The effect of donor/recipient body surface area ratio on outcomes in pediatric kidney transplantation

Complex Bench Surgery Does Not Increase the Risk of Vascular Complications after Pediatric Kidney Transplantation

INTRODUCTION

 Vascular complications are severe complications of pediatric kidney transplantation (KT). We aimed to investigate whether a complex bench surgery (BS) affects the outcomes.

METHODS

 All pediatric KT performed at the University Hospital of Padua from 2015 to 2019 were analyzed, comparing those in which a standard BS was possible to those that necessitated a complex BS. The rates of vascular complications, patients' outcome, and graft survival were compared in the two groups.

RESULTS

 Eighty KTs were performed in 78 patients with a median age of 11 years (interquartile range [IQR] 4.3-14) and a median body weight of 24 kg (IQR 13-37). Thirty-nine donor kidneys (49%) needed a complex BS due to anomalies of renal veins in 12 (31%) and renal arteries in 16 (41%). The remaining 11 grafts (28%) underwent an elongation of the vein. There was no difference in the rate of primary graft non function (p = 0.97), delayed graft function (p = 0.72), and overall survival (p = 0.27). The rates of vascular complications, bleedings, and venous graft thrombosis were similar (p = 0.51, p = 0.59, p = 0.78, respectively). No arterial thrombosis or stenosis was reported.

CONCLUSION

 Complex BS did not compromise survival of the graft and did not put the allograft at risk of vascular complications, such as bleedings or thrombosis.

The Predictive Value of Donor Renal Functions, Graft Weight, Recipient Body Mass Index, and Human Leucocyte Antigen Match Regarding Early Graft Functions

Background and objective Graft performance is the most important postoperative parameter for patients undergoing kidney transplantation (KTx). The renal function of the donor is reported to be correlated with graft function after KTx. The body mass index (BMI) is also one of the important parameters involved in the prediction of graft function. The aim of this retrospective study was to examine the relationship between early postoperative graft function in patients undergoing KTx and donor cystatin C and estimated glomerular filtration rate (e-GFR) levels, graft weight/recipient BMI (G/B) ratio, and human leukocyte antigen (HLA) tissue compatibility. Materials and methods A total of 215 cases (215 donors, 215 recipients) who underwent KTx at our center between January 2018 and December 2022 were included in the study. Patients' age, sex, BMI, preoperative donor serum cystatin C and e-GFR levels, HLA tissue compatibility, graft weights, and recipient creatinine levels were recorded one week postoperatively. The Kolmogorov-Smirnov test and histogram plots were used to analyze the conformity of the variables to the normal distribution and Spearman's correlation test was used to analyze the relationship between variables. Results A negative correlation was identified between recipient creatinine level and G/B ratio and donor e-GFR (r = -0.256 and -0.137, respectively). Donor cystatin C level showed a positive correlation with recipient creatinine level (r = 0.242). No significant correlation was noted in terms of tissue matching rates (p = 0.616). Conclusion Although these three parameters are correlated with early graft functions, the graft weight/recipient BMI ratio has the strongest correlation.

Donor-Recipient BSA Matching Is Prognostically Significant in Solitary and En Bloc Kidney Transplantation From Pediatric Circulatory Death Donors

Background.

As the rate of early postoperative complications decline after transplant with pediatric donation after circulatory death (DCD) kidneys, attention has shifted to the long-term consequences of donor–recipient (D-R) size disparity given the pernicious systemic effects of inadequate functional nephron mass.

Methods.

We conducted a retrospective cohort study using Organ Procurement and Transplantation Network data for all adult (aged ≥18 y) recipients of pediatric (aged 0–17 y) DCD kidneys in the United States from January 1, 2004 to March 10, 2020.

Results.

DCD pediatric allografts transplanted between D-R pairs with a body surface area (BSA) ratio of 0.10–0.70 carried an increased risk of all-cause graft failure (relative risk [RR], 1.36; 95% confidence interval [CI], 1.10–1.69) and patient death (RR, 1.32; 95% CI, 1.01–1.73) when compared with pairings with a ratio of >0.91. Conversely, similar graft and patient survivals were demonstrated among the >0.70–0.91 and >0.91 cohorts. Furthermore, we found no difference in death-censored graft survival between all groups. Survival analysis revealed improved 10-y patient survival in recipients of en bloc allografts (P = 0.02) compared with recipients of single kidneys with D-R BSA ratios of 0.10–0.70. A similar survival advantage was demonstrated in recipients of solitary allografts with D-R BSA ratios >0.70 compared with the 0.10–0.70 cohort (P = 0.02).

