Transplantation of pediatric cadaver kidneys into adult recipients

Long-term Outcomes of Single and Dual En Bloc Kidney Transplants From Small Pediatric Donors: An ANZDATA Registry Study

Kidney transplants from small pediatric donors are considered marginal and often transplanted as dual grafts. This study aimed to compare long-term outcomes between recipients of single kidney transplants (SKTs) and dual en bloc kidney transplants (EBKTs) from small pediatric donors.

Methods

Data were obtained from the Australia and New Zealand Dialysis and Transplant Registry. All adult recipients of kidney transplants from donors aged ≤5 y were identified. The primary outcome of interest was death-censored graft survival by donor type. The secondary outcomes were early graft loss, delayed graft function, serum creatinine posttransplantation, acute rejection, and patient survival.

Results

There were 183 adult recipients of kidney transplants from donors aged ≤5 y old. Of these, 60 patients had EBKT grafts, 79 patients had SKT grafts, and 44 patients had grafts of unknown type. Compared with SKT donors, EBKT donors had lower mean age (P < 0.001) and body weight (P < 0.001). There was no significant difference in death-censored graft survival between the groups, with median survival of 23.8 y (interquartile range 21.2-25) in the EBKT cohort and 21.8 y (11.6-26.8) in the SKT cohort (hazard ratio 1.3; 95% confidence interval, 0.59-2.64; P = 0.56). EBKT grafts had lower acute rejection rates than SKT grafts (P = 0.014). There was no significant difference observed between groups with respect to early graft loss, delayed graft function, posttransplantation serum creatinine posttransplantation, or patient survival.

Conclusions

EBKT and SKTs from small pediatric donors are associated with excellent long-term graft survival rates.

En Bloc Kidney Transplantation: A Retrospective Study of an 18-year Experience in a Single Institution

Background

Renal transplantation is facing a shortage of grafts. En bloc kidney transplantation (EBKT) from pediatric donors could increase the number of available grafts.

Objective

To describe the surgical technique as well as the long-term functional and morphological results of EBKT.

Design setting and participants

We performed a retrospective study of all the EBKT procedures performed in Lyon between 2002 and 2020. Electronic medical records were checked with an analysis of demographics, and peri- and postoperative results.

Outcome measurements and statistical analysis

A descriptive analysis of donor and recipient characteristics, perioperative data, complications, and renal function was performed.

Results and limitations

Between 2002 and 2020, 21 EBKT procedures were performed. Donors had a mean weight of 8.6 kg and a mean age of 12 mo, with a mean cold ischemia time of 11 h and 30 min. Receivers had a mean age of 30 yr and a body mass index of 20. The mean follow-up time was 62 mo, with patient survival of 100% and graft survival of 95%. There were 13 reinterventions comprising one early unilateral transplantectomy for thrombosis. Renal function was excellent, and the morphological findings described an important growth in size in the first 2 yr before attaining the adult size. This study's limitations include its retrospective nature and a small number of participants.

Conclusions

The present study reports excellent results with EBKT and supports the pursuit and spread of this technique.

Patient summary

In this report, we describe the technique and results of en bloc kidney transplantation. We found that results are excellent for renal function and patient survival. We conclude that en bloc kidney transplantation should be considered to increase the number of grafts.

Kidney transplantation outcomes for adult recipients of pediatric donor kidneys

Despite a paucity of data assessing transplantation of deceased-donor pediatric donor kidneys into adult recipients, utilization of pediatric organs is declining in the UK, likely due to concerns that such organs may have inferior outcomes. However, we hypothesized that these concerns may be unfounded. As such, the aim of the study was to compare kidney transplant outcomes between adult recipients of pediatric and adult deceased-donor organs. Data were collected from the UK Transplant Registry for all adult (18+ years) deceased-donor single-kidney transplant recipients between January 2000 and January 2016. Univariable and multivariable analyses were undertaken, to compare a range of outcomes between recipients of kidneys from pediatric and adult donors. Transplants were stratified by the donor age (years) as follows: 0-16 (n = 666), 17-18 (n = 465), and 19-44 (n = 7378). Recipients of pediatric donor kidneys were observed to have improved long-term graft function, with a median creatinine at 1 year of 109 vs. 117 μmol/L for recipients of donors aged 0-16 vs. 19-44 years (P < .001). However, on multivariable analysis, this was not found to correspond to a significant difference in patient (P = .914) or graft survival (P = .190) between the donor age groups. Subgroup analysis within the younger donors found no significant differences in recipient outcomes between donors aged 0-6, 7-12, and 13-16 years. In this population cohort study, we identified excellent outcomes among adult recipients of pediatric donor kidneys. Pediatric donors are a valuable source of organs for adult recipients in an era where organ demand is rising.

