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DOUBLE VERSUS SINGLE RENAL ALLOGRAFTS FROM AGED DONORS

Andrés, Amado1 4; Morales, José Mará1; Herrero, Juan Carlos1; Praga, Manuel1; Morales, Enrique1; Hernández, Eduardo1; Ortuño, Teresa1; Rodçio, José Luis1; Martñez, Miguel Angel2; Usera, Gabriel2; Dáz, Rafael3; Polo, Gregorio3; Aguirre, Filógenes3; Leiva, Oscar3

Clinical Transplantation

Background. The age limit of the cadaver kidney donors is increasing in response to the growing demand for renal transplantation. Simultaneous double kidney transplantation (SDKT) with kidneys obtained from elderly adults has been proposed to increase the transplantation number and improve its results. However, if SDKT is performed when there are no clear indications, a negative effect could be produced on the total number of transplanted patients as both kidneys would be used for only one recipient.

Material and

Methods. In December 1996 we designed a transplantation protocol to be able to extend the selection of cadaver kidney donors with normal serum creatinine levels without establishing any age limit. A pregraft renal biopsy was always performed to analyze the glomerulosclerosis (GE) percentage whenever the donors were 60 years of age or older. A SDKT was performed in a single recipient when the donor age was 75 years or older or when the donors between 60 and 74 years old had a GE rate of more than 15%. On the contrary, a single kidney transplantation was performed in two different recipients for kidneys from donors between 60 and 74 years of age with a GE rate of less than 15%. Kidneys having GE rates of more than 50% were discarded for transplantation. Donor kidneys from subjects younger than 60 years of age were always used for a single kidney transplantation.

Results. Based on the above mentioned protocol, from December 1996 to May 1998, 181 patients received a kidney transplantation in our hospital. These patients were divided into three groups: group I which included the SDKT recipients (n=21), group II or single kidney recipients from 60- to 74-year-old donors (n=40), and group III or recipients from <60-year-old donors (n=120). The mean follow-up time was 15±5 months (range 6–24). Mean donor age was 75±7 years in group I, this was significantly higher than in group II (67±4, P <0.001) and group III (37±15, P <0.001). The primary nonfunction rate was low in the three groups, there being no statistically significant differences (5, 5, and 4%, respectively). A significantly greater percentage of patients from group I (76%) presented immediate renal graft function as compared with group II (43%, P <0.01) and III (50%, P <0.05). The acute rejections rate was very low in all three groups (9.5, 7.5, and 22%, respectively) with significant differences between groups II and III (P <0.05). No significant differences between the different groups were observed for one year actuarial patient survival (100, 95, and 98%, respectively) or graft survival rates (95, 90, and 93%, respectively). The 6-month serum creatinine levels were excellent in the three groups, although there were significant differences between groups I and II (1.6±0.3 vs. 1.9±0.6 mg/dl, P <0.05), II and III (1.9±0.6 vs. 1.4±0.4 mg/dl, P <0.001), and I and III (P <0.05).

Conclusions. Simultaneous double kidney transplantations make it possible to use kidneys from extremely elderly donors (>75 years) or those whose GE>15%. In addition, kidneys from donor 60–74 years old in which the GE<15% can be used for single kidney transplantations in two different recipients with excellent results.

Departments of Nephrology, Pathology, and Urology, Hospital 12 de Octubre, Madrid, Spain

1 Department of Nephrology.

2 Department of Pathology.

3 Department of Urology.

Received 5 January 1999.

Accepted 17 September 1999.

4 Address correspondence to: Amado Andrés, M.D., Departamento de Nefrología, Hospital 12 de Octubre, Crta de Andalucía Km 5.400, 28041 Madrid, Spain

In developed countries, lack of donors is the main obstacle to fully satisfy kidney transplantation demand. Consequently, the number of patients on the waiting list for a renal transplantation has been increasing in recent years (1–3). To solve this problem, many transplantation teams have increased the cadaver donor age limit (4–13). This policy has resulted in a greater mean age in cadaver kidney donors (2, 14). However, it is quite well known that kidney graft survival from older donors, although satisfactory, is not as good as that from younger donors (8). Thus, kidney transplantation teams use stricter criteria when selecting kidneys from older cadaver kidney donors with the consequent result that the number of kidneys obtained from these donors and finally discarded for transplantation has also been increasing in recent years (15, 16).

