A 100% 2-year graft survival can be attained in high-risk 15-kg or smaller infant recipients of kidney allografts

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.

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.

Assessment of prophylactic heparin infusion as a safe preventative measure for thrombotic complications in pediatric kidney transplant recipients weighing <20 kg

Small-sized kidney recipients (<20 kg) are at high risk of allograft vessel thrombosis. HP has been used to mitigate this risk but may infer an increase in bleeding risks. Therefore, we aim to determine whether HP is a safe means to prevent thrombosis in small kidney transplant patients by comparing those who have received HP and those who have NHP. A retrospective review of patients < 20 kg who underwent kidney transplant in our institution from 2000 to 2015 was performed. At our institution, unfractionated heparin 10 units/kg/hour is used as HP since 2009. Patients at increased risk of thrombosis (previous thrombosis, thrombophilia, nephrotic syndrome) and bleeding (therapeutic doses of heparin, diagnosis of coagulopathy) were excluded. Fifty-six patients were identified (HP n = 46; NHP n = 10). Baseline demographics were similar between HP and NHP. There was no statistical difference in frequency of transfusions, surgical re-exploration, or thrombotic events between HP and NHP. The HP group was more likely to have drop in Hb > 20 g/L (67.4% vs 30.0%, P = 0.038), and those who had drop in Hb > 20 g/L were more likely to also require pRBC transfusions (63.0% vs 20.0%, P = 0.017). Within the HP group, those who had bleeding complications had similar Hb levels as those who did not at baseline and post-transplant. Outcomes in the HP and NHP groups were no different with respect to thrombosis or significant bleeding complications requiring pRBC transfusions or surgical intervention. Future prospective studies are required to investigate the balance of preventing thrombosis and risks of pRBC transfusions for small-sized kidney recipients.

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.

Renal transplantation in children weighing <15 kg: does concomitant lower urinary tract dysfunction influence the outcome?

BACKGROUND

We reviewed our experience with renal transplantation (RTx) in children weighing <15 kg to determine if the presence of lower urinary tract dysfunction (LUTD) influenced the outcome.

METHODS

Between 1987 and 2012, 68 RTx were performed in patients weighing less than 15 kg, including 17 with associated LUTD and 51 without. We detailed the lower urinary tract management in these patients, and compared graft survival rates and estimated clearance 12 and 60 months after RTx between groups.

RESULTS

None of the patients without LUTD required any lower urinary tract surgery vs 8 out of 17 (47 %) with LUTD (p = 0.0001). The latter included a temporary incontinent urinary diversion in 5 cases (29 %), namely 2 vesicostomies and 3 cutaneous ureterostomies. After comparable follow-ups, there was no difference in patient survival, graft survival, and glomerular filtration rates between groups.

CONCLUSIONS

Provided that there is appropriate bladder management, a concomitant LUTD does not adversely influence the outcome of RTx in patients weighing less than 15 kg. However, 50 % of our patients required lower urinary tract reconstruction and, in 30 %, a temporary incontinent urinary diversion was placed at RTx, since lower urinary tract function could not be assessed reliably, the patient was not collaborative enough to be involved in a voiding program, and/or the RTx was prioritized.

Surgical complications and graft function following live-donor extraperitoneal renal transplantation in children 20 kg or less

OBJECTIVES

To evaluate the effect of patient, surgical, and medical factors on surgical complications and graft function following renal transplantation (Tx) in children weighing ≤ 20 kg, because the number of this challenging group of children is increasing.

PATIENTS AND METHODS

Between June 2009 and October 2013, 26 patients received living donor renal allotransplant using the extraperitoneal approach (EPA). The immunosuppression regimen was composed of prednisolone, mycophenolate mofetil, and ciclosporin or tacrolimus.

RESULTS

The mean weight was 16.46 ± 2.61 kg. Mean cold ischemia time was 53.85 ± 12.35 min. The graft survival rate (GSR) and patient survival rate (PSR) were 96% at 3 years. Acute rejection episodes (AREs) occurred in eight patients (30%). Postoperative surgical complications were ureteral leakage (3), vesicoureteric reflux (2), and renal vein thrombosis (2) (with one graft nephrectomy). Mean follow-up was 37.5 ± 7.4 months.

