Liver transplant allocation policies and outcomes in United States: A comprehensive review

Table 1 Model for end-stage liver disease exception points granted

Year of policy implementation	MELD exception points granted
	T2 lesion (A single nodule with diameter ≥ 2 cm and ≤ 5 cm or 2-3 lesions each between 1-3 cm)	T1 lesion (A single nodule ≥ 1 cm and < 2 cm)
February 2002	29 points	24 points
February 2003	24 points	20 points
April 2004	24 points	No exception points
March 2005	22 points	No exception points
October 2015	Natural MELD score at the time of listing	No exception points
	28 points after 6 mo with maximum 34 exception points
May 2019	MMaT-3	No exception points

MELD: Model for end-stage liver disease; MMaT-3: Median MELD at transplant-3.

Table 2 Lesions eligible for downstaging protocols

Number of lesions	Size	Description
1	> 5 cm and ≤ 8 cm
2-3	At least one lesion > 3 cm and all ≤ 5 cm	Total diameter of all lesions ≤ 8 cm
4-5	Each < 3 cm	Total diameter of all lesions ≤ 8 cm

Table 3 Organ procurement and transplantation network imaging classification for class 5 lesions in patients with cirrhosis

OPTN class	Description	Comments
0	Incomplete are technically in adequate study	No MELD exception points
5A	Lesion size ≥ 1 cm and ≤ 2 cm	Increased contrast enhancement in the late hepatic arterial phase along with either: (1) Wash out during late contrast phases and peripheral rim enhancement (capsule or pseudocapsule); and (2) Biopsy consistent with HCC
5A-g	Lesion size ≥ 1 cm and ≤ 2 cm	Increased contrast enhancement in the late hepatic arterial phase along with growth ≥ 50% documented on serial CT or MR obtained ≤ 6 mo apart
5B	Lesion size ≥ 2 cm and ≤ 5 cm	Increased contrast enhancement in the late hepatic arterial phase along with either: (1) Wash out during late contrast phases; (2) Peripheral rim enhancement (capsule or pseudocapsule); (3) Growth ≥ 50% documented on serial CT or MR obtained ≤ 6 mo apart in the absence of ablative therapy; and (4) Biopsy consistent with HCC
5T	Prior local regional therapy for HCC	Any residual lesion or perfusion defect at the site of prior class 5A, 5A-g, 5B lesion

OPTN: Organ procurement and transplantation network; MELD: Model for end-stage liver disease; HCC: Hepatocellular carcinoma.

Table 4 Conditions eligible for non-hepatocellular carcinoma standard model for end-stage liver disease-exceptions

Condition	Requirements for exception points	MELD score assigned
CCA	Un-resectable hilar CCA with biopsy/cytology consistent with malignancy or CA19-9 > 100 U/mL or aneuploidy	MMaT-3
	Center must have written protocol regarding selection of criteria, neoadjuvant therapy, operative staging for metastatic disease
	Imaging to exclude metastatic disease
HPS	Evidence of portal hypertension without any evidence of underlying significant pulmonary disease	MMaT-3
	PaO2 < 60 mmHg on room air
	ECHO or lung scan confirming intra-pulmonary shunt
POPH	Evidence of portal hypertension along with MPAP > 35 mmHg and PVR > 3 woods unit	MMaT-3
	MPAP < 35 mmHg and PVR < 5.1 woods unit post treatment of pulmonary hypertension
FAP	Biopsy proven amyloid along with TTR gene mutation and able to walk independently	MMaT-3
	Must be on heart transplant wait list or EF > 40% on ECHO within 30 d
Cystic fibrosis	Genetic analysis confirmation needed	MMaT-3
	FEV1 below 40% of predicted FEV1 with 30 d prior to initial request
HAT	HAT within 2 wk of OLT	40
Primary hyperoxaluria	AGT deficiency proven on liver biopsy/genetic analysis	MMaT
	On kidney transplant list with eGFR ≤ 25 mL/min on two instances 42 d apart

CA19-9: Carbohydrate antigen 19-9; FEV1: Forced expiratory volume at one second; TTR: Transthyretin; AGT: Alanine glyoxylate aminotransferase; MELD: Model for end-stage liver disease; CCA: Cholangiocarcinoma; HPS: Hepatopulmonary syndrome; MPAP: Mean pulmonary artery pressure; FAP: Familial amyloid polyneuropathy; HAT: Hepatic artery thrombosis; PVR: Pulmonary vascular resistance; POPH: Portopulmonary hypertension.