OPTN/SRTR 2022 Annual Data Report: Liver

OPTN/SRTR 2022 Annual Data Report: Liver

Allison J. Kwong1, W. Ray Kim1,2, John R. Lake2,3, David P. Schladt2, Erin M. Schnellinger4, Katrina Gauntt4, Meghan McDermott4, Samantha Weiss4, Dzhuliyana K. Handarova4, Jon J. Snyder2,5,6, Ajay K. Israni2,5,6

1Division of Gastroenterology and Hepatology, Stanford University, Palo Alto, CA

2Scientific Registry of Transplant Recipients, Hennepin Healthcare Research Institute, Minneapolis, MN

3Division of Gastroenterology, Hepatology, and Nutrition, University of Minnesota, Minneapolis, MN

4Organ Procurement and Transplantation Network, United Network for Organ Sharing, Richmond, VA

5Department of Epidemiology and Community Health, University of Minnesota, Minneapolis, MN

6Department of Medicine, Hennepin Healthcare, University of Minnesota, Minneapolis, MN

Abstract

In 2022, liver transplant activity continued to increase in the United States, with an all-time high of 9,527 transplants performed, representing a 52% increase over the past decade (2012-2022). Of these transplants, 8,924 (93.7%) were from deceased donors and 603 (6.3%) were from living donors. Liver transplant recipients were 94.5% adult and 5.5% pediatric. The overall size of the liver transplant waiting list contracted, with more patients being removed than added, although 10,548 adult patients still remained on the waiting list at the end of 2022. Alcohol-associated liver disease continued to be the leading diagnosis among both candidates and recipients, followed by metabolic dysfunction–associated steatohepatitis. Simultaneous liver-kidney transplant was the most common multiorgan combination, with 800 liver-kidney transplants performed in 2022; in addition, there were 303 new listings for kidney transplant via the safety net mechanism. Among adults added to the liver waiting list in 2021, 39.9% received a deceased donor liver transplant within 3 months; 45.7%, within 6 months; and 54.5%, within 1 year. Pretransplant mortality decreased to 12.3 deaths per 100 patient-years in 2022, although still 15.6% of removals from the waiting list were for death or being too sick for transplant. Graft and patient survival outcomes after deceased donor liver transplant improved, approximating pre–COVID-19 pandemic levels, with 5.1% mortality observed at 6 months; 6.8%, at 1 year; 12.7%, at 3 years; 19.8%, at 5 years; and 35.7%, at 10 years. Five-year graft and patient survival rates after living donor liver transplant exceeded those of deceased donor liver transplant. Candidates receiving model for end-stage liver disease exception points for hepatocellular carcinoma constituted 15.5% of transplants performed in 2022, with similar transplant rates and posttransplant outcomes compared to cases without hepatocellular carcinoma exception. In 2022, more pediatric liver transplant candidates were added to the waiting list and underwent transplant compared with either of the preceding 2 years, with an uptick in living donor liver transplant volume. Although pretransplant mortality has improved after the recent policy change prioritizing pediatric donors for pediatric recipients, still, in 2022, 50 children died or were removed from the waiting list for being too sick to undergo transplant. Posttransplant mortality among pediatric liver transplant recipients remained notable, with death occurring in 4.0% at 6 months, 6.0% at 1 year, 8.2% at 3 years, 9.8% at 5 years, and 13.9% at 10 years. Similar to adult living donor recipients, pediatric living donor recipients had better 5-year patient survival compared with deceased donor recipients.

Keywords: Allocation, distribution, liver transplant, waiting list

1 Adult Liver Transplantation in the United States

1.1 Waiting List

There were 24,186 adult candidates on the liver transplant waiting list at any point during 2022, a 10.7% decrease compared with 2012 (Figure LI 2). There were 11,324 waitlisted adults at the beginning of 2022; 12,862 were added and 13,638 were removed during the calendar year, leaving 10,548 on the waiting list at the end of 2022 (Figure LI 1, Table LI 4).