Recently, Cecka et al. (11) have demonstrated that there is better long-term graft survival with kidneys from older donors in older rather than in younger recipients as long as graft loss was not considered to exist when the recipient died with a functioning renal transplantation. These potential older recipients for whom these older donor kidneys would be directed form a group which is presently increasing the renal transplantation waiting lists due to the successful results of dialysis and renal transplantation in them (17, 18).

However, Gaber et al. (19) have described a correlation between the degree of glomerulosclerosis (GE) in the transplanted kidneys and the later outcome of the transplantation. The results of the kidney transplantation were worse as the percentage of GE increased, and there was a higher incidence of delayed graft function, greater graft lost, and worse middle term serum creatinine level. GE correlated with the donor’s age and death by nontraumatic cerebrovascular accident but not with their serum creatinine levels (19).

Recently, the policy of using simultaneous double kidney transplantation (SDKT) from adult cadaver donor kidneys has been successfully established (15, 20–23). Previously, several different transplantation center teams had discarded the former kidneys for used in transplantation mainly due to the high probability that significant glomerulosclerosis would exist because they were obtained from elderly donors and/or those having a history of arterial hypertension and/or diabetes. However, if this policy of using SDKT were to be generalized without using solid criteria, many patients on the waiting list would be denied the possibility of a transplantation as an excessive use of kidneys would occur.

Therefore, guidelines must be established regarding the kidneys from older donors to know when a single or simultaneous double graft should be used to increase the number of donors without increasing the number of discarded kidneys or decreasing the number of transplanted recipients. In December 1996, our team began a new policy to obtain optimum use of kidneys from extremely old donors by single or double transplantations in older recipients.

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MATERIALS AND METHODS

In December 1996, our Hospital started a protocol to obtain maximum use of the cadaver kidney from elderly donors (older than 60 years). The study period was 18 months.

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Protocol description.

After verifying normal renal function in the donor cadaver kidney accepted by our team, a gross examination of the kidneys was performed and their size, coloring, presence of scars and cysts, and renal vessel characteristics were assessed. After this examination, if the donor was younger than 60, it was decided whether the kidneys could be used for transplantation or should be discarded. If the kidneys had been obtained from ≥60-year-old patients and were grossly suitable, a wedge biopsy was performed. Freezing techniques were used to process the material obtained and the percentage of glomerulosclerosis was assessed. When the GE rate was <15%, in kidneys from donors between 60 and 74 years, a single renal transplantation was performed in two different recipients. A double renal allograft was carried out in a single recipient if the age of the donor ranged from 60 to 74, and the percentage of glomerulosclerosis was 15% or more (considering the highest percentage of the two biopsies of both kidneys from the same donor). A double kidney transplantation was always performed if the kidney donor was 75 years or older. Those kidneys in which the glomerulosclerosis percentage was more than 50% or in which there were severe interstitial or vascular changes were discarded for transplantation. In the case of a double kidney transplantation, each kidney was implanted extraperitoneally in each iliac fossae. Two different incisions were done, using the common end-to-side vascular anastomosis in the iliac vessels. Urinary tract reconstruction was performed by bilateral antireflux transvesical ureterocystostomy.

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Selection of recipients.

Similar recipient/donor age and good HLA histocompatibility should exist regarding recipient selection.

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Immunosuppressant therapy.

Our immunosuppressant protocols were based on a three-drug therapy with corticosteroids (CS), Cyclosporine A (CSA) or FK506, and Micophenolate Mofetil (MMF). The initial doses of CSA (5 mg/kg/day) or FK-506 (0.1 mg/kg/day) were lower in donor recipients older than 60. These were progressively tapered to maintain total blood levels at 100–150 and 5–7 ng/ml, respectively. On the contrary, donor recipients younger than 60 were treated with initial doses of CSA of 10 mg/kg/day or FK-506 of 0.2 mg/kg/day which were slowly tapered to maintain total blood levels of 150–300 and 8–15 ng/ml, respectively.

Cadaver kidney graft recipients with very prolonged cold ischemia time or those coming from hemodynamically unstable donors could receive sequential antithymocyte globulin (ATG) therapy. Hyperimmunized recipients (panel reactive antibodies more than 50%), and patients receiving a second or more transplantation could be treated with quadruple therapy. Such therapy consisted in one course of 7 to 10 days of ATG and CS, CSA or FK506, and MMF. Ganciclovir prophylaxis anti-CMV treatment was carried out in all the ATG-treated patients. All the study patients received 9 months of cotrimoxazole prophylaxis against Pneumocystis.