Survival Benefit of En Bloc Transplantation of Small Pediatric Kidneys in Children

BACKGROUND

En bloc transplantation of small pediatric kidneys in children may help expand the existing deceased donor pool; however, studies examining the long-term outcomes of en bloc transplantation in children are few.

METHODS

We used the Scientific Registry of Transplant Recipients to identify 149 pediatric en bloc recipients transplanted from October 1, 1987 to December 31, 2017. We used propensity scores to match 148 en bloc with 581 non-en bloc deceased donor recipients (matching variables: transplant age, gender, race, pretransplant dialysis, transplant center, and year). We evaluated patient and graft survival using Kaplan-Meier and Fleming-Harrington weighted log-rank test and examined survival benefit of en bloc transplantation versus remaining on the waiting list using the sequential Cox approach. We divided the study period into three 10-y intervals to assess the effect of era on outcomes.

RESULTS

Compared with non-en bloc recipients, en bloc recipients had lower 1-y graft survival (78.9% versus 88.9%; P = 0.007); however, when stratified by transplant era, lower 1-y survival was only observed in the oldest era (1987-1997). En bloc recipients had superior 10-y patient (89.0% versus 80.4%; P = 0.04) and graft survival (51.6% versus 39.9%; P = 0.04) compared with non-en bloc recipients. After multivariate adjustment, en bloc transplantation was associated with superior patient survival compared with remaining on the waiting list (adjusted hazard ratio: 0.58; 95% confidence interval: 0.36-0.95; P = 0.03).

CONCLUSIONS

En bloc transplantation of small pediatric kidneys in children is associated with superior long-term patient and graft survival. The increased risk of 1-y graft loss among en bloc recipients only appeared in the oldest era.

Small Split Pediatric Kidneys to Expand the Donor Pool: An Analysis of Scientific Registry of Transplant Recipients (SRTR) Data

BACKGROUND

Increased use of pediatric deceased donor kidneys could enlarge the deceased donor kidney pool. Kidney transplant outcomes from small pediatric donors were compared with those from ideal kidney (IK) and expanded criteria kidney (ECK) donors to understand the optimal use of pediatric donor kidneys.

METHODS

Kaplan-Meier analyses compared long-term patient and death-censored graft survival of en bloc kidney (EBK) and split kidney (SpK) transplants from small pediatric donors (aged ≤8 y and weight <30 kg) with those from IK and ECK. Posttransplant serum creatinine) was compared among these cohorts. Deceased donor kidney disposition was determined from small pediatric donors with ≥1 organ transplanted.

RESULTS

Patient and death-censored graft survival were similar among recipients of IK, EBK, and SpK transplants, and were superior to those of recipients of ECK. EBK and SpK transplants from donors 5-30 kg had first-year graft loss similar to ECK. Long-term graft survival and serum creatinine with kidneys from SpK donors >10 kg were better than that with ECK donors. About 3901 transplants were performed from 3660 pediatric donors (53% yield).

CONCLUSIONS

Pediatric kidneys can augment the kidney donor pool and should not be considered ECK. If 90% of kidneys from donors (aged ≤8 y and weight <30 kg) with ≥1 organ transplanted been used (as SpK when >10 kg) an additional 159 kidney transplants per year could have been performed. Expanding the use of pediatric kidneys should be further explored by the transplant community.

