Types of transplants

Transplantation is the transfer of an organ or tissue from one person to another or from one body part to another. Concentrated efforts continue in search of compensation for or suitable replacements for deficient tissues and organs. The indication for organ transplantation is irreversible functional failure of the organ. The goals of transplantation include changing appearance, restoring function, or improving quality of life. (More information is available at www.unos.org and www.organdonor.gov.)

Certain tissues and whole organs can be transplanted and grafted to restore bodily function. The type of transplant selected depends on the purpose of the graft, anatomic function, and availability of the tissue or organ. The types of biologic transplants are listed in Box 45-1.

Tissue transplantation

Some tissues can function normally even after being moved from one area of the patient’s body to another (autologous) or after being obtained from another human donor (allogenous):

Tissue transplants can be either autografts or allografts. Xenograft (from another species) transplants are in the research phases. The American Association of Tissue Banks sets standards for retrieving, processing, storing, and labeling tissues and for donor criteria for allografts (Box 45-2). Tissue for transplantation is procured from suitable cadaver (nonliving or brain dead) donors, either heartbeating or nonheartbeating, or from a living donor. Table 45-1 details the procurement parameters for tissue allografts. (Additional information is available from the National Institute of Transplantation at www.transplantation.com or the United Network for Organ Sharing at www.unos.org.)

Potential donors are screened to avoid the transmission of infection or disease. Cultures are taken at the time of procurement for microbiologic and serologic testing.⁸ Tissue is not transplanted until negative test results are obtained; tissue is discarded if the test result is positive. Living bone donors are tested for HIV immediately after donation and again after 90 days because seroconversion can be delayed. Recipients also should be tested and should be negative for HIV and hepatitis B virus (HBV). A baseline is essential to establish that the patient was not infected by the act of grafting. Patients with HIV or HBV are not barred from receiving an allograft, but baseline data can help rule out causes for rejection or infection. Incidences of graft failure and superinfection are high in patients who are immunocompromised with HIV.

Banked tissues are labeled with the donor’s name and identification number, pertinent medical history, the pathology report of the donor, final culture and serology reports of donors, type and site of donation, date and time of procurement, and method of procurement and preservation.

Organ transplantation

Organ transplantation can be a lifesaving treatment for some end-stage diseases. Although tissue grafts are commonplace, transplantation of functional, whole, vital organs presents physiologic, philosophic, and ethical dilemmas. A biologically related donor (referred to as a living related donor) makes a supreme sacrifice to become an organ donor; therefore, cadavers are the primary source of organs for transplant.⁷ Organ donation is the ultimate gift of life and is given by the donor to the recipient. Transplantation can restore the recipient to near-normal physiologic status.

Ethical concerns cross religious and cultural boundaries.^6,9 Table 45-2 gives examples of religious and cultural groups and their positions about organ donation and transplantation.^6,9 Some traditionalist beliefs do not support donation because the body of the dead should not be altered in any way. Modernist beliefs have transcended many old ways by pointing out that the body is not needed for passage into the afterlife.^6,9 Information about religious and cultural views about donation can be found at www.organdonor.gov and www.lifebanc.org.

Kidney transplantation was initially the most successful and principal clinical application of organ transplantation. If a kidney graft fails, the patient may survive by returning to hemodialysis indefinitely before receiving another transplant.⁵ This option does not exist for transplants of the heart, liver, pancreas, or lungs. No practical prolonged artificial support exists for these organs in the event of an allograft failure.

Transplantation of each organ involves unique technical and physiologic problems, but the major barriers and causes of transplant failure are immunologic rejection and infection.⁸ Immunodeficiency depends on the amount of immunosuppression the patient receives to prevent rejection. Immunosuppressive agents leave the patient prone to opportunistic infection. Reverse protective isolation may be advisable if the patient has development of leukopenia, a decrease in white blood cells. In other aspects of care, transplant recipients are similar to other critical surgical patients with severe chronic illnesses who need measures that minimize the risk of infection.

The American Society of Transplant Surgeons (www .asts.org) and the International Society of Transplantation meet regularly to exchange ideas and information among people of different scientific backgrounds. The aim is to achieve the best possible patient survival rather than merely transplant survival.

The Organ Transplant Registry of the American College of Surgeons, in conjunction with the National Institutes of Health, collects data on transplantation procedures and approves and funds various registries. The Federal Organ Transplantation and Procurement Act of 1983 provided financial grants for the initial development of regional organ procurement centers and a transplant registry.

A national task force has also been established to analyze medical, legal, ethical, economic, and social issues of concern in organ procurement and transplantation.²

Organ banks collect organs and tissues from donors, exchange organs geographically, and register patients in need of a transplant. The register includes information about the patient’s blood grouping and tissue typing. Computer lists of patients waiting for donor organs are maintained by the United Network for Organ Sharing (UNOS) and the North American Transplant Coordinator Organization 24-Hour Alert. Regional organ procurement organizations coordinate with these registries to match donated organs with compatible recipients nationwide. The position of the recipient on the waiting list is determined by the severity of the illness.

Other countries have similar mechanisms. For example, the United Kingdom Transplant Register has membership in the Euro Transplant Register. Organs procured within the United Kingdom can be transported by air to another country in Europe, and vice versa, for a histocompatible recipient. The number of patients awaiting transplants exceeds the supply of available donor organs. As a result, many patients die while waiting for a suitable organ to become available.⁷

Many people carry a signed Uniform Donor Card or other identification (e.g., the reverse side of a driver’s license) that states that certain or all organs and tissues may be removed for transplantation in the event of death. Such cards, or a living will, constitute legal written consent under the Uniform Anatomical Gift Act enacted by all 50 states. Written or telephone consent is still obtained from the family of a potential donor before procurement may commence.⁷

Time is paramount when critical organs are involved because their value depends on preservation of maximum functional viability. The time factor is less urgent with less critical tissue. When a potential donor has been identified, a transplantation coordinator contacts the regional registry and procurement team.

Organ procurement

Immunologic rejection and the shortage of donor organs remain the principal deterrents to transplantation. The goal is selection of a donor-recipient match with adequate histocompatibility to permit an organ to function without complications. Organs and tissues come from two primary sources: cadaver (heartbeating and nonheartbeating) and living related donors (Table 45-3).

TABLE 45-3

Organ Procurement Parameters

Age of Donor	Physiologic Status of Donor	Time Between Procurement and Transplantation	Other Considerations
HEART
Female: 0-40 years	Heartbeating cadaver donor	3-6 hours, fresh tissue	Heartbeating cadaver donor: total heart and segments of great vessels
Male: 0-35 years	Nonheartbeating cadaver donor	Cryopreserved valves can be used within 1-2 years	Nonheartbeating cadaver donor: heart valves only Size match is important Donor criteria include no cardiac disease and normal cardiac enzymes Only gold members can continue reading. Log In or Register to continue Share this: Click to share on Twitter (Opens in new window) Click to share on Facebook (Opens in new window) Like this: Like Loading... Related Related posts: Physiologic maintenance and monitoring of the perioperative patient Ambulatory surgery centers and alternative surgical locations Thoracic surgery Urologic surgery Stay updated, free articles. Join our Telegram channel Join Tags: Berry _ Kohns Operating Room Technique Apr 6, 2017 | Posted by admin in GENERAL SURGERY | Comments Off on Organ procurement and transplantation Full access? Get Clinical Tree Get Clinical Tree app for offline access Get Clinical Tree app for offline access %d