The proportion of candidates aged 50-64 years on the liver waiting list has steadily declined and was 47.4% in 2022, with a commensurate increase in the proportion of candidates aged 65 years or older (27.4%), 35-49 years (19.3%), and 18-34 years (6.0%) (Figure LI 3). The composition of the waiting list in terms of sex and race and ethnicity remained relatively unchanged: 61.2% male, 38.8% female, 68.6% White, 18.7% Hispanic, 6.3% Black, 4.7% Asian, 1.1% Native American, and 0.6% Multiracial (Figure LI 4, Figure LI 5). Of the candidates remaining on the waiting list at the end of 2022, 84.2% reported living in a metropolitan area based on their permanent zip code; 56.7% were less than 50 miles from the transplant center, 18.8% were within 50-<100 miles, 9.3% were within 100-<150 miles, 8.0% were within 150-<250 miles, and 6.5% were 250 miles or farther (Table LI 1).

Obesity, defined as a body mass index (BMI) of 30 kg/m2 or greater, was observed in 41.3% of adult candidates in 2022; 17.3% had a BMI of 35 kg/m2 or greater (Figure LI 8). Of adults waiting for liver transplant, 3.0% had a history of prior liver transplant (Figure LI 10); 47.8% had blood type O, 38.2% had type A, 11.0% had type B, and 3.0% had type AB (Figure LI 9).

Alcohol-associated liver disease remained the most common primary diagnosis, at 37.5% of adult liver transplant candidates in 2022; this represents a 66.0% increase since 2012 (Figure LI 6). The prevalence of metabolic dysfunction–associated steatohepatitis (MASH), formerly known as nonalcoholic steatohepatitis, also increased, to 20.0% of candidates in 2022, with a commensurate decrease in the other/unknown category (15.8%). The prevalence of hepatitis C virus (HCV) (7.2%), cholestatic liver disease (7.3%), and acute liver failure (1.7%) on the waiting list continued to decrease. Hepatocellular carcinoma (HCC), which typically occurs in the context of chronic liver disease due to the aforementioned etiologies, was reported as the primary diagnosis for the remaining 10.5% of candidates.

The severity of liver disease, based on the last laboratory model for end-stage liver disease (MELD) score during the calendar year, increased in 2022, with a greater proportion of candidates with MELD scores of 25-34 (16.2%), 35-39 (5.0%), and 40 or greater (5.2%) compared with previous years (Figure LI 7).

1.2 Waitlist Outcomes

The overall deceased donor transplant rate among adult waitlist candidates continued to rise, and at 77.5 transplants per 100 patient-years in 2022, was more than double the rate from 2012 (Figure LI 11). This increase occurred across all age groups, sexes, racial and ethnic groups, and blood types (Figure LI 12, Figure LI 13, Figure LI 14, Figure LI 16). Still, male candidates had higher transplant rates compared with female candidates (80.1 versus 73.4 transplants per 100 patient-years), a disparity that may be addressed in part by the updated MELD scoring system (MELD 3.0) that was implemented in July 2023. Candidates with blood type AB had a much higher transplant rate compared with candidates of all other blood types (190.3 transplants per 100 patient-years compared with 108.7 for blood type B, 71.3 for blood type A, and 71.7 for blood type O). Transplant rates for patients with and without HCC exception points equalized in 2021, related to a series of policy changes over the preceding decade, and remained similar in 2022 (Figure LI 15).

Among adults listed for liver transplant in 2017-2019, only 7.7% remained on the waiting list after 3 years; 57.1% received a deceased liver transplant, 2.9% received a living donor liver transplant, 9.0% died, and 23.3% were removed from the list for other reasons (Figure LI 17). Among candidates who were added to the waiting list in 2021, 39.9%, 45.7%, and 54.5% received a deceased donor liver transplant within 3 months, within 6 months, and within 1 year, respectively—all increases compared with previous years (Figure LI 18). By comparison, only 39.6% of candidates listed in 2012 received a deceased donor liver transplant within 1 year; 49.8%, within 5 years; and 50.6%, within 10 years.

