2 The acute shortage of deceased donors in the UK – recommendations set in an international context

Introduction

Although there has been a shortage of deceased donors for as long as organ transplantation has been part of established clinical practice, that shortage has never been more extreme – or been perceived to be so – than it is now. This is the result of a number of factors, of which perhaps the most important is the very success of transplantation. It would be facile to suggest that the problems of rejection have been overcome – but certainly acute, early rejection has almost disappeared as a cause of graft loss. Chronic graft loss, which may or may not be primarily immunological, remains a major issue but current immunosuppressive regimens are continuing to improve the long-term outcome for transplant recipients (primarily through early outcomes) and transplantation has also become safer. As a result more patients are surviving their first, failed transplant and are in need of a re-transplant. More importantly, the relative success and safety of transplantation means that far more patients are being considered suitable for transplantation – it is not that long ago that, for kidney transplantation, ‘older’ patients were those over the age of 60, and many centres were reluctant to list such patients. Similarly, patients with diabetes were thought to represent too high a risk in some centres.

Fifteen years ago the deceased organ donor rate in the UK was broadly in line with that of most other western European countries. Sadly that is no longer the case and of those countries with well-developed organ donation and transplant services, we now sit uncomfortably close to the bottom of the league table (Fig. 2.1). Of our closer neighbours only Denmark and The Netherlands have a lower donor rate (expressed as donors per million population) and many have rates close to double that of the UK. The rate in Spain is now nearly three times higher.¹

Figure 2.1 Deceased organ donors rates for Europe and the USA, 2006.

There have been considerable efforts in recent years to address this problem and in the case of donors after cardiac death (previously known as non-heart-beating donors) these efforts have met with considerable success. The number of such donors is still relatively small (approximately 20% of all deceased donors) but it has risen by 350% in the past 6 years. However, the number of donors after brain death (heart-beating donors) has fallen over the same time period by 14%, and such donors remain the bedrock of liver, heart and lung transplantation. In part to compensate for this lack of deceased donors, the number of living donor kidney transplants has increased markedly (Fig. 2.2) and now accounts for 33% of all kidney transplants. Nothing demonstrates the critical shortage of deceased donors more clearly than the willingness of donors, recipients and clinicians to put at risk the life of a fit healthy person in this way.

Figure 2.2 Number of deceased and living donors in the UK, 1 April 1997–31 March 2007. HB, heart-beating; NHB, non-heart-beating.

The need for transplantation

That there is a shortage of suitable organ donors is beyond dispute, but the true extent of the shortage in the UK is far less clearly established. The obvious starting point for any assessment of the need for transplantation would seem to be the number of patients waiting for a transplant – or, more specifically, the number of new patients added to the list each year. However, these figures give only a partial answer to the question because they reflect exactly what they say and – crucially – do not reflect the number of patients who may benefit from a transplant that are not added to the waiting list. There is some form of rationing of access to all forms of transplantation but the details differ from organ to organ.

For many years in the UK the number of patients added to the kidney transplant list was relatively static at just over 2000 adults each year (and approximately 100 paediatric patients) but the number increased markedly between 2004 and 2006 and has now reached over 3300 per year. More patients aged over 40 are being registered and the increase is most marked in those over 60 years of age. The number of patients of Asian origin has doubled. As a result, the number of patients actively waiting for a kidney transplant is rising more rapidly than ever before (Fig. 2.3).

Figure 2.3 Deceased donor kidney programme in the UK, 1 April 1997–31 March 2007. Number of donors, transplants and patients on the active transplant list at 31 March.

For the kidney transplant list there are published national assessment criteria modified from the European Best Practice Guidelines.² The underlying principle is that patients should have an anticipated survival post-transplant of at least 2 years and this is combined with a series of clinical parameters. Some of these can be assessed accurately but inevitably many are a question of judgement and it is notable that – relatively recently – the proportion of dialysis patients aged under 65 years that were listed for a transplant varied across the UK from 23% to 67%.³

Currently in the UK over 23 000 patients are receiving dialysis whilst the active kidney transplant list stands at 6691. There are undoubtedly a number of patients receiving renal replacement therapy for whom a transplant would be inappropriate even if there were a surplus of kidneys available, but it is also highly likely that clinicians would lower their subconscious ‘threshold’ if more kidneys were available.

When these figures are combined with the increasing number of patients that receive a living-donor kidney before dialysis is needed, and who are never listed for a deceased donor transplant, it is clear that the minimum number of kidney transplants that is needed each year is of the order of 3500–4000, and that if the clinical criteria were to be relaxed the true need could be far greater.

Clinical practice in liver and cardiothoracic transplant centres is more complex. For a patient with renal failure, listing for a transplant offers a possible escape, eventually, from dialysis and some patients are relatively content to dialyse for many years even though that hope is never realised. For patients with end-stage liver, heart or lung disease, however, there is no realistic alternative and many clinicians are reluctant to hold out the hope of a life-saving transplant to more patients than are realistically likely to be able to receive an organ. As a result, the number of patients listed for a liver transplant in the last financial year was 814, for a heart transplant was 194 and for lung transplantation was 204. Despite this practice, between 10% and 15% of these patients die before a transplant becomes available, or are removed from the list because their condition deteriorates beyond the point at which transplantation is appropriate.

Very detailed clinical criteria for listing for liver transplantation were introduced in September 2007, building on earlier guidelines that had been used for a number of years and which were designed to restrict access to the waiting list to patients with an anticipated 5-year survival post-transplant of over 50%. Similar, though less detailed, criteria are also available to assess patients for heart and lung transplantation. However, there are no reliable data to identify accurately the number of patients who could benefit from transplantation and it is very clear that there are many patients whose survival would be greater with a transplant than without that are never listed.

