Produção Nacional
Revisado por pares
Comparing the Dynamics of Kidney and Liver Transplantation Waiting List in the State of Sao Paulo, Brazil
2007; Wolters Kluwer; Volume: 84; Issue: 9 Linguagem: Inglês
10.1097/01.tp.0000287192.32090.2b
ISSN1534-6080
AutoresEleazar Chaib, Eduardo Massad,
Tópico(s)Organ Transplantation Techniques and Outcomes
ResumoSão Paulo is a pioneer Brazilian state on transplantation surgery. Kidney and liver transplantation was first performed at Sao Paulo Medical School (1, 2). Since then, the patient waiting list for both kidney and liver transplantation has increased now approximately 600 and 150 new cases, respectively, per month are referred to a single list at the central organ procurement organization. Kidney and liver transplantation has been saving and improving lives for many years. Data have been presented indicating that survival with kidney transplant exceeds survival on dialysis. Because patients survive longer with a transplant than on dialysis, kidney transplantation waiting list is now under great demand in our state. The gap between the number of transplantable organs from deceased donors and the number of patients awaiting transplantation continues to increase each year. During the past decade the number of kidney transplants performed has increased, but the number of people developing end-stage renal disease (ESRD) has increased at a greater rate especially, consequently cadaveric and live donation are not meeting the current demand for organs transplantation. The number of people waiting for kidney transplantation in our state is approximately 3.04 times the number who receives transplants, considering live and cadaveric kidneys transplants performed. The aim of this study was to compare the performance of our state kidney and liver transplantation program and analyze when the number of transplantations for both will meet our waiting list demand. METHODS AND RESULTS We collected official data from State Center of Transplantation–State Secretariat of Sao Paulo about our kidney and liver transplantation program between July 1997 to October 2004. Only cadaveric liver transplantations were recorded but for kidney transplantations were collected both cadaveric and living related donors. The data related to actual number of liver and kidney transplantation (Tr), the incidence of new patients on the list (I), and the number of patients who died in the waiting list (D) in the State of Sao Paulo since 1997 are shown in Table 1.TABLE 1: Actual number of liver and renal transplantation, Tr, the incidence of new patients in the list, I, and the number of patients who died in the waiting list, D, in the State of São Paulo since 1997As described in Chaib and Massad (3), we projected the size of the waiting list, L, by taking into account the incidence of new patients per year, I, the number of transplantations carried out in that year, Tr, and the number of patients that died in the waiting list, D. The dynamics of the waiting list is given by the difference equation: That is, the list size at time t+1 is equal to the size of the list at the time t, plus the new patients getting into the list at time t, minus those patients who died in the waiting list at time t, and minus those patients who received a graft at time t. The variables I, and D, from 2004 onward were projected by fitting an equation by maximum likelihood, in the same way that we did for Tr. The waiting list, compared with the number of transplantations, can be seen in Figure 1. Note that, provided the conditions of the present day, the projected curves will never meet each other. In other words, the list size grows at a rate much higher than the number of transplantations actually done.FIGURE 1.: Logarithm of the projected number of transplants conducted and of patients in the waiting lists for kidney (continuous line) and liver (dotted line) transplantation. Note that the curves representing the number of transplants and of patients in the waiting list will never meet each other.DISCUSSION The biggest challenge facing the fields of transplantation is the critical shortage of donors organs, which has led to a dramatic increase in the number of patients on the waiting list as well as in their waiting time. Kidney and liver transplantation is the treatment of choice for most of both patient with ESRD and chronic or acute hepatic insufficiency (HI). Optimal outcomes occur, respectively, when kidney and liver transplantation is performed as early as possible after the onset of ESRD and HI and risks of both death and graft failure increase with the length of time on dialysis and hepatic clinical supporting measures. To prevent patients from developing life-threatening complications, transplant physicians must therefore make timely decisions to enlist their patients for transplantation. Ideally, kidney and liver transplantation should be performed early enough so that the patient