The pretransplant mortality rate decreased in 2022 to 12.3 deaths per 100 patient-years, from a peak of 17.9 deaths per 100 patient-years in 2014, despite the increased severity of liver disease in waitlist candidates (Figure LI 19). Like the overall deceased donor transplant rate, this decrease in pretransplant mortality occurred across all age groups (Figure LI 20), sexes (Figure LI 22), and etiologies of liver disease (Figure LI 23), yet female candidates still had an increased pretransplant mortality rate compared with male candidates (13.3 versus 11.7 deaths per 100 patient-years). Candidates with MASH and acute liver failure had higher pretransplant mortality rates (17.5 and 17.3 deaths per 100 patient-years, respectively) compared to candidates with other etiologies, with the lowest rates observed among those with cholestatic liver disease (9.45 deaths per 100 patient-years) and HCC (9.91 deaths per 100 patient-years). The pretransplant mortality rate remained highest among candidates with MELD scores of 40 or greater (based on the first active laboratory MELD score during the year) at 218.8 deaths per 100 patient-years in 2022, followed by those with MELD scores of 35-39 (179.2 deaths per 100 patient-years) (Figure LI 24). Pretransplant mortality was lower in candidates with an HCC exception compared to those without (10.1 versus 12.6 deaths per 100 patient-years), which has been sustained despite the policy change in 2019 that systematically lowered waitlist priority for patients with HCC (Figure LI 25). Overall, pretransplant mortality rates by donation service area still varied, ranging from 5.9 to 31.1 deaths per 100 patient-years (Figure LI 26).

Liver transplant was the most common reason for waitlist removal among adults in 2022, including 8,462 from a deceased donor and 515 from a living donor. The next most common reasons were “other” (1,434), being too sick for transplant (1,091), death (1,031), and condition improved with transplant no longer being needed (983) (Table LI 5). Removal for death or being too sick made up 15.6% of removals from the liver transplant waiting list. Deaths within 6 months after removal from the waiting list for reasons other than transplant or death decreased from 36.3% in 2012 to 13.3% in 2022 (Figure LI 27). This was similar across sexes and racial and ethnic groups (Figure LI 30, Figure LI 31). Candidates in the highest laboratory MELD score category (40 or greater at the time of removal) were actually less likely than those with MELD scores in the 35-39 and 25-34 categories to die within 6 months of removal (Figure LI 28).

1.3 Donation

The number of deceased liver donors (including adult and pediatric), defined as donors from whom the liver was recovered for transplant, continued to increase, reaching an all-time high of 9,812 in 2022, a nearly 50% increase since 2012 (Figure LI 32). In contrast to the increase in donation from older age groups, the absolute number of donors younger than 18 years has remained relatively stable during that period, representing 6.8% of donors in 2022 compared with 10.2% in 2012 (Figure LI 33, Figure LI 35). The sex and racial and ethnic composition of donors remained relatively unchanged in 2022: 62.4% male, 37.6% female, 61.8% White, 18.4% Black, 15.7% Hispanic, and 2.9% Asian (Figure LI 36, Figure LI 37). The proportion of livers with positive HCV antibody increased again in 2022, making up 9.6% of deceased donor livers recovered in 2022 (Figure LI 34, Figure LI 38). Anoxia remained the most common cause of death among deceased liver donors (47.5%), followed by head trauma (24.9%) and CVA/stroke (24.8%) (Figure LI 47).

Overall, 9.9% of livers (including adult and pediatric) were recovered and not transplanted, a value that has increased over the past 5 years from a low of 8.6% in 2018 (Figure LI 40). Livers from older donors were less likely to be transplanted, with 14.2% of livers recovered from donors aged 55 years or older and 11.4% of those from donors aged 40-54 years not transplanted (Figure LI 41). No major differences by sex, race and ethnicity, or donor cause of death were observed (Figure LI 42, Figure LI 43, Figure LI 44). Livers from donation after circulatory death (DCD) were much less likely to be transplanted than livers recovered from donation after brain death (26.8% versus 7.2%), although the rate of DCD livers recovered but not transplanted has decreased overall, from 32.2% in 2012 (Figure LI 47). Utilization of DCD livers may be anticipated to increase with wider availability of machine perfusion. Livers with positive HCV antibody were not more likely to be recovered for transplant and not transplanted than those without (9.4% versus 10.0%), nor were livers with positive HCV antibody considered to be at increased risk of disease transmission compared with those without (9.0% versus 10.2%) (Figure LI 45, Figure LI 46).

