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Organ Donation and Transplantation in the UK—The Last Decade

A Report From the UK National Transplant Registry

Johnson, Rachel J.; Bradbury, Lisa L.; Martin, Kate; Neuberger, James On behalf of the UK Transplant Registry

Author Information
doi: 10.1097/01.TP.0000438215.16737.68
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SUMMARY

Over the decade between 2003 and 2012, the UK has seen major changes in how organ donation and transplantation is delivered. The number of deceased organ donors has increased from 709 (12.0 per million population [pmp]) to 1,164 (18.3 pmp); this increase has been predominantly a result of an increase in donors after circulatory death (DCD) (from 1.1 pmp to 7.9 pmp) while the numbers of donors after brain death (DBD) has remained broadly stable (around 10.5 pmp). The donor population has become older (from 14% 60 years or over to 35%) and heavier (from 14% with body mass index ≥30 kg/m2 to 23%). Despite these changes in demographic factors, the number of organs retrieved from DBD donors has risen from a mean of 3.6 to 4.0 per donor and for DCD donors from 2.2 to 2.6. The number of transplants in adults in 2012 was 2,709 (967 DBD, 708 DCD, and 1,034 living) for kidney alone, 246 pancreas (including 172 kidney and pancreas), 792 (611 DBD, 142 DCD, 36 living, and 3 domino) for liver, 136 for heart only, and 179 (145 DBD and 34 DCD) for lung only. Median waiting times to transplant for adult patients were 1,167, 339, 141, 293, and 311 days, respectively. The proportion of adult non-urgent registrants in 2009 (2007 for kidneys) who were removed from the waiting list or died awaiting a graft within 1 year was 3% for kidneys, 6% for pancreas, 19% for liver, 27% for heart, and 24% for lung. Outcomes after solid organ transplants are improving; for adult patients grafted between 2003 and 2005, 5-year graft survival for kidney is 84% (DBD), 87% (DCD), and 92% (living donor), for simultaneous kidney and pancreas 72%, and for pancreas alone 50% (DBD). Five-year patient survival for liver is 77% (DBD) and 68% (DCD), heart 67%, and lung 52% (DBD).

Although rates of organ donation and transplantation have increased in the UK, this has been almost solely because of a rise in DCD donation. Although donor age and weight is increasing, graft survival has generally improved. Despite a recent fall in the number of patients on the transplant waiting list, there remains a significant gap between the need for transplantation and the number of organs available from deceased and living donors.

The implementation of a new strategy following the recommendations of the Organ Donation Task Force in 2008 has had a major impact in bringing together clinicians involved in both organ donation and transplantation, and these changes and clinical enthusiasm have been instrumental in achieving success. With an emphasis on the need to increase the family consent rate for organ donation, which has failed to show any improvement over the last 5 years, a new UK strategy for organ donation and transplantation, introduced in 2013, will further increase organ transplantation in the UK.

INTRODUCTION

Over the last decade, in the UK, as elsewhere, there have been major advances in supporting solid organ donation and transplantation. Coincidental with the many advances in public health and safety, and the clinical management of both potential and actual donors, management of people with end-stage disease has improved. Developments in organ preservation and retrieval, in surgical and anesthetic management and postoperative care, immunosuppression, and tolerance have all contributed not only to better outcomes but to making transplantation more accessible as surgeons accept older and higher risk recipients and as more contraindications (such as infection with hepatitis B virus or HIV) have been removed. These events, all welcome, have combined to make the donor pool smaller and higher risk and the number of people who would benefit from transplantation greater.

For organ transplantation to succeed, a robust administrative, legislative, and ethical framework must be in place, and the last decade has seen major changes (Table 1). Of those milestones listed, two have had major impact: the formation of NHS Blood and Transplant (NHSBT) as a special authority of the NHS and the report of the Organ Donation Task Force. NHSBT was formed in 2006 with the merger of the National Blood Service with UK Transplant. The merger was primarily as a consequence of the wish to reduce the number of “quangos” (quasi-autonomous non-governmental organizations) and gave NHSBT the statutory authority, among other responsibilities, for ensuring a supply of organs for transplantation, for maintaining the National Transplant Waiting List, and for the selection and allocation of solid organs from deceased donors. The remit for organ donation covers all four UK nations (England, Scotland, Wales, and Northern Ireland) and is the only NHS body that has a UK-wide remit. However, NHSBT does not commission organ transplantation: commissioning of donation, transplantation, and donor characterization is done now at a national level for all four nations, but the nations work together as organs donated by deceased donors are considered a national resource. The second major impact was the publication of the report of the Organ Donation Task Force. This task force, chaired by Elisabeth Buggins, recognized the relatively weak performance of the UK in organ donation and made 14 recommendations. It was suggested that implementation of all recommendations should result in a 50% increase in deceased donors over 5 years: the recommendations were put in place and, as can be seen in the following pages, the target was achieved, despite a falling potential donor pool and more higher risk donors, primarily because of an increase in donors after circulatory death. The strategy based on the recommendations lasted until 2013 and a new strategy until 2020 was launched in July 2013. A further recent development has been the transposition into UK law of the recent EU Directive on the Standards and Safety of Organs for Transplantation, which has placed a further layer of regulation on the organ donation and transplantation pathway; the full impact of these changes is yet to be seen.

