Intestine

OPTN/SRTR 2017 Annual Data Report: Intestine

Abstract

Despite improvements in medical and surgical treatment of intestinal failure, intestine transplant continues to play an important role. In 2017, 109 intestine transplants were performed, 62 in adults and 47 in children, reflecting the changed age distribution over the past decade of candidates waitlisted for intestine and intestine-liver transplant from largely pediatric to increasing proportions of adults. In 2017, 56.0% of candidates on the intestine list at any time during the year were aged younger than 18 years, with a decrease over time in those aged younger than 6 years and an increase in those aged 6-17 years. Adults accounted for 44.0% of candidates on the list at any time during the year, with an increase since 2013 in those aged 18-34 years and a decrease in those aged 35 years or older. By age, the pretransplant mortality rate was highest for adult candidates at 7.9 per 100 waitlist-years and lowest for pediatric candidates at 3.7 per 100 waitlist-years. Patient survival varied by age and type of transplant, and was lowest for adult intestine-liver recipients (1- and 5-year survival 66.7% and 42.6%, respectively) and highest for pediatric intestine recipients (1- and 5-year survival 86.2% and 75.4%, respectively).

Introduction

Medical and surgical advances in treatments of intestinal failure have led to a continued decrease in the number of transplants over the past decade. Patient survival has improved, and morbidity associated with parenteral nutrition, including liver failure, has declined. Nevertheless, intestine transplant still plays an important role in the treatment of intestinal failure. Intestine transplants may be performed in isolation, with a liver transplant, or as part of a multi-visceral transplant including any combination of liver, stomach, pancreas, colon, spleen, and kidney. There are notable differences in patients and transplant outcomes for intestine transplants with and without liver. Information on the waiting list, transplants, and outcomes is presented for both types of transplants, referred to as intestine-liver and intestine transplants, respectively.

Waiting List

Over the past decade, the number of new patients added to the intestine transplant waiting list has steadily declined, reaching a low of 155 in 2017 compared with 301 in 2006 (Figure IN 1). Almost equal numbers of new patients were added to the waiting list for intestine (76) and for intestine-liver (79) transplants. Among the 257 prevalent patients on the waiting list at the end of 2017, 153 (59.5%) were waiting for intestine and 104 (40.5%) for intestine-liver transplant (Figure IN 2, Table IN 4). Over the past decade, the age distribution of candidates waitlisted for intestine and intestine-liver transplant shifted from primarily pediatric to increasing proportions of adults (Figure IN 3). In 2017, 56.0% of candidates on the intestine waiting list were aged younger than 18 years, with a decrease over time in those aged younger than 6 years and an increase in those aged 6-17 years. Adults account for 44.0% of candidates on the list, with an increase in those aged 18-34 years and a decrease in those aged 35 years or older. The racial/ethnic distribution has remained relatively consistent (Figure IN 5). The most common etiology of intestinal failure remained short-gut syndrome (SGS; 51.1%), which encompasses a large group of diagnoses (Figure IN 6). In 2017, 44.7% of candidates were on the waiting list for less than 1 year, 16.5% for 1 to less than 2 years, and 38.8% for 2 or more years (Figure IN 7).

Characteristics of intestine and intestine-liver candidates on the waiting list at the end of 2017 were similar with respect to age and race (Table IN 1). Intestine candidates were 58.8% female and intestine-liver candidates 38.5% female. Considering disease etiology, pseudo-obstruction, necrotizing enterocolitis, and non-congenital SGS were more common among intestine transplant candidates and enteropathies and congenital SGS were more common among intestine-liver candidates (Table IN 2). Intestine-liver candidates were more often status 1 than intestine candidates (52.9% vs. 32.7%). Listing for retransplant was more common among intestine-liver candidates than among intestine candidates (Table IN 3). Transplant rates and trends varied by candidate age and transplant type (intestine, intestine-liver) but transplant rates have decreased for all groups over the past decade (Figure IN 10). In 2017, transplant rates were higher for intestine-liver candidates than for intestine candidates. Transplant rates were 90.7 per 100 waitlist-years for pediatric intestine-liver candidates and 60.7 per 100 waitlist-years for adult intestine-liver candidates, compared with 37.7 for pediatric intestine-alone candidates and 17.5 for adult intestine-alone candidates.

Of the 84 candidates removed from the intestine waiting list in 2017, 50 (60.0%) underwent deceased donor transplant, 4 (4.8%) died, 11 (13.1%) were removed from the list because their condition improved, and 2 (2.4%) were considered too sick to undergo transplant (Table IN 5). Of the 84 candidates removed from the intestine-liver waiting list, 57 (67.9%) underwent deceased donor transplant, 11 (13.1%) died, 4 (4.8%) were removed from the list because their condition improved, and 2 (2.4%) were considered too sick to undergo transplant. Regarding 3-year outcomes, 64.8% of intestine transplant candidates listed in 2014 underwent deceased donor transplant, 5.7% died, 6.7% were removed from the list, and 22.9% were still waiting in 2017 (Figure IN 11). Of intestine-liver candidates listed in 2014, 68.6% underwent deceased donor transplant, 10.5% died, 15.2% were removed from the list, and 5.7% were still waiting in 2017 (Figure IN 12). Among candidates listed in 2016-2017, median time to transplant was 5.2 months for adult and 8.2 months for pediatric intestine-liver transplant candidates, and 4.7 months for adult intestine transplant candidates (Figure IN 13). The median was not observed for pediatric intestine transplant candidates; the median for those listed in 2014-2015 was 46.9 months.