Acute rejections were treated with pulse steroid therapy (methylprednisolone 1 g/day) for 3 consecutive days. If the rejection episode was steroid resistant, then a course of OKT3 or ATG was given during 7 to 10 days (never more than 14 doses).

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Definitions of renal graft evolution variables.

Delayed graft function was considered to exist if the recipient required at least one dialysis in the early posttransplantation period. “Primary nonfunction” (PNF) of the graft was defined as when the renal graft had never worked at any time in the posttransplantation evolution, and the recipient continued to required dialysis. All the patients who died without recovering renal function were included in this group.

Diagnosis of acute rejection was established by biopsy or empirically in those cases in which renal biopsy could not be performed. In the latter, the rejection diagnosis was based on increased serum creatinine levels that could not be explained by any other toxic or hemodynamic factors, and which could be lowered with antirejection therapy.

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Variables analyzed.

The donor variables collected from the medical records were: age, gender, history of hypertension or diabetes, causes of brain death, serum creatinine levels at the time of the death, and percentage of glomerulosclerosis on pregraft biopsy. Recipient-dependent variables were: age, gender, etiology of renal failure, time on dialysis, number of previous transplantations, HLA histocompatibility, panel reactive antibodies, type of immunosuppression, CSA, and FK506 doses and blood levels, cold ischemia time, immediate renal function incidence, delayed renal function incidence, number of dialyses required, incidence of PNF, incidence of acute rejection, incidence of acute corticosteroid-resistant rejection, actuarial graft and patient survival, serum creatinine levels at 1, 3, 6, and 12 and months of evolution, surgical, and infectious complications, causes for graft lost, and causes of death.

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Statistical analyses.

The results of the quantitative variables were expressed as mean±SD and those of the qualitative variables as proportions. The Student’s t test and χ2 test were used to test the differences between the quantitative and qualitative variables, respectively. Graft and patient survival was calculated with the Kaplan Meier analyses. Comparison between groups was performed with log rank test.

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RESULTS

According to our protocol, 181 patients were transplanted in our institution with cadaver kidneys in the study period. These recipients were classified into three groups: group I (n=21) were recipients of SDKT from donors older than 60; group II (n=40) were recipients of single renal graft from donors aged 60 to 74 with less than 15% of glomerulosclerosis on pregraft biopsy; and group III (n=120) were recipients of single renal transplantation from donors younger than 60. Mean follow-up was 15±5 months (range 6–24). Before initiating this new protocol for donors over 60 years of age, 34% of the donor kidneys for this age group were discarded for transplantation in our program. This figure decreased to 18% during the period in which the protocol was applied.

Table 1 shows the general characteristics of the donors from the three groups. Group I donors had a significantly higher mean age than the other two groups, because this group included extremely elderly donors (12 were older than 75 and three exceeded 80) (Fig. 1). However, the mean age of the group II donors was also very high, with 26 donors (65%) older than 65 years (11 of whom were older than 70) (Fig. 1). There was a significantly higher rate of arterial hypertension in groups I and II than those of group III donors. Only a few donors had a history of type II diabetes mellitus and they were included in groups I and II. Nontraumatic stroke was the most common cause of death in both groups for the aged donors and reached a 70% incidence in group II. There were no significant differences in serum creatinine levels in the donors at the time of renal extraction. The percentage of glomerulosclerosis on pregraft biopsy was significantly higher in group I than in group II, in agreement with that established in our protocol.

Table 1

Table 1

Figure 1

Figure 1

Table 2 shows the characteristics of the recipients from the three groups. Group III recipient age was significantly lower than that of groups I and II, in accordance with our recipient selection policy that established that the donor and recipient ages should be similar. However, the high mean age in the group I recipients was slightly but significantly lower than the mean recipient age in group II. The mean mismatches in the six HLA, A, B, and DR loci were lower in the group III recipients. The only 10 patients with panel reactive antibodies of more than 50% who received a graft during our trial are included in group III. The most frequently used initial immunosuppressant therapy was a triple therapy consisting of CS+CSA+MMF. Twenty-one patients from group III, four patients from group II and five patients from group I were also treated with ATG. Twenty recipients from group III and five recipients from group II received triple therapy with FK506, although several recipients were changed from CSA to FK506 during the evolution of the trial so that 48 patients were taking this drug at the end of the follow-up. Three recipients were administered initial immunosuppressant treatment with rapamycine, but only one continued on such therapy at the end of the follow-up. As could be expected from our immunosuppressant protocol, the CSA doses and levels were significantly higher in group III than in the groups II and I and the FK506 levels and doses were also higher in group III (Table 2).