Very small pediatric donor kidney transplantation in pediatric recipients

Kidneys from very small pediatric donors (age <5 years, weight <21 kg) may be a means to increase the donor pool for pediatric recipients. Transplantation of small pediatric kidneys is more commonly performed in adult recipients due to the increased risks of technical complications, thrombosis, and early graft failure. While these risks are abrogated in adult recipients by limiting the donor weight to ≥10 kg and using the EB technique, it is unknown whether pediatric recipients achieve comparable results. US national data were assessed for all first-time, deceased-donor, kidney-only pediatric recipients, 1/1996-10/2013, who received very small pediatric donor grafts or grafts from ideal adult donors. We identified 57 pediatric EB, 110 pediatric SK, and 2350 adult transplants. The primary outcome was 3-year all-cause graft survival. Kaplan-Meier curves showed worse outcomes for pediatric grafts compared to adult ideal grafts (P=.042). On multivariate analysis, pediatric recipients of SK grafts had significantly higher HRs (aHR 2.01, 95% CI 1.34-3.00) and pediatric recipients of EB grafts had somewhat higher non-significant HRs (1.57; 95% CI 0.88-2.79) for graft survival. These results suggest cautionary use of very small pediatric donors as a source to expand the donor pool for pediatric candidates.

Single vs dual (en bloc) kidney transplants from donors ≤ 5 years of age: A single center experience

AIM: To compare outcomes between single and dual en bloc (EB) kidney transplants (KT) from small pediatric donors.

METHODS: Monocentric nonprospective review of KTs from pediatric donors ≤ 5 years of age. Dual EB KT was defined as keeping both donor kidneys attached to the inferior vena cava and aorta, which were then used as venous and arterial conduits for the subsequent transplant into a single recipient. Donor age was less useful than either donor weight or kidney size in decision-making for kidney utilization as kidneys from donors < 8 kg or kidneys < 6 cm in length were not transplanted. Post-transplant management strategies were standardized in all patients.

RESULTS: From 2002-2015, 59 KTs were performed including 34 dual EB and 25 single KTs. Mean age of donors (17 mo vs 38 mo, P < 0.001), mean weight (11.0 kg vs 17.4 kg, P = 0.046) and male donors (50% vs 84%, P = 0.01) were lower in the dual EB compared to the single KT group, respectively. Mean cold ischemia time (21 h), kidney donor profile index (KDPI; 73% vs 62%) and levels of serum creatinine (SCr, 0.37 mg/dL vs 0.49 mg/dL, all P = NS) were comparable in the dual EB and single KT groups, respectively. Actuarial graft and patient survival rates at 5-years follow-up were comparable. There was one case of thrombosis resulting in graft loss in each group. Delayed graft function incidence (12% dual EB vs 20% single KT, P = NS) was slightly lower in dual EB KT recipients. Initial duration of hospital stay (mean 5.4 d vs 5.6 d) and the one-year incidences of acute rejection (6% vs 16%), operative complications (3% vs 4%), and major infection were comparable in the dual EB and single KT groups, respectively (all P = NS). Mean 12 mo SCr and abbreviated MDRD levels were 1.17 mg/dL vs 1.35 mg/dL and 72.5 mL/min per 1.73 m²vs 60.5 mL/min per 1.73 m² (both P = NS) in the dual EB and single KT groups, respectively.

CONCLUSION: By transplanting kidneys from young pediatric donors into adult recipients, one can effectively expand the limited donor pool and achieve excellent medium-term outcomes.

Donor-recipient size mismatch in paediatric renal transplantation

Introduction. End stage renal failure in children is a rare but devastating condition, and kidney transplantation remains the only permanent treatment option. The aim of this review was to elucidate the broad surgical issues surrounding the mismatch in size of adult kidney donors to their paediatric recipients. Methods. A comprehensive literature search was undertaken on PubMed, MEDLINE, and Google Scholar for all relevant scientific articles published to date in English language. Manual search of the bibliographies was also performed to supplement the original search. Results. Size-matching kidneys for transplantation into children is not feasible due to limited organ availability from paediatric donors, resulting in prolonged waiting list times. Transplanting a comparatively large adult kidney into a child may lead to potential challenges related to the surgical incision and approach, vessel anastomoses, wound closure, postoperative cardiovascular stability, and age-correlated maturation of the graft. Conclusion. The transplantation of an adult kidney into a size mismatched paediatric recipient significantly reduces waiting times for surgery; however, it presents further challenges in terms of both the surgical procedure and the post-operative management of the patient's physiological parameters.

Outcome of single pediatric deceased donor renal transplantation to adult kidney transplant recipients

INTRODUCTION

In times of organ shortage more kidneys were transplanted in 'expanded criteria kidney' programs. This study examines the outcome of adult kidney recipients from pediatric donors.