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TABLE 1:
Some significant milestones to provide a framework for UK Organ Donation and Transplantation

Against this evolving background, some of the UK data are presented relating to organ donation and transplantation. The UK Transplant Registry was first formally established in 1972, and it has grown to become a major national resource. Today, the Registry includes the Potential Donor Audit, the National Transplant Waiting List, and records of all transplants from deceased and living donors in the UK with follow-up of both patient and graft. There are links with the Office for National Statistics (ONS) Register so that all recipient deaths are captured. It is important to acknowledge the contribution of all those who have contributed to making the Registry a complete picture of UK donation and transplantation; without the consistent and enthusiastic support of clinicians, clerical staff and managers in donor hospitals, commissioners, retrieval teams and the statistics team, data management staff, IT staff, and managers in NHSBT, the Registry would be less complete and a far less valuable national resource.

It is recognized that without donation, there is no transplantation and therefore the data presented here represent the commitment and enthusiasm of a very wide spectrum of people: intensive care and emergency department doctors and nurses, anesthetists, microbiologists, radiologists, pathologists, clinical scientists, transplant surgeons, physicians and nurses, laboratory scientists, the pharmaceutical industry, ethicists, managers, statisticians, researchers, and, most importantly, donors and their families.

Details of policies and patient data including outcomes are available on the NHSBT website (www.odt.nhs.uk).

NATIONAL OVERALL DATA

During the last decade, there has been a progressive increase in the number of deceased solid organ donors in the UK (Fig. 1), from 709 in 2003 to 1,164 in 2012. This increase has been a result of an increase in donation after circulatory death (DCD) from 1.1 to 7.9 donors per million population (pmp) between 2003 and 2012, a time when organ donation after brain death (DBD) has remained static at approximately 10.4 pmp (Fig. 2). During this decade, the profile of donors has changed with a progressive increase in both age (Fig. 3) and body mass index (BMI) (Fig. 4), so that the proportion of donors aged 60 years and over has increased from 14% to 35% and the proportion of donors who were obese (BMI ≥30 kg/m2) has increased from 14% to 23%. The mean age of donors in 2012 was 54 years for DCD donors and 49 years for DBD donors. In 2012, of the 1,164 deceased solid organ donors, most died from cerebral trauma and 93% were classified as white with only 2% each Asian and Black (Table 2).

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FIGURE 1:
Number of deceased donors in the UK, January 1, 2003 to December 31, 2012.
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FIGURE 2:
Donor rates per million population in the UK, January 1, 2003 to December 31, 2012.
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FIGURE 3:
Age of deceased donors in the UK, January 1, 2003 to December 31, 2012.
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FIGURE 4:
BMI of deceased donors in the UK, January 1, 2003 to December 31, 2012. Note that BMI cannot be determined for all deceased donors, thus numbers indicated in this figure are the numbers of donors for which BMI was available, not total numbers of donors.
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TABLE 2:
Demographic characteristics of organ donors in the UK, January 1 to December 31, 2012

Between 2008 and 2012, the total number of transplants has increased from 3,508 to 4,100 (Table 3). The number of transplants from deceased donors has increased from 2,548 to 3,027.

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TABLE 3:
Transplants performed in the UK, January 1, 2008 to December 31, 2012

There is a discrepancy between the percentage increase in number of deceased donors and the smaller percentage increase in number of organ transplants. This is largely attributable to the increase in DCD rather than DBD donation; not only are organ donation rates higher from DBD donors compared with DCD donors (Fig. 5), the proportion of organs retrieved from DBD donors that are subsequently transplanted is also higher: in excess of 90% for all DBD donor organs except pancreas (59%), compared with 73% to 85% of DCD organs (50% for pancreas). In 2012, 2% of DBD donors and 14% of DCD donors did not result in any organ transplants.

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FIGURE 5:
Organ donor rates per million population in the UK, January 1 to December 31, 2012.