Conclusions.

Inferior patient survival is likely associated with systemic sequelae of insufficient renal functional capacity in size-disparate DCD kidney recipients, which can be overcome by appropriate BSA matching or en bloc transplantation. We therefore suggest that in DCD kidney transplantation, D-R BSA ratios of 0.10–0.70 serve as criteria for en bloc allocation or alternative recipient selection to optimize the D-R BSA ratio to >0.70.

Factors associated with long-term graft survival in pediatric kidney transplant recipients

Pediatric kidney transplant recipients generally have good outcomes post-transplantation. However, the younger age and longer life span after transplantation in the pediatric population make understanding the multifactorial nature of long-term graft survival critical. This investigation analyzes factors associated with 10-year survival to identify areas for improvement in patient care. Kaplan-Meier with log-rank test and univariable and multivariable logistic regression methods were used to retrospectively analyze 7785 kidney transplant recipients under the age of 18 years from January 1, 1998, until March 9, 2008, using United Network for Organ Sharing (UNOS) data. Our end-point was death-censored 10-year graft survival after excluding recipients whose grafts failed within one year of transplant. Recipients aged 5-18 years had lower 10-year graft survival, which worsened as age increased: 5-9 years (OR: 0.66; CI: 0.52-0.83), 10-14 years (OR: 0.43; CI: 0.33-0.55), and 15-18 years (OR: 0.34; CI: 0.26-0.44). Recipient African American ethnicity (OR: 0.67; CI: 0.58-0.78) and Hispanic donor ethnicity (OR: 0.82; CI: 0.72-0.94) had worse outcomes than other donor and recipient ethnicities, as did patients on dialysis at the time of transplant (OR: 0.82; CI: 0.73-0.91). Recipient private insurance status (OR: 1.35; CI: 1.22-1.50) was protective for 10-year graft survival. By establishing the role of age, race, and insurance status on long-term graft survival, we hope to guide clinicians in identifying patients at high risk for graft failure. This study highlights the need for increased allocation of resources and medical care to reduce the disparity in outcomes for certain patient populations.

Long-term outcomes of adult-size and size-matched kidney transplants in small pediatric recipients

INTRODUCTION

Adult-size kidneys are usually used for kidney transplantation in small pediatric recipients, but the influence of graft size in transplant outcome remains controversial. Our aim is to compare long-term transplant outcomes of using adult-size and size-matched kidneys in small pediatric recipients.

MATERIALS AND METHODS

Since 1999, 61 of 226 kidney transplants were achieved in recipients weighing <20 kg with 5 years of follow-up. Patients were analyzed according to the graft size received: (group-A) adult-size (n = 32), (group-B) size-matched (n = 29). Kidney size (KS), glomerular filtration rate (GFR) proteinuria and rejection were compared between groups at transplant time (T₀), at one (T₁), two (T₂), five years (T₅), and at the end of the follow-up (T_F) (median follow-up 8.47(0-17) years). Graft and patient survival were determined and compared between groups.

RESULTS

Mean KS was significantly different between groups at T₀ (A:11.3 ± 1.1 cm, B:8.8 ± 0.9 cm), (pT₀<0.01), group-B evidenced graft growth, reaching similar sizes to group-A at T₅ (A:11.7±1 cm, B:11.2±1 cm; pT₅ = 0.13) and T_F (A:12.2 ± 1.1 cm, B:12.4 ± 1.2 cm; pT_F = 0.63), and group-A had a slight graft growth at T_F (pT₀-T_F<0.01). Mean Schwartz-GFR at T₀ was greater in group-A (138 ± 33 ml/min/1.73 m²) than group-B (109 ± 34 mL/min/1.73 m²) (pT₀ = 0.01); during follow-up, it evidenced a reduction in group-A (T₅:90 ± 27, T_F:71 ± 24 mL/min/1.73 m²; pT₀-T₅<0.01; pT₀-T_F<0.01), meanwhile in group-B was stable until T₅ (104 ± 33 mL/min/1.73 m²; pT₀-T₅ = 0.54), declining at T_F (76 ± 31 mL/min/1.73 m²; pT₀-T_F<0.01); with no significant differences at T₁, T₂, T₅, and TF between groups. Similar results were observed in mean Filler-GFR of both groups (Figure). Proteinuria and episodes of rejection were no significantly different between groups during the follow-up (p > 0.01; p = 0.23). Graft and patient survival at 5 and 10 years did not show significant differences (p = 0.45; p = 0.10).