Among candidates on the waiting list in 2016-2017, by age, pretransplant mortality was higher for adults, at 7.9 per 100 waitlist-years, and lower for pediatric patients, at 3.7 per 100 waitlist-years (Figure IN 14). Pretransplant mortality was similar for the different etiologies of organ failure (Figure IN 16). Regarding age and type of transplant, pretransplant mortality was highest for pediatric intestine-liver and lowest for adult intestine candidates (respectively, 18.8 vs. 1.9 deaths per 100 waitlist-years in 2016-2017) (Figure IN 17).

Donation

The number of recovered organs in 2017 was the lowest yet, at 108 (Figure IN 18). The largest proportions of intestine donors in 2017 were aged younger than 5 years (33.3%) and 18-34 years (30.6%) (Figure IN 19). Most intestine donors were white (67.6%, Figure IN 20). The overall rate of intestines recovered for transplant and not transplanted was 4.5% in 2016-2017 (Figure IN 22). The most common cause of death among deceased intestine donors has been head trauma, 50.9% in 2017 (Figure IN 25).

Transplant

The number of intestine transplants performed decreased to its second-lowest level, 109, in 2017 (Figure IN 26). In 2017, 19 programs were performing intestine transplants, six programs only in children, five only in adults, and eight in both adults and children (Figure IN 34). The median annual program volume was 3 intestine transplants in 2017; the 95th percentile of program volume was 20 transplants (Figure IN 35). In 2017, 67.0% of intestine transplants were performed at programs performing 10 or more transplants, and 22.0% of intestine transplants were performed at programs performing 3-9 per year (Figure IN 36).

The age distribution of intestine and intestine-liver transplant recipients changed substantially over the past decade, with adult recipients outnumbering pediatric recipients in 2017, 62 vs. 47 (Figure IN 27). In 2007, there were 87 adult recipients and 111 pediatric recipients. In 2017, almost half of intestine-liver recipients were aged younger than 18 years, 49.1% vs. 36.5% of intestine recipients (Table IN 6). SGS (congenital and non-congenital) was the main cause of disease leading to both intestine and intestine-liver transplant (Table IN 7). The proportion of recipients who waited a year or more for an intestine transplant was 15.4%, compared with 17.6% for intestine-liver recipients (Table IN 8).

Immunosuppression

Regarding induction therapy in 2017, 59.0% of intestine transplant recipients, with and without a liver, received T-cell depleting agents, 14.0% received interleukin-2 receptor antagonists, and 30.0% reported no induction (Figure IN 31). The initial (from transplant to 1 year follow-up) immunosuppression agent regimens used most commonly in 2017 were tacrolimus and steroids (44.0%) followed by tacrolimus, mycophenolate mofetil and steroids, and other (20.0%) (Figure IN 32).

Outcomes

Graft failure has declined since the late 1990s, but plateaued over the past decade. The age-, sex-, and race-adjusted graft failure rate among intestine transplant recipients was 12.7% at 6 months and 19.4% at 1 year for transplants in 2015-2016, 39.0% at 3 years for transplants in 2013-2014, 52.3% at 5 years for transplants in 2011-2012, and 66.8% at 10 years for transplants in 2007-2008 (Figure IN 37). Among intestine-liver transplant recipients, the graft failure rate was 22.7% at 6 months, and 26.8% at 1 year for transplants in 2015-2016, 36.9% at 3 years for transplants in 2013-2014, 42.0% at 5 years for transplants in 2011-2012, and 55.8% at 10 years for transplants in 2007-2008 (Figure IN 38). For intestine transplants in 2010-2012, Figure IN 39 shows 5-year graft survival curves by recipient age and Figure IN 40 shows survival by organ transplanted. For intestine transplants with or without a liver in 2010-2012, 1- and 5-year graft survival was 77.5% and 57.9%, respectively, for recipients aged younger than 18 years, and 72.0% and 43.5%, respectively, for recipients aged 18 years or older (Figure IN 39). One- and 5-year graft survival was 74.5% and 46.5%, respectively, for intestine recipients, and 74.5% and 55.2%, respectively, for intestine-liver recipients (Figure IN 40). The number of recipients alive with a functioning intestine graft steadily increased over time to 1189 on June 30, 2017; 42.4% were pediatric intestine-liver transplant recipients (Figure IN 43). The incidence of first acute rejection in the first year post-transplant varied by age group and transplant procedure. Among recipients in 2015-2016, incidence of acute rejection was highest in pediatric intestine recipients (60.5%) and lowest in adult intestine-liver recipients (31.1%) (Figure IN 44). For recipients who underwent transplant in 2005-2015, 9.6% of intestine recipients (Figure IN 46) and 6.9% of intestine-liver recipients (Figure IN 47) developed post-transplant lymphoproliferative disorder within 5 years post-transplant. Incidence was highest among recipients who were negative for Epstein-Barr virus (EBV), 11.6% of intestine recipients. Patient survival for transplants in 2010-2012 varied by age and type of transplant. Patient survival was lowest for adult intestine-liver recipients (1- and 5-year survival 66.7% and 42.6%, respectively) and highest for pediatric intestine recipients (1- and 5-year survival 86.2% and 75.4%, respectively) (Figure IN 48).

