Improved Outcomes of Kidney Transplantation in Infants (Age < 2 years): A Single-Center Experience

Should children receive a kidney transplant before 2 years of age?

BACKGROUND

The optimal age of kidney transplantation for infants and toddlers with kidney failure is unclear. We aimed to evaluate the patient survival associated with kidney transplantation before 2 years of age versus remaining on the waitlist until ≥2 years.

METHOD

We used the Scientific Registry of Transplant Recipients to identify all children added to the deceased-donor waitlist before 2 years of age between 1/1/2000 and 4/30/2020. For each case aged <2 years at transplant, we created a control group comprising all candidates on the waitlist on the case's transplant date. Patient survival was evaluated using sequential Cox regression. Dialysis-free time was defined as graft survival time for cases and the sum of dialysis-free time on the waitlist and graft survival time for controls.

RESULTS

We observed similar patient survival for posttransplant periods 0-3 and 4-12 months but higher survival for period >12 months for <2-year decreased-donor recipients (aHR: 0.32; 95% CI: 0.13-0.78; p = .01) compared with controls. Similarly, patient survival was higher for <2-year living-donor recipients for posttransplant period >12 months (aHR: 0.21; 95% CI: 0.06-0.73; p = .01). The 5-year dialysis-free survival was higher for <2-year deceased- (difference: 0.59 years; 95% CI: 0.23-0.93) and living-donor (difference: 1.84 years; 95% CI: 1.31-2.25) recipients.

CONCLUSION

Kidney transplantation in children <2 years of age is associated with improved patient survival and reduced dialysis exposure compared with remaining on the waitlist until ≥2 years.

Postoperative surgical complications after pediatric kidney transplantation in low weight recipients (<15 kg): a systematic review

PURPOSE OF REVIEW

Kidney transplantation in low-weight recipients (<15 kg) is a challenging surgery with special characteristics. We proposed to perform a systematic review to determine the postoperative complication rate and the type of complications after kidney transplantation in low-weight recipients (<15 kg). The secondary objectives were to determine graft survival, functional outcomes, and patient survival after kidney transplantation in low-weight recipients.

METHODS

A systematic review was performed according to preferred reporting items for systematic reviews and meta-analyses. Medline and Embase databases were searched to identify all studies reporting outcomes on kidney transplantation in low-weight recipients (<15 kg).

RESULTS

A total of 1254 patients in 23 studies were included. The median postoperative complications rate was 20.0%, while 87.5% of those were major complications (Clavien ≥3). Further, urological and vascular complications rates were 6.3% (2.0-11.9) and 5.0% (3.0-10.0), whereas the rate of venous thrombosis ranged from 0 to 5.6%. Median 10-year graft and patient survival were 76 and 91.0%.

SUMMARY

Kidney transplantation in low-weight recipients is a challenging procedure complicated by a high rate of morbidity. Finally, pediatric kidney transplantation should be performed in centers with expertise and multidisciplinary pediatric teams.

The John S. Najarian symposium: The past, present, and future of surgery and transplantation, May 20, 2022, Minneapolis, MN

Dr John S Najarian (1927-2020), chairman of the Department of Surgery at the University of Minnesota from 1967 to 1993, was a pioneer in surgery, clinical immunology and transplantation. A Covid-delayed Festschrift was held in his honor on May 20, 2022. The speakers reflected on his myriad contributions to surgery, transplantation, and resident/fellow training, as well as current areas of ongoing research to improve clinical outcomes. Of note, Dr Najarian was a founder of the journal Clinical Transplantation.

Good outcomes after pediatric intraperitoneal kidney transplant

BACKGROUND

Kidney transplantation in small children is technically challenging. Consideration of whether to use intraperitoneal versus extraperitoneal placement of the graft depends on patient size, clinical history, anatomy, and surgical preference. We report a large single-center experience of intraperitoneal kidney transplantation and their outcomes.

METHODS

We conducted a retrospective review of pediatric patients who underwent kidney transplantation from April 2011 to March 2018 at a single large volume center. We identified those with intraperitoneal placement and assessed their outcomes, including graft and patient survival, rejection episodes, and surgical or non-surgical complications.