MATERIALS AND METHODS

This single-center retrospective analysis evaluated eight adult patients who received a kidney from a deceased pediatric donor (age 5-17) between 06/2000 and 09/2011.

RESULTS

The median donor age was 14 years (range 5-17). The median recipient age was 49 years (range 25-57). The median cold ischemia time was 13.3 h (range 4.3-20.1), while the median warm ischemia time was 53 min (range 42-60). The median follow-up was 35.8 months (range 7-142). Acute rejection was observed in 50.0% of cases. The median HLA mismatch was 2.0. The median 1-year creatinine level was 0.95 mg/dl, the uncensored 1-year graft survival was 75.0% and the 3-year graft survival 62.5%, respectively. No recipient died within the follow-up period. As severe surgical complications, one stenosis of the renal artery and one lymphocele needing surgical revision were observed.

CONCLUSIONS

Renal transplantation of a deceased single pediatric donor to an adult recipient can be performed safely and shows a good outcome. Wherever feasible, single pediatric kidney transplantation can double the number of recipients over an 'en-bloc' transplantation. The price for a single pediatric kidney transplant may be a higher vascular complication rate and a higher rejection risk. Despite the higher risks, transplantation of a single pediatric donor kidney should be performed when accomplishable.

Long-term outcomes of single paediatric vs. ideal adult renal allograft transplants in adult recipients

AIM

To compare the outcomes of single paediatric vs. adult kidneys transplanted into adult recipients.

METHODS

A retrospective single-centre review of 38 single cadaver kidney transplants from donors less than five yr of age to wait-listed patients of low body mass index (BMI). Survival of grafts and quality of renal function were compared with 121 similarly low BMI recipients of grafts from donors 18-45 yr of age that were transplanted during the same period. Immunosuppression consisted of sirolimus, minimal-dose cyclosporine and prednisone. The mean age of the paediatric vs. adult donors was 2.8+/-1.0 and 31.1+/-9.2 yr, respectively (p<0.01) and of the recipients, 42.0+/-12.4 and 45.7+/-14.8 yr, respectively (p=NS). The mean BMI of paediatric vs. adult donor kidney recipients was 21.8+/-2.9 and 22.4+/-2.0 kg/m2 (p=NS). Sixty-six per cent of paediatric donor recipients were women compared with 44% of adult donor recipients (p=0.03).

RESULTS

Death censored actuarial graft survivals at one and five yr for recipients of paediatric vs. adult donor grafts were 93 and 84% compared with 93 and 85% (p=NS). There were no graft losses because of technical complications in the paediatric kidney donor group. At one and five yr post-transplantation, the mean estimated creatinine clearances of the paediatric donor graft recipients were 52.9+/-19.6 and 54.0+/-17.8 mL/min, respectively, compared with 56.4+/-19.8 and 49.1+/-21.7 mL/min for recipients of adult donor grafts at the same times (p=NS).

CONCLUSION

Transplantation of single paediatric donor kidneys into low BMI adult recipients provided equivalent outcomes to those of grafts from adult donors between the ages of 18 and 45 yr.

Transplantation of adult recipients by single cadaveric kidneys from pediatric donors weighing < or = 25 kg can be a reliable option

The evidence in favor of transplanting single allografts from cadaveric pediatric donors into adult recipients is equivocal. This study was performed to assess the outcome of transplantation of single kidneys from pediatric donors weighing < 25 kg. Thirty-five adults transplanted by renal allografts from pediatric donors weighing < 25 kg were compared with 30 matched recipients of kidneys from adult donors. Donors in study group were aged 4.2 +/- 2.1 years weighing 16.0 +/- 5.3 kg. In the study group, surgical complications occurred in five of 35 patients, in the control group four of 30. Serum creatinine reached nadir in 47.5 days in study group versus 30 days in controls (P < 0.01). Serum creatinine at 1 and 3 years were comparable in both groups. A 38.9% had proteinuria at 1 year in the study group compared with 22.7% in controls (P = 0.36). One-year graft survival was 91.7% in the study group versus 92.8% for controls. The surgical complications and graft survival in the study group was comparable with that of controls. The incidence of proteinuria may be more frequent, but does not appear to impact graft function. The use of single, as compared with paired, pediatric donor kidneys would allow more patients to be transplanted with equivalent results.