It is apparent from this that the waiting list at any given time is a very poor indication of the need for transplantation, representing as it does not only the balance between new patients listed and those removed from the list following a transplant or their death or deterioration, but also the inevitable rationing of access to a transplant list that is a consequence of the shortage of donors. However, the waiting list continues to rise, and the gap between ‘supply’ and ‘demand’ is rising (Fig. 2.4). For the record, the active UK transplant lists at 27 December 2007 were:

Figure 2.4 Number of deceased donors and transplants in the UK, 1 April 1997–31 March 2007, and patients on the active transplant lists at 31 March.

Kidney	6691
Kidney/pancreas	229
Liver	307
Heart	85
Heart–lung	20
Lung	258
Other	20

It should also be noted that the organ allocation system might have a direct impact on waiting list practice. For example, in the USA for many years a major part of the liver allocation algorithm was the time for which the patient had been listed. As a result clinicians would happily list patients with slowly progressive liver disease who were several years away from needing a liver transplant, in the hope that by the time the patient’s liver function had deteriorated the patient would have accumulated enough waiting time to be allocated an organ. At one time the USA (population 300 million) liver waiting list approached 15 000 patients – the highest year-end figure reached in the UK (population 60 million) is 360. The move to a Mayo End-stage Liver Disease (MELD)-based allocation system in the USA (i.e. primarily on the basis of clinical need) has seen the waiting list fall markedly.⁴

There is one further source of information that gives some indication of the need for transplants – the Council of Europe annual Transplant Newsletter.¹ This provides international figures on organ donation and transplantation, although it is the donation figures that are most widely known. The transplant figures are revealing, although international comparisons can be fraught with difficulties. For each organ, Table 2.1 shows the transplant rate per million population (pmp) in 2006 in the UK and the range in five of the western European countries with the highest rates (Spain, France, Belgium, Norway and Sweden).

Table 2.1 Transplant rate per million population (pmp) in 2006 in the UK and the range in five western European countries *

Organ	Transplant rate (pmp)
Organ	UK	Europe
Kidney	23.2	25.7–46
Liver	10.7	13.2–23.5
Heart	2.6	4.4–7.4
Lung	2.0	3.3–8.4

* Spain, France, Belgium, Norway and Sweden.

These figures show not only the poor record of the UK in organ transplant rates, but also give an indication of the number of patients that actually receive a transplant in countries with higher donation rates. It seems inescapable that the need for organ donors is likely to be at least 50% greater – probably double – the rate currently being achieved in the UK and that there is also a need to increase significantly the proportion of donors whose hearts and lungs are suitable for transplantation.

Nor is the need likely to diminish in the foreseeable future. There are several disturbing trends in the UK that will make even greater demands on donation and transplantation in the coming years. There is a general expectation that an ‘epidemic’ of liver failure associated with hepatitis C is only 5–10 years away, the incidence of diabetes and obesity in the general population are increasing, there are an increasing number of patients with congenital heart disease surviving into adulthood who will require heart transplants, the need for lung transplantation for patients with cystic fibrosis will continue, and (as noted above) the first evidence of the rising need for kidney transplantation amongst the BME (black and minority ethnic) population is now appearing. The acute shortage of donors is very real, and it is almost inevitable that the gap between supply and demand will increase unless radical steps are taken to bring organ donation in the UK very much closer to those in similar western European countries.

Current obstacles to organ donation in the UK

Introduction

There are a number of ‘external’ factors that will undoubtedly have an impact on organ donation rates – although the extent of that impact is a matter of debate. The overwhelming majority of deceased donors after brain death are patients whose clinical care has been provided in critical care units, although there is a small but increasing number of such patients that are identified in Accident and Emergency departments. It is inescapable that the number of intensive care beds in a local region or country will influence clinical practice in the admission to ICU of patients with catastrophic brain injury and it is notable that Spain, with its donor rate that is three times greater than that of the UK, has many more critical care beds pro rata than the UK. Differences in the number of road traffic accident deaths and the incidence of intracerebral bleeding may also have an impact when making international comparisons, and when appropriate adjustments are made some of the international variation can perhaps be explained.^5,⁶

There are also concerns about the definitions used in international comparisons.⁷ The donation rate can be expressed most meaningfully in terms of the number of potential donors that become actual donors – i.e. the ‘conversion rate’⁸ – and the number of potential donors is, at least in part, influenced by some of these ‘external’ factors.

However, what is essential in any donation system is to maximise the conversion rate, and there is clear evidence that the UK is not succeeding in this regard. The UK Transplant Potential Donor Audit (PDA) was established in April 2003 ⁹ and, whilst it is acknowledged that the format of the PDA can be improved, it provides important information. The data for the past 2 years¹⁰ suggest that over 20% of patients in whom brainstem death was a possible diagnosis were not in fact tested, that only 81% of patients certified dead after brainstem tests were referred to the donor coordinator network, and that the consent rate when the potential donor’s family were approached was only 61%. The overall conversion rate was 48%. Even allowing for uncertainties about the PDA it is clear that at each stage of the process that can lead to organ donation there are patients who could potentially be donors after brain death who do not in fact become donors.

For potential donors after cardiac death the situation is even less satisfactory, although the caveats about the data are perhaps greater. The referral rate for such potential donors was only 32% and the conversion rate was 12%.