In 2022, there were 603 living donor liver transplants (including adult and pediatric) performed (Figure LI 55). Most donors were related (44.5%) or distantly related (11.1%; defined as a biological relative other than a parent, child, full or half sibling) to the recipient, whereas 21.5% were directed donations and 4.2% were from a spouse or partner (Figure LI 48). A small but growing number of living donor liver transplants (37 [6.4%]) were performed as a paired donation. Living donors were more likely to be female (58.5%) and White (78.4%) (Figure LI 50, Figure LI 51). Very few (4.5%) living donors were aged 55 years or older; 16.4% of living donors were obese (BMI of 30 kg/m2 or greater) (Figure LI 49, Figure LI 53). In most cases, the right lobe of the liver was used for transplant (75.1%) (Figure LI 52).

1.4 Transplants

In 2022, a record 9,527 liver transplants (adult and pediatric) were performed in the United States, inclusive of adult, pediatric, retransplant, and multiorgan recipients, which is a 50% increase since 2012 (Figure LI 54). Of these, 8,924 (93.7%) were from deceased donors and 603 (6.3%) were from living donors (Figure LI 55). The number of pediatric recipients has remained relatively constant over the past decade, whereas the number and proportion of adult recipients have increased (Figure LI 56). In terms of sex and race and ethnicity, 61.9% were male; 38.1%, female; 68.8%, White; 18.1%, Hispanic; 6.9%, Black; 4.4%, Asian; 1.1%, Native American; and 0.7%, Multiracial (Figure LI 57, Figure LI 58). Alcohol-associated liver disease was again the most common indication for liver transplant overall, making up 38.6% of transplants, followed by MASH at 18.8% (Figure LI 59).

Among the 9,001 adult recipients in 2022, 94.3% received livers from deceased donors and 5.7% from living donors (Table LI 8). Of all 9,001 adult recipients, 62.4% were male; 37.6%, female; 70.1%, White; 17.7%, Hispanic; 6.3%, Black; and 4.2%, Asian (Table LI 6). Compared with a decade ago, there was a higher proportion of recipients aged 35-49 years (22.8% in 2022 versus 16.9% in 2012), aged 65 years or older (21.9% versus 14.6%), with BMI of 35 kg/m2 or greater (15.5% versus 12.7%), and with Medicaid insurance (17.0% versus 12.8%). Most liver transplants (51.4%) were covered by private insurance, followed by Medicare (26.4%) and Medicaid (17.0%). In 2022, based on the rural-urban commuting area designation of their home zip code, 83.4% of recipients lived in metropolitan areas compared with 14.9% in nonmetropolitan areas; 56.9% lived less than 50 miles from the transplant center, 16.9% within 50-<100 miles, 9.8% within 100-<150 miles, 7.3% within 150-<250 miles, and 7.9% 250 miles or farther.

Alcohol-associated liver disease was the primary diagnosis for 40.8% of adult liver transplants in 2022, up from 17.0% in 2012 (Table LI 7). This was followed by MASH (19.9%) and other/unknown (14.5%). In 10.9% of recipients, HCC was the primary diagnosis, down from 19.7% in 2012. Cholestatic liver disease (7.1%), HCV (4.4%), and acute liver failure (2.3%) were less frequently the primary diagnosis. The proportion of recipients who underwent transplant with HCC MELD exception points was 15.5% in 2022, down from 27.0% in 2012. In 2022, recipients most commonly had blood type O (45.5%), followed by type A (36.4%), type B (13.4%), and type AB (4.7%). Regarding MELD score or urgency status at transplant, 14.2% of recipients had an allocation MELD score of 14 or lower, 26.2% had a MELD of 15-24, 36.4% had a MELD of 25-34, 11.0% had a MELD of 35-39, 9.8% had a MELD of 40 or greater, and 2.3% were status 1A.