Outcome of renal transplants from pediatric donors <5 yr of age

AIM

Outcomes of single renal transplants from donors <5 yr old have traditionally been inferior to those from older donors. We retrospectively studied our experience with patients who received renal transplants, either individually or en bloc, from young donors (<5 yr of age) to determine the utility of these organs. We also compared the outcomes of these transplant patients maintained on either cyclosporine- (CyA) or tacrolimus-based (TRL) immunosuppression regimens.

PATIENTS

Ninety-eight patients received transplants at our center from donors <5 yr of age between August 1993 and August 2003. They were followed-up from 12 months to 11 yr. Patients were divided into four groups based on whether they received single or en bloc transplants, and whether CyA or TRL was the base immunosuppressive agent. Patients in group I (n = 13) received single pediatric kidneys and were treated with CyA regimens; group II patients (n = 26) also received single pediatric kidneys, but were treated with TRL regimens; group III patients (n = 31) were transplanted en bloc and were treated with CyA; and group IV patients (n = 28) received en bloc transplants and were treated with TRL.

RESULTS

One-year patient and death-censored graft survival was not significantly different between recipients of en bloc vs. single grafts (i.e. 88 and 85% vs. 90 and 87%, respectively), or between the four treatment groups (group I: 85 and 85%, group II: 92 and 88%, group III: 87 and 84%, and group IV: 89 and 86%, respectively). The overall 1-yr rejection rate was 30% (29 of 98), which was significantly higher in the CyA-treated patients 19 of 44; i.e. 43%, than in TRL-treated patients 10 of 54, i.e. 19%, p = 0.03). In the en bloc recipients, seven grafts (12%) were lost as a result of vascular thrombosis. Notably, none of the single kidneys were lost because of vascular thrombosis. At the end of follow-up the creatinine levels of both groups were comparable.

CONCLUSIONS

Pediatric donor kidneys transplanted individually provide for equal patient and graft survival when compared with en bloc transplants. TRL can be used reduce the detrimental effect of acute rejection on graft growth and function when compared with CyA. Single use of such kidneys can safely and efficaciously be transplanted into adult recipients, greatly expanding the donor pool.

Assessment of Factors Determining Graft Size in Transplant of Cadaver Kidneys from Child Donors

BACKGROUND

Kidneys from child donors are very efficient at adapting to the recipient organism. This research aims to verify the size of kidney grafts from pediatric donors after transplant and to identify factors responsible for the size attained by these kidneys. Moreover, it aims to seek relationships between size and function of the transplanted pediatric kidney.

METHODS

Seventy-seven renal transplants performed at least 6 months earlier, with cadaver donor 15 years old or younger, had ultrasound measurements of the graft and renal function assessment. Potential factors for graft volume were analyzed using bivariate analysis, followed by multiple linear regression.

RESULTS

After a follow up of 4.2+/-3.3 years posttransplant, the grafts presented the following range of measures: length 10.61+/-1.13 cm, width 4.67+/-0.84 cm, and depth 4.76+/-0.99 cm. Graft volumes were 126.62+/-47.76 cm. Bivariate analysis showed that (1) age of both donor and recipient at transplantation; (2) sex of recipient; (3) occurrence of acute rejection episodes were statistically significant. After multivariate analysis, age and sex of recipients were the only significant factors influencing graft volume; child kidneys reached greater volumes when transplanted into adult and male individuals. Larger volume kidneys presented significantly more proteinuria. No difference was evident with regard to creatinine clearance values or urinary retinol binding protein among kidneys of differing sizes.

CONCLUSIONS

The size of the recipient (age and sex) is the main factor responsible for volumes achieved by kidneys from pediatric donors. The volume attained by these kidneys demonstrated no relationship with glomerular or tubular function of the organ.

Transplantation of pediatric kidneys to adult recipients: An analysis of 13 cases

INTRODUCTION

The shortage of cadaveric donors for kidney transplantation has prompted many centers to expand the criteria used for donor selection to increase the organ supply. The use of cadaveric pediatric kidneys has been suggested as a means to overcome the shortage. However, some studies indicate that kidneys from pediatric donors show inferior results to those from adult donors. In this retrospective study we examined the outcome of kidney transplantation using cadaveric pediatric donors.

