Predicting wait time for pediatric kidney transplant: a novel index.

BACKGROUND: Over one thousand pediatric kidney transplant candidates are added to the waitlist annually, yet the prospective time spent waiting is unknown for many. Our study fills this gap by identifying variables that impact waitlist time and by creating an index to predict the likelihood of a pediatric candidate receiving a transplant within 1 year of listing. This index could be used to guide patient management by giving clinicians a potential timeline for each candidate's listing based on a unique combination of risk factors. METHODS: A retrospective analysis of 3757 pediatric kidney transplant candidates from the 2014 to 2020 OPTN/UNOS database was performed. The data was randomly divided into a training set, comprising two-thirds of the data, and a testing set, comprising one-third of the data. From the training set, univariable and multivariable logistic regressions were used to identify significant predictive factors affecting wait times. A predictive index was created using variables significant in the multivariable analysis. The index's ability to predict likelihood of transplantation within 1 year of listing was validated using ROC analysis on the training set. Validation of the index using ROC analysis was repeated on the testing set. RESULTS: A total of 10 variables were found to be significant. The five most significant variables include the following: blood group, B (OR 0.65); dialysis status (OR 3.67); kidney disease etiology, SLE (OR 0.38); and OPTN region, 5 (OR 0.54) and 6 (OR 0.46). ROC analysis of the index on the training set yielded a c-statistic of 0.71. ROC analysis of the index on the testing set yielded a c-statistic of 0.68. CONCLUSIONS: This index is a modest prognostic model to assess time to pediatric kidney transplantation. It is intended as a supplementary tool to guide patient management by providing clinicians with an individualized prospective timeline for each candidate. Early identification of candidates with potential for prolonged waiting times may help encourage more living donation including paired donation chains.

A novel risk score for predicting prolonged length of stay following pediatric kidney transplant.

BACKGROUND: Kidney transplants (KT) are accepted as the kidney replacement therapy of choice for children with kidney failure. The surgery itself may be more difficult especially in small children, and often leads to significant hospital stays. There is little research on predicting prolonged length of stay (LOS) in children. We aim to examine the factors associated with prolonged LOS following pediatric KT to help clinicians make informed decisions, better counsel families, and potentially reduce preventable causes of prolonged stay. METHODS: We retrospectively analyzed the United Network for Organ Sharing database for all KT recipients less than 18 years old between January 2014 and July 2022 (n = 3693). Donor and recipient factors were tested in univariate and multivariate logistic analysis using stepwise elimination of non-significant factors to create a final regression model predicting LOS longer than 14 days. Values were assigned to significant factors to create risk scores for each individual patient. RESULTS: In the final model, only primary diagnosis of focal segmental glomerulosclerosis, dialysis prior to KT, geographic region, and recipient weight prior to KT were significant predictors of LOS longer than 14 days. The C-statistic of the model is 0.7308. The C-statistic of the risk score is 0.7221. CONCLUSIONS: Knowledge of the risk factors affecting prolonged LOS following pediatric KT can help identify patients at risk of increased resource use and potential hospital-acquired complications. Using our index, we identified some of these specific risk factors and created a risk score that can stratify pediatric recipients into low, medium, or high risk groups. A higher resolution version of the Graphical abstract is available as Supplementary information.

Ureteral stricture after pediatric kidney transplantation: Is there a role for percutaneous antegrade ureteroplasty?

INTRODUCTION: Ureteral obstruction following pediatric kidney transplantation occurs in 5-8% of cases. We describe our experience with percutaneous antegrade ureteroplasty for the treatment of ureteral stricture in pediatric kidney transplant patients. METHODS: We retrospectively reviewed all pediatric kidney transplantation patients who presented with ureteral stricture and underwent percutaneous antegrade ureteroplasty at our institution from July 2009 to July 2021. Variables included patient demographics, timing of presentation, location and extent of stricture, ureteroplasty technique and clinical outcomes. Our primary outcome was persistent obstruction of the kidney transplant. RESULTS: Twelve patients met inclusion criteria (4.2% of all transplants). Median age at time of ureteroplasty was 11.5 years (range: 3-17.5 years). Median time from kidney transplantation to ureteroplasty was 3 months. Patency was maintained in 50% of patients. Seven patients (58.3%) required additional surgery. Four patients developed vesicoureteral reflux. Patients with persistent obstruction had a longer time from transplant to ureteroplasty compared to those who achieved patency (19.3 vs 1.3 months, p = 0.0163). Of those treated within 6 months after transplantation, two patients (25%) required surgery for persistent obstruction (p = 0.06). All patients treated >1 year after transplantation had persistent obstruction following ureteroplasty (p = 0.06). CONCLUSION: Percutaneous antegrade ureteroplasty can be considered a viable minimally invasive treatment option for pediatric patients who develop early ureteral obstruction (<6 months) following kidney transplantation. In patients who are successfully treated with ureteroplasty, 67% can develop vesicoureteral reflux into the transplant kidney. Patients who fail early percutaneous ureteroplasty or develop obstruction >1 year after transplantation are best managed with surgical intervention.