Table 2

Table 2

Table 3 shows the most outstanding data on the posttransplantation evolution of the recipients in the three groups. The mean follow-up time was similar in the three groups. The mean cold ischemia time was long in all three of our groups but it was significantly longer in groups I and II. Notably, double renal graft recipients had a significantly higher rate of immediate renal function than the other two groups and those patients in group I who suffered graft renal function delay required a significantly lower number of posttransplantation hemodialysis sessions. The highest incidence of delayed graft function was observed in group II. PNF incidence was low in the three groups. Graft thrombosis and exitus were the main causes of PNF. Only one patient from group III had a PNF due to acute rejection.

Table 3

Table 3

The incidence of acute rejection using a triple immunosuppressant regime with MMF was very low in the three groups (Table 3). The low percentage of rejections in group I and II patients stands out, this being lower than 10%. Group II showed the lowest rejection rate, the difference being statistically significant in regards to group III. Acute rejection was diagnosed by renal biopsy in one case (50%) in group I, in two cases (66%) in group II and in 23 cases (88%) in group III. All groups I and II rejections were corticosteroid-sensitive. The six patients who suffered a corticosteroid nonresponsive rejection and required treatment with antilymphocytic globulins belonged to group III. Three of them totally lost renal function before the third posttransplantation month.

Table 3 shows actuarial graft and patient survival rates at 3, 6, and 12 months of evolution. These values are excellent for the three groups, there being no significant differences among them. To calculate graft survival, a group I recipient was considered to have a functional graft if at least one of the grafts maintained its functionality so that the patient did not require dialysis. At 6 months, which was the minimum follow-up period, renal function was conserved in 93% of group III recipients and 95% of those in groups I and II. Mortality rate at 6 months was 0, 3, and 2% in groups I, II, and III, respectively.

Surgical complications are shown in Table 4. The early renal graft thrombosis incidence was higher in group I. Five (12%) renal graft thrombosis occurred in four patients among the 42 implants in group I. In one patient, this thrombosis was bilateral and occurred in the early postoperative due to arterial causes. In the other three patients it was only unilateral, two of which occurred in the early postoperative, also due to arterial causes, and the other on the fourth day of evolution simultaneously with an acute rejection episode. However, renal function was preserved in these three patients as the contralateral renal graft remained functional. The other most commonly appearing surgical complication was the development of lymphoceles that compressed the urinary tract. Most of these cases were produced in group III, although no significant differences for the groups were found. There was scarce incidence of urinary tract fistulae and no surgical wound infections were observed in any of the groups.

Table 4

Table 4

The incidence of cytomegalovirus (CMV) infection was significantly higher in the double renal graft group (6 cases or 28.5%) (Table 4). Three of these six recipients had received immunosuppressant therapy with ATG and specific prophylactic treatment against CMV with ganciclovir in the immediate posttransplant period. Donor/recipient CMV serological status of renal transplantations from all groups was positive/positive in 159 cases, negative/negative in 2 cases, and negative/positive in 17 cases. There were only three cases with CMV positive/negative status which were found, one in group II and two in group III. These patients were treated prophylactically with ganciclovir and anti-CMV hyperimmune globulin and CMV infection did not develop. The clinical picture of CMV infection was mild in 18 of the 19 cases found in all the groups. In these 18 cases, only fever and viremia were observed with no visceral involvement. The only patient who had visceral involvement (pneumonitis) belonged to group III, and had not received ATG at any time. Response to intravenous ganciclovir was excellent in all nineteen patients. No other opportunistic infections were observed.

Most of the complications which led to renal graft lost were produced in the immediate posttransplantation period and resulted in PNF (see Table 3). Late complications that led to the remaining renal graft losses were two cases of acute rejection and one exitus with functioning renal graft in group III and one case of late thrombosis (seventh month) of the renal graft after a renal artery transluminal angioplasty due to stenosis and one exitus with functioning renal graft in group II.