DISCUSSION

Despite the initial kidney size difference between groups, we have demonstrated that they tended to the same size during the follow-up. Adult-size kidneys presented a slight size increase in the long-term, suggesting that they have some growth potential in small recipients, in contrast to previous literature. Mean GFR between groups showed no significant differences in the long-term, suggesting that optimal graft perfusion and function can be achieved despite the size of the graft. We have demonstrated that there were no significant differences in long-term graft and patient survival; this results were similar to the most recent literature about this topic and different from the 90-2000s decades literature.

CONCLUSIONS

Adult-size kidneys may be transplanted to small recipients (<20 kg) with comparable outcomes to size-matched kidneys, with no significant differences in long-term KS, GFR, proteinuria, rejection, graft or patient survival.

Comparison of live donor predonation and post-transplant kidney volumes and glomerular size in pediatric patients weighing less than 15 kg - a retrospective study

Renal transplantation of adult-size kidneys presents a size mismatch in small children. This study presents a comparison of live donor predonation and recipient post-transplant kidney volumes (k-vol) and glomerular size at 1 year after transplantation. We analyzed 47 pediatric renal transplant recipients weighing <15 kg between 2009 and 2017. The k-vol before and 1 year after transplantation and glomerular size at implant and 1 year post-transplant were evaluated. We estimated the relationships between these changes and graft function, and the factors associated with k-vol. Pretransplant k-vol was 158.1 ± 25.1 ml, and the k-vol at 1 year post-transplant was significantly reduced by -17.2% to 132.3 ± 27.3 ml (P < 0.001). Implant glomerular size showed the diameter was 165.3 ± 15.1 µm and the area 20 737.1 ± 3230.6 µm² . One-year post-transplant, the glomerular diameter was 150.6 ± 11.4 µm and the area 17 428.3 ± 2577.9 µm² , significantly reduced compared with implantation values (both P < 0.001). The change in k-vol was affected by pretransplant abdominal cavity (ml/200 ml cavity volume, partial regression coefficient = 0.029, SE = 0.009, P = 0.004) and recipient's weight gain (ml/5% of weight gain, partial regression coefficient = 0.020, SE = 0.006, P = 0.002). In small pediatric transplants, an adult-size kidney is acceptable with reduction in k-vol. Moreover, the post-transplant k-vol might be regulated by pretransplant physique and post-transplant somatic growth.

Non-immunologic allograft loss in pediatric kidney transplant recipients

Non-immunologic risk factors are a major obstacle to realizing long-term improvements in kidney allograft survival. A standardized approach to assess donor quality has recently been introduced with the new kidney allocation system in the USA. Delayed graft function and surgical complications are important risk factors for both short- and long-term graft loss. Disease recurrence in the allograft remains a major cause of graft loss in those who fail to respond to therapy. Complications of over immunosuppression including opportunistic infections and malignancy continue to limit graft survival. Alternative immunosuppression strategies are under investigation to limit calcineurin inhibitor toxicity. Finally, recent studies have confirmed long-standing observations of the significant negative impact of a high-risk age window in late adolescence and young adulthood on long-term allograft survival.

Impact and Application of Donor/Recipient Body Surface Area on Kidney Transplantation from Pediatric Donor to Adult Recipient

BACKGROUND

Insufficient nephron dosing is closely associated with poor graft function and graft loss. Donor/recipient body surface area (D/R BSA) has been proven to be one of the useful predictors for sufficient nephron dosing. However, little is known regarding the impact and application of D/R BSA on kidney transplantation from pediatric donor to adult recipient.

METHODS

We retrospectively analyzed 26 cases of kidney transplantations from pediatric donors to adult recipients, which were performed in our center from 2010 through 2014. Patients were divided into 2 groups based on D/R BSA: group A, <0.8; and group B, ≥0.8. All recipients received a single kidney. Demographics of donors and recipients, early postoperative complications, estimated glomerular filtration rate (eGFR), and short-term (≤1 y) graft survival were compared between groups to evaluate the impact of D/R BSA on kidney transplantations from pediatric donors.