Good outcomes for arteriovenous fistula with buttonhole cannulation for chronic hemodialysis in children and adolescents.

BACKGROUND: Arteriovenous fistula (AVF) is the preferred access for chronic hemodialysis (HD) in children and adolescents, but central venous catheter use is still high. METHODS: Retrospective chart review of children and adolescents with AVF created between January 2003 and December 2015 was performed to assess primary failure (PF), maturation time, functional primary and functional cumulative patency, and potential risk factors for AVF dysfunction. RESULTS: Ninety-nine AVF were created in 79 patients (54% male; 7-24 years; 16-147 kg) by experienced surgeons. Duplex ultrasonography vein mapping was used to assist with site selection. PF occurred in 17 AVF (17%) in 14 patients. Patient age, gender, ethnicity, underlying disease, time on dialysis, and AVF site were not associated with PF or patency. Coagulation abnormality was positively associated with PF (p = 0.03). Function was achieved in 82 AVF (83%) in 77 patients (97%). Median maturation time was 83 days (range 32-271). AVF were accessed via buttonholes. Functional primary patency was 95%, 84%, and 53% at 1, 2, and 5 years. Overall 1- and 2-year functional cumulative patency was 95%, but lower for small patients 16-30 kg (88%) and those greater than 80 kg (91%). The 5-year patency rate was 80%, but significantly lower for 16-30 kg (59%) and greater than 80 kg (55%). Risk analysis showed significantly better patency for 31-45 kg and 46-80 kg groups (p < 0.01), non-obese BMI (p = 0.01), and buttonhole self-cannulation (p = 0.03). CONCLUSIONS: This study provides more information about successful AVF with buttonhole cannulation in pediatric hemodialysis patients lending additional support for AVF use in pediatrics. A higher resolution version of the Graphical abstract is available as Supplementary information.

International Pediatric Transplant Association (IPTA) position statement supporting prioritizing pediatric recipients for deceased donor organ allocation.

A position statement of the International Pediatric Transplant Association endorsing prioritizing pediatric recipients for deceased donor organ allocation, examining the key ethical arguments that serve as the foundation for that position, and making specific policy recommendations to support prioritizing pediatric recipients for deceased donor organ allocation globally.

A modified Kidney Donor Risk Index for pediatric kidney transplant recipients.

BACKGROUND: The Kidney Donor Risk Index (KDRI) by Rao et al. was developed to measure the quality of kidney allografts. While Rao's KDRI has been found to be a robust measure of kidney allograft survival for adult kidney transplant recipients, many studies have indicated the need to create a distinct pediatric KDRI. METHODS: Our retrospective study utilized data from the United Network for Organ Sharing database. We examined 9295 deceased donor recipients' data for age < 18 years from 1990 to 2020. We performed a multivariate Cox regression to determine the significant recipient and transplant factors impacting pediatric kidney allograft survival. RESULTS: Multivariate analysis found 5 donor factors to be independently associated with graft failure or recipient death: age, female sex, anoxia as the cause of death, history of cigarette use, and cold ischemia time. Using receiver operator characteristic (ROC) curve analysis and analyzing the predictive value of each KDRI at 1, 5, and 10 years, the proposed pediatric KDRI had a statistically significant and higher predictive value for pediatric recipients at 5 (0.60 versus 0.57) and 10 years (0.61 versus 0.57) than the Rao KDRI. CONCLUSIONS: The proposed pediatric KDRI may provide a more accurate and simpler index to assess the quality of kidney allografts for pediatric recipients. However, due to the mild increase in predictive capabilities over the Rao index, the study serves as a proof of concept to develop a pediatric KDRI. Further studies should focus on increasing the index's predictive capabilities. A higher resolution version of the Graphical abstract is available as Supplementary information.