Most adult liver transplant recipients (61.0%) waited less than 90 days, with only 13.0% waiting longer than 1 year (Table LI 8). Overall, waiting times in 2022 were shorter compared with 2012. The proportion of adults who received DCD livers increased to 11.3% in 2022 from 4.6% in 2012, while the proportion of those who received split livers remained low at 0.9%. The proportion of recipients with a history of previous transplant decreased to 3.5% in 2022 from 5.1% in 2012.

There were 800 simultaneous liver-kidney transplants in 2022, representing a stable proportion (8.4%) of liver transplant recipients over the past several years since the introduction of standardized medical eligibility criteria for simultaneous liver-kidney transplant in 2017 (Figure LI 60). Most recipients (89.3%) qualified for kidney listing because of chronic kidney disease, and 8.8% qualified because of sustained acute kidney injury (Figure LI 61).

1.5 Outcomes

Among liver transplants performed in 2021, the most recent year for which at least 1 full year of follow-up was available, graft failure occurred in 6.4% of adult deceased donor liver transplant recipients at 6 months and in 8.4% at 1 year, which are improvements from the previous year and closer to prepandemic levels (Figure LI 67). Longer term graft outcomes for recipients of deceased donor liver transplant were similar to those in previous years, with a graft failure frequency of 14.6% at 3 years for transplants in 2019, 21.6% at 5 years for transplants in 2017, and 38.1% at 10 years for transplants in 2012. Overall survival for adult deceased donor liver transplant recipients followed a similar pattern, with 5.1% mortality at 6 months, 6.8% at 1 year, 12.7% at 3 years, 19.8% at 5 years, and 35.7% at 10 years (Figure LI 69).

For adult recipients of deceased donor liver transplant in 2015-2017, the 5-year survival outcomes were lower among older recipients (65 years or older) compared with those in the younger age groups (Figure LI 70, Figure LI 86); among Black and Native American recipients compared with those in other race and ethnicity categories (Figure LI 71, Figure LI 87); and among men compared with women (Figure LI 72, Figure LI 88). Graft survival rates were highest for cholestatic (81.0%) and alcohol (80.3%) etiologies and lowest for acute liver failure (76.8%) and HCC (77.0%) (Figure LI 73). Patient survival rates by etiology followed a similar pattern (Figure LI 89). Recipients in the highest laboratory MELD category (40 or greater) had somewhat inferior graft and patient survival outcomes compared with those in lower MELD categories, but still had 75.3% graft and 76.9% patient survival at 5 years (Figure LI 74, Figure LI 90). Graft outcomes were equivalent between recipients with and without HCC exception points, as well as across BMI categories (Figure LI 76, Figure LI 77). The 5-year graft survival rate among recipients of DCD livers was 75.3%, compared with 79.2% for recipients of livers donated after brain death (Figure LI 75).

Outcomes for adult living donor liver transplant recipients have improved and were superior to those of deceased donor recipients, with graft failure occurring in 5.1% at 6 months, 6.5% at 1 year, 12.4% at 3 years, 15.9% at 5 years, and 32.5% at 10 years (Figure LI 68). Recipients with MASH and cholestatic liver disease had the highest 5-year graft survival: 86.6% and 86.3%, respectively. Five-year graft survival was notably worse among those with a diagnosis of acute liver failure (57.1%), although the absolute number of patients in this category was small (Figure LI 81). Similarly, worse outcomes were observed in the higher MELD score categories (MELD 25-34: 69.4%, MELD 35-39: 66.7%), whereas outcomes were similar between MELD of 14 or lower (83.7%) and MELD 15-24 (82.9%) (Figure LI 82). Five-year patient survival outcomes among living donor liver transplant recipients also exceeded those of deceased donor liver transplant recipients. Patterns similar to those seen with deceased donor transplants were observed, with lower survival rates among recipients aged 65 years or older, those with acute liver failure or HCC, and those with MELD of 25 or greater (Figure LI 91, Figure LI 92, Figure LI 94). No differences by sex or race and ethnicity were observed (Figure LI 79, Figure LI 80, Figure LI 93).