MATERIALS AND METHODS

From October 1990 to May 2002, 13 adult patients received pediatric renal transplants including two that were transplanted en bloc. The patients were divided into two groups based upon donor age: group I donors were 18 months to 6 years old; the seven recipients were of mean age 47.3 years. Group II donors were 7 to 15 years old; the six recipients were of mean age 43.6 years old. Cyclosporine-based immunosuppressive regimens were used in both groups.

RESULTS

The patient survival rate was 85.7% in group I and 100% in group II. The graft survival rates at the first and third posttransplant year in group I were 71.4% (5/7) and 57.1% (4/7) and in group II, 66.7% and 50%, respectively. The frequency of urinary complications in group I was 28.5% (2/7) and in group II 33.3% (2/6). There was one case of venous thrombosis in group II.

CONCLUSION

Pediatric renal grafts may be used with reasonable safety. However, surgical complications remain a significant problem especially with younger pediatric grafts.

Superior long-term results of simultaneous pancreas-kidney transplantation from pediatric donors

The shortage of cadaveric donors for simultaneous pancreas-kidney transplantation has prompted the use of cadaveric organs from pediatric donors. The long-term outcome and its impact on overall long-term survival are unknown. A total of 680 recipients receiving cadaver Simultaneous pancreas-kidney (SPK) transplantation from pediatric and adult donors between July 1986 and September 2001 were analyzed and compared. Ten-year kidney and pancreas graft survival for SPK transplantation from donors aged <18 years (n = 142) were 80% and 72%, respectively, compared to 61% pancreas and kidney graft survival from donors > or =18 years of age (n = 538; p = 0.03 and 0.05, respectively). Five years post-transplant, blood glucose, HbA1c and creatinine clearance were significantly better in recipients from pediatric donors (85.3 +/- 13 mg/dL, 5.5 +/- 3.5% and 65.6 +/- 16 mL/min, respectively), compared to recipients from adult donors (95.1 +/- 29 mg/dL, 5.9 +/- 3.5% and 58.3 +/- 17 mL/min; p = 0.001, 0.01 and 0.002, respectively). Causes of graft failure for kidney and pancreas transplants were similar between the two groups. No statistically significant difference was observed in patient survival between recipients from pediatric donors compared to adult donors (85% vs. 76%, p = 0.29). When recipients of SPK from pediatric donors were stratified according to age (3-11 years and 12-17 years) and compared, no difference in kidney or pancreas graft survival was observed (kidney 76.4% vs. 81.3%, p = 0.15; pancreas 75% vs. 76%, p = 0.10, respectively). Pediatric donors represent a valuable source of organs, providing excellent short- and long-term outcomes. Wide utilization of pediatric organs will substantially increase the donor pool.

Transplantation of Pediatric En Bloc Cadaver Kidneys into Adult Recipients: A Single-Center Experience

Faced with an extreme shortage of organs transplant professionals continue to explore various strategies to expand the donor pool. Transplantation of kidneys from older and very young donors are two such options. Although kidneys from young donors (less than 5 years of age) have been associated with a high rate of technical complications and suboptimal results, use of these kidneys en bloc has been advocated to improve the outcomes. We reviewed our experience with en bloc kidney transplantation at the University of Kentucky over the past 10 years. Between 1991 and 2000 ten patients underwent kidney transplantation using kidneys en bloc from donors <5 years age. The mean age of the donors was 2.8 years with a mean weight of 16 kg (range 13–21). Mean age of the recipients was 42 years. One patient lost the graft on day one from venous thrombosis. One patient lost the graft 7 years post-transplant from chronic rejection. All of the remaining patients are doing well with functioning grafts (mean follow-up 4.5 years; range 6 months to 10 years). Both one-year and five-year graft survival rates are 89 per cent. The present study confirms that excellent results can be achieved with kidney transplantation using kidney transplantation using kidneys en bloc from donors younger than 5 years of age.