is able to tolerate the surgery yet sufficiently late in the course of the disease so that prolonged survival is unlikely without kidney and liver transplant. In practice, however, determining such an optimal time for transplantation may not be that straightforward. The number of kidney and liver transplantations increased approximately 1.85- and 1.84-fold (541 to 1001 and from 160 to 295) from 1988 to 2004, respectively. On the other hand, the number of patients on the kidney and liver waiting list increased approximately 2.74 and 2.71(from 1598 to 2741 and 553 to 1500), respectively; as one would be expect, the number of deaths of listed patients increased approximately 1.97- and 2.09-fold (from 492 to 974 and from 321 and 671), respectively (Fig. 1). The deaths of listed patients are unacceptable. Many reasons could be pointed to explain these data: (1) the current supply of donors livers is insufficient to meet the need and organ donation has been stagnant or increased by only a few percent in recent years; (2) there are many kidney and liver centers that is doing much fewer transplants than one would expect; and (3) the kidney and liver transplant teams in the public university hospital are doing much fewer kidney and liver transplants than would be expected because of both the full-team capacity of working and the shortage of specialized transplant teams. When we analyzed only 2003 Brazilian kidney and liver waiting list transplantation, we could see that 4.7 liver transplantations were performed per million inhabitants; we should be performing at least 20 liver transplantations per million inhabitants. This chart was even worse when we looked at the kidney transplantation program. Only 18.5 kidney transplantations were performed per million of inhabitants; we should be performing at least 60 kidney transplantations per million of inhabitants. Based on these data the necessity of liver and kidney transplantation according with the waiting list would be 33 and 179.2 transplantations respectively/million of inhabitants (4). Because kidneys and livers are a limited national resource, our proposal is as follows: (1) improve organ donation campaign because we know that we do not already reach the full capacity of donation (currently 7.09 per million inhabitants) (4). (2) Concentrate funding resources in public university hospitals both to improve the kidney and liver transplantation performance and also add more transplants teams. (3) Change the law and start using nonheart-beating donors (NHBD). NHBD programs remain unpopular despite the potential to increase the donor pool by up to 30% (5). A number of legal, ethical and logistic reasons as well as medical concerns are responsible for this and have even compromised existing NHBD programs (6). In recent years, there has been a re-evaluation of the use of NHBDs for renal transplantation. Although some studies have shown poorer graft survival for NHBD kidneys (7, 8), others have demonstrated favorable graft survival compared with heart beating donors (9–12) despite the detrimental effects of warm ischemic damage in NHBDs with consequent high rates of delayed graft function. The use of NHBD offers a large potential of resources for renal transplantation. The process of graft selection involves a significant number of potential grafts being discarded because they are judged to be nonviable. The reported discard rate of kidneys from NHBD is significant, with estimates ranging from 50% to 65% with uncontrolled donors (13). As far as the NHBD for liver transplantation is concerned, Abt et al. (14) have emphasized the importance of short cold ischemic time for liver grafts. When the cold ischemic time was less than 8 hr, there was 10.8% of graft failure within 60 days of transplantation, which increased to 30.4% and 58.3% when the cold ischemia time was greater than 8 and 12 hr, respectively. The combination of warm and cold ischemia in NHBDs appears to make these grafts more susceptible to biliary complications. A greater incidence of ischemic cholangiopathy has been reported (14, 15). D’Alessandro et al. (16) also recognized increased incidence of ischemic biliary complications in NHBD liver graft recipients from donors older than 40 years of age. Finally, a word of caution: all of our results are based on a projection of a number of transplantation actually done, assuming that current trend will persist in the future, therefore, the conclusions must take this assumption into account. In conclusion, unless we change the current trend of the number of kidney and liver transplantations performed in our state, we will see that projections of Figure 1 will prove correct, that is, we will never meet our waiting list demands in the years to come. Eleazar Chaib Eduardo Massad Department of Gastroenterology and LIM 01 University of Sao Paulo School of Medicine Sao Paulo, Brazil
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