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.

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.

The pediatric solid organ transplant experience with COVID-19: An initial multi-center, multi-organ case series.

The clinical course of COVID-19 in pediatric solid organ transplant recipients remains ambiguous. Though preliminary experiences with adult transplant recipients have been published, literature centered on the pediatric population is limited. We herein report a multi-center, multi-organ cohort analysis of COVID-19-positive transplant recipients ≤ 18 years at time of transplant. Data were collected via institutions' respective electronic medical record systems. Local review boards approved this cross-institutional study. Among 5 transplant centers, 26 patients (62% male) were reviewed with a median age of 8 years. Six were heart recipients, 8 kidney, 10 liver, and 2 lung. Presenting symptoms included cough (n = 12 (46%)), fever (n = 9 (35%)), dry/sore throat (n = 3 (12%)), rhinorrhea (n = 3 (12%)), anosmia (n = 2 (8%)), chest pain (n = 2 (8%)), diarrhea (n = 2 (8%)), dyspnea (n = 1 (4%)), and headache (n = 1 (4%)). Six patients (23%) were asymptomatic. No patient required supplemental oxygen, intubation, or ECMO. Eight patients (31%) were hospitalized at time of diagnosis, 3 of whom were already admitted for unrelated problems. Post-transplant immunosuppression was reduced for only 2 patients (8%). All symptomatic patients recovered within 7 days. Our multi-institutional experience suggests the prognoses of pediatric transplant recipients infected with COVID-19 may mirror those of immunocompetent children, with infrequent hospitalization and minimal treatment, if any, required.

Chronic kidney disease impacts health-related quality of life of children in Uganda, East Africa.

BACKGROUND: Limited data exist about causes of chronic kidney disease (CKD) and impact on health-related quality of life (HRQoL) in African children. We evaluated types of kidney disease in Ugandan children 0-18 years and compared HRQoL in children with CKD or with benign or resolving kidney disease (non-CKD) to assess predictors of HRQoL. METHODS: Demographic, socioeconomic, and clinical data were obtained for this cross-sectional study. Pediatric Quality of Life Core Scale™ (PedsQL) was used to survey 4 domains and overall HRQoL. CKD and non-CKD scores were compared using unpaired t test. HRQoL predictors were evaluated using linear and logistic regression analyses. RESULTS: One hundred forty-nine children (71 CKD, 78 non-CKD; median age 9 years; male 63%) had the following primary diseases: nephrotic syndrome (56%), congenital anomalies of the urinary tract (CAKUT) (19%), glomerulonephritis (17%), and other (8%). CAKUT was the predominant etiology (39%) for CKD; 63% had advanced stages 3b-5. Overall HRQoL scores were significantly lower for CKD (57 vs. 86 by child report, p < 0.001; 63 vs. 86 by parent proxy report, p < 0.001). Predictors of lower HRQoL were advanced CKD stages 3b-5, primary caregiver non-parent, vitamin D deficiency, and anemia. CONCLUSION: Like other parts of the world, CAKUT was the main cause of CKD. Most CKD children presented at late CKD stages 3b-5. Compared with non-CKD, HRQoL in CKD was much lower; only two-thirds attended school. Vitamin D deficiency and anemia were potentially modifiable predictors of low HRQoL. Interventions with vitamin D, iron, and erythropoietin-stimulating agents might lead to improved HRQoL.

Successful kidney transplantation in a small child with end-stage renal disease due to angiotensin receptor blocker fetopathy and atretic inferior vena cava.

Kidney transplantation is the treatment of choice in pediatric patients with end-stage renal disease. This population presents technical challenges particularly in those less than 20 kg due to anomalous anatomy, vascular access issues prior to transplantation, and a generally small size for age. Standard allograft outflow is usually achieved utilizing the iliac veins or IVC. When use of the iliocaval system is not feasible, alternative anastomosis must be considered. Herein, we report a case of a pediatric kidney transplantation where successful allograft outflow was achieved using the SMV when he was found to have an atretic IVC intraoperatively. In this setting, use of the portal system was required to achieve adequate allograft outflow. We created a donor iliac graft for added length to anastomose the renal vein with the SMV. In the setting of IVC occlusion with poor drainage, we utilized a patent vessel with larger caliber for outflow to reduce the risk of high venous pressures, allograft failure, venous rotation, and thrombosis. We conclude that the SMV may serve as an alternative outflow tract in the small pediatric patient and provides the vessel caliber needed to reduce the risks of complications.