Long-term results of en bloc transplantation of pediatric kidneys into adults using a vicryl mesh envelope technique

En bloc transplantation of pediatric kidneys into adults is a suitable measure to help correct the shortage of available kidneys. This practice, however, is not widespread because of the high incidence of vascular complications. Our institution has previously described a vicryl mesh technique for en bloc kidneys, with an attempt to reduce the incidence of vascular complications. The purpose of this study was to evaluate the long-term results of recipients with en bloc kidneys stabilized with this technique. The charts of 644 adult renal transplants performed between July 1987 and July 1999 were reviewed. During this period, 14 adult patients have received 14 pairs of en bloc pediatric kidneys using the vicryl mesh technique. All patients received OKT3 as an induction immunosuppression with cyclosporine started 10-14 d after the transplant. The median donor age was 24 months (range 14-84 months), and the median recipient age was 49 yr (range 23-68 yr). The mean recipient weight was 79 kg (range 60-114 kg). The mean cold ischemia time was 14.2 hr. None of the patients developed vascular or urological complications. Delayed graft function and moderate acute rejection occurred in one patient each. At a mean follow-up of 51 months (range 7-96 months), all 14 patients maintained excellent renal function with a mean creatinine of 1.01 mg/dL. Renal measurements pre-operatively and at follow-up ultrasound examinations were available in 9 patients, and the mean length of the kidneys had grown approximately 5.0 cm. These data demonstrate that minimal vascular and immunological complication rates can be achieved with pediatric en bloc kidneys using the vicryl mesh envelope technique.

Recipient age and weight affect chronic renal allograft rejection in rats

Nephron doses and immune responses change with age. Therefore, age is a potential risk factor for graft survival after kidney transplantation. The aim of this study was to determine whether age-related differences are of importance for long-term outcomes after renal transplantation. Kidneys from Fisher 344 rats were orthotopically transplanted into nephrectomized Lewis rats. Kidneys were transplanted using donors and recipients of three age levels, i.e., young (8 wk of age), adult (16 wk of age), and old (40 wk of age). Rats were killed 24 wk after transplantation, and functional, morphologic, and molecular evaluations were performed. Recipient age, rather than donor age, determined graft survival rates. No significant correlation was observed between donor kidney weight on the day of transplantation and morphologic results. Advanced recipient age was associated with reduced creatinine clearance, more severe histologic injuries, including extended glomerular sclerosis, interstitial fibrosis, and vascular lesions, more pronounced cellular infiltration, and greater expression of transforming growth factor-beta and platelet-derived growth factor A and B chains. Although no significant correlation between donor age or kidney weight on the day of transplantation and morphologic results was observed, there was a significant correlation between recipient body weight on the day of transplantation and allograft injury. It is concluded that recipient age and weight affect chronic renal rejection. Renal allografts may benefit from young recipient age but may deteriorate in old recipients, suggesting effects of recipient functional demand on long-term outcomes.

Does renal mass exert an independent effect on the determinants of antigen-dependent injury?

The aim of this retrospective study was to determine whether nephron mass may exert a direct, independent effect on immunological tolerance. To this end, data corresponding to patients transplanted with en block pediatric kidneys (EBPK) (n=48) were compared with those of renal transplants with a low risk of hyperfiltration (LRH) comprised of recipients of a kidney from young donors (age 5-40 years) (n=173), and transplants with a high risk of hyperfiltration (HRH) comprised of patients who had received a graft from an elderly donor (older than 55 years) (n=91). All the patients had been subjected to the same immunosuppressive treatment. The median follow-up period was 54 months (6-127 months). The EBPK group showed lowest serum creatinine and highest creatinine clearance levels at each follow-up time. The rate of proteinuria >500 mg/day was 5.7% in EBPK, 7.4% in LRH, and 27.3% in HRH (P=0.000). The incidence of acute corticoresistant rejection was minor in EBPK (7.0% in EBPK, 21.3% in LRH, and 23.3% in HRH; P=0.04). Logistic regression analysis showed that the type of transplant was predictive of acute corticoresistant rejection [RR 5.33 (95% confidence interval (CI) 1.15-24.62) for HRH and RR 4.75 (95%CI 1.06-21.27) for LRH, P=0.03]. Multivariate analyses for graft failure due to chronic rejection and for graft failure due to acute rejection according to Cox's regression analysis demonstrated that HRH transplant was a significant predictive variable of both types of failure [4.08 (95%CI 1.27-13.04) for graft loss due to chronic rejection and 8.69 (95%CI 1.69-44.67) for graft loss due to acute rejection]. The present stratification of data according to nephronal mass would appear to indicate that the greater the mass, the lower the incidence of both acute and chronic rejection. This finding lends support to the hypothesis that a large mass of transplanted tissue relative to recipient mass may dampen the immune response.