RESULTS

Forty-six of 168 pediatric kidney transplants (27%) were placed intraperitoneally in children mean age 5.5 ± 2.3 years (range 1.6-10 years) with median body weight 18.2 ± 5 kg (range 11.4-28.6 kg) during the study period. Two patients (4%) had vascular complications; 10 (22%) had urologic complications requiring intervention; all retained graft function. Thirteen patients (28%) had prolonged post-operative ileus. Eight (17%) patients had rejection episodes ≤6 months post-transplant. Only one case resulted in graft loss and was associated with recurrent focal segmental glomerular sclerosis (FSGS). Two patients (4%) had chronic rejection and subsequent graft loss by 5-year follow-up. At 7-year follow-up, graft survival was 93% and patient survival was 98%.

CONCLUSIONS

The intraperitoneal approach offers access to the great vessels, which allows greater inflow and outflow and more abdominal capacity for an adult donor kidney, which is beneficial in very small patients. Risk of graft failure and surgical complications were not increased when compared to other published data on pediatric kidney transplants.

Pearls and Pitfalls in Pediatric Kidney Transplantation After 5 Decades

Worldwide, over 1,300 pediatric kidney transplantations are performed every year. Since the first transplantation in 1959, healthcare has evolved dramatically. Pre-emptive transplantations with grafts from living donors have become more common. Despite a subsequent improvement in graft survival, there are still challenges to face. This study attempts to summarize how our understanding of pediatric kidney transplantation has developed and improved since its beginnings, whilst also highlighting those areas where future research should concentrate in order to help resolve as yet unanswered questions. Existing literature was compared to our own data of 411 single-center pediatric kidney transplantations between 1968 and 2020, in order to find discrepancies and allow identification of future challenges. Important issues for future care are innovations in immunosuppressive medication, improving medication adherence, careful donor selection with regard to characteristics of both donor and recipient, improvement of surgical techniques and increased attention for lower urinary tract dysfunction and voiding behavior in all patients.

Kidney Transplantation in Small Children: Association Between Body Weight and Outcome-A Report From the ESPN/ERA-EDTA Registry

BACKGROUND

Many centers accept a minimum body weight of 10 kg as threshold for kidney transplantation (Tx) in children. As solid evidence for clinical outcomes in multinational studies is lacking, we evaluated practices and outcomes in European children weighing below 10 kg at Tx.

METHODS

Data were obtained from the European Society of Paediatric Nephrology/European Renal Association and European Dialysis and Transplant Association Registry on all children who started kidney replacement therapy at <2.5 y of age and received a Tx between 2000 and 2016. Weight at Tx was categorized (<10 versus ≥10 kg) and Cox regression analysis was used to evaluate its association with graft survival.

RESULTS

One hundred of the 601 children received a Tx below a weight of 10 kg during the study period. Primary renal disease groups were equal, but Tx <10 kg patients had lower pre-Tx weight gain per year (0.2 versus 2.1 kg; P < 0.001) and had a higher preemptive Tx rate (23% versus 7%; P < 0.001). No differences were found for posttransplant estimated glomerular filtration rates trajectories (P = 0.23). The graft failure risk was higher in Tx <10 kg patients at 1 y (graft survival: 90% versus 95%; hazard ratio, 3.84; 95% confidence interval, 1.24-11.84), but not at 5 y (hazard ratio, 1.71; 95% confidence interval, 0.68-4.30).

CONCLUSIONS

Despite a lower 1-y graft survival rate, graft function, and survival at 5 y were identical in Tx <10 kg patients when compared with Tx ≥10 kg patients. Our results suggest that early transplantation should be offered to a carefully selected group of patients weighing <10 kg.

Uncovering a Long-term Graft Survival Advantage Afforded by Infant Renal Transplants-An Organ Procurement and Transplantation Network Database Analysis

Background.

Renal transplants (Tx) are performed infrequently in infants, due to concerns related to poor outcomes. The aim of our study was to compare graft failure rates in infant (<1 y) renal Tx recipients compared with older children.

Methods.

Retrospective cohort study of pediatric renal Tx recipients from 2000 to 2015, using the Organ Procurement and Transplant Network database. A log-linear event history regression model for time to graft failure, adjusting for age group and important confounders, was used to estimate post-Tx graft failure probabilities.

Results.