Potential Donor Audit

For over a decade, NHSBT has worked with hospital clinicians and Specialist Nurses for Organ Donation to conduct an audit (potential donor audit—PDA) of all deaths occurring in those aged 75 years or under in Intensive Care Units and more recently Emergency Departments in UK hospitals. The PDA shows that there are approximately 1,200 eligible DBD1 and approximately 3,000 eligible DCD2 donors each year (Fig. 6). One of the biggest barriers to organ donation is the low family consent rate in the UK (Table 4), and this has changed very little over time, despite the infrastructure changes as a result of the implementation of the Organ Donation Taskforce recommendations.

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FIGURE 6:
Number of eligible DBD and DCD donors, January 1, 2010 to December 31, 2012. Note that Emergency Departments (ED) have been included in the PDA since April 1, 2010. Eligible donors who die in the ED account for less than 10% of eligible donors.
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TABLE 4:
DBD and DCD key metrics from the Potential Donor Audit, January 1, 2010 to December 31, 2012
  1. Eligible donors after brain death (DBD) are defined as patients for whom death was confirmed following neurological tests and who had no absolute medical contraindications to solid organ donation.
  2. Eligible donors after circulatory death (DCD) are defined as patients who had treatment withdrawn and death was anticipated within 4 hours, with no absolute medical contraindications to solid organ donation.

KIDNEY TRANSPLANTATION

Donation

The number of kidneys donated from DBD donors has remained static at about 1,200 per year over the last 10 years, although there has been a slight increase in the proportion of retrieved kidneys not subsequently transplanted (from 3% to 6%). In contrast, the number of kidneys donated from DCD donors has increased from 125 in 2003 to 965 in 2012 with the proportion that are retrieved but not transplanted increasing from 8% to 17%.

Waiting List

The number of new registrants each year for a deceased donor kidney-only transplant has increased from 1,917 to 2,647 in 2012 (Fig. 7). During this time, the numbers of patients on the waiting list has risen from 5,072 on December 31, 2003 to a peak of 6,991 at the end of 2008 but has fallen each year since then, to reach 6,302 at the end of 2012. This represents a 10% drop in the number of active transplant list kidney-only patients and coincides with an increase in the number of deceased and living donor transplants.

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FIGURE 7:
Number of new active kidney registrations and patients on the active transplant list at December 31 in the UK, January 1, 2003 to December 31, 2012.

Allocation

There are 23 designated adult kidney transplant centers in the UK and 10 pediatric centers. All kidneys from DBD donors were first allocated on a fully national basis in 1998 (1). The scheme was based on two principles: equity of access to transplant and transplant utility (maximizing outcomes). It included three tiers based on the degree of donor or recipient HLA matching. Allocation arrangements were reviewed in 2004 and 2005 and a revised national kidney allocation scheme (NKAS) was introduced for all kidneys from DBD donors in 2006 (2). The scheme was based on the same principles but with less emphasis on HLA matching and is still in place. Factors included in the prioritization of patients for individual donor kidneys are waiting time, HLA match and age combined (to prioritize well-matched transplants for younger patients—to maximize outcomes and minimize resultant sensitization), donor-recipient age difference, distance between donor and recipient (to reflect cold ischemia time), blood group match, and HLA-B and /DR homozygosity. Highly sensitized patients (≥85% calculated Reaction Frequency) are prioritized for 000 HLA-A, B, DR mismatched grafts, and pediatric patients (<18 years) are generally given priority over adult patients. This allocation scheme is based on five tiers, with less emphasis on HLA matching beyond 000 HLA-A, B, DR mismatches than the previous scheme:

  • Tier A—000 mismatched pediatric patients of high priority (highly sensitized or HLA-DR homozygous)
  • Tier B—000 mismatched pediatric patients—others
  • Tier C—000 mismatched adult patients of high priority (highly sensitized or HLA-DR homozygous)
  • Tier D—000 mismatched adult patients—others and favorably matched pediatric patients (100, 010, 110 mismatches)
  • Tier E—All other eligible patients (which excludes any possible transplants with either two HLA-B plus one DR mismatch or two DR mismatches).

Full details of the scheme can be found at http://www.odt.nhs.uk/transplantation/policies/.

In contrast, kidneys from DCD donors have historically been allocated on a regional basis, although it is planned to introduce a national allocation scheme for DCD kidneys in 2014. The scheme will be based on that for DBD donor kidneys, although it reflects the particular importance of cold ischemia time in DCD kidney transplantation and has more of an emphasis on local donor-recipient allocation.

