Marginal donors: a viable solution for organ shortage

Organ shortage crisis: problems and possible solutions

The demand for organ transplantation has rapidly increased all over the world during the past decade due to the increased incidence of vital organ failure, the rising success and greater improvement in posttransplant outcome. However, the unavailability of adequate organs for transplantation to meet the existing demand has resulted in major organ shortage crises. As a result there has been a major increase in the number of patients on transplant waiting lists as well as in the number of patients dying while on the waiting list. In the United States, for example, the number of patients on the waiting list in the year 2006 had risen to over 95,000, while the number of patient deaths was over 6,300. This organ shortage crisis has deprived thousands of patients of a new and better quality of life and has caused a substantial increase in the cost of alternative medical care such as dialysis. There are several procedures and pathways which have been shown to provide practical and effective solutions to this crisis. These include implementation of appropriate educational programs for the public and hospital staff regarding the need and benefits of organ donation, the appropriate utilization of marginal (extended criteria donors), acceptance of paired organ donation, the acceptance of the concept of "presumed consent," implementation of a system of "rewarded gifting" for the family of the diseased donor and also for the living donor, developing an altruistic system of donation from a living donor to an unknown recipient, and accepting the concept of a controlled system of financial payment for the donor. As is outlined in this presentation, we strongly believe that the implementation of these pathways for obtaining organs from the living and the dead donors, with appropriate consideration of the ethical, religious and social criteria of the society, the organ shortage crisis will be eliminated and many lives will be saved through the process of organ donation and transplantation.

New concepts in organ transplantation

Over the past several decades, many factors have led to higher rates of patient and graft survival in organ transplantation. These factors include enhanced immunosuppressants available in recent years such as Neoral, Prograf, sirolimus, mycophenolate mofetil and anti-interleukin-2 receptor monoclonal antibodies. In addition, other new drugs, such as FTY 720, FK 778, anti-CD20, anti-CD40, and anti-CH52 monoclonal antibodies, are now being tested in clinical studies. Furthermore, there have been advances in surgical techniques, such as the piggyback method without venovenous bypass, side-to-side anastomosis of the hepatic veins, use of vascular staplers, biliary duct-to-duct anastomosis with or without tube drainage, microsurgical hepatic artery anastomosis and laparoscopic donor nephrectomy. Finally, better patient and donor selection criteria with regard to HBV- and HCV-seropositive donors, diabetic donors, donors with malignancies, older donors, ABO-incompatible donors, and non-heart-beating donors have been combined with optimal timing of transplantation, better options for treating early surgical and late medical complications, and improved management in intensive-care units. Other noteworthy scientific and social development are on the horizon namely genetic advances in xenografting and cell transplantation, and induction of immunologic tolerance. This article reviews the current developments that have significantly improved graft and patient survival among solid-organ transplants.

Underutilization of pancreas donors

BACKGROUND

Transplantation of the pancreas has become the treatment of choice for selected patients with type 1 diabetes mellitus. With the current shortage of cadaver donors and the increasing number of diabetic patients on the transplant waiting list, there is a critical need to optimally use all available pancreas grafts for transplantation. We have therefore explored the use of traditionally "less-than-ideal" pancreas donors, including pediatric (4-10 years), older (>or=45 years), obese (weight >or=200 lb), and non-heart-beating donors and donors with an elevated amylase (75% greater than normal values).

METHODS

A total of 620 primary simultaneous pancreas-kidney transplantations were performed at our center. We analyzed the ratio of livers to pancreata transplanted at our center and compared this to the United Network for Organ Sharing database. Using univariate and multivariate analyses, we then assessed the impact of these less-than-ideal donors on patient survival, graft survival, and postsurgical complications after simultaneous pancreas-kidney transplantation.

RESULTS

A substantial nationwide underutilization of pancreata from donor procurements is demonstrated in the United Network for Organ Sharing database. By using these less-than-ideal donors, the ratio of liver to pancreata procured can be reduced to 1.25:1. Graft survival was not significantly different in patients receiving transplants from obese, non-heart-beating, pediatric, or hyperamylasemic donors compared with grafts from ideal donors. However, grafts from donors 45 years of age or older had significantly lower 1- and 5-year graft survival rates (76% and 65% vs. 90% and 80%, P=0.006).

CONCLUSIONS

This study demonstrates that utilization of pancreas grafts from selected, less-than-ideal donors results in good overall outcomes and could potentially expand the organ donor pool.

Diabetic kidneys can safely expand the donor pool

BACKGROUND

The demand for organs has increased exponentially with a new name added to the United States waiting list every 16 min. As such, kidneys from medically marginal donors are being considered for transplantation more frequently, including kidneys from individuals already at risk for renal disease, e.g., diabetic donors.

METHODS

We compared outcomes when using kidneys from donors with type 1 diabetes mellitus (D1) or type 2 diabetes mellitus (D2) at our center as a function of time. All patients with available data who underwent renal transplantation were evaluated (n=2013).