RESULTS

All demographics and early postoperative complications of group A were similar to those of group B (P > .05). eGFR in group A and group B at 1, 3, 6, and 12 months after transplantation were: 63.2 ± 5.0 vs 74.0 ± 7.6 (P = .008), 66.2 ± 4.9 vs 75.8 ± 5.9 (P = .004), 69.0 ± 4.8 vs 79.0 ± 6.3 (P = .004), and 69.4 ± 7.9 vs 79.2 ± 8.4 (P = .033). Short-term graft survival of group A was inferior to that of group B (62.5% vs 94.4%; P = .042).

CONCLUSIONS

We conclude that recipients with high D/R BSA are more likely to have better graft function. It is possible to make optimal allocation of pediatric donor kidneys on the basis of D/R BSA ≥0.8.

Laparoscopic donor nephrectomy for the pediatric recipient population: Risk factors for adverse outcomes

Kidney transplantation is the optimal treatment of ESRD in children. Some studies have reported inferior outcomes in recipients of LDN allografts who are ≤ 5 yr of age. We performed a retrospective review of pediatric recipient outcomes of 110 LDN allografts at our institution and examined predictors of adverse outcomes. Subgroup analysis was performed by dividing recipients into three age categories: 0-5 yr, 6-17 yr, and ≥ 18 yr. There was no significant difference between incidences of DGF or ARE between groups. Kaplan-Meier analysis demonstrated 100% allograft survival in 0- to 5-yr-old recipients, nearly reaching statistical significance (p = 0.07) for outcome superior to that of the two older age groups. Pretransplant HD was associated with increased risk of DGF (p = 0.05). Significant risk factors for ARE were recipient weight >15 kg (p = 0.033) and multiple renal arteries (p = 0.047). Previous ARE was associated with an increased risk of allograft failure (p = 0.02). LDN is not associated with increased risk of DGF, ARE, or allograft failure in the youngest recipients. These findings support an aggressive pursuit of preemptive transplantation even in the youngest pediatric allograft recipients.

Donor kidney glomerular filtration rate and donor/recipient body surface area ratio influence graft function in living related kidney transplantation

OBJECTIVE

This study seeks to account for the possibility that single kidney glomerular filtration rate (SKGFR) and donor/recipient (D/R) body surface area (BSA) ratio could act as cofactors for evaluating potential living related donors.

METHODS

The study population included 204 cases of LKRs with a functional graft that were regularly followed up for more than 2 years. Based on SKGFR and D/R BSA ratio, the recipients were divided into six groups: group A (SKGFR < 40 mL/min, D/R BSA ratio ≤ 0.8), group B (SKGFR < 40 mL/min, 0.8 < D/R BSA ratio < 1.2), group C (SKGFR < 40 mL/min, D/R BSA ratio ≥ 1.2), group D (SKGFR ≥ 40 mL/min, D/R BSA ratio ≤ 0.8), group E (SKGFR ≥ 40 mL/min, 0.8 < D/R BSA ratio < 1.2), and group F (SKGFR ≥ 40 mL/min, D/R BSA ratio ≥ 1.2). The database included donor, recipient, and transplant variables. Renal function of the recipients was recorded at 1 week, 2 weeks, 1 month, 3 months, 6 months, 12 months, and 24 months post-transplantation, respectively.

RESULTS

The declining rate of SCr and graft eGFR in stable periods post-transplantation in group A were always worse than the other five groups, and the difference was statistically significant (p < 0.05). The declining rate of SCr and graft eGFR in stable periods post-transplantation in groups C and F were always better than the other four groups, and the difference was statistically significant (p < 0.05).

CONCLUSIONS

Both SKGFR and D/R BSA ratio should be considered for choosing potential living related donors. Donors with SKGFR < 40 mL/min and D/R BSA ratio ≤ 0.8 should be carefully selected. Satisfactory graft function in donors with SKGFR < 40 ml could be achieved if their D/R BSA ratio is >0.8.