In 2696 Tx followed for a median of 6.1 y, 704 failures were observed. Significant predictors of graft failure were year of Tx (for each year after 2000, rates were 8.6% lower), Black race-ethnicity (63% higher compared with Whites), and number of HLA matches. For infants (n = 27), estimated graft failure percentage (95% confidence interval) within the first 1-, 2-, and 5-y post-Tx were 10.4 (0.1–21.1), 11.9 (1.2–22.6), and 16.4 (4.9–27.9). For the 1- to 11-y-olds (n = 1429), these were 3.8 (3.0–4.6), 6.3 (5.4–7.3), and 13.6 (12.2–15.0), respectively, and for the 12+ y olds (n = 1240), they were 3.8 (3.1–4.5), 8.1 (7.2–9.0), and 19.9 (18.1–21.7), respectively (P < 0.001 for 5-y graft failure rate across age groups).

Conclusions.

Infant renal Tx recipients experience a higher graft failure rate in the first year, compared with older cohorts, but over longer intervals, cumulative failure rates are comparable or even lower. To minimize early graft losses such Tx should be performed in experienced centers.

Survival and transplant outcomes among young children requiring kidney replacement therapy

BACKGROUND

Young children starting kidney replacement therapy (KRT) suffer high disease burden with unique impacts on growth and development, timing of transplantation and long-term survival. Contemporary long-term outcome data and how these relate to patient characteristics are necessary for shared decision-making with families, to identify modifiable risk factors and inform future research.

METHODS

We examined outcomes of all children ≤ 5 years enrolled in the Australia and New Zealand Dialysis and Transplant Registry, commencing KRT 1980-2017. Primary outcomes were patient and graft survival. Final height attained was also examined. We used generalized additive modelling to investigate the relationship between age and graft loss over time post-transplant.

RESULTS

In total, 388 children were included, of whom 322 (83%) received a kidney transplant. Cumulative 1-, 5- and 10-year patient survival probabilities were 93%, 86% and 83%, respectively. Death censored graft survival at 1, 5 and 10 years was 93%, 87% and 77%, respectively. Most children were at least 10 kg at transplantation (n = 302; 96%). A non-linear relationship between age at transplantation and graft loss was observed, dependent on time post-transplant, with increased risk of graft loss among youngest recipients both initially following transplantation and subsequently during adolescence. Graft and patient survival have improved in recent era.

CONCLUSIONS

Young children commencing KRT have good long-term survival and graft outcomes. Early graft loss is no reason to postpone transplantation beyond 10 kg, and among even the youngest recipients, late graft loss risk in adolescence remains one of the greatest barriers to improving long-term outcomes.

Strategy to Enable and Accelerate Kidney Transplant in Small Children and Results of the First 130 Transplants in Children ≤15 kg in a Single Center

BACKGROUND

Proper care of young children in need of kidney transplant (KT) requires many skilled professionals and an expensive hospital structure. Small children have lesser access to KT.

METHODS

We describe a strategy performed in Brazil to enable and accelerate KT in children ≤15 kg based on the establishment of one specialized transplant center, focused on small children, and cooperating with distant centers throughout the country. Actions on 3 fronts were implemented: (a) providing excellent medical assistance, (b) coordinating educational activities to disseminate expertise and establish a professional network, and (c) fostering research to promote scientific knowledge. We presented the number and outcomes of small children KT as a result of this strategy.

RESULTS

Three hundred forty-six pediatric KTs were performed in the specialized center from 2009 to 2017, being 130 in children ≤15 kg (38%, being 41 children ≤10 kg) and 216 in >15 kg (62%). Patient survival after 1 and 5 years of the transplant was 97% and 95% in the "small children" group, whereas, in the "heavier children" group, it was 99% and 96% (P = 0.923). Regarding graft survival, we observed in the "small children" group, 91% and 87%, whereas in the "heavier children" group, 94% and 87% (P = 0.873). These results are comparable to the literature data. Groups were similar in the incidence of reoperation, vascular thrombosis, posttransplant lymphoproliferative disease, and estimated glomerular filtration rate.

CONCLUSIONS

The strategy allowed an improvement in the number of KT in small children with excellent results. We believe this experience may be useful in other locations.

Survival after Kidney Transplantation during Childhood and Adolescence

BACKGROUND AND OBJECTIVES

Survival in pediatric kidney transplant recipients has improved over the past five decades, but changes in cause-specific mortality remain uncertain. The aim of this retrospective cohort study was to estimate the associations between transplant era and overall and cause-specific mortality for child and adolescent recipients of kidney transplants.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Data were obtained on all children and adolescents (aged <20 years) who received their first kidney transplant from 1970 to 2015 from the Australian and New Zealand Dialysis and Transplant Registry. Mortality rates were compared across eras using Cox regression, adjusted for confounders.