CONCLUSION

Excellent PSR and GSR can be achieved in low weight (<20 kg) recipients. Even in very low weight patients, the EPA was used. No cases were reported with primary graft non-function due to use of living donors, increasing pre-Tx body weight to at least 10 kg and maintaining adequate filling pressure before graft reperfusion. The presence of related donors and use of induction therapy and tacrolimus decreased the rate of ARE while the presence of pre-Tx lower urinary tract surgical interventions increased the rate of ureteric complications, but this was statistically insignificant.

Vascular anastomosis for paediatric renal transplantation and new strategy in low-weight children

The technical aspects of RT in low-weight children should be specific, particularly with regard to VA. This retrospective study assesses the main VA options in paediatric RTs and proposes a new strategy for renal artery trajectory when using the Ao and the right iVC. The sample included 81 patients and was categorized into a group of children weighing <16 kg and the other group of children weighing 16 kg or more. The smaller children received the graft predominantly on the Ao and iVC (63%); however, the VA options varied in children weighing more than 16 kg, with anastomoses predominantly to the common iliac vessels (46%). In the first group, when the Ao was the selected vessel for anastomosis on the right side, the trajectory adopted for the transplanted kidney artery was posterior to the iVC. This strategy may reduce the risk of compression of the iVC by the renal artery of the donor kidney and may reconstitute the normal anatomy of the renal artery. Moreover, it did not represent a risk factor for graft loss in this sample.

Kidney transplantation in children weighing less than 15 kg: extraperitoneal surgical access-experience with 62 cases

Small children are a challenging group in whom to perform KT. This retrospective study analyzed the results of 62 KTs in children weighing <15 kg, performed between 1998 and 2010, using extraperitoneal access and anastomosis of the renal vessels of donors to the aorta and IVC or iliac vessels of the recipients. Thirty-two (51.6%) grafts were LRDTs and 30 (48.4%) were DDRTs-28 of them pediatric. The mean age at KT was 3.7 ± 2.2 yr (1-12), and the mean weight was 12.3 ± 2.1 kg (5.6-14.9). Ten children weighed <10 kg, and five (8.1%) children presented previous thrombosis of the venous system. At one and five yr, patient survival was 93.2% and 84.2%, and graft survival was 85.2% and 72.7%. There were no differences between the rates for LRDT and DDRT. There were six vascular complications (four vascular thromboses, one laceration, and one renal artery stenosis) and two perirenal collections. Extraperitoneal access is a valid KT technique in children weighing <15 kg.

Kidney transplantation complications related to psychiatric or neurological disorders

Defining absolute psychiatric or neurological contraindications among kidney transplantation candidates is controversial, especially taking into account that graft outcomes are similar to other groups of patients. The social support network should be exhaustively evaluated to ensure adherence to immunosuppressive therapy and minimization of complications resulting from the neuropsychiatric disorder. We reviewed transplants (n = 668) in our center between January 2001 and August 2008 searching for patients with a diagnosis of neurological or psychiatric disease before renal transplantation. We also reviewed demographic data, social support networks, patient and graft survivals as well as transplant complications. Twelve patients were transplanted with neurological or psychiatric disorders: seven with cognitive impairment and five with psychiatric diseases. Nine patients had good social support networks. The mean follow-up time was 2.65 +/- 2.42 years. The graft loss rate was 34% (n = 4), including only one attributed to a mental disorder, namely, nonadherence to immunosuppressive therapy. Regarding complications, four were related to the neuropsychiatric disorder: hypoglycemia due to insulin overdose, aspiration pneumonia because of altered pharynx-larynx motility, hyponatremia related to diuretic abuse, and malnutrition plus dehydration. Patient survival in this period was 91.7%. The one patient died due to multiple organ failure secondary to respiratory sepsis with a functioning graft. In summary, neuropsychiatric disorders should not be considered to be contraindications for kidney transplantation although a social support network is essential and must be carefully evaluated.

