Urologic Evaluation and Management of Pediatric Kidney Transplant Patients

Posterior urethral valves and kidney transplantation: Identifying opportunities for improvement

BACKGROUND

Posterior urethral valves (PUV) represents a heterogenous spectrum in which guidelines for management are lacking particularly for those patients facing end-stage kidney disease and transplant. In this study we aim to 1) evaluate our long term PUV pediatric transplant outcomes compared to those without lower urinary tract dysfunction and 2) assess our PUV cohort for trends in bladder management and evaluate outcomes to inform development of institutional guidelines.

MATERIALS AND METHODS

A retrospective cohort analysis of all patients with a diagnosis of PUV who underwent kidney transplant from 2000 to 2023 was completed. A matched cohort of patients without lower urinary tract dysfunction was identified for comparison of graft function. Charts of PUV patients were reviewed for both sociodemographic and clinical variables. Patients were classified by bladder management at the time of transplantation into three separate groups for analysis: voiding, clean intermittent catheterization, and incontinent diversion. Primary outcomes of interest were eGFR, graft failure, and UTIs post-transplant.

RESULTS

45 patients met inclusion criteria. 69% were on dialysis prior to transplant. 51% of grafts were from a deceased donor. Bladder management consisted of voiding (62%), CIC (4 via urethra, 10 via channel) (31%), and incontinent diversion (7%). 20% underwent augmentation cystoplasty (5 = ureter, 2 = gastric, 1 = colon, and 1 = ileum) prior to or at the time of transplant. Median follow up duration was 5.4 years (3.0, 10.8). Patients on CIC had higher rates of UTI; however, we found no significant difference in graft function outcomes (eGFR, graft failure) between bladder management groups or year of transplant. VUR in the transplant kidney was associated with vesicostomