Liver Transplantation and Hepatocellular Carcinoma

Question 1

Most common indications for liver transplant?

Answer 1

Hep C
Alcohol
Cholestasis
Cryptogenic / NASH
(with Hepatocellular Carcinoma contributing to many of the other causes)

Question 2

5 proximal indications (i.e. complications of liver disease) for liver transplant?

Answer 2

Variceal Bleeding
Ascites
Hepatorenal Syndrome
Hepatic Encephalopathy
Hepatic Dysfunction

Question 3

2 main questions when evaluating patient for liver transplant?

Answer 3

Is there a need?

Is there a contraindication?

Question 4

For trivia.. what scoring system was used to prioritize liver transplants prior to 2002?
Problems with it?

Answer 4

Child-Pugh Scoring System
The ascites and hepatic encephalopathy criteria left room for subjectivity.
Also was only for chronic liver disease.

Question 5

What scoring system is used today to prioritize liver transplants?

Answer 5

Model for End Stage Liver Disease

Higher score = worse disease / prognosis

Question 6

What variables are the in MELD score?

Answer 6

Serum creatinine
Serum bilirubin
INR
Cause of cirrhosis (0 for alcohol, 1 for otherwise)

Question 7

What MELD score predicts an 85% 3 month survival?

Answer 7

MELD score of 22

Question 8

At about what MELD score is the break even point? (below which people are better off without transplant, and above which people benefit from transplant?)

Answer 8

15-17

Question 9

What’s the major weakness of MELD?

How is this accounted for?

Answer 9

Weakness: lab values in MELD aren’t altered in some severe disease with a high risk of death - e.g. Hepatocellular carcinoma (HCC).
For this, MELD exception points are used.

Question 10

How do MELD exception points work?

Answer 10

People, e.g. with HCC, are given initial MELD score of 22. (85% 3mo mortality risk)
Every 3 months, MELD score is increased such that it corresponds with a 10 percent increase in mortality risk.

Question 11

Take-home point about established MELD exception points?

What if something isn’t an established exception point?

Answer 11

They’re mainly extra-hepatic disease manifestations.

If something isn’t established, can present case to a regional review board to get MELD exception.

Question 12

What 4 anastomoses must be made in a liver transplant?

Answer 12

Bile duct
Portal vein
Hepatic artery
Hepatic vein

Question 13

Which 2 indications have the best graft survival rates?

Answer 13

Cholestasis and alcoholic liver disease.

Question 14

In a living donor transplant, what determines how much liver is given?

Answer 14

The size of the recipient - a young child can be given just a small part. An adult typically gets the whole right functional lobe.

Question 15

Is donating a part of your liver dangerous?

Answer 15

Yes. 0.1 - 0.5% mortality.

Question 16

What’s one environmental exposure (not HBV) that greatly increases risk of hepatocellular carcinoma (HCC) if you’re living in say, Shanghai?

Answer 16

Aflatoxin B1 - made by some aspergillus

Question 17

How can you screen for HCC in patients with increased risk?

Answer 17

Ultrasound -but US can’t distinguish HCC from other solid lesions.

Question 18

How can you diagnose HCC by blood flow?

Answer 18

As dysplasia progresses to HCC, the predominance of its blood supply becomes arterial (instead of from portal veins).

Question 19

How is CT used to determine if a lesion is HCC?

Answer 19

Contrast in arterial blood -> HCC will light up.
Contrast in portal veins -> Liver will light up, but HCC won’t.
(“arterial phase” and “portal venous phase” apparently refer to the fact that when you give IV contrast, it first gets into arterial blood, then a few seconds later it’s more in the portal circulation… then it evens out - thanks, Vinayak)

Question 20

What usually kills people with HCC?

Answer 20

Liver failure - not metstasis

Question 21

3 “nonsurgical” local therapies for HCC?

Answer 21

Radiofrequency Ablation (heat a probe jabbed in there with radio waves)/
Transarterial Chemoembolization (TACE).
Radiation.

Question 22

What’s the idea behind Transarterial Chemoembolization (TACE)?

Answer 22

Tumor’s getting mostly arterial blood, so if you embolize the hepatic artery, the tumor will be mostly starved for blood, slowing growth.

Question 23

What kind of chemotherapy is used for HCC?

Answer 23

Sorafenib - a multikinase inhibitor… but this only extends survival about 2 months.

Question 24

What criteria must be met in order for a person with HCC to qualify for transplant?

Answer 24

No LN or vascular invasion
No extrahepatic spread
Milan Criteria for size / number:
 - 1 tumor > 2cm but < 5cm
 - 3 tumors each < 3cm
(note that risks exceed benefit for transplant when there's only 1 tumor and it's < 2cm)

Question 25

Is HCC meeting Milan criteria a MELD exception point?

Answer 25

Yep.