Lymphocele after pediatric kidney transplantation: incidence and risk factors

Lymphocele is a well-known postoperative complication after kidney transplantation. The aim of this study was to analyze time trend incidence, risk factors, and outcome of post-transplant lymphocele in a large pediatric cohort. This is a retrospective single institution review of 241 pediatric kidney transplants performed from 2000 to 2013. Etiology of end-stage renal disease, recipient age and gender, transplant year, BMI percentile for age, type of dialysis, living/non-living related donor, acute rejection, and multiple transplantations were analyzed in association with lymphocele formation. Fourteen of 241 (5.81%) children developed a postoperative lymphocele. There has been a reduction in the incidence of lymphocele after 2006 (3.22% vs. 8.55%, p < 0.05). Significant risk factors for lymphocele were older age (≥11 yr), transplant before 2006, male gender, BMI percentile for age ≥95%, and multiple transplantations (p < 0.05). The one-yr graft survival was significantly reduced in the group with lymphocele compared with control (81.2% vs. 92.51%, p < 0.04). This is the first pediatric report showing the following risk factors associated with post-transplant lymphocele: age ≥11 yr, male gender, BMI for age ≥95%, and multiple transplantations. A lymphocele can contribute to graft loss in the first-year post-transplant.

Delayed graft function in pediatric deceased donor kidney transplantation: donor-related risk factors and impact on two-yr graft function and survival: a single-center analysis

There is mounting evidence that the quality of organs from cadaver donors may be influenced by events occurring around the time of brain death. Aim of this present study was to analyze the correlation of DGF with brain-dead donor variables in a single-center pediatric population and to evaluate DGF influence on patients- and grafts outcome. End-points of the study were DGF prevalence, DGF donor-related risk factors, graft function, patient- and graft survival rate, respectively, at six, 12, and 24 months FU. The univariate analysis showed that donor age above 15 yr and vascular cause of donor brain death represented risk factors for DGF. The multivariate analysis confirmed as independent risk factors for DGF donor age >15 yr. At six months FU, DGF showed a negative impact on graft function. In conclusion, among all considered brain-dead donor resuscitation parameters, just non-traumatic cause of death turned out to be of impact for DGF. Donor age >15 yr represented the only independent risk factor for prolonged DGF in our series of children. At two-yr FU, DGF showed a transient negative impact on six-month graft function.

Early protocol biopsies in pediatric renal transplantation: interest for the adaptation of immunosuppression

GPB are often performed in PRT to detect subclinical acute rejection or IF/TA. Reducing immunosuppression side effects without increasing rejection is a major concern in PRT. We report the results of GPB in children transplanted with a steroid-sparing protocol adapted to immunological risk. Children under 18 yr who received a renal transplantation between April 1, 2009 and May 31, 2012 were included. Immunosuppression consisted of an antibody induction therapy, tacrolimus, and MMF for all recipients. CSs were administered to children under five yr old, or receiving a second allograft. Twenty-eight children were included, 50% were CSs free. GPB were performed between three and six months. IF/TA was documented in seven biopsies; four of these seven children were CS free. One child, with CSs, presented a borderline rejection, and another child, steroid free, with significant inflammatory interstitial infiltrate, considered as a subclinical rejection, was treated with CSs pulses. The median eGFR was stable (74, 67.5, and 82 mL/min/1.73 m² at, respectively, seven days, three months, and one yr). Patient and graft survival were 100%. These results have to be confirmed in a larger cohort, with long-term follow-up.

Does graft mass impact on pediatric kidney transplant outcomes?

BACKGROUND

The aim of this study is to assess the evolution of renal size and function in pediatric transplant patients according to the graft mass/recipient size ratio.

METHODS

Fifty pediatric renal transplant recipients were followed over 2 years. Grafts were weighed, and three different graft mass/m(2) ratios were determined: (1) low graft mass (58 g/m(2), range 31-57 g/m(2)), (2) median (142 g/m(2), range 59-141 g/m(2)) and high (267 g/m(2), range 143-353 g/m(2)). Patients underwent repeated ultrasound Doppler scans and repeated measurements of estimated glomerular filtration rate (eGFR; 1 week and 1, 6, 12 and 24 months), urinary retinol-binding protein (RBP) and proteinuria (1 week and 6, 12 and 24 months).

