Organ Transplant (& Tissue): Types, Indications & Risks

An organ transplant is a surgery that aims to remove a healthy organ, cells or tissues from a living or dead donor for implantation in a person who has a serious disease. The most common transplants performed are of the heart, liver, lung, kidney, cornea and bone marrow.

Generally, this surgery is indicated when other medical treatments have not been successful. The procedure resores normal systemic functioning in the recipient's body, which reduces the risk of further complications and improving overall quality of life.

Recovery from an organ transplant varies depending on the type of surgery performed. Initially, recovery takes place in the hospital, but after discharge, the patient must undergo frequent medical follow-ups and exams. The patient must also take daily immunosuppressants on a lifelong basis.

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Indications for surgery

Transplant surgery is typically indicated for the following cases: 

  • Serious and irreversible disease, in which all other types of treatment were not effective in restoring health. The transplant is expected to reduce the risk of complications, improve quality of life or reduce the risk of death.
  • Malformations or lack of a uterus, in women who wish to become pregnant;
  • Restoring vision in people with irreversible damage to the cornea;
  • Cryopreservation of the ovaries to preserve fertility, in cases of women undergoing cancer treatment with chemotherapy, radiation therapy or surgery.

Bone marrow transplants can be indicated for patients with cancer, specifically leukemia, lymphoma or multiple myeloma, or in cases of aplastic anemia, sickle cell anemia or thalassemia.

How the transplant is done

The transplant surgery methods depend on the organ or tissue being substituted: 

1. Bone marrow transplant

A bone marrow transplant is one of the most common types of transplant surgeries. It is recommended by the onco-hematologist, mainly in cases of leukemia, lymphoma or multiple myeloma, which are cancers that affect blood cell production in the bone marrow.

This type of transplant can be done with cells from the person's own bone marrow, also known as an autologous transplant, or with cells from a compatible donor, also known as an allogeneic transplant.

2. Heart transplant

A heart transplant is performed with the objective or restoring heart function by replacing a diseased heart with a healthy one from a compatible deceased donor.

This surgery is recommended by a cardiologist when the patient's heart disease is at a severely advanced stage and is no longer responding to the normally recommended treatments. The patient is also at a greater risk of developing heart failure.

3. Liver transplant

A liver transplants aims to restore the function of a sick liver by replacing the entire liver from a deceased donor or part of the liver from a living donor. 

This surgery is recommended by the liver specialist in cases of liver cirrhosis or chronic, fulminant or autoimmune hepatitis.

4. Kidney transplant

A kidney transplant is the most common type of solid organ transplant to be performed, and is recommended by a nephrologist to treat cases of advanced chronic kidney disease. This condition causes the kidney to lose its ability to filter the blood and eliminate waste from the body. .

This type of transplant is indicated for patients with irreversible renal damage to the kidney. It can be performed with a kidney from a living or deceased donor.

5. Lung transplant

A lung transplant is recommended by a pulmonologist for the treatment of serious lung diseases that is in its advanced stages. It can be an option for the treatment of end-stage pulmonary fibrosis, chronic obstructive pulmonary disease (COPD), pulmonary hypertension or cystic fibrosis.

This type of transplant is done using a donated lung from a deceased person.

6. Uterine transplant

A uterine transplant may be recommended by a gynecologist for women of reproductive age, from 20 to 40 years old. It is often indicated women with no uterus or with a uterine malformations requiring uterine removal. 

This type of transplant can be performed for women who wish to become pregnant, and involves removing the uterus from a living or brain-dead donor.

7. Stool transplant

A stool or fecal transplant is a type of transplant in which feces are transferred from a healthy person to another person with bowel-related diseases.

The objective of this transplant is to restore normal gut bacteria levels, which promote healthy functioning of the intestines. 

8. Ovarian transplant

An ovarian transplant involves removing tissue from the person's own ovary before undergoing chemotherapy or radiation therapy, as these interventions can negatively affect fertility.

