CTP CTP Organ Viability Assessment & Machine Perfusion

Question 1

What is the primary advantage of hypothermic machine perfusion (HMP) over cold static storage for kidney preservation?

Accepted Answer

Continuous washout of metabolic waste products and delivery of nutrients

Answer

Complete elimination of ischemia-reperfusion injury

Answer

Ability to store organs indefinitely without deterioration

Answer

Lower cost compared to static cold storage

Question 2

Which perfusion parameter measured during hypothermic machine perfusion (HMP) is most predictive of early graft function after kidney transplantation?

Accepted Answer

Resistance index (vascular resistance)

Answer

Flow rate only

Answer

Perfusate temperature

Answer

Duration of perfusion

Question 3

In normothermic machine perfusion (NMP) of the liver, what substrate is essential to include in the perfusate to maintain hepatocyte function?

Accepted Answer

Red blood cells (RBCs) to provide oxygen delivery

Answer

Hypertonic glucose solution

Answer

Nitrogen gas to maintain anaerobic metabolism

Answer

Calcium-free crystalloid solution

Question 4

During normothermic regional perfusion (NRP) of abdominal organs in a DCD donor, what is the primary physiologic goal?

Accepted Answer

Restore aerobic metabolism and allow cellular repair before procurement

Answer

Cool organs to 4°C before removal

Answer

Flush blood from the organ vasculature

Answer

Test organ function under transplant conditions

Question 5

What is the Kidney Donor Profile Index (KDPI), and what value is considered the threshold for 'expanded criteria donor' status?

Accepted Answer

A risk score from 0–100%; KDPI ≥85% defines high-risk/ECD kidneys

Answer

A numerical index from 1–10; values above 7 define expanded criteria

Answer

A composite score based solely on donor age and creatinine

Answer

A binary classification with no numerical threshold

Question 6

Lactate clearance in the perfusate during normothermic machine perfusion (NMP) of a liver is used as a viability marker because:

Accepted Answer

A functioning liver actively metabolizes lactate, indicating restored aerobic metabolism

Answer

Lactate accumulation confirms successful cold storage

Answer

Rising lactate levels indicate the organ is safely preserved

Answer

Lactate is a substrate required for bile production