RESULTS

A total of 1810 recipients (median age at transplantation 14 years, 58% male, 52% living donor) were followed for a median of 13.4 years. Of these, 431 (24%) died, 174 (40%) from cardiovascular causes, 74 (17%) from infection, 50 (12%) from cancer, and 133 (31%) from other causes. Survival rates improved over time, with 5-year survival rising from 85% for those first transplanted in 1970-1985 (95% confidence interval [95% CI], 81% to 88%) to 99% in 2005-2015 (95% CI, 98% to 100%). This was primarily because of reductions in deaths from cardiovascular causes (adjusted hazard ratio [aHR], 0.25; 95% CI, 0.08 to 0.68) and infections (aHR, 0.16; 95% CI, 0.04 to 0.70; both for 2005-2015 compared with 1970-1985). Compared with patients transplanted 1970-1985, mortality risk was 72% lower among those transplanted 2005-2015 (aHR, 0.28; 95% CI, 0.18 to 0.69), after adjusting for potential confounders.

CONCLUSIONS

Survival after pediatric kidney transplantation has improved considerably over the past four decades, predominantly because of marked reductions in cardiovascular- and infection-related deaths.

Perioperative renal transplantation management in small children using adult-sized living or deceased donor kidneys: A single-center experience

Kidney transplantation remains the treatment of choice for children with ESRD. Optimal perioperative management is critical in small recipients of ASK to assure adequate graft perfusion. We present a single-center experience outlining management for patients weighing <20 kg who underwent primary renal transplantation with ASKs between 2007 and 2016. Sixty-three patients met study criteria and underwent 34 living-related, six living-unrelated, and 23 deceased donor kidney transplants. Median age and weight at transplant were 25 months (IQR 18-37 months; range 11 months-6 years) and 11.0 kg (IQR 9.2-14.5 kg; range 7.1-19.5 kg). Eighty-nine percent of patients required vasoactive agents intra-operatively, with twenty patients requiring prolonged vasoactive agents post-operatively. Intra-operatively, patients received 51.9 mL/kg of crystalloid, 27.3 mL/kg of 5% albumin, and 13.6 mL/kg of packed red blood cells. Most (93.7%) patients were extubated on POD#0. Weights peaked on post-operative days three through five. Over a median follow-up of 49 months (IQR 31-86 months; range 0-130 months), four grafts were lost, two due to thrombosis and two secondary to chronic rejection. There was one patient death six months post-transplant due to causes unrelated to transplantation. Graft survival at 1, 5, and 10 years was 98.4%, 96.6%, and 84.2%, respectively. Of surviving allografts, the median 1, 5, and 10 years post-transplant eGFR was 122.9, 90.0, and 59.2 mL/min/1.73 m² as determined by the 2009 Schwartz formula. Renal transplantation in small children using ASKs requires meticulous perioperative management including adequate fluid resuscitation and judicious use of pressors to assure adequate graft perfusion. The use of ASKs from living or deceased donors results in satisfactory short and long-term outcomes.

Is Preoperative Preparation Time a Barrier to Small Children Being Ready for Kidney Transplantation?

BACKGROUND

Small children are less frequently transplanted when compared with older. The objective of the present study was to compare the preparation time for transplantation in children of different weights and to identify factors associated with a delay in the workup of small children.

METHODS

We report on a retrospective cohort comprising all children referred for renal transplantation (RTx) workup between 2009 and 2017. The main outcome was transplantation workup time, defined as the time elapsed between the first consultation and when the child became ready for the surgery.

RESULTS

A total of 389 children (63.5% males) were selected, with a median weight of 18 kg (interquartile range, 11-32). Patients were categorized into 2 groups: group A (study group): ≤15 kg (n = 165) and group B (control group): >15 kg (n = 224). The probability of being ready for RTx was comparable between groups A and B. The cumulative incidence rate difference between groups is -0.05 (95% confidence interval, -0.03 to 0.02). The median time for RTx workup was 5.4 (2.4-9.4) in group A and 4.3 (2.2-9.0) months in group B (P = 0.451). Moreover, the presence of urinary tract malformation was associated with the need for longer transplantation workup time (P < 0.001).

CONCLUSIONS

In children >7 kg, the workup time for transplantation is not related to body weight. In a specialized center, children weighing 7-15 kg became ready within the same timeframe as children weighing >15 kg, despite the smaller children had greater difficulty being nourished, dialyzed, and a greater need for surgical correction of the urinary tract pretransplant.