This ovarian tissue is frozen, or cryopreserved, and then transferred back to the woman once cancer treatment is over and when the woman is ready to restore fertility and try for pregnancy. 

9. Corneal transplant

A corneal transplant is performed by an ophthalmologist and involves replacement of a sick cornea with a healthy one from a deceased donor.

This type of transplant is performed when other treatment options have not been effective, particularly in cases of keratoconus, eye burns, ocular herpes or fungal keratitis.

10. Pancreatic transplant

A pancreatic transplant involves removing the pancreas of a deceased donor and transferring it to the recipient. Different from other transplant surgeries, the sick pancreas remains in place. 

This type of transplant is normally recommended by the endocrinologist to treat cases of type 1 diabetes in which blood glucose cannot be controlled with the use of insulin or when the person has other serious complications, such as kidney failure.

Organs and tissue that can be transplanted 

Organs and tissues that can be transplanted from a non-living donor include: 

  • Heart, valves, arteries and veins
  • Lungs
  • Cornea
  • Pancreas
  • Liver
  • Intestines
  • Uterus
  • Bones, muscles or skin 

A living donor is able to donate parts of the liver, lungs or bone marrow, as well as one kidney or a uterus. 

Types of transplants

The main types of transplants are categorized as:

1. Autologous transplants

An autologous transplant is a type of transplant in which the person's own tissues are transferred from one area of the body to another.

2. Allogenic transplants

An allogeneic transplant consists of transferring tissues from a healthy person to the recipient, as long as the donor and recipient are genetically similar.

3. Syngeneic transplants

Similar to allogenic transplants, the syngeneic transplant is performed using the tissue from one person to the other, but specifically from an identical brother or sister.

4. Heterologous transplants

This type of transplant consists of the transfer of an organ, tissue or cells from a donor that is completely different from the recipient. 

5. Xenotransplantation

Xenotransplantation or xenogenic transplantation is a rarer type of transplant, in which the organ or tissues come from an animal and are transplanted into a human.

How to determine compatibility 

Before the transplant is performed, blood tests are carried out on both the donor and recipients to verify compatibility of the organ, tissue or cells to reduce the chances of rejection.

As long as they are compatible, the donor and recipient do not have to be related.

Transplant wait lists

To receive an organ, the doctor must first register the patient with the country's national transplant waiting list.

The waiting list goes both by order of registration and takes other factors into consideration, such as the location of the donor and recipient. 

Wait list factors

Factors that determine when a person on the list can receive their organ include: 

  • Date of registration
  • Health status and severity of the disease
  • Compatibility 
  • Location of the donor and the recipient 

Furthermore, the transplant wait list can also be affected by age, with children generally having priority, in addition to adults with diseases in advanced stages.

How soon should organs be transplanted

The organ should be transplanted as quickly as possible. There is a deadline referred to as the ischemia time, which is the time between the removal of the organ from the donor and the implantation of the organ in the recipient.

This time to perform the transplant varies according to the organ, with the heart taking 4 hours, the kidney taking 48 hours, the lung taking 6 hours, and the liver and pancreas taking 12 hours.

Transplant recovery

Recovery from transplant surgery depends on the type of transplant performed. 

In general, the initial recovery takes place in the hospital for a few weeks so that the patient can be closely monitored for any reactions or rejections. This helps to prevent any complications that may occur

Following discharge, recovery continues at home, with regular medical monitoring and the use of daily immunosuppressants taken to prevent organ rejection.

Risks of transplant surgery

Some complications that can emerge following transplant surgery include: 

  • Organ rejection
  • Infections
  • Kidney problems
  • Bleeding or hemorrhages
  • Gout
  • Atherosclerosis

The use of immunosuppressants are also associated with side effects, such as osteoporosis, weight gain, diabetes, swelling, skin changes or even an increased risk for skin cancer or lymphoma.

Although they are rare, general anesthesia from surgery can trigger complications like anaphylactic shock, nausea, vomiting, drop in blood pressure, chills, tremors, fever or infection.