Induction therapy was used in 30.4% of adult liver transplants in 2022, and 69.9% of adult liver transplant recipients received steroid-containing immunosuppressive regimens (Figure LI 65, Figure LI 66). Acute rejection within the first year after liver transplant occurred more frequently with decreasing age, at a rate of 19.1% in recipients aged 18-34 years compared with 8.44% in those aged 65 years or older (Figure LI 83). No notable differences were seen in the incidence of acute rejection based on induction agent status or type (interleukin-2 receptor antibody versus T-cell depleting agent versus none) (Figure LI 84). The overall incidence of posttransplant lymphoproliferative disorder at 5 years posttransplant was 1.0%, and among Epstein-Barr virus (EBV)–negative patients was 2.0% (Figure LI 85).

In 2022, there were 725 new listings for kidney transplant with a previous history of liver transplant. The number of listings within 60-<365 days after liver transplant notably increased after the implementation of the safety net provision in 2017, with 303 new listings in 2022 (Figure LI 62). The most common diagnosis among new kidney transplant listings was hepatorenal syndrome (28.8%), followed by calcineurin inhibitor nephrotoxicity (18.9%) and diabetes (17.7%) (Figure LI 63).

2 Pediatric Liver Transplantation in the United States

2.1 Summary

In 2022, pediatric liver transplant activity increased, with more candidates added to the waiting list and more who underwent transplant compared with the preceding 2 years. In total, 526 pediatric liver transplants were performed: 439 (83.5%) deceased donor and 87 (16.5%) living donor (Figure LI 107, Figure LI 108). Overall, living donor transplant has increased in the past decade, and living donor recipients continue to have better long-term graft and patient survival compared with deceased donor recipients. Since February 2020, coinciding with the implementation of acuity circles, donations from pediatric donors have been prioritized for children nationally before being offered to adults within a 500–nautical mile radius, and pediatric pretransplant mortality has overall decreased compared with the years preceding this policy change. Although improved, candidates younger than 1 year still had the highest pretransplant mortality rates among pediatric age groups, and 50 children died on the waiting list or were removed for being too sick to undergo transplant (Table LI 13). Recipient mortality remains notable, with death observed in 6.0% of pediatric liver transplant recipients at 1 year, 9.8% at 5 years, and 13.9% at 10 years (Figure LI 121).

2.2 Waiting List

In 2022, there were 741 new registrants added to the pediatric liver transplant waiting list, and 704 were removed, leaving 438 candidates on the list at the end of the calendar year (Figure LI 95, Table LI 12). Of the 1,142 candidates on the waiting list during the year (Figure LI 96), those aged 1-5 years (32.3%) and 12-17 years (23.7%) made up the largest age groups, followed by younger than 1 year (19.4%), 6-11 years (16.8%), and 18 years or older (7.7%) (Figure LI 97). In terms of race and ethnicity, White registrants continued to make up the largest group on the waiting list (46.1%), followed by Hispanic (25.6%), Black (17.6%), Asian (7.2%), Multiracial (3.1%), and Native American (0.5%) registrants (Figure LI 98).

The overall deceased donor liver transplant rate for pediatric waitlist candidates in 2022 was higher than that for adults, at 103.5 transplants per 100 patient-years (Figure LI 101). The transplant rate was highest for candidates younger than 1 year (188.6 transplants per 100 patient-years), but this rate was lower compared with those of previous years (Figure LI 102). Pretransplant mortality remained steady at a rate of 6.0 deaths per 100 patient-years, with the highest mortality rate still among candidates younger than 1 year at 9.4 deaths per 100 patient-years (although a significant decrease compared with previous years) (Figure LI 104, Figure LI 105). In 2022, 50 children died on the waiting list or were removed for being too sick for transplant (Table LI 13).