Outcome From Listing

Of the 2,987 adult kidney-only registrants joining the transplant list in 2007, 20% were transplanted within the first year and 65% in the first 5 years (Fig. 8). In comparison, 77% were still waiting at the end of the first year and 16% at 5 years. Five years after registration, 8% of patients had died before receiving a graft and 11% had been removed from the list for various reasons. Waiting times vary between patients, but the median wait based on patients registering between January 1, 2006 and December 31, 2009 is 1,167 days for adults and 346 days for pediatric patients. Patients of blood groups O and B wait longest (over 1,300 days), while blood group AB patients have the shortest wait (approximately 600 days) (Table 5).

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FIGURE 8:
Post-registration outcome for 2,987 new adult kidney only registrations made in the UK, January 1, 2007 to December 31, 2007.
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TABLE 5:
Median waiting times to kidney transplant, by blood group

Transplant Activity

The total number of kidney-only transplants in the UK has increased by 17% in the last 4 years: from 2,307 in 2008 to 2,709 in 2012 (Table 3). This reflects a slight increase in the number of living donor kidneys (from 924 to 1,034—12%) and in DBD kidneys (from 944 to 967—2%) but a greater increase in DCD kidneys (from 439 to 708—61%). The total number of kidney transplants (including multi-organ transplants) has increased from 1,748 in 2003 to 2,901 in 2012 (Fig. 9); this has been a result of an increase in living donor transplants (from 7.6 to 16.3 pmp) and DCD kidney transplants (from 1.9 to 11.7 pmp) while the number of DBD kidney transplants has actually fallen (from 20.0 to 17.7 pmp) (Fig. 10). Of the 2,709 transplants in 2012, 128 (5%) were in pediatric patients.

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FIGURE 9:
Number of kidney transplants in the UK, January 1, 2003 to December 31, 2012.
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FIGURE 10:
Kidney transplant rates per million population in the UK, January 1, 2003 to December 31, 2012.

Living donor kidney transplants: there has been a progressive increase in the number of living donor kidney transplants between 2003 and 2010 although numbers since then have stabilized. Although the number of transplants from genetically related donors has increased from 348 in 2003 to 532 in 2012, as a proportion of activity, the rate has fallen from 77% to 51% (Fig. 11). This is because of an increase in transplants from genetically unrelated donors—either directed (compatible and incompatible) or indirect through paired or altruistic donation schemes (3) (referred to as the National Living Kidney Donor Sharing Schemes). The number of altruistic donors (non-directed donors) has increased from 3 in 2007 to 60 in 2012. The paired exchange and ABO- and HLA-incompatible programs are also important factors in increasing living kidney donor transplantation and the access to transplantation for hard-to-match recipients.

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FIGURE 11:
Living donor kidney transplants in the UK, January 1, 2003 to December 31, 2012.

Pre-emptive kidney transplants: The number of pre-emptive kidney transplants in adults from DBD donors has doubled over the decade from 5% to 11%. In 2012, of the 2,709 kidney-only transplant recipients, 2,642 (98%) had reported dialysis status at time of transplant. Of these transplants, 559 (21%) were pre-emptive (20% of adults and 35% of pediatric patients). In both adult and pediatric patients, a higher proportion of living donor than deceased donor kidney transplants were pre-emptive of the need for dialysis: 35% versus 11% of adults and 39% versus 30% of pediatric patients.

HLA matching: Looking at HLA match of DBD kidney transplants according to total HLA-A+B+DR mismatches shows that the implementation of the revised DBD kidney allocation scheme in 2006 has been associated with an increase in the proportion of recipients receiving a DBD kidney with three to four HLA mismatches, but not at the expense of 000 HLA-A, B, DR mismatched grafts In addition, there are now very few grafts with 5 or 6 mismatches (Fig. 12). This pattern reflects the design of the allocation scheme which enabled many more long waiting patients to undergo transplantation. The DBD allocation scheme actually uses HLA mismatch classified in four groups:

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FIGURE 12:
Adult kidney-only transplants from DBD in the UK by HLA mismatch, January 1, 2003 to December 31, 2012.

The proportion of level 3 mismatches increased with the introduction of the 2006 NKAS (2) to facilitate transplantation of more long waiting patients. DCD kidney transplants are less well matched, reflecting the local allocation arrangements (Fig. 13). This will change as national allocation arrangements are introduced.

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FIGURE 13:
Adult kidney-only transplants from DCD in the UK by HLA mismatch, January 1, 2003 to December 31, 2012.

