Editing Organ transplantation (section)

== Types of donor ==
Organ donors may be living or may have died of [[brain death]] or circulatory death. Most deceased donors are those who have been pronounced brain dead. Brain dead means the cessation of brain function, typically after receiving an injury (either traumatic or pathological) to the brain, or otherwise cutting off blood circulation to the brain ([[drowning]], [[suffocation]], etc.). Breathing is maintained via [[Life Support|artificial sources]], which, in turn, maintains heartbeat. Once brain death has been declared, the person can be considered for organ donation. Criteria for brain death vary. Because less than 3% of all deaths in the US are the result of brain death, the overwhelming majority of deaths are ineligible for organ donation, resulting in severe shortages. It is important to note currently that patients that have been pronounced brain dead are one of the most common and ideal donors, since often these donors are young and healthy, thus leading to high quality organs.<ref>{{cite journal |last1=Ackerman |first1=Adam |last2=Clark |first2=David |last3=Lipinska |first3=Judyta |last4=Chung |first4=Bruce |last5=Whiting |first5=James |title=Organ donation after trauma: A 30-year review |journal=Journal of Trauma and Acute Care Surgery |date=July 2019 |volume=87 |issue=1 |pages=130–133 |doi=10.1097/TA.0000000000002322 |pmid=31033896 |s2cid=139101919 }}</ref>

Organ donation is possible after cardiac death in some situations, primarily when the person is severely brain-injured and not expected to survive without artificial breathing and mechanical support.  Independent of any decision to donate, a person's next-of-kin may decide to end artificial support. If the person is expected to expire within a short period of time after support is withdrawn, arrangements can be made to withdraw that support in an operating room to allow quick recovery of the organs after circulatory death has occurred.{{cn|date=March 2025}}

Tissues 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." Also, more than 60 grafts may be obtained from a single tissue donor. Because of these three factors{{snd}}the ability to recover from a non-heart-beating donor, the ability to bank tissue, and the number of grafts available from each donor{{snd}}tissue transplants are much more common than organ transplants. The [[American Association of Tissue Banks]] estimates that more than one million tissue transplants take place in the United States each year.{{cn|date=March 2025}}

=== 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). Regenerative medicine may one day allow for laboratory-grown organs, using person's own cells via stem cells, or healthy cells extracted from the failing organs.{{citation needed|date=September 2024}}

=== Deceased donor ===
Deceased donors (formerly cadaveric) are people who have been declared brain-dead and whose organs are kept viable by [[Medical ventilator|ventilators]] or other mechanical mechanisms until they can be excised for transplantation. Apart from brainstem-dead donors, who have formed the majority of deceased donors for the last 20 years, there is increasing use of after-circulatory-death donors (formerly non-heart-beating donors) to increase the potential pool of donors as demand for transplants continues to grow.<ref>{{Cite journal|last1=Ledinh|first1=H.|last2=Bonvoisin|first2=C.|last3=Weekers|first3=L.|last4=de Roover|first4=A.|last5=Honoré|first5=P.|last6=Squifflet|first6=J.P.|last7=Meurisse|first7=M.|last8=Detry|first8=O.|date=September 2010|title=Results of Kidney Transplantation From Donors After Cardiac Death|journal=Transplantation Proceedings|volume=42|issue=7|pages=2407–14|doi=10.1016/j.transproceed.2010.07.055|pmid=20832517}}</ref> Prior to the legal recognition of brain death in the 1980s, all deceased organ donors had died of circulatory death.  These organs have inferior outcomes to organs from a brain-dead donor.<ref name="deceaseddonoroutcome">{{Cite journal | last1 = Merion | first1 = R. M. | last2 = Pelletier | first2 = S. J. | last3 = Goodrich | first3 = N. | last4 = Englesbe | first4 = M. J. | last5 = Delmonico | first5 = F. L. | title = Donation After Cardiac Death as a Strategy to Increase Deceased Donor Liver Availability | doi = 10.1097/01.sla.0000239006.33633.39 | journal = Transactions of the ... Meeting of the American Surgical Association | volume = 124 | issue = 4 | pages = 220–27 | year = 2006 | pmid =  16998364| pmc = 1856553}} {{link note|note=subscription required for full access}}</ref> For instance, patients who underwent liver transplantation using donation-after-circulatory-death allografts have been shown to have significantly lower graft survival than those from donation-after-brain-death allografts due to biliary complications and [[Liver transplantation#Recovery and outcomes|primary nonfunction in liver transplantation]].<ref>{{cite journal |author1=Vera, M.E|author2=Lopez-Solis, R.|author3=Dvorchik, I.|author4=Morris, W. | year = 2009 | title = Liver Transplantation Using Donation After Cardiac Death Donors: Long-Term Follow-Up from a Single Center | journal = American Journal of Transplantation | volume = 9 | issue = 4| pages = 773–881 | doi=10.1111/j.1600-6143.2009.02560.x| pmid = 19344466 | s2cid = 7891692 | doi-access = free }}</ref> However, given the scarcity of suitable organs and the number of people who die waiting, any potentially suitable organ must be considered.  Jurisdictions with medically [[assisted suicide]] may co-ordinate organ donations from that source.<ref>{{cite news |last1=Ogilvie |first1=Megan |title=An Ontario man chose a medically assisted death at home. In a world first, he was able to donate his lungs |url=https://www.thestar.com/news/gta/2021/03/07/an-ontario-man-chose-a-medically-assisted-death-at-home-in-a-world-first-he-was-able-to-donate-his-lungs.html |access-date=11 March 2021 |work=[[Toronto Star]] |date=7 March 2021}}</ref>