In 2022, the most common reason for removal was deceased donor liver transplant (63.9%), then living donor liver transplant (12.5%), followed by condition improved and transplant no longer needed (11.2%), too sick for transplant (4.3%), and death (2.8%), among others (Table LI 13). After 3 years of follow-up, 67.1% of pediatric candidates listed in 2017-2019 had received a deceased donor liver transplant, 10.0% received a living donor liver transplant, 3.3% died, 15.2% were removed from the waiting list for other reasons, and 4.4% were still waiting for a liver transplant (Figure LI 100).

2.3 Transplants

In 2022, there were 526 pediatric liver transplants performed in the United States, closer to prepandemic volumes; 439 (83.5%) were deceased donor and 87 (16.5%) were living donor (Figure LI 107, Figure LI 108). Over the past decade, the proportion of living donor transplants has increased, to 16.5% in 2022 from 9.9% in 2012.

The number and proportion of adolescent (age 12-17 years) liver transplant recipients have increased, at 128 (24.3%) of pediatric liver transplants in 2022, although most transplants were still in children aged 5 years or younger (age <1 year, 27.6%; age 1-5 years, 32.3%) (Figure LI 109). Recipient demographic information, including age at the time of transplant, race and ethnicity, insurance type, and place of residence, has remained similar over the past decade. In 2022, 81.4% reported living in a metropolitan area based on their permanent zip code. Regarding distance from transplant center, 45.8% of recipients were less than 50 miles; 15.2%, within 50-<100 miles; 9.9%, within 100-<150 miles; 12.4%, within 150-<250 miles; and 14.4%, 250 miles or farther (Table LI 14). Recipients with a history of prior transplant made up 5.7% (Table LI 16).

Biliary atresia remained the leading indication for pediatric liver transplant in 2022 (37.3%), followed by other/unknown diagnosis (23.4%), metabolic (15.0%), acute liver failure (9.5%), hepatoblastoma (7.6%), and other cholestatic condition (7.2%) (Table LI 15). At the time of transplant, 13.1% of recipients were status 1A and 22.1% were status 1B, while 4.6%, 17.9%, 15.0%, and 27.4% had allocation MELD/pediatric end-stage liver disease (PELD) scores of 40 or greater, 25-39, 15-24, and 14 or lower, respectively. The use of technical variant grafts in pediatric liver transplant over the past decade has been relatively unchanged—in 2022, 59.7% were whole liver; 23.2%, partial liver; and 17.1%, split liver (Figure LI 110). In 2022, only one pediatric patient (0.2%) received a DCD liver graft, and 4.2% of grafts were ABO incompatible (Table LI 16).

In 2022, most pediatric liver transplant recipients received no induction therapy (61.2%) and steroid-containing initial immunosuppression regimens (78.1%) (Figure LI 111, Figure LI 112).

2.4 Outcomes

Within 1 year of transplant, 22.1%-29.0% of pediatric liver transplant recipients (transplants done in 2021) had at least one episode of rejection (Figure LI 119). Among pediatric recipients who underwent transplant in 2011-2017, posttransplant lymphoproliferative disorder was reported in 2.0% after 1 year, 3.5% after 3 years, and 4.1% after 5 years, with approximately twofold incidence among recipients negative for EBV compared with those positive for EBV (Figure LI 120).