Outcomes Posttransplant

Unadjusted adult patient and graft survival remain good despite increasing donor age, with a slight but progressive rise in 1-year graft survival but stable patient survival in recipients of DBD kidneys (Fig. 14), whereas the outcomes of both graft and patient after DCD kidney transplantation are much improved over early experience (2000–2002), yet see a small deterioration in recent years, reflecting the increasingly higher risk donors (Fig. 15). Living donor graft survival rates for adult patients also show improvement over time with 96% of patients surviving at least 5 years after their transplant (Fig. 16). There has been a progressive improvement in graft outcomes for pediatric recipients of DBD kidneys while patient survival rates remain very high (Fig. 17). Similarly, graft and patient survival after living donation have improved since 2002 (Fig. 18).

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FIGURE 14:
Adult kidney recipients-donor after brain death, January 1, 2000 to December 31, 2011.
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FIGURE 15:
Adult kidney recipients-donor after circulatory death, January 1, 2000 to December 31, 2011.
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FIGURE 16:
Adult kidney recipients-living donor, January 1, 2000 to December 31, 2011.
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FIGURE 17:
Pediatric kidney recipients-donor after brain death, January 1, 2000 to December 31, 2011.
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FIGURE 18:
Pediatric kidney recipients-living donor, January 1, 2000 to December 31, 2011.

PANCREAS (AND KIDNEY/PANCREAS) TRANSPLANTS

Donation

There has been a steady increase in the number of pancreases donated from both DBD and DCD donors over the 10 years 2003 to 2012: from 86 to 345 DBD pancreases and from none to 92 DCD pancreases, although only around two thirds of DBD and half the retrieved DCD pancreases are transplanted. The lower usage rate relative to other organs is related to a higher incidence of pancreas damage during retrieval because of the positioning of the organ within the body creating a more complex retrieval process. Relatively minor injury to the capsule that would not affect the liver or kidney makes a pancreas not safe to transplant.

Waiting List

The number of new registrants for pancreas and islets increased progressively from 83 in 2003 to 383 in 2008 and since then has remained around 275. The number of patients awaiting a pancreas has followed a similar pattern, peaking in 2009 (Fig. 19). Of those who were listed in 2009, 35% had been transplanted and 6% had been removed or died at the end of the first year (Fig. 20).

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FIGURE 19:
Number of new active pancreas and islet registrations and patients on the active transplant list at December 31 in the UK, January 1, 2003 to December 31, 2012.
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FIGURE 20:
Post-registration outcome for 290 new adult pancreas-only, and kidney and pancreas registrations made in the UK, January 1, 2009 to December 31, 2009.

Allocation

In the UK, there are eight designated vascularized pancreas transplant centers and seven pancreas islet transplant centers. Until December 2010, pancreases were allocated on a regional basis. However, thereafter pancreases were allocated on a national basis, using an allocation system based on HLA mismatch, waiting time, sensitization, travel time from retrieval to implantation hospital, donor BMI, dialysis status, and donor and recipient age match. The weight given to distance (as a surrogate of cold ischemic time) is much greater for DCD donors than for DBD donors. Donor BMI is used to direct pancreases from lower BMI donors primarily (but not exclusively) to vascularized pancreas waiting list patients and those from higher BMI donors primarily to islet waiting list patients.

Outcome From Listing

Of the 290 registrants joining the pancreas transplant list in 2009, 35% were transplanted within the first year and 74% in the first 3 years (Fig. 20). In comparison, 59% were still waiting at the end of the first year and 8% at 3 years. Three years after registration, 5% of patients had died before receiving a graft and 13% had been removed from the list for various reasons. The median waiting time to pancreas transplant is 339 days (95% CI 303–375 days), with some variation according to blood group (Table 6).

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TABLE 6:
Median waiting times to pancreas transplant, by blood group

Transplant Activity

The first pancreas islet cell transplant was performed in the UK in 2005, and in 2012, there were 37 islet transplants carried out compared with 209 whole organ grafts. Of the 246 transplants, 46 (19%) were from DCD donors (Fig. 21), corresponding to a transplant rate of 3.9 pmp in 2012 (3.1 from DBD) (Fig. 22).

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FIGURE 21:
Number of pancreas and islet transplants in the UK, January 1, 2003 to December 31, 2012.
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FIGURE 22:
Pancreas and islet transplant rates per million population in the UK, January 1, 2003 to December 31, 2012.

Most of the pancreas transplants are simultaneous pancreas and kidney transplants (Fig. 23); the proportion of pancreas after kidney transplants has fallen. The great majority of pancreas transplants are for type 1 diabetes. Very few pancreas transplants are performed in pediatric patients (<18 years).