Combined liver-kidney transplantation in children: indications and outcome

Although it remains a relatively infrequent procedure in children, CLKT has become a viable option for a select group of pediatric patients with severe liver and kidney disease. Most are performed for rare primary diseases such as PH1, but a selected few are performed in the setting of concomitant hepatic and renal failure of uncertain etiology and prognosis. This article reviews the indications for and outcomes following CLKT in children. While it focuses on the specific primary diseases which impact liver and kidney function simultaneously, it addresses the indications based on concomitant hepatic and renal failure, such as seen in the hepatorenal syndrome, as well.

Renal transplantation in children younger than 6 years old

Herein we report our experience in renal transplantation in 38 children (40 transplants), ages 1 to 5 years, between 1989 and 2005. Demographics as well as patient and graft survivals are reported. Mean age at transplantation was 3.3 +/- 1.3 years, and mean weight was 14 kg (range, 5.7-25 kg); 92.5% were Caucasian, 7.5% African-Brazilian. The main etiology for end-stage renal disease (ESRD) was uropathic/vesicoureteral reflux (45%) followed by glomerulopathy (25%), congenital/hereditary diseases (10%), and hemolytic uremic syndrome (12.5%). Prior to transplantation, 5% were on hemodialysis, 85% on peritoneal dialysis, and 10% preemptive. All children were followed for at least 6 months posttransplantation, except 2 who died in the first month. In 75% of cases, kidneys were obtained from living-related donors, and in 25% from deceased donors. Thirty-nine kidneys were extraperitoneally placed. Primary immunosuppressant therapy consisted of cyclosporine (61%), tacrolimus (39%), mycophenolate (49%), and azathioprine (51%). A steroid-free protocol was used in 17% of patients. In the last 21 cases, basiliximab or daclizumab was added. There were 13 (32.5%) graft losses (4 artery/vein thromboses, 3 chronic rejections, 3 deaths, 3 other causes). The 5-year patient and graft survival rates were 89.6% and 72.2%. We have concluded that renal transplantation can be performed with good long-term results in children younger than 6 years old.

Outcomes of dialysis initiated during the neonatal period for treatment of end-stage renal disease: a North American Pediatric Renal Trials and Collaborative Studies special analysis

OBJECTIVE

We sought to determine the outcomes of initiating long-term dialysis of neonates and children aged > 1 to 24 months with end-stage renal disease.

PATIENTS AND METHODS

By querying the North American Pediatric Renal Trials and Collaborative Studies database, we obtained information on 193 neonates (< or = 1 month of age) and 505 children (> 1-24 months of age) with a presumptive diagnosis of end-stage renal disease who initiated long-term dialysis. Dialysis characteristics and likelihood of hospitalization were compared using the chi2 test, and duration of hospitalization was compared using the Wilcoxon 2-sample test. Product limit methods were implemented, and the log rank test was used to compare time-to-event analyses. Multivariate analyses were performed using Cox proportional hazards models.

RESULTS

Neonates with end-stage renal disease were more likely to receive peritoneal dialysis versus hemodialysis than older children with end-stage renal disease. Moreover, neonates who initiated dialysis during the first month of life were just as likely to terminate dialysis as were the older children. Rates of renal transplantation were significantly lower in the neonates compared with the older children, but neonates were more likely to recover function of the native kidney. Although neonates were more often hospitalized, their overall risk of mortality was similar to that observed in older children.

CONCLUSIONS

Neonates with a presumptive diagnosis of end-stage renal disease may initiate long-term dialysis during the first month of life with outcomes comparable to those of patients who initiate dialysis later in infancy.

Renal Transplantation in Children 15 Kg or Less: The British Columbia Children’s Hospital Experience

PURPOSE

Small infants are the most challenging group of patients to undergo renal transplantation.

PURPOSE

We reviewed the transplantation experience at our institution with children less than 15 kg at transplantation.

MATERIALS AND METHODS

We retrospectively reviewed the records of 24 recipients in a 20-year period. Technical and allograft outcomes were compared to those in the North American Pediatric Renal Transplant Cooperative Study database.