Correction to: Recurrence of nephrotic syndrome following kidney transplantation is associated with initial native kidney biopsy findings : A Midwest Pediatric Nephrology Consortium (MWPNC) study.

The original version of this article unfortunately contained a mistake. The subtitle "A Midwest Pediatric Nephrology Consortium (MWPNC) study" was missing. The correct title including subtitle is given above.

Recurrence of nephrotic syndrome following kidney transplantation is associated with initial native kidney biopsy findings.

BACKGROUND AND OBJECTIVES: Steroid-resistant nephrotic syndrome (SRNS) due to focal segmental glomerulosclerosis (FSGS) and minimal change disease (MCD) is a leading cause of end-stage kidney disease in children. Recurrence of primary disease following transplantation is a major cause of allograft loss. The clinical determinants of disease recurrence are not completely known. Our objectives were to determine risk factors for recurrence of FSGS/MCD following kidney transplantation and factors that predict response to immunosuppression following recurrence. METHODS: Multicenter study of pediatric patients with kidney transplants performed for ESKD due to SRNS between 1/2006 and 12/2015. Demographics, clinical course, and biopsy data were collected. Patients with primary-SRNS (PSRNS) were defined as those initially resistant to corticosteroid therapy at diagnosis, and patients with late-SRNS (LSRNS) as those initially responsive to steroids who subsequently developed steroid resistance. We performed logistic regression to determine risk factors associated with nephrotic syndrome (NS) recurrence. RESULTS: We analyzed 158 patients; 64 (41%) had recurrence of NS in their renal allograft. Disease recurrence occurred in 78% of patients with LSRNS compared to 39% of those with PSRNS. Patients with MCD on initial native kidney biopsy had a 76% recurrence rate compared with a 40% recurrence rate in those with FSGS. Multivariable analysis showed that MCD histology (OR; 95% CI 5.6; 1.3-23.7) compared to FSGS predicted disease recurrence. CONCLUSIONS: Pediatric patients with MCD and LSRNS are at higher risk of disease recurrence following kidney transplantation. These findings may be useful for designing studies to test strategies for preventing recurrence.

Intra-procedural continuous dialysis to facilitate interventional catheterization in pediatric patients with severe renal failure.

BACKGROUND: Interventional catheterization procedures may be needed for patients with severe renal failure who are dependent on dialysis. To avoid the risk of fluid overload and electrolyte derangement during complex procedures in this oliguric/anuric patient population, we performed intra-procedural dialysis, either continuous renal replacement therapy (CRRT) or continous cycling peritoneal dialysis (CCPD). METHODS: We performed a retrospective review of a cohort of pediatric patients, ages 0-18 years, with dialysis-dependent renal failure who received CRRT or CCPD during catheterization procedures from January 2013 to March 2016. RESULTS: Eight patients underwent a total of nine interventional catheterization procedures while receiving intra-procedural dialysis. Median age was 4.5 years (range 8 months to 17 years) and weight, 11.6 kg (11.2-62.6 kg). Six patients had end-stage renal disease (ESRD) and two patients had acute kidney injury (AKI), one due to hepatorenal syndrome and one due to multifactorial causes associated with congenital heart disease. The most common reason for catheterization was occlusive venous thrombosis requiring recanalization. CRRT was used during five cases and CCPD during four cases. Median procedure time was 337 min (95-651 min) and median contrast dose 4.2 mL kg-1 (1.2-8.2 mL kg-1 ). Euvolemia was maintained based on pre- and post-catheterizations weights, and no significant electrolyte abnormalities occurred based on lab monitoring during and post-procedure. CONCLUSIONS: Intra-procedural dialysis using CRRT or CCPD enables even small pediatric patients with severe renal failure to undergo long and complex interventional catheterizations by reducing the risk of fluid overload and electrolyte abnormalities. Collaboration between nephrology, cardiology, and dialysis teams is necessary for successful management of this challenging patient population.