Table 5 shows the serum creatinine levels in recipients with functioning grafts at 1, 3, 6, and 12 months posttransplantation. In general, the mean serum creatinine levels were excellent although those found in groups I and III were significantly better than those of group II. However, the serum creatinine levels in 25 group II recipients (63%) were under 2 mg/dl at the end of the follow-up period. No statistically significant differences were observed in the serum creatinine levels between groups I and III in the four time periods analyzed, except at the 6-month evaluation.

Table 5

Table 5

None of the four patients who died had received a double renal graft. Causes of death were cardiogenic shock and aspergillosis, respectively, in the two group III recipients and gastric hemorrhage and lung carcinoma in the two group II recipients.

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DISCUSSION

The results of our series of simultaneous double renal transplantation from extremely aged donors (mean age 75±7 years) and a mean glomerulosclerosis percentage of 19±10% are excellent. In addition, the low incidence of delayed graft function and acute rejection episodes and the good middle term serum creatinine levels obtained by the recipients should be emphasized.

However, the results of single renal grafts from donors older than 60 years of age, when the guidelines of our protocol are considered (i.e., donors <75 years and glomerulosclerosis percentage <15%), are excellent. With a mean donor age of 67±4 years and graft glomerulosclerosis of 5±4%, these patients presented excellent graft and patient survival in single renal transplantation, there being no statistically significant differences with the double renal graft recipient group or control group, and maintained excellent serum creatinine levels at 1 year (1.9±0.8 mg/dl).

The mean donor age in our series of double renal grafts is much greater than that of all the series using this technique that have been published up to now in the literature. In addition, the mean age of our single renal graft advanced age donor group also exceeds that of the donors of these same series of double grafts (15, 20–23). After they reviewed their results on double and single renal grafts retrospectively, Alfrey et al. (22) recommended double kidney transplantations when the donor creatinine clearance was lower than 90 ml/min by the Crockcoft-Gault formula and the donor age was equal to or more than 59 years, and recommended that the cold ischemia time of the kidneys be limited to no more than 24 hr. The single renal graft outcome in the Alfrey’s series in which these circumstances occurred was worse. Nevertheless, these authors suggest that these criteria should be reviewed and improved with new data (24).

We have used a morphological criterion of the percentage of glomerulosclerosis in the pregraft biopsy to establish the indication of double renal grafts with kidneys from donors older than 60 years. This criterion is easy to quantify and highly efficient when predicting renal graft outcome (19). In view of our results, our protocol has been very useful to establish the double or single renal graft indication when the donor is aged 60 years or more. In addition, it has made it possible to perform single or double kidney implants with kidneys from extremely aged donors (12 of them older than 75 years and 3 older than 80 years). Such kidneys had not been routinely used in renal transplantation up to now.

Due to the excellent results of the double transplantation found in our series, it can be suggested that the 70- to 79- and 80- to 89-year-old population groups should be considered as potential organ donors, groups that had not been considered adequate for kidney donations until now (25). The nontraumatic stroke incidence for these age groups is hundreds of times higher than in a younger population (26), and brain death appears in many of the cerebral vascular events. Up to now, due to their age, these extremely elderly patients with brain death were not considered as potential donors and thus no steps were taken to initiate the donation process (27). This study opens up the possibility of using the kidneys from these extremely old donors, which will undoubtedly increase the number of cadaver kidney donors and reduce the number of recipients on the waiting list.

The existence of worse serum creatinine levels in single kidney graft recipients from donors older than 60 years confirms our policy of using these kidneys in elderly recipients. In such recipients, by using a triple immunosuppressive therapy with micophenolate mofetil and low doses of CSA or FK506, it has been possible to avoid nephrotoxicity and also to obtain a low incidence of acute rejection episodes. The extremely low incidence of acute rejection in this group of patients will be a positive factor to maintain the long-term graft function (28, 29). Moreover, the lower life expectancy in those elder patients, above all when in dialysis (30), justifies single kidney transplantation from aged donors. Most of the renal grafts will still be functioning when the recipient dies (11).