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FIGURE 23:
Pancreas and islet transplants in the UK by type, January 1, 2003 to December 31, 2012.

Outcomes Posttransplant

Simultaneous pancreas kidney (SPK) transplants: graft survival has improved since 2003 to 2005, and most recent transplants have 1-year DBD graft survival of 84% and patient survival of 96% (Fig. 24). Outcomes of SPK transplants from DCD are slightly better (Fig. 25), but given the relatively small numbers and the potential selection bias, it is not certain whether this difference is of any clinical significance.

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FIGURE 24:
Simultaneous kidney and pancreas transplants-donor after brain death, January 1, 2003 to December 31, 2011.
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FIGURE 25:
Simultaneous kidney and pancreas transplants-donor after circulatory death, January 1, 2009 to December 31, 2011.

Pancreas-only transplants: although patient survival remains over 90%, there has been little change in graft survival over the decade, with 1-year DBD and DCD graft survival around 70% (Figs. 26 and 27).

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FIGURE 26:
Pancreas-only transplants – donor after brain death, January 1, 2003 to December 31, 2011.
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FIGURE 27:
Pancreas-only transplants – donor after circulatory death, January 1, 2009 to December 31, 2011.

LIVER TRANSPLANTATION

Donation

Although there is some fluctuation, there has been a slight increase in the number of donated livers from both DBD and a greater increase in DCD livers. The proportion of DCD livers is increasing as a percentage of all deceased donor livers and currently accounts for around one quarter of livers retrieved. The proportion of livers retrieved but not transplanted is greater for DCD than DBD: there are various causes for this difference, but the most commonly cited reason is poor quality of the liver. In 2012, there were 610 DBD liver donors and 194 DCD liver donors.

Waiting List

There are seven designated liver transplant centers: six in England and one in Scotland. In 2007, the criteria for access to the national transplant waiting list were revised. Patients could be listed when their life expectancy without transplant was estimated to be less than following a transplant at 1 year. The prognosis was measured using the UK Model for End-Stage Liver Disease (UKELD) (4) and, given a 1-year survival of 91%, a UKELD score of 53 is a requirement for listing (5). For those with primary liver cell cancer, the Milan criteria (6) were used. There was also a class of variant syndromes where either liver transplantation is indicated for unacceptable quality of life (such as intractable encephalopathy) or where the UKELD score did not reflect the patient’s prognosis (such as those with hepatopulmonary syndrome). Patients should also have a probability of life expectancy after transplantation of at least 50% at 5 years with a quality of life acceptable to the patient.

Over the last 6 years, there has been a progressive increase in the number of patients listed each year (Fig. 28); the number of adults on the waiting list has increased gradually from 2003 but appears to have plateaued in the last year.

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FIGURE 28:
Number of new active liver registrations and patients on the active transplant list at December 31 in the UK, January 1, 2003 to December 31, 2012.

Allocation

Those with fulminant hepatic failure or early graft failure (within 7 days) are eligible for super-urgent listing and have access to donated livers across the UK. If there are no suitable super-urgent recipients, donated livers are allocated to the local center and offered to other centers if there is no suitable recipient. To ensure equity of access to transplantation, the allocation zone for each designated center is adjusted to ensure there is a similar risk of death for patients listed at each center.

Outcome From Listing

Of those adults who were listed for elective liver-only transplants during 2009, two thirds had received a graft within 1 year (Fig. 29) and 14% were still waiting; 19% had either died before a graft was available or were removed from the elective list, primarily because they became too sick.

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FIGURE 29:
Post-registration outcome for 893 new elective liver-only registrations made in the UK, January 1, 2009 to December 31, 2009.

The median waiting time to liver transplant is 141 days (95% CI 131–151 days), with some variation according to blood group (Table 7).

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TABLE 7:
Median waiting times to liver transplant, by blood group

Transplant Activity

Liver transplants: the number of liver transplants has shown a progressive increase in activity over the last decade, from 633 in 2003 to 816 in 2012 (Fig. 30). This increase, corresponding to rates of transplantation of 10.7 to 12.9 pmp (Fig. 31), has been primarily caused by a rise in DCD donors; the number of DBD donors has remained fairly static. There has been a small rise in living donors but numbers remain very small (in 2012, just 39 [4.5%] of the 816 liver transplants were from living donors, some of whom were domino transplants). There was one altruistic living liver donation in 2012. The majority of the deceased donor liver transplants were whole livers, with split livers accounting for 16% of the transplants and reduced grafts for 1%. Indications for those livers that are suitable for splitting have been agreed: when there is no suitable super-urgent listed patient, a liver should be split when the donor has the following characteristics: donors after brain death who are aged less than 40 years, weigh more than 50 kg, and have been in the Intensive Care Unit for less than 5 days. All such donors must be offered for splitting (if there is an appropriate pediatric recipient) if there is no super-urgent, hepatoblastoma, multivisceral, or combined lung and liver patient registered.

