Increased access to transplantation for blood group B cadaveric waiting list candidates by using A2 kidneys: time for a new national system?
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Since blood group B end-stage renal disease (ESRD) patients have less access to donor kidneys and a higher minority composition than any other blood group, the United Network for Organ Sharing (UNOS) approved a voluntary national kidney allocation variance to allow organ procurement organizations (OPOs) to preferentially allocate A2 and A2B kidneys to B candidates. The Midwest Transplant Network OPO has preferentially allocated and transplanted kidneys from blood group A2 and A2B donors to our blood group B waiting list candidates for more than 7 years to increase access to kidneys for the B candidates on our OPO-wide waiting list. Between 1994 and 2000, a total of 121 blood group B ESRD patients from our OPO-wide cadaveric kidney waiting list were transplanted. Thirty-four per cent (41/121) of those B candidates received either an A2 or an A2B kidney. One- and 5-year graft survival rates for the group of B recipients of A2 or A2B kidneys were 91 and 85% (died with functioning graft [DWFG] censored), respectively, which were not significantly different from those of 91 and 80% for the 80 B recipients of B or O kidneys (Wilcoxon = 0.48; log-rank = 0.55). These data support the national trial for additional OPOs to voluntarily allocate A2 and A2B kidneys preferentially to B waiting list candidates, thus increasing access of blood group B patients to renal transplantation. (+info)
Analysing the various obstacles to cornea postmortem procurement.
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AIMS: In many countries the number of corneal donations is far too low to graft all patients on waiting lists within reasonable time. The aim of this study was to define specifically what practical changes are to be implemented to fully meet corneal graft demand. METHODS: The list of potential donors drawn by the coordination team from 1 January to 31 December 1999 was compared with that of all patients who had died during the same period. In each identified record, the parameters which permitted or precluded effective collection of cornea specimens were analysed, and the reasons why other records were not identified were investigated. RESULTS: Among the 1112 patients who died in 1999, coordinating nurses were able to identify 451 records (40.5 %) including 329 patients aged between 18 and 85 years (29.5%). After excluding 184 patients (55.9 %) who presented with medical contraindications, the coordinating nurses were able to meet the relatives of only 55 out of 145 patients (38%) and obtained their agreement in 39 cases (71% approval rate). Therefore, relatives' refusal was the cause for the absence of collection in only 5.5% of cases (16/290). The number of corneas procured amounted to 11.8% of identified records and 3.5% of all deceased patients. CONCLUSION: French law and regulations regarding tissue collection are based on consent presumption but it requires that verifications be made with the relatives to ensure that potential donors were not, before their death, opposed to such tissue procurement. That provision implies a high degree of organisation on the part of coordinating teams. It was demonstrated that donation shortage is no longer the result of relatives' refusal but rather because of logistical difficulties (potential donors not identified and problems in reaching relatives). It appears necessary therefore to strengthen coordinating teams with sufficient staff levels for wider donor identification. Those teams should also find ways to keep closer contact with relatives, so as to meet the maximum transparency targets required by public opinion and regulations and to graft all patients awaiting corneal transplantation. (+info)
Redrawing organ distribution boundaries: results of a computer-simulated analysis for liver transplantation.
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For several years, the Organ Procurement and Transplantation Network/United Network for Organ Sharing (UNOS) Liver and Intestinal Transplantation Committee has been examining effects of changes and proposed changes to the liver allocation system. The Institute of Medicine recently recommended that the size of liver distribution units be increased to improve the organ distribution system. Methods to achieve this and the potential impact on patients and transplant centers of such a change are evaluated in this study. In hypothetical scenarios, we combined geographically contiguous organ procurement organizations (OPOs) in seven different configurations to increase the size of liver distribution units to cover populations greater than 9 million persons. Using the UNOS Liver Allocation Model (ULAM), we examined the effect of 17 different organ allocation sequences in these proposed realignments and compared them with those predicted by ULAM for the current liver distribution system by using the following primary outcome variables: number of primary liver transplantations performed, total number of deaths, and total number of life-years saved. Every proposed new liver distribution unit plan resulted in fewer primary transplantations. Many policies increased the total number of deaths and reduced total life-years saved compared with the current system. Most of the proposed plans reduced interregional variation compared with the current plan, but no one plan consistently reduced variation for all outcome variables, and all reductions in variations were relatively small. All new liver distribution unit plans led to significant shifts in the number of transplantations performed in individual OPOs compared with the current system. The ULAM predicts that changing liver distribution units to larger geographic areas has little positive impact on overall results of liver transplantation in the United States compared with the current plan. Enlarging liver distribution units likely will result in significant shifts in organs across current OPO boundaries, which will have a significant impact on the activity of many transplant centers. (+info)
Ooplasm donation in humans: the need to investigate the transmission of mitochondrial DNA following cytoplasmic transfer.
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The use of cytoplasmic transfer as an assisted reproductive technique has generated much attention. This arises as donor mitochondria are introduced into the cytoplasm of the recipient oocyte. The consequences are the possible transmission of two mitochondrial (mt)DNA populations to the offspring. This pattern of inheritance is in contrast to the strictly maternal manner in which mtDNA is transmitted following natural fertilization and ICSI. This paper discusses the advantages of using such a technique to enhance embryonic development from poor quality oocytes with respect to the low copy number of mtDNA found in some oocytes following superovulation protocols. However, it also cautions against using such a technique before a clearer understanding of the patterns of inheritance and transmission of mtDNA has been established and suggests that animal models be utilised to do so. (+info)
A relationship between traditionally motivated patterns and gamete donation and surrogacy in urban areas of Greece.