On the contrary, the excellent creatinine levels reached in the double implant patients with a low incidence of acute tubular necrosis and acute rejection in spite of the advanced age of the donors makes us reconsider the age of the recipients that we should select. Given that immediate renal function and acute rejection episodes are the main parameters affecting the long-term evolution of the graft (28, 29, 31–33), these double renal grafts are in the best situation for long-term survival. Although the advanced age of the donors is a negative factor for the long-term survival (34, 35), this is compensated for by the double renal graft as the number of nephrons is increased. Thus, due to the increase in nephrons, the mechanisms of glomerulosclerosis by hyperfiltration that provoke long-term loss of the renal graft will also decrease (36). If the double renal graft recipients age is lowered, from the surgical point of view, we must keep in mind that there may be successive transplants and that surgically usable fields should be available in both iliac fossae to be used in successive renal graft placements.

The incidence of surgical complications was not very high in each group. It should be highlighted that no surgical wound infection was observed. The only important point that merits comment is the higher incidence of graft thrombosis in the double graft group, however, this difference was only statistically significant when compared with the control group. Given the donor and recipient ages, the atherosclerotic changes in the renal and iliac arteries increase the risk of arterial graft thrombosis. The double implantation procedure made it possible for three of the four recipients with graft thrombosis to maintain their renal function with the contralateral functioning kidney. However, this complication warns us about the need to be very meticulous in the selection of the double implant recipients and to discard those recipients with severe atherosclerosis and calcifications in the aortoiliac tract.

A high incidence of mild CMV infection in the double renal graft group was observed. However, the clinical picture only consisted in viremia and fever and the patient response to treatment with ganciclovir was excellent. Three of the five patients in this double transplantation group who presented this infectious complication had been treated with ATG and prophylactic ganciclovir. We have no clear explanation to this fact, which hypothetically could be related to the greater volume of transplanted kidney tissue.

In conclusion, double renal graft with kidneys from extremely aged donors is a technique that provides highly satisfactory short-term results and opens new perspectives to increase the number of donors, thus increasing the number of renal transplants and reducing the waiting lists. However, the rational use of kidneys from donors aged 60 to 74 years old in single transplant, keeping the percentage of glomerulosclerosis (<15%) in mind, also provides excellent results. In all, by using our protocol, we extend the age limit of cadaver renal donors with good results and rationalize the use of kidneys from donors older than 60 years for single or double transplantation, thus optimizing the number of transplant recipients. Recipient and donor ages must be matched when older cadaver kidney donors are used.

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Acknowledgments.

We thank to the National Organization of Transplants in Spain and especially all the Spanish Hospital Transplant Coordinators, without whose efforts to detect and obtain the elderly donors it would not have been possible to perform the renal transplants in this series.