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FIGURE 30:
Number of liver transplants in the UK, January 1, 2003 to December 31, 2012.
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FIGURE 31:
Liver transplant rates per million population in the UK, January 1, 2003 to December 31, 2012.

Most deceased donor liver transplant recipients are elective (ranging between 78% and 88% and was 88% in 2012): of those non-emergency patients, indications included alcohol-related liver disease and liver cell cancer (Fig. 32). Of course, many recipients have multiple diagnoses (such as hepatitis C virus and cancer), but the indications shown relate to the primary diagnosis according to the Roberts classification (7). Of the 816 liver transplants in 2012, 111 were in pediatric patients (defined as ≤16 years).

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FIGURE 32:
Deceased donor liver transplants in the UK by indication, January 1, 2003 to December 31, 2012.

Outcomes Posttransplant

Survival of adults receiving DBD livers is improving with time, with 1-year patient survival of 93% (Fig. 33). In contrast, there has been little improvement in the survival of adults receiving a DCD liver, with current 1-year patient survival of 85%. Survival of pediatric liver recipients of a DBD graft remains stable at over 94% at 1 year (Fig. 34).

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FIGURE 33:
Adult liver recipients-patient survival, January 1, 2000 to December 31, 2011.
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FIGURE 34:
Pediatric liver recipients-donor after brain death, January 1, 2000 to December 31, 2011.

CARDIOTHORACIC TRANSPLANTATION

Donation

Lungs: The number of lungs donated in the UK by DBD donors has remained stable at around 300 per year, but, possibly as a consequence of the introduction of ex vivo lung perfusion, the number of lungs donated but not transplanted has fallen from 16% in 2003 to 6% in 2012. In the last 5 years, the number of lungs retrieved from DCD donors has risen to 68 in 2012, although still constitutes a relatively small proportion of the total number of lungs transplanted.

Hearts: the number of donated hearts retrieved fell from 163 in 2003 to 116 in 2010, but has since increased to 140 in 2011 and 135 in 2012. No hearts have been retrieved but not transplanted in the last 2 years.

Waiting List

There are six designated heart and lung transplant units in the UK.

The number of new registrants for lung or heart-lung transplants has remained fairly stable over the last decade (Fig. 35), although the number on the waiting list has fallen by 25% over the last 10 years to 243 at the end of 2012. The median waiting time to lung transplant is 311 days, with patients of blood groups O and B having the longest wait to transplant (Table 8).

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TABLE 8:
Median waiting times to transplant, by organ and blood group
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FIGURE 35:
Number of new active lung, and heart and lung registrations and patients on the active transplant list at December 31 in the UK, January 1, 2003 to December 31, 2012.

The number of new registrants for heart transplantation remained at about 200 per year until 2010, but has increased to approximately 250 new patients per year in the last 2 years (Fig. 36). The waiting list has more than doubled since 2007, with 180 patients on the active transplant waiting list at the end of 2012. The median waiting time to heart transplant is 293 days, with patients of blood group O having the longest wait to transplant (Table 8).

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FIGURE 36:
Number of new active heart registrations and patients on the active transplant list at December 31 in the UK, January 1, 2003 to December 31, 2012.

Allocation

Both hearts and lungs are allocated at present on a regional basis, but this is under review. There is no significant difference in patient outcome from listing between centers, suggesting, perhaps, that there is no inequity of access to transplant. Suitable hearts and lungs not accepted by the regional center are offered to other centers in rotation. The current allocation system for hearts is that there is an urgent category (defined as those on short-term mechanical support, long-term mechanical support with complications, intra-aortic balloon pump, high inotrope requirement, or noninvasive ventilation) and a non-urgent category. Hearts are first offered to the regional center for an urgent recipient and then nationally for an urgent recipient. If there is no suitable urgent recipient nationally, the organ is offered for non-urgent patients in the local region, then nationally, then internationally. There is no urgent category for lungs, so lungs are just offered regionally, and then to other centers on a rota basis.

Outcome From Listing

Of the 260 adults listed during 2009 for a lung-only transplant, 43% had undergone transplantation in the first year, one third remained on the list, and 24% had been removed or died (19%) waiting for a graft (Fig. 37). Of those 115 adults listed for a non-urgent heart during 2009, 49% had retrieved a graft within 1 year and 24% remained on the list. Of the remainder, 15% had died and 12% had been removed from the list, usually as they were too sick (Fig. 38).

