ORGAN TRANSPLANTATION

ORGAN TRANSPLANTATION 

Organ transplantation is a medical procedure in which an organ is removed from one body and placed in the body of a recipient, to replace a damaged or missing organ. The donor and recipient may be at the same location, or organs may be transported from a donor site to another location. 

Organs that are successfully transplanted include the heart, kidneys, liver, lungs, pancreas, intestine, thymus and uterus. Tissues include bones, tendons, cornea, skin, heart valves, nerves and veins. Worldwide, the kidneys are the foremost commonly transplanted organs, followed by the liver and then the heart. Cornea and musculoskeletal grafts are the foremost commonly transplanted tissues; these outnumber organ transplants by more than tenfold.

Types of transplant

 The various types of transplants includes the following

    1. Autotransplant 

    2. Allotransplant 

    3. Isotransplant

    4. Xenotransplant

Autotransplant- 

Autotransplantation is the transplantation of organs, tissues, or even particular proteins from one part of the body to another in the same person. The autologous tissue transplanted by such a procedure is called an autograft or autotransplant 

Allotransplant-

Allotransplant is the transplantation of cells, tissues, or organs to a recipient from a genetically non-identical donor of the same species. The transplant is called an allograft, allogeneic transplant, or homograft. Most human tissue and organ transplants are allografts. 

Isotransplant- 

Isotransplant is the transplantation of organs or tissues are transplanted from a donor to a genetically identical recipient (such as an identical twin). Isografts are differentiated from other types of transplants because while they are anatomically identical to allografts, they do not trigger an immune response. 

Xenograft- 

Xenotransplant or heterologous transplant is the transplantation of living cells, tissues or organs from one species to another. Such cells, tissues or organs are called xenografts or xenotransplants.

 Types of Donors

 Organ donors may be living or may have died of brain death or circulatory death. Tissue may be recovered from donors who die of either brain or circulatory death. In general, tissues may be recovered from donors up to 24 hours past the cessation of heartbeat. In contrast to organs, most tissues (with the exception of corneas) can be preserved and stored for up to five years, meaning they can be "banked."

 

Organ donors can be of two types 

     1. Living Donor 

     2. Deceased Donor 

Living donor- 

 In living donors, the donor remains alive and donates a renewable tissue, cell, or fluid (e.g., blood, skin), or donates an organ or part of an organ in which the remaining organ can regenerate or take on the workload of the rest of the organ (primarily single kidney donation, partial donation of liver, lung lobe, small bowel). 

Deceased donor-

 Deceased donors are people who have been declared brain-dead and whose organs are kept viable by ventilators or other mechanical mechanisms until they can be excised for transplantation