RESULTS

The volume of renal tissue increased by 12 ± 5.6 cm(3) at 24 months (p = 0.035) in the low graft mass and decreased by -14 ± 7 cm(3) (p = 0.046) in the high graft mass. The eGFR increased when either low (30 ± 5 ml/min/1.73 m(2), p < 0.001) or median (19 ± 4 ml/min/1.73 m(2), p < 0.001) graft mass was transplanted but remained stable when high graft mass was transplanted. The resistive index (RI) presented a significant decrease throughout early follow-up in the transplants involving low and median graft mass, whereas a slight rise was observed in those involving high graft mass. A significant difference was apparent 6 months post-transplant. Transplants of low and median graft mass were associated with an initial higher urinary RBP. No significant differences in proteinuria were detected.

CONCLUSIONS

Small kidneys undergo increases in volume and function without escalation of either proteinuria or urinary RBP, characterizing an adequate adaptation to the recipient. Children receiving larger kidneys present a reduction in volume, stable GFR and higher RI at 6 months.

Anorectal malformation and associated end-stage renal disease: management from newborn to adult life

BACKGROUND/OBJECTIVE

Renal failure remains one of the most significant causes of morbidity in patients with anorectal malformations (ARM). In the modern era, an increasing number of children born with ARM and genito-urinary (GU) anomalies reach adulthood and require continued multidisciplinary care for the rest of their life. The aim of this study is to present our institutional experience in the management of pediatric chronic renal failure related to severe GU anomalies and anorectal malformations.

METHODS AND RESULTS

Three hundred twenty-one patients with ARM have been followed at our institution since 1987. Six patients developed end-stage renal disease (ESRD) and received a kidney transplant at different ages. One patient is currently followed for mild, progressive chronic renal failure. These seven cases are reported along with a broad discussion concerning etiology of renal failure, neonatal surgical management, pediatric dialysis, urologic issues, and kidney transplantation.

CONCLUSION

Complex GU anomalies associated with ARM require a long-term approach by specialized pediatric and adult clinicians to optimize the care of this selected population of patients.

[Outcomes of pediatric renal transplantation in France]

Significant progress has been observed in pediatric renal transplantation over the last 20 years, leading to an increase in graft and patient survival. Mortality is low and is mainly due to infections, neoplasias and complications related to the initial disease. Graft survival is 67% at 10 years. Factors which influence graft survival are: donor type (results are better with a live donor), donor age, recipient age (with 2 periods at risk:<2 years old and teenagers), HLA incompatibilities, and recurrence of the initial disease. Chronic allograft nephropathy (CAN) is the major cause of late graft loss. Poor compliance, especially in teenagers, may lead to late rejections and graft loss. Calcineurin inhibitors nephrotoxicity is in part responsible for the development of CAN, thus treatments and the role of mTOR inhibitors will probably evolve. These different factors are discussed in this article.

Long-term impact of donor-recipient size mismatching in deceased donor kidney transplantation and in expanded criteria donor recipients

BACKGROUND

The degree to which recipient/donor (R/D) size mismatching leads to nephron underdosing and worse kidney allograft survival remains poorly defined, particularly in the setting of preexisting nephron loss such as the expanded criteria donor (ECD).

METHODS

We performed a retrospective analysis of 69,737 deceased donor transplants followed by a subset analysis of ECD transplants using data from the Scientific Registry of Transplant Recipients from 1992 to 2005. Ratios of R/D body surface area (BSA) were used to estimate nephron disparity and segregate pairs.

RESULTS

In the entire cohort, severe BSA disparity (R/D BSA>1.38 m) was associated with slightly worse 10-year unadjusted graft survival (35% for severe BSA disparity vs. 39% in pairs of comparable size, P<0.0001). In multivariate analysis, BSA disparity was associated with a 15% increased risk of graft loss (hazard ratio 1.15, P<0.0001). Within ECD cohorts, severe BSA disparity was associated with a decrease in 10-year unadjusted graft survival of greater magnitude than the overall cohort (10% for severe BSA disparity vs. 22% in pairs of comparable size, P<0.0004). On multivariate analysis, severe R/D BSA disparity was associated with worse allograft survival similar to the entire cohort (hazard ratio 1.18, P=0.04).

CONCLUSIONS

Recipients receiving kidneys from substantially smaller donors have a statistically higher rate of graft loss that is more pronounced in ECD kidneys. Although severe R/D size disparity is an independent risk factor for graft loss, the magnitude of this risk requires consideration in the context of other risk factors for the graft loss and the hazards of dialysis.