Figure List

Waiting list

Deceased donation

Figure IN 18. Deceased intestine donor count by age
Figure IN 19. Distribution of deceased intestine donors by age
Figure IN 20. Distribution of deceased intestine donors by race
Figure IN 21. Rates of intestines recovered for transplant and not transplanted by donor age
Figure IN 22. Rates of intestines recovered for transplant and not transplanted by donor sex
Figure IN 23. Rates of intestines recovered for transplant and not transplanted by donor race
Figure IN 24. Rates of intestines recovered for transplant and not transplanted, by donor risk of disease transmission
Figure IN 25. Cause of death among deceased intestine donors

Transplant

Outcomes

Table List

Waiting list

Table IN 1. Demographic characteristics of candidates on the intestine transplant waiting list on December 31, 2017
Table IN 2. Clinical characteristics of candidates on the intestine transplant waiting list on December 31, 2017
Table IN 3. Listing characteristics of candidates on the intestine transplant waiting list on December 31, 2017
Table IN 4. Intestine transplant waitlist activity, 2017
Table IN 5. Removal reason among intestine transplant candidates, 2017

Transplant

Table IN 6. Demographic characteristics of intestine transplant recipients, 2017
Table IN 7. Clinical characteristics of intestine transplant recipients, 2017
Table IN 8. Transplant characteristics of intestine transplant recipients, 2017

A line plot for candidates listed for intestine transplant on december 31 each year; the in category increases by 41.7% from 108 candidates at 2006 to 153 candidates at 2017; the in to li category decreases by 14.0% from 121 candidates at 2006 to 104 candidates at 2017; and the all category increases by 12.2% from 229 candidates at 2006 to 257 candidates at 2017. — **Figure IN 2. Candidates listed for intestine transplant on December 31 each year**
Candidates concurrently listed at multiple centers are counted once. Those with concurrent listings and active at any program are considered active. IN, intestine without liver; IN-LI, intestine-liver.

A line plot for distribution of candidates waiting for intestine transplant by age; the less than 6 category decreases by 45.3% from 53.7 percent at 2006 to 29.4 percent at 2017; the 6 to 17 category increases by 91.5% from 13.9 percent at 2006 to 26.6 percent at 2017; the 18 to 34 category increases by 60.0% from 11.5 percent at 2006 to 18.4 percent at 2017; and the greater than or equal to 35 category increases by 22.6% from 20.9 percent at 2006 to 25.6 percent at 2017. — **Figure IN 3. Distribution of candidates waiting for intestine transplant by age**
Candidates waiting for transplant at any time in the given year. Candidates listed concurrently at multiple centers are counted once. Age is determined at the later of listing date or January 1 of the given year. Active and inactive candidates are included.

A line plot for distribution of adults waiting for intestine transplant by sex; the male category is 52.9 percent at 2006 and remains relatively constant with a value of 51.5 percent at 2017; and the female category is 47.1 percent at 2006 and remains relatively constant with a value of 48.5 percent at 2017. — **Figure IN 4. Distribution of adults waiting for intestine transplant by sex**
Candidates waiting for transplant at any time in the given year. Candidates listed concurrently at multiple centers are counted once. Active and inactive patients are included.

A line plot for distribution of candidates waiting for intestine transplant by race; the white category decreases by 10.9% from 65.2 percent at 2006 to 58.1 percent at 2017; the black category increases by 31.4% from 16.3 percent at 2006 to 21.4 percent at 2017; the hispanic category is 14.5 percent at 2006 and remains relatively constant with a value of 15.5 percent at 2017; the asian category is 2.6 percent at 2006 and remains relatively constant with a value of 2.6 percent at 2017; and the other/unknown category increases by 67.1% from 1.4 percent at 2006 to 2.4 percent at 2017. — **Figure IN 5. Distribution of candidates waiting for intestine transplant by race**
Candidates waiting for transplant at any time in the given year. Candidates listed concurrently at multiple centers are counted once. Active and inactive candidates are included.