Immunologic and patient selection strategies for successful utilization of less than 15 kg pediatric donor kidneys--long term experiences with 40 transplants

Renal transplantation using infant donors is associated with significantly less graft survival (GS) and increased morbidity, especially from very young and small donors. We report our results using specific strategies to determine which age and size donor require en bloc renal transplant reconstruction and associated immunologic protocols for optimization of subsequent GS. Forty cadaveric pediatric en bloc renal transplants were performed. Mean donor age was 23.6+/-18.4 months with subgroups: 2-12 months, n=14; 13-24 months, n=19; and 25-60 months, n=7. Mean donor weight was 14.4+/-4.5 kg. All kidneys were placed in primary, nonsensitized (peak PRA = 7.9+/-5.6%) adult (41.6+/-16 years) recipients. Low weight was preferred (62.4+/-12.8 kg). Mean cold ischemia time was 26.9+/-8.6 hr. Immunosuppression consisted of quadruple immunosuppression (QI) with OKT3 induction. All patients had ureteral stents placed intraoperatively. Mean follow-up was 16.9 months. Actuarial GS at 12, 24, and 33 months were 100% (n=13), 85% (n=20), and 71% (n=7), respectively. Total GS was 35/40=88%. All grafts functioned immediately and there were no technical losses. Biopsy proven rejections occurred in 12 (30%) patients, developing at 16-167 days postoperatively (mean = 50.3 days). Mean serum creatinine at one week and 1, 6, 12, and 18 months were 2.1+/-2.0, 1.5+/-0.8, 1.3+/-0.5, 1.1+/-0.4, and 0.9+/-0.4 mg/dl, respectively. Functional isotopic renography, as well as sonographic monitoring reflected rapid initial and continued growth in these kidneys. Mean BP at 12 and 24 months postoperatively were 145/83+/-18/13 and 122/76+/-20/10 mmHg, respectively, with no significant proteinuria noted. Excellent results with minimal complications utilizing very small and young infant donors can be achieved with QI immunosuppression, and selection of low immune reactive and noncomplicated adult recipients. Additionally, maximal renal dosing by minimizing recipient weight may prevent future hyperfiltration damage.

Long-term results with single pediatric donor kidney transplants in adult recipients

PURPOSE

We investigated whether transplantation of single pediatric donor kidneys into adults leads to an increased incidence of functional allograft impairment and complications, as previously reported.

MATERIALS AND METHODS

To evaluate long-term functional outcome using single pediatric donor kidneys 60 adults (study group) who underwent transplantation between March 1973 and December 1988 using single pediatric donor kidneys 6 years old or younger (mean donor age plus or minus standard deviation 41.1 +/- 17.9 months) were compared to 58 matched adults (control group) who underwent transplantation with adult kidneys (mean donor age 29.7 +/- 10.8 years). The groups were identical for era of transplantation, recipient age, sex and followup (82 versus 83 months).

RESULTS

There was no difference in patient survival between the study and control groups (p = 0.26). In the study group there were an increased requirement for early dialysis (45 versus 24%, p = 0.02), a higher incidence of proteinuria (greater than 0.8 gm./24 hours, 67 versus 48%, p = 0.04) and a higher incidence of rejection within the first 6 months (80 versus 64%, p = 0.05). There was also an increased incidence of graft failure from acute rejection in the study group. Early differences in serum creatinine levels in the 2 groups dissipated after 3 months. Renal allograft histopathology revealed no significant difference in the incidence of focal segmental glomerulosclerosis in the study versus control groups after transplantation (22.9 versus 13.3%, p = 0.70). However, focal segmental glomerulosclerosis manifested sooner after transplantation in study than control patients (mean 37 versus 82 months). After transplantation proteinuria developed in study patients with focal segmental glomerulosclerosis at a mean of 4.6 months compared to 31.8 months in controls with post-transplant focal segmental glomerulosclerosis. Graft survival in the study group was superior when cyclosporine was given rather than conventional noncyclosporine based immunosuppression. Five-year graft survival rates were 48 versus 44% for cyclosporine treated and 33 versus 44% for conventionally treated study versus control patients.

CONCLUSIONS

These data suggest that with cyclosporine immunosuppression transplanting single pediatric kidneys into adults yields the same long-term functional graft outcome as adult donor kidneys.