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FIGURE 37:
Post-registration outcome for 260 new lung-only registrations made in the UK, January 1, 2009 to December 31, 2009.
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FIGURE 38:
Post-registration outcome for 115 new non-urgent heart-only registrations made in the UK, January 1, 2009 to December 31, 2009.

Transplant Activity

Lung: the number of lung and heart-lung transplants shows a variable but progressive increase over the last decade with an increase in the number of lungs from DCD donors (from <1% in 2003 to 19% in 2012) (Fig. 39). There was one living donor transplant in 2007. The deceased donor activity translates into transplant rates of 2.3 and 0.5 pmp for DBD and DCD donors in 2012, respectively (Fig. 40). Chronic obstructive pulmonary disease and suppurative lung disease remain the commonest indications for lung transplantation.

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FIGURE 39:
Number of deceased donor lung, and heart and lung transplants in the UK, January 1, 2003 to December 31, 2012.
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FIGURE 40:
Lung, and heart and lung transplant rates per million population in the UK, January 1, 2003 to December 31, 2012.

Heart: the number of hearts transplanted in the UK has remained fairly static and disappointingly low (Fig. 41) with a slight fall in the rate of heart transplants, from 2.4 to 2.2 pmp (Fig. 42), possibly reflecting the marginal increase in DBD donors and the rising age and BMI of those donors. There has been an increase in the proportion of heart transplants in the urgent category, such that the majority of heart transplants are in urgent patients (from 26% in 2003 to 68% in 2012). The commonest indication for heart transplantation remains dilated cardiomyopathy (>50%), but the proportion transplanted for congenital heart disease has shown a progressive increase, doubling over the last 10 years to 13% of transplants in 2012. Relatively few pediatric patients (defined as those aged <16 years) undergo transplantation each year: 3 (2%) of lung transplants and 23 (17%) of heart transplants in 2012.

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FIGURE 41:
Number of heart transplants in the UK, January 1, 2003 to December 31, 2012.
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FIGURE 42:
Heart transplant rates per million population in the UK, January 1, 2003 to December 31, 2012.

Outcomes Posttransplant

Lung: 1-year survival of adults undergoing DBD donor lung transplantation has improved since before 2006, but remains around 85% (Fig. 43). Survival of adults receiving a lung from a DCD donor is currently 86% at 1 year (Fig. 43).

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FIGURE 43:
Adult lung recipients-patient survival, January 1, 2000 to December 31, 2011.

Heart: outcomes for both adult and pediatric heart recipients remain relatively unchanged at around 80% and 88%, respectively, at 1 year (Fig. 44).

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FIGURE 44:
Heart recipients-patient survival, January 1, 2000 to December 31, 2011.

THE NEXT DECADE

Over the last decade, the number of organ transplants in the UK has increased as a result of increasing use of organs from donors after circulatory death and because of an increase in living donor transplantation. The Organ Donation Taskforce supported the increase in deceased organ donors and a 50% increase in deceased organ donor numbers was achieved in the 5 years to March 2013. It is clear that the increase has been achieved by using increasingly “high risk” donors and organs as older and less suitable donors are referred and accepted for transplantation.

The next decade promises further increases in organ donation and transplantation as donor management, organ preservation, and perfusion techniques develop to maximize the number of suitable organs for transplant. The new UK strategy “Taking Organ Transplantation to 2020” emphasizes the need to address all areas within the donor pathway, but particularly acknowledges the need to increase family consent rates for organ donation, which remain low in the UK.

ACKNOWLEDGMENTS

The UK National Transplant Registry gratefully acknowledges the contribution of all those who have contributed data to make the Registry as comprehensive as possible.

The current registry in NHS Blood and Transplant was developed by the UK Transplant Support Service Authority, which became UK Transplant before being incorporated into NHS Blood and Transplant.

There are many people who have and continue to support the Registry, and without their help and hard work, the Registry could not be effective. We would like to thank the transplant surgeons and physicians, the health care professionals working in the Emergency Departments and Intensive Therapy Units, the data managers and the recipient points of contacts in the transplant centers, the histocompatibility and immunogenetics laboratory staff, the Specialist Nurses and Clinical Leads in Organ Donation, the members of the Donation Committee and the Solid Organ Advisory Groups, and the members of the Directorate of Organ Donation and Transplantation and the Department of Statistics and Clinical Audit of NHS Blood and Transplant.

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