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REFERENCES

1. Official report on Transplant Activities of Council of Europe. Ed by FM Merieux Lyon France 1996. Transplant 1994; 7: 1.
2. UNOS 1996. Annual Report and the UNOS Scientific Registry of Transplant Recipients. Richmond, VA: UNOS.
3. Cohen B, Dámaro J, DeMeester J, Persijkn GG. Changing patterns in organ donation in Eurotransplant. Transplant Int 1997; 10:1.
4. Campistol JM, Manalich M, Andrew J, Oppenheimer F, Ricart MJ, Vilardell J. Rising age limit for kidney donors. Lancet 1989; 2:744.
5. Rao KV, Kasiske BL, Odlund AD, Ney AL, Andersen RC. Influence of cadaver donor age on posttransplant renal function and allograft outcome. Transplantation 1990; 49:91.
6. Pirsch JD, D’Alessandro AM, Sollinger HW, et al. The effect of donor age, recipient age, and HLA match on immunologic allograft survival in cadaveric kidney transplantation recipients. Transplantation 1992; 53:55.
7. Sumrani N, Daskalakis P, Miles AM, Hong JH, Sommer BG. The influence of donor age on function of renal allografts from live related donors. Clin Nephrol 1993; 39:260.
8. Alexander JW, Bennett LE, Breen TJ. Effects of donor age on outcome of kidney transplantation. Transplantation 1994; 57:871.
9. Kumar A, Kumar RV, Srinadh ES, et al. Should elderly donors be accepted in a live related renal transplant program? . Clin Transplant 1994; 8:523.
10. Lloveras J, Arias M, Andrés A, et al. Five-year Follow-up of 250 recipients of cadaveric kidney allografts from donors older than 55 years of age. Transplant Proc 1995; 27:981.
11. Cecka JM, Terasaki PI. Optimal use for older donor kidneys: older recipients. Transplant Proc 1995; 5 (27):801.
12. Shapiro R, Vivas C, Scantlebury P, et al. “Suboptimal” kidney donors. Transplantation 1996; 62:1242.
13. Cofán F, Oppenheimer F, Campistol JM, et al. Advanced age donors in the evolution of renal transplantation. Transplant Proc 1995; 27:2248.
14. Memoria de la Organización Nacional de Trasplantes 1997. Rev Esp Trasp 1998; 7: 61.
15. Johnson LB, Kuo PC, Dafoe DC, et al. Double adult renal allografts: a technique for expansion of the cadaveric kidney donor pool. Surgery 1996; 120:580.
16. Andrés A, Herrero Jc, Praga M, Segura J, Rodicio JL, Morales JM. Trasplante renal con donantes de edad avanzada. Nefrología 1998; 18 (4):50.
17. Isael N, Hakin RM, Helderman JH. Renal replacement therapies in the elderly. Renal Transplantation Am J Kidney Dis 1994; 23:1.
18. Andreu J, De la Torre M, Oppenheimer F, et al. Renal Transplantation in the elderly recipients. Transplant Proc 1992; 24:120.
19. Gaber LW, Moore LW, Alloway RR, Amiri MH, Vera SR, Gaber AO. Glomerulosclerosis as a determinant of posttransplant function of older donor renal allografts. Transplantation 1995; 60:334.
20. Johnson LB, Kuo PC, Dofoe DC, et al. The use of bilateral adult renal allografts. A method to optimize function from donor kidney with suboptimal nephrol mass. Transplantation 1996; 61:1261.
21. Johnson LB, Kuo PC, Schweitzer EJ, et al. Double renal allografts successfully increase utilization of kidneys from older donors within a single organ. Procurement Organization Transplantation 1996; 62:1581.
22. Alfrey EJ, Lee CM, Scandling JD, Paulakis M, Markezich AJ, Dafoe DC. When should expanded criteria donors kidneys be used for single versus dual kidney transplants? . Transplantation 1997; 64:1142.
23. Lee CM, Scandling JD, Shen GK, Salvatierra O, Dafoe DC, Alfrey EJ. The Kidneys that nobody wanted. Transplantation 1996; 62:1832.
24. Dafoe DC, Alfrey EJ. Dual allograft: expansion of the donor pool from an overlooked source. Transplant Int 1998; 11:164.
25. First MR. Expanding the donor pool. Semin Nephrol 1997; 17:373.
26. Tompson DW, Furla AJ. Clinical epidemiology of stroke. In: Neurologic Clinics, W.B. Saunders, Philadelphia: 1996; 14: 309.
27. Matesanz R, Miranda B, Felipe C. Organ procurement and renal transplant in Spain: The impact of transplant coordination. Nephrol Dial Transplant 1994; 9:475.
28. Gulanikar AC, MacDonald AJ, Sungurtekin U, Belitsky P. The incidence and impact of early rejection episodes on allograft outcome in recipients of first cadaver kidney transplant. Transplantation 1992; 53:323.
29. Hostetter TH. Chronic transplant rejection. Kidney Int 1994; 46:266.
30. United States Renal Data System. USRDS 1995 annual data report. U.S. Department of Health and Human Services. The National Institute of Health Diabetes and Digestive and Kidney Diseases, Bethesda, MD, August 1995.
31. Feldman HF, Gangner R, Berlin JA, et al. Delayed function reduces renal allograft survival independent of acute rejection. Nephrol Dial Transplant 1996; 11:1306.
32. Shoskes DA, Halloran PF. Delayed allograft function in renal transplantation: etiology, management, and long-term significance. J Urol 1996; 155:1831.
33. Almond PS, Matas A, Guillinghan K, et al. Risk factors for chronic rejection in renal allograft recipients. Transplantation 1993; 55:752.
34. Chertow GM, Brenner B, Mackenzxie HS, Milford EL. Non-inmunologic predictors of chronic renal allograft failure: data from the United Network of Organ Sharing. Kidney Int 1995; 48:S48.
35. Cosio FG, Qiu W, Henry ML, et al. Factors related to the donors organ are major determinants of renal allograft function and survival. Transplantation 1996; 62:1571.
36. Brenner BM, Cohen RA, Milford EL. In renal transplantation, one size may not fit all. J Am Soc Nephrol 1992; 3:162.
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