RESULTS

Since the inception of our program 24 recipients weighing 15 kg or less who were 6 years or younger have undergone transplantation. Seven grafts (29%) were from living donors. At transplantation mean age was 3.1 years (range 1.8 to 5.7) and mean weight was 13.4 kg (range 9.0 to 15.7). Average cold and warm ischemic times were 14.1 hours (range 3.4 to 37.2) and 23.1 minutes (range 21 to 41), respectively. Early complications were ureteral stricture requiring pyeloureterostomy in 1 case, reversible acute tubular necrosis in 2 and early arterial thrombosis salvaged by immediate thrombectomy in 1. Delayed complications were arterial stenosis requiring angioplasty in 2 cases, and 3 delayed deaths related to malignant hypertension in 2 and sepsis in 1. No grafts were lost due to thrombosis. Mean serum creatinine at years 1 to 3 and 5 were 48.5, 67.5, 79.1 and 84.4 mumol/l, respectively. Graft survival was 92% (22 patients after censoring 1 who died with a functioning graft) at 2 and 5 years. Overall results compare favorably to those in the North American Pediatric Renal Transplant Cooperative Study.

CONCLUSIONS

With a multidisciplinary team effort successful results can be achieved in this challenging group of patients.

Pediatric renal transplantation with considerations for successful outcomes

Renal transplantation in the pediatric population, although conceptually similar to that in adults, differs in many aspects. This review will focus on the issues unique to the pediatric recipient. In particular, we will focus on the incidence and etiology of end stage renal disease in children, and the results as measured by patient and graft survival. Pretransplant surgical considerations of timing of the transplant, management of congenital urologic abnormalities and the abnormal bladder will be addressed. Etiologies of renal failure unique to the pediatric population will be discussed, including autosomal recessive polycystic kidney disease, congenital nephrotic syndrome, inferior vena cava thrombosis, and primary hyperoxaluria Type 1. Lastly, special transplant surgical considerations including transplantation of an adult-size kidney (ASK) into an infant or small child and ureteral implantation, management of the urinary bladder, and fluid management in infants and small children will be discussed.

Ureteral stenosis in HDAF pig-to-primate renal xenotransplantation: a phenomenon related to immunological events?

The aim of this study was to analyze the incidence of ureteral stenosis in a life-supporting human decay-accelerating factor (hDAF) transgenic pig-to-cynomolgus monkey kidney transplantation model and determine the role of possible immunological events in its pathogenesis. Thirty consecutive bi-nephrectomized cynomolgus monkeys received a kidney from hDAF transgenic pigs with or without a ureteral stent. Four monkeys were euthanized prematurely after transplantation. In the remaining 26 cases, the mean survival was 24 +/- 19 days. Except in one case, there was a close relationship between ureter and kidney in terms of type and severity of rejection. There were six ureteral stenoses; five were repaired by stent positioning and resurgery extended survival for an additional 16 +/- 10 days. The stenotic ureters showed diffuse acute humoral xenograft rejection (AHXR), while all cases with no or only focal signs of ureteral rejection never revealed ureteral obstruction. Use of a ureteral stent extends the survival of a xenografted primate, thereby helping to clarify the immunological events surrounding the onset of AHXR in kidneys in long-term xenograft recipients.

Kidney transplants for children under 1 year of age - a single-center experience

From September 20, 1970 to October 24, 2001, we performed 46 kidney transplants in infants under 1 yr old at the University of Minnesota. This article reviews the preoperative care, surgical technique, and immunosuppression. Recipients included 16 females and 30 males; the youngest recipient was 6 wk old. The mean pretransplant height was 62.8 cm, which increased to 77 cm at 1 yr post-transplant and to 104 cm at 5 yr. We used 40 living donors (all but 1 were related to the recipient) and 6 cadaver donors. The overall actuarial graft survival was 85% at 1 yr and 70% at 5 yr. In the cyclosporine era, graft survival improved to 91% at 1 yr and 80% at 5 yr. Death with function was the most common cause of graft loss (n = 5), followed by biopsy-proven chronic rejection (n = 4), biopsy-proven recurrent disease (n = 3), and graft thrombosis (n = 2). Patient survival was 91% at 1 yr and 86% at 5 yr. In the cyclosporine era, patient survival was 100% at 5 yr and 85% at 10 yr. We concluded that an early transplant is the best treatment option for infants under 1 yr old with chronic renal failure. Whenever possible, adult living kidney donors should be used.

