Which organs are transplantable and what are the donor sources and candidate criteria?

Transplantable Organs and Tissues

A cadaveric donor can provide kidneys (2), liver (1), heart (1), lungs (2), pancreas (1), and tissues including corneas, skin, bone, and heart valves. 1

Solid Organs Available for Transplantation

The following solid organs are routinely transplanted with established protocols and outcomes:

• Kidneys: The most commonly transplanted organ, with approximately 18,277 kidney transplants performed from cadaveric donors over a 5-year period, representing over 90% organ utilization 2
• Liver: Approximately 2,957 liver transplants performed from the same donor pool 2
• Heart: Approximately 3,425 heart transplants performed 2
• Lungs: Both single and double lung transplants are performed 2, 3
• Pancreas: Approximately 411 pancreatic grafts transplanted 2
• Small intestine: Available but performed in smaller numbers 2, 4

Multi-Organ Transplantation

Combined organ transplantation is increasingly performed for specific indications:

• Simultaneous liver-kidney transplantation: Indicated for polycystic liver-kidney disease 5, 3
• Combined heart-liver transplantation: Indicated for patients with congenital heart disease and cardiac cirrhosis, particularly after Fontan procedure 5
• Heart-lung transplantation: Performed in select cases 2

Tissues Available for Transplantation

Tissue donation is almost always possible, even when solid organs are not viable. 1

Available tissues include:

• Corneas: Routinely transplanted 6
• Skin: Used for burn victims and wound coverage 1
• Bone: Used for orthopedic and dental procedures 1
• Heart valves: Used for cardiac valve replacement 1
• Blood vessels: Including umbilical veins 6
• Dura mater: For neurosurgical procedures 6

Donor Sources

Brain Death Donors (Heart-Beating Donors)

Brain death donors have been the primary source of organs for 25-30 years and allow procurement of all solid organs. 1

• These donors are legally deceased after meeting standardized neurological criteria 7
• Allow optimal organ preservation with minimal warm ischemia time 6
• Specified solid organs covered include kidney, liver, heart, lung, and pancreas 6

Donation After Circulatory Death (DCD) - Non-Heart-Beating Donors

DCD donors can provide viable kidneys, livers, and lungs. 1

Specific organs suitable from DCD donors:

• Kidneys: May be slow to function initially, but 5-year graft survival equals heart-beating donor kidneys 6
• Liver: Early results are encouraging, though with higher discard rates 1
• Lungs: Growing evidence supports successful transplantation 6
• Tissues: Corneas and other tissues remain viable 6

Living Donors

While not extensively covered in the provided guidelines, living donation is an established source for:

• Kidney transplantation (most common)
• Liver transplantation (partial liver grafts)
• Lung transplantation (lobar transplants, rare)

Candidate Criteria Overview

General Requirements

All transplant candidates must meet specific criteria established by the United Network for Organ Sharing (UNOS):

• Organ failure: The fundamental indication for all transplants is end-stage organ failure 3
• Medical suitability: Each organ has unique criteria that must be met prior to transplantation 3
• ABO compatibility: Primary consideration to prevent hyperacute rejection 8

Absolute Contraindications

The following are universal contraindications across organ types:

• Active malignancy with high metastatic potential: Risk of tumor transmission to recipients 7
• Severe transmissible infections: Prevents donor-derived infection 7
• HIV infection: Donors must be screened for HIV-1, HIV-2 through behavioral screening, physical examination, and laboratory testing 6

Donor Screening Requirements

All donors must undergo comprehensive screening to prevent disease transmission. 6

Required screening includes:

• Behavioral screening: Assessment for HIV risk behaviors 6
• Physical examination: Signs and symptoms of HIV and other infections 6
• Laboratory testing: HIV-1, HIV-2, hepatitis B virus, hepatitis C virus 6

Organ-Specific Procurement Considerations

Heart Procurement

Visual inspection and palpation of the heart are the final steps in determining donor suitability, with palpable thrills over great vessels or obvious atherosclerotic lesions precluding transplantation. 8

Technical requirements:

• Dissect aorta and pulmonary artery superiorly to the level of the innominate artery and bifurcation 8
• Encircle and dissect superior vena cava to the level of the azygous vein 8
• Divide inferior vena cava at the diaphragm 8
• Divide pulmonary veins at pericardial reflections 8
• Store in iced saline solution with St. Thomas solution providing up to 5 hours of safe cold storage 8

Bone Marrow/Stem Cells

Approximately 2,200 bone marrow transplants involving allogeneic marrow occurred in the United States in 1991, with 435 from unrelated donors. 6

Sources include:

• Bone marrow from related and unrelated donors 6
• Peripheral blood stem cells for autologous and allogeneic transplantation 6
• Cord blood stem cells for related and unrelated donor transplantation 6

Critical Timing Considerations for DCD

For DCD donors, withdrawal of life support should occur in the operating room to minimize warm ischemia time. 7

Key timing requirements:

• Each additional hour of cold ischemia increases graft-failure risk by approximately 6% in DCD liver transplantation 7
• Mandatory standoff interval of 2-5 minutes after death declaration confirms irreversibility before organ recovery 7
• Anticipated prolonged warm ischemia time is an absolute contraindication 7

Common Pitfalls

• Inadequate warm ischemia management: The fundamental problem with DCD is warm ischemia, which may lead to suboptimal transplanted organ function 6
• Inadequate dissection of great vessels: Can lead to technical difficulties during heart implantation 8
• Injury to sinoatrial node: During superior vena cava division can cause post-transplant arrhythmias 8
• Failure to maintain hemodynamic stability: After brain death declaration, continuous monitoring of intraarterial pressure, central venous pressure, and urinary output is mandatory 8
• Inadequate donor management: Including failure to treat diabetes insipidus with vasopressin and maintain electrolyte balance 8