RESULTS

Forty-two individuals were recipients of D1 or D2 donor kidneys. Thirty of these individuals did not have diabetes (R0). All patients received quadruple sequential immunosuppression with cyclosporine (CsA) or tacrolimus (FK506). Donor serum creatinine (Scr) values were not significantly different. D2 kidneys came from older donors (mean age, 56+/-10.4 years; P< or =0.01 vs. D1 and D0 donors). Mean discharge Scr was greater in nondiabetic D2 recipients (D2/R0, 2.45+/-1.3 mg/dl; P=0.0016 vs. D0/R0), and transplantation of D1 or D2 kidneys was associated with a significantly increased frequency of posttransplant proteinuria (P=0.0089). Interestingly, R0 recipients of D1 or D2 kidneys were more likely to initiate oral hypoglycemic therapy after transplant (P=0.04). However, rejection episodes were not significantly different among groups, and long-term graft survival and patient survival were similar among groups.

CONCLUSIONS

These data suggest that diabetic kidneys can be safely used without risk to patient or graft survival. Preexisting diabetic injury in the donor may increase the risk for proteinuria, compromised renal function, and posttransplant glucose intolerance.

The use of expanded criteria cadaver and live donor kidneys for transplantation

The use of expanded criteria donors (non-traditional donors) can help lessen the current shortage of kidneys available for transplantation. The use of older donors has accounted for a large measure of the increase in the organ donation rate; however, the most significant factors found to impact on transplant success negatively traditionally have been shown to be extremes of donor age and last-hour urine output. Less significant variables affecting success rates are average systolic blood pressure, terminal serum creatinine, and days of hospitalization. With the appropriate selection of organs from expanded donors, acceptable outcomes can be obtained. When living donors are selected properly, kidneys with anatomic variants without pathologic significance can be used safely. Kidneys with a heightened potential for the development of progressive disease should not be transplanted. Efforts to decrease the cold ischemia time by increasing the use of kidneys from expanded criteria donors may improve the outcome of transplantation further. Advances in surgical techniques, preservation solutions, and methods for predicting eventual long-term renal function in kidneys from expanded donors will be critical in allowing precise selection criteria for kidneys for transplantation, resulting in the optimum use of a scarce and precious resource. Until options such as xenotransplantation become clinically feasible, the challenge will be to identify which donor organs previously considered suboptimal can be used safely to expand the organ donor pool.

Psychosocial aspects of the organ transplant experience: what has been established and what we need for the future

This article briefly describes the current status and limitations of the organ transplant process that has now become a routine medical procedure. The article discusses how transplantation is not a cure for end-stage organ disease but an alternative form of treatment with both potential medical and psychosocial problems. Both transplant candidates and recipients encounter psychosocial problems. The article examines how these psychosocial problems affect transplant patients prior to transplant, immediately following surgery, and posttransplant. The psychosocial problems include psychiatric diagnoses, individual and family adjustment and relationship problems, sexual dysfunction, return-to-work (RTW) difficulties, and compliance problems and variables related to noncompliance. The article also reviews the special problems of pediatric and adolescent transplant recipients. The need for empirically supported interventions is noted in each of the problem areas. The author outlines problems with previous research studies that hamper solid interpretations of the data, and discusses literature suggesting that the psychosocial problems of transplant candidates and recipients are likely to be underreported. The article concludes with recommendations about the need to switch research efforts toward intervention studies in the problem areas already solidly identified by the literature.

Long-term renal function in on-heart-beating donor kidney transplantation: a single-center experience

BACKGROUND

One of the most serious problems facing major transplant programs is the severe shortage of organs. Expansion of the donor pool to include nontraditional donors, such as non-heart-beating donors (NHBDs), would considerably expand the availability of organs.

METHODS

Between 1983 and 1996, we performed a total of 125 non-heart-beating cadaveric renal transplantations under cyclosporine-based or tacrolimus-based immunosuppression. Thirty-nine recipients were females and 86 were males. Total ischemic time (TIT) and warm ischemic time (WIT) were an average of 761+/-347 min (322-2027 min) and 7.4+/-13.1 min (0-45 min), respectively.

RESULTS

Of the 125 transplanted kidneys from NHBDs, 98 (78.4%) developed delayed graft function (DGF), which lasted a mean of 16+/-21 days (range 3-37 days). One hundred and eight patients (86.4%) were off dialysis by the time of discharge. Of the 125 grafts, 11 (8.8%) were primary nonfunction. The average of the nadir of serum creatinine levels, which was evaluated using 108 patients who were off dialysis by the time of discharge, was 1.4+/-0.5 mg/dl. The lowest creatinine levels (nadir) were under 2.0 mg/dl in 98 (78.4%) of the 125 patients. Acute rejection occurred in 64 (51.2%) of the 125 recipients. Patient survival rates were 90% at 5 years and 88% at 10 years. Graft survival rates were 65% at 5 years and 46% at 10 years. We tried to find the risk factors that affected graft survival. We examined the various possible risk factors, including harvesting condition (controlled versus uncontrolled), HLA-AB mismatches, HLA-DR mismatches, graft weight, donor age and sex, recipient age and sex, posttransplant DGF, acute rejection, WIT, and TIT. However, no significant risk factor was identified except acute rejection. We tried to discover the risk factors that caused primary nonfunction. Possible risk factors, including donor age, TIT, WIT, graft weight, and harvesting condition were compared, but no significant risk factor was identified. Long-term renal function was evaluated by serum creatinine levels. Serum creatinine levels at 1, 5, and 10 years were 1.76+/-0.7 mg/dl, 1.7+/-0.96 mg/dl, and 1.53-/+0.6 mg/dl, respectively.

CONCLUSIONS

In conclusion, our data demonstrated that the procurement of kidneys from NHBDs leads to acceptable long-term graft survival and renal function, despite a high incidence of DGF.