Superior Long-Term Results of Renal Transplantation in Children under 5 Years of Age

Despite improving overall results of pediatric renal transplantation children under 5 years of age remain a high-risk group with poorer outcomes often because of a higher rate of surgical complications. This retrospective report details a 12-year experience at a single center and examines the outcome in this high-risk group of patients. We reviewed the medical records of 21 children under 5 years of age who received renal transplantation at Loma Linda University Medical Center between July 1988 and August 2000. The patients were evaluated regularly by the same pediatric nephrologist throughout the study period at our outpatient clinic. Mean recipient age was 3 ± 1.2 (range 2–5) years; weight at transplantation was 13.3 ± 5.4 kg. Ten (48%) patients received living related donor (LRD) kidneys and 11 (52%) received cadaver (CAD) kidneys. Mean donor ages for CAD and LRD were 14.4 ± 10 years and 26.6 ± 4.9 years, respectively. The mean cold ischemia time (CAD only) was 23.3 ± 10.6 hours. Renal dysplasia (n = 8) and obstructive uropathy (n = 5) were the most common primary diagnoses. Maintenance immunosuppression consisted of Azathioprine or mycophenolate mofetil (MMF), cyclosporine or tacrolimus and prednisone. Mean follow-up was 80.1 ± 51.4 months. Twelve (57%) grafts have a follow-up >5 years. Patient survival was 100 per cent Overall graft survival at one, 3, 5, and 10 years were 95, 95, 88, and 88 per cent respectively. Graft survival for LRD recipients was 100 per cent No graft was lost as a result of a technical problem or vascular thrombosis. One graft each was lost because of delayed graft function complicated by severe cytomegalovirus infection and chronic rejection. At one year the mean serum creatinine was 0.6 ± 0.2 mg/dL with a mean calculated glomerular filtration rate of 93 ± 32 mL/min. All 17 children who are now of school age are attending school. We conclude that excellent rehabilitation and superior long-term patient and graft survival can be achieved with renal transplantation in children of this age group with the use of good surgical techniques and close follow-up.

Outcome of reaching end stage renal failure in children under 2 years of age

AIMS

To determine the outcome of children who reach end stage renal failure before the age of 2 years.

METHODS

Using a retrospective questionnaire, 10 years' data were collected from the paediatric nephrology units in Britain and Ireland (1988 to 1997, follow up 1.3-11.5 years).

RESULTS

A total of 192 children were identified; 0.31/million/year. Most had congenital or inherited conditions, and there were more boys. Latterly, half were diagnosed antenatally. Ninety per cent were dialysed initially, most using home peritoneal cyclers, some by haemodialysis through central lines. Five per cent recovered sufficient function to come off dialysis. Most required tube feeding (often gastrostomy) and erythropoietin; some needed growth hormone. A total of 56% received a transplant (2% without prior dialysis) at (medians) 2.6 years and 12.3 kg. The 2 and 10 year survival of first kidneys was 78%. Growth improved following transplantation. Fourteen per cent died because treatment was not started or was withdrawn. Most had particularly complex renal conditions, or additional major non-renal diagnoses. Typically, decisions not to treat were made mutually between clinicians and families. When treatment was continued, 71% survived, and few had serious non-renal conditions. Most attended normal schools, and by 6 years of age, less than 10% still required dialysis. Infants starting treatment under and over 1 month of age fared equally well.

CONCLUSIONS

By school age, most infants treated for end stage renal failure will have a functioning transplant, reasonable growth, and will attend a normal class, regardless of the age at which they commence treatment. Treatment is seldom sustained in children who have serious additional medical conditions. It is reasonable to treat infants with uncomplicated renal failure.