CCTC Organ Procurement and Preservation 2 — Questions and Answers
Question 1: Which component of University of Wisconsin (UW) solution primarily prevents cellular swelling during cold storage?
- Glucose
- Lactobionate (Correct answer)
- Albumin
- Heparin
Correct answer: Lactobionate
Lactobionate is an impermeant anion in UW solution that maintains osmotic balance outside the cell, preventing cellular swelling during hypothermic storage.
Question 2: What is the primary mechanism of organ injury during reperfusion following cold ischemia?
- Hyperacute rejection mediated by preformed antibodies
- Generation of reactive oxygen species causing oxidative damage (Correct answer)
- Activation of the adaptive immune response
- Bacterial infection from contaminated preservation solution
Correct answer: Generation of reactive oxygen species causing oxidative damage
Ischemia-reperfusion injury occurs when reintroduction of oxygen leads to a burst of reactive oxygen species that damage cellular membranes and trigger an inflammatory cascade.
Question 3: Machine perfusion of kidneys offers which primary advantage over static cold storage?
- Eliminates the need for HLA matching
- Reduces post-transplant immunosuppression requirements
- Allows continuous viability assessment and active removal of ischemic byproducts (Correct answer)
- Decreases the risk of surgical complications at implantation
Correct answer: Allows continuous viability assessment and active removal of ischemic byproducts
Machine perfusion maintains metabolic activity, continuously flushes harmful metabolic byproducts, and enables real-time assessment of renal resistance and perfusate biomarkers.
Question 4: What is the generally accepted maximum cold ischemia time for a cardiac transplant?
- 4–6 hours (Correct answer)
- 8–12 hours
- 18–24 hours
- 24–36 hours
Correct answer: 4–6 hours
Heart transplants require cold ischemia times under 4–6 hours because the heart is exceptionally sensitive to prolonged ischemic injury.
Question 5: Compared to DBD (donation after brain death) organs, DCD organs have a higher risk of which complication?
- Hyperacute rejection
- Delayed graft function (Correct answer)
- Chronic allograft nephropathy
- CMV infection
Correct answer: Delayed graft function
DCD kidneys experience warm ischemia during the withdrawal of life support and cardiac arrest period, leading to tubular injury and increased rates of delayed graft function.
Question 6: Which term describes the period when a DCD organ is at body temperature without adequate blood flow before cold flush?
- Cold ischemia
- Primary warm ischemia (Correct answer)
- Secondary ischemia
- Normothermic perfusion
Correct answer: Primary warm ischemia
Primary warm ischemia in DCD refers to the time from circulatory arrest to organ cold perfusion, during which the organ is at body temperature without sufficient blood flow.
Question 7: What is the typical maximum cold ischemia time for a liver transplant to achieve acceptable outcomes?
- 4–6 hours
- 12–24 hours (Correct answer)
- 30–36 hours
- 48–60 hours
Correct answer: 12–24 hours
Liver transplants are generally performed within 12–24 hours of procurement, with outcomes worsening significantly when cold ischemia exceeds 12–15 hours.
CCTC Organ Procurement and Preservation 2
Which component of University of Wisconsin (UW) solution primarily prevents cellular swelling during cold storage?