains stem cells that are important for blood formation. However, the process of obtaining stem cells is becoming increasingly donor-friendly. It is becoming increasingly rare that a bone is actually punctured in order to obtain stem cells, but so-called stem cell apheresis is used instead. This involves administering a substance to the donor that stimulates blood formation and increases the content of stem cells in the circulating blood so that they can be filtered out. The bone marrow or stem cells can come from the patient himself or from another donor, which must, however, be compatible.
The patient is intensively prepared to receive the bone marrow or stem cell donation. A highly effective radio-chemo therapy destroys all blood-forming cells in the patient, which often causes the cancer to die as well. Then the donor material is added to the blood and the blood-forming system can normalize.
The suppression of the immune system can lead to infections that people with functioning immune cells would not get. Organ damage and dangerous vein occlusions can also occur.
After a successful and uncomplicated stem cell transplant, there is a possibility that cancer will develop again. After the transplant, the burden on the patient must be kept as low as possible, which is why a medicinal immunosuppression must be carried out here as well. In this way, cancer can be completely healed for life.
Read more on the topic: Bone marrow donation and stem cell donation
Kidney transplant
Kidney transplantation usually involves the Donor kidney in the patient's pelvic cavity transplanted without removing the impaired kidneys. This makes the procedure a little less complicated and prevents complications at least at this point. The organ is connected to the vascular system of the leg and the bladder.
In many cases, the donor is still alive and has a family or marital relationship with the patient. Since a person can get by with one kidney, this type of organ transplant can have one Living donation be considered. The aim of this therapy option is to mostly dialysis patients To deliver patients from permanent renal replacement therapy, which can significantly improve quality of life. The patients notice an improvement in performance, the death rate falls and the metabolic situation improves. Also the costs of treatment are seen in a long-term Kidney transplant cheaper than with years of dialysis therapy.
Before a kidney transplant, the compatibility of the donor organ checked become. In addition, the patient is allowed to no severe heart condition, a difficult one Cancer or one current infection to have. With a successful organ transplant and uncomplicated follow-up care, a kidney transplant works the longest of all transplanted organs.
Liver transplant
Every year around 1000 patients in Germany are given new liver parts. The donor organs originate mostly from the deceasedone liver can be shared between two needy patients. A Living donation is to some extent also possible. In this way, parents can donate parts of their liver for their sick children without suffering great damage or disadvantages - the liver can regenerate itself well.
The multitude of diseases that disturb or destroy the liver in its function and structure makes liver transplants an important therapeutic approach for various diseases. The diseases can be of different nature, although only a few are mentioned here: Liver parenchyma diseases in which the liver tissue is caused by a virushepatitis or through alcohol abuse is permanently damaged; Diseases of the biliary tract, for example chronic inflammation or increasing blockage of the bile ducts; Metabolic diseases like Wilson disease, Galactosemia, or glycogen storage disease; Vascular diseases in the liver, caused by viruses, drug use or pregnancy, among other things HELLP syndrome can arise; Liver cancers and liver injuries.
An organ transplant of the liver is allowed not done if the patient is under a Portal vein thrombosis suffers. The portal vein is the main vessel of the liver and can endanger the health of the donor organ if it is blocked by thrombus. The psychological background of the patient must also be analyzed before an operation. Is there a Liver transplantation must not be performed if you are addicted to alcohol or drugsotherwise the organ would be stressed too much.
Successful liver transplantation with long-term patient survival is highly dependent on the compatibility of all cellular factors. Strong immunosuppression can increase the likelihood that there will be no rejection and that full function will be maintained. Complications can result from bleeding or incomplete connection of the bile duct system.
Heart transplant
Since the heart outside the human circulation has the shortest shelf life of all organs suitable for transplantation, the assignment of a donor organ and the organ transplant itself must be initiated as quickly as possible. The only reason for a heart transplant usually represents a severe heart failure represent.
The indication, the urgency of a transplant, is calculated individually for each patient in advance. In this context a Rating System which relates to the functioning of the heart. For example, the Heart rate, the Stroke volume and the average Blood pressure. Who gets a potential donor heart depends on various factors. It takes into account how urgently the patient needs a new heart and how long the patient has been waiting for a new organ. In addition, the time between the removal and the transplantation, i.e. the delivery and operation time, must be taken into account (maximum 3 to 4 hours). The size of the heart depends on the body weight or structure of the organ donor, which is why the difference between donor and recipient not more than 20% may be. The organ must also be largely compatible at the cellular level.
During the operation the patient has to go to a Life-support-machine connected before the heart can be removed. The patient's body is cooled down to 26-28 ° C (Hypothermia) to minimize cell decay. The new organ is connected to the patient's blood vessels and then the heart is set in motion again. Through the Follow-up treatment with strong immunosuppressants can a Rejection reaction possibly prevented, which is most likely in the first four weeks.