Amnioinfusions to Treat Early Onset Anhydramnios Caused by Renal Anomalies: Background and Rationale for the Renal Anhydramnios Fetal Therapy Trial

Anhydramnios caused by early anuria is thought to be universally fatal due to pulmonary hypoplasia. Bilateral renal agenesis and early fetal renal failure leading to anhydramnios constitute early pregnancy renal anhydramnios (EPRA). There have been successful reports of amnioinfusions to promote lung growth in the setting of EPRA. Some of these successfully treated EPRA fetuses have survived the neonatal period, undergone successful dialysis, and subsequently received a kidney transplant. Conversely, there are no reports of untreated EPRA survivors. This early success of amnioinfusions to treat EPRA justifies a rigorous prospective trial. The objective of this study is to provide a review of what is known about fetal therapy for EPRA and describe the Renal Anhydramnios Fetal Therapy trial. We review the epidemiology, pathophysiology, and genetics of EPRA. Furthermore, we have performed systematic review of case reports of treated EPRA. We describe the ethical framework, logistical challenges, and rationale for the current single center (NCT03101891) and planned multicenter trial.

Clinical implication of renal allograft volume to recipient body surface area ratio in pediatric renal transplant

Our study aims to assess the clinical implication of RAV/rBSA ratio in PRT as a predictor for attained renal function at 1 year post-transplantation and its association with surgical complications. A retrospective cohort was performed for PRT cases from January 2000 to December 2015 in our institution. Extracted clinical information includes the recipient's demographics, donor type, renal allograft characteristics, arterial, venous and ureteral anastomoses, vascular anastomosis time while kidney off ice, overall operative time, and estimated blood loss. The RAV/rBSA was extrapolated and assessed for its association with renal graft function attained in 1 year post-transplantation and surgical complications within 30-day post-transplantation. A total of 324 PRTs cases were analyzed. The cohort consisted of 187 (52.4%) male and 137 (42.3%) female recipients, with 152 (46.9%) living donor and 172 (53.1%) deceased donor renal transplants, and an overall median age of 155.26 months (IQR 76.70-186.98) at time of renal transplantation. The receiver operating characteristic identified that a RAV/rBSA ratio of 135 was the optimal cutoff in determining the renal graft function outcome. Univariate and multivariate analyses revealed the relative OR for RAV/rBSA ≥ 135 ratio in predicting an eGFR ≥ 90 attained within 1 year post-transplant was highest among younger pediatric recipients (<142.5 months) of deceased kidney donors (OR = 11.143, 95% CI = 3.156-39.34). Conversely, Kaplan-Meier analysis revealed that RAV/rBSA ratio ≥ 135 is associated with lower odds of having eGFR <60 (OR = 0.417, 95% CI = 0.203-0.856). The RAV/rBSA ratio was not associated nor predictive of transplant-related surgical complications. Our study determined that the RAV/rBSA ratio is predictive of renal graft function at 1-year PRT, but not associated with any increased surgical complications.

A case series of perioperative variables in relation to short-term outcomes in pediatric renal transplant recipients

Multiple perioperative variables have been shown in existing literature to influence long-term outcomes of pediatric RTx, such as allograft survival. Their impact on short-term outcomes is not as well-documented. This case series aims to investigate the effects of nine perioperative variables on two short-term outcomes in pRTR: 1-week post-operative eGFR and post-operative LOS. A total of 73 pRTR transplanted over 3 years from 2012 to 2014 at a single center were studied retrospectively and statistical analyses were performed. There was higher 1-week post-operative eGFR in pRTR who received living donor transplants compared to those who received deceased donor transplants (P=.01), with mean eGFR of 135 mL/min/1.73 m² and 82 mL/min/1.73 m² , respectively. Aorta-IVC anastomosis was associated with longer LOS compared to iliac vessel anastomosis (P=.03), with median LOS of 19 and 13 days, respectively. There were no significant effects on 1-week eGFR or LOS of the seven other variables: pRTR age and gender, donor age, preoperative donor SBP, intraoperative mean CVP before graft perfusion, intraoperative median SBP z score after graft perfusion, and intraoperative fluid volume. Living donor transplants were associated with higher 1-week post-operative eGFR compared to deceased donor transplants. Aorta-IVC anastomosis was significantly associated with longer LOS compared to iliac vessel anastomosis.