Among pediatric deceased donor liver recipients for transplants in 2011-2021, graft failure occurred in 5.9% at 6 months, 8.0% at 1 year, 13.1% at 3 years, 13.7% at 5 years, and 20.3% at 10 years from transplant (Figure LI 113). Fewer living donor recipients developed graft failure, occurring in 5.2% at 6 months, 6.5% at 1 year, 7.6% at 3 years, 8.3% at 5 years, and 11.5% at 10 years from transplant (Figure LI 114). For transplants in 2015-2017, the 5-year graft survival was highest for deceased donor recipients who were aged 6-11 years at the time of transplant (90.1%), followed by younger than 1 year (86.7%), 12-17 years (84.3%), and 1-5 years (83.5%) (Figure LI 115). By diagnosis, 5-year graft survival was highest for deceased donor recipients with metabolic conditions (95.5%), followed by biliary atresia (90.3%), acute liver failure (82.8%), other cholestatic conditions (79.2%), hepatoblastoma (78.8%), and other/unknown (77.8%) (Figure LI 116). Deceased donor recipients who underwent transplant at a MELD/PELD score of 35-39 had the lowest 5-year graft survival at 75.4%, whereas survival exceeded 84.8% for all other MELD categories including 40 or greater (Figure LI 117). At all time points, living donor recipients had better graft survival compared with deceased donor recipients, with a 5-year graft survival of 91.5% compared with 85.5%, respectively (Figure LI 118).

Recipient mortality remains notable in pediatric liver transplant; death occurred in 4.0% of deceased and living donor recipients at 6 months, 6.0% at 1 year, 8.2% at 3 years, 9.8% at 5 years, and 13.9% at 10 years from transplant (Figure LI 121). Similar to adult living donor recipients, pediatric living donor recipients had better 5-year patient survival compared with deceased donor recipients (94.8% versus 89.5%) (Figure LI 125).

List of Figures

List of Tables




**New adult candidates added to the liver transplant waiting list.** A new candidate is one who first joined the list during the given year, without having been listed in a previous year. Previously listed candidates who underwent transplant and subsequently relisted are considered new. Active and inactive patients are included.

Figure LI 1: New adult candidates added to the liver transplant waiting list. A new candidate is one who first joined the list during the given year, without having been listed in a previous year. Previously listed candidates who underwent transplant and subsequently relisted are considered new. Active and inactive patients are included.




**All adult candidates on the liver transplant waiting list.** Adult candidates on the list at any time during the year. Candidates listed at more than one center are counted once per listing.

Figure LI 2: All adult candidates on the liver transplant waiting list. Adult candidates on the list at any time during the year. Candidates listed at more than one center are counted once per listing.




**Distribution of adults waiting for liver transplant by age.** Candidates waiting for transplant at any time in the given year. Candidates listed at more than one center are counted once per listing. Active and inactive candidates are included. Age is determined at the earliest of transplant, death, removal, or December 31 of the year.

Figure LI 3: Distribution of adults waiting for liver transplant by age. Candidates waiting for transplant at any time in the given year. Candidates listed at more than one center are counted once per listing. Active and inactive candidates are included. Age is determined at the earliest of transplant, death, removal, or December 31 of the year.




**Distribution of adults waiting for liver transplant by sex.** Candidates waiting for transplant at any time in the given year. Candidates listed at more than one center are counted once per listing. Active and inactive patients are included.

Figure LI 4: Distribution of adults waiting for liver transplant by sex. Candidates waiting for transplant at any time in the given year. Candidates listed at more than one center are counted once per listing. Active and inactive patients are included.




**Distribution of adults waiting for liver transplant by race and ethnicity.** Candidates waiting for transplant at any time in the given year. Candidates listed at more than one center are counted once per listing. Active and inactive patients are included.

Figure LI 5: Distribution of adults waiting for liver transplant by race and ethnicity. Candidates waiting for transplant at any time in the given year. Candidates listed at more than one center are counted once per listing. Active and inactive patients are included.




**Distribution of adults waiting for liver transplant by diagnosis.** Candidates waiting for transplant at any time in the given year. Candidates listed at more than one center are counted once per listing. Active and inactive patients are included. HCC, hepatocellular carcinoma; HCV, hepatitis C virus; MASH, metabolic dysfunction--associated steatohepatitis.

Figure LI 6: Distribution of adults waiting for liver transplant by diagnosis. Candidates waiting for transplant at any time in the given year. Candidates listed at more than one center are counted once per listing. Active and inactive patients are included. HCC, hepatocellular carcinoma; HCV, hepatitis C virus; MASH, metabolic dysfunction–associated steatohepatitis.