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BACKGROUND: Although gamete receipt or donation has become an integral part of infertility management, previous research in the field of social attitudes and intention to use medical technologies is limited. The aim of this paper was to investigate people's intentions to receive or donate sperm, oocyte or uterus (surrogacy) and to identify possible motivational patterns explaining this intention. METHODS: Personal interviews were conducted with 365 men and women of reproductive age (18-45 years). Stratified random sampling was performed to select the men and women for interview. The content of the instrument used was derived from in-depth qualitative interviews with physicians experienced in assisted reproductive technologies, as well as from people who had recourse to gamete donation and surrogacy. RESULTS: The results obtained highlighted the following major aspects: (i) approximately 50% of the survey's participants would be prepared to receive/donate sperm and oocyte; (ii) the results from multiple regression analysis suggest that the 'traditional gender roles' pattern is positively associated with 'intention to use gamete donation and surrogacy'. On the contrary, 'confidence in emotional relationship' is negatively associated with 'intention to use gamete donation and surrogacy, and (iii) men are more likely than women to report 'intention to use gamete donation and surrogacy'. CONCLUSION: These data suggest that specific motivational patterns of the population need to be thoroughly analysed and taken into consideration, in order that appropriate counselling be addressed to individuals and couples. (+info)
Consensus conference report: maximizing use of organs recovered from the cadaver donor: cardiac recommendations, March 28-29, 2001, Crystal City, Va.
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The shortage of available donor hearts continues to limit cardiac transplantation. For this reason, strict criteria have limited the number of patients placed on the US waiting list to approximately 6000 to 8000 per year. Because the number of available donor hearts has not increased beyond approximately 2500 per year, the transplant waiting list mortality rate remains substantial. Suboptimal and variable utilization of donor hearts has compounded the problem in the United States. In 1999, the average donor yield from 55 US regions was 39%, ranging from 19% to 62%. This report provides the detailed cardiac recommendations from the conference on "Maximizing Use of Organs Recovered From the Cadaver Donor" held March 28 to 29, 2001, in Crystal City, Va. The specific objective of the report is to provide recommendations to improve the evaluation and successful utilization of potential cardiac donors. The report describes the accuracy of current techniques such as echocardiography in the assessment of donor heart function before recovery and the impact of these data on donor yield. The rationale for and specific details of a donor-management pathway that uses pulmonary artery catheterization and hormonal resuscitation are provided. Administrative recommendations such as enhanced communication strategies among transplant centers and organ-procurement organizations, financial incentives for organ recovery, and expansion of donor database fields for research are also described. (+info)
Is MELD really the definitive score for liver allocation?
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The best system for organ allocation is still a controversial issue. The aim of this study was to study the accuracy of four different scores to predict mortality on the waiting list and, thus, their usefulness to determine organ allocation. We retrospectively compared two groups of patients, those who died on waiting list (group D) and those who successfully underwent transplantation (group T) during the same time period. Four scores, at the time of entering the waiting list and just before liver transplantation or death, were evaluated. The evaluated scores were as follows: (1) the Child-Pugh classification; (2) the Model for End-Stage Liver Disease (MELD) score; (3) the Freeman scale; and (4) the Guardiola et al index. The mortality rate on waiting list was 15.9%. All studied scores, except Freeman scale, were higher in group D at the time of entrance on waiting list (MELD, 17.4 +/- 8 v 12.3 +/- 6, P = .02; Child, 9.9 +/- 2 v 7.7 +/- 2, P = .002; Freeman, 9.7 +/- 4 v 7.3 +/- 3.9, P = .09; Guardiola, 2.6 +/- 0.9 v 1.7 +/- 0.7, P = .001). C-statistics of all scores were similar and in all cases lower than 0.8 (MELD, 0.75; Child, 0.78; Freeman, 0.65; Guardiola, 0.79). None of the studied scores have an excellent accuracy to predict prognosis of patients on waiting list, mainly in case of populations with high proportion of hepatocellular carcinoma. Although the MELD score is rapidly available, standardized, and objective, it does not reflect the severity of patients with cancer or metabolic disorders. (+info)
The new liver allocation system: moving toward evidence-based transplantation policy.
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In 1999, the Institute of Medicine suggested that instituting a continuous disease severity score that de-emphasizes waiting time could improve the allocation of cadaveric livers for transplantation. This report describes the development and initial implementation of this new plan. The goal was to develop a continuous disease severity scale that uses objective, readily available variables to predict mortality risk in patients with end-stage liver disease and reduce the emphasis on waiting time. Mechanisms were also developed for inclusion of good transplant candidates who do not have high risk of death but for whom transplantation may be urgent. The Model for End-Stage Liver Disease (MELD) and Pediatric End-Stage Liver Disease (PELD) scores were selected as the basis for the new allocation policy because of their high degree of accuracy for predicting death in patients having a variety of liver disease etiologies and across a broad spectrum of liver disease severity. Except for the most urgent patients, all patients will be ranked continuously under the new policy by their MELD/PELD score. Waiting time is used only to prioritize patients with identical MELD/PELD scores. Patients who are not well served by the MELD/PELD scores can be prioritized through a regionalized peer review system. This new liver allocation plan is based on more objective, verifiable measures of disease severity with minimal emphasis on waiting time. Application of such risk models provides an evidenced-based approach on which to base further refinements and improve the model. (+info)