Patients with a new heart are most likely to die from one Infection with bacteria or fungi, following the operation. The immune system is too weak due to the suppression to fight off pathogens. About the half of all heart transplant patients within the first 5 years after surgery Vascular disease on the heart, called transplant vasculopathy.With this it can be a clinically normal one Heart attack come.
Lung transplant
For a lung transplant, only one or more lung lobes, an entire lung, or both lobes can be used. Depending on the previous illness, a choice is made between the various options. The following diseases most often make a lung transplant necessary in the end-stage: therapy-resistant Sarcoid, COPD (Chronic obstructive pulmonary disease), Pulmonary hyperinflation (Emphysema), Lung parenchyma disease (Fibrosis), Cystic fibrosis, chronic inflammation or dilation of the bronchi, and large lung lesions.
In the surgery becomes the rib cage opened from the front and in the case of bilateral transplantation, one lung at a time is replaced. This is usually not using a heart-lung machine necessary, which reduces the surgical effort. However, if there are circulatory disorders during the operation or if the oxygen saturation falls into a critical range, it may still be necessary to use it.
Other Complications may bleeding or Rejection reactions be in hindsight. For example, if the patient has a Heart failure, one Blood poisoning (sepsis), Liver or kidney failure, cancer or a Addiction disorder (Alcohol, drugs, medication) the organ transplant may not be carried out. Lung transplantation is only done in large clinics (mainly university clinics). Therefore, the planning of the mostly very spontaneous operation should be based on this.
Corneal transplant
The corneal transplant is that most commonly performed transplant. In Germany alone, around 5000 such operations are carried out every year. This number would be even higher if more people made themselves available as donors after their death - the need is far above the supply.
The transplant can either be carried out as a whole or only for individual layers. First of all, the receiver in a ophthalmological surgery removes the cornea in order to be able to insert the donation material. This is called if all corneal layers are transferred perforating keratoplasty. When transferring individual layers, one speaks of lamellar keratoplasty.
As an alternative to a donation, a Corneal preparation are made from the body's own stem cells. A rejection of the transplant is impossible because it is the body's own cells.
An organ transplant of the cornea may be necessary due to the following diseases: corneal malformation, keratoconus, scarring of the cornea, injuries to the eye with involvement of the cornea or infections that affect the eyes and attack the cornea.
Organ donation process
If an organ donor dies, his personal data will be sent to the German Foundation for Organ Transplantation (DSO), which in turn is called the highest authority Eurotransplant contacted. Eurotransplant is a medical center that coordinates the award of organ transplants across Europe.
Once a suitable organ has been found for a patient on the transplant list, everything has to happen quickly. After the death of the donor, the tissue becomes more and more damaged over time and must therefore be rinsed with a tissue-preserving solution, stored in a cool place and used quickly for a successful transplantation.
The different organs are there can be kept for different lengths of time outside the functioning physical circulation. The heart has the lowest shelf life at only 4 hours. In the larger organs, the Kidneys can be transplanted with the greatest possible interval - within 36 hours. Cornea is not subject to as strong blood flow as the other organs, is therefore more robust and can be stored refrigerated for up to 72 hours.
All sorts of things Organ recipient must therefore contactable at any time so that an immediate admission to a corresponding hospital can take place. Within 2 to 3 hours the organ recipient must be able to contact the responsible Transplant center to introduce.
At a Living donation is the operation easier to plan and can be done without the time pressure. A large number of discussions and examinations should encourage both sides to reconsider the procedure and ensure the compatibility of the transferred tissue. Of the Donor must be final Explain the decision to a commissionwho can then decide for or against the intervention. It must be ensured that the donor acts of his own free will.
The organ recipient must also be prepared for the operation. This preparation includes both an early and extensive investigation as well as influencing the Immune system of the patient. On the one hand, the examinations serve to determine risk factors such as inflammation and certain high-risk pre-existing diseases. Besides the Laboratory diagnostics of blood and urine becomes one EKG written, a X-ray image made by the lungs, the belly by Ultrasonic examined and one Colonoscopy carried out. In addition, the blood type of the patient is determined and the tissue is typed to avoid the risk of a Rejection reaction is minimized. Another aspect of preparing the patient for the organ transplant is what is called Immunosuppression. The immune system is largely suppressed in order to keep the body's reaction to the foreign organ as low as possible.
The operation itself is carried out with different effort depending on the organ. Organs that are part of the circulatory system - heart and lungs - have to go through a Life-support-machine be replaced in their function. This is a very large procedure, which results in a long hospital stay and extensive rehabilitation measures. The function of the transplanted organ must be constantly checked in the period after the operation, on the one hand to ensure the patient's health and on the other hand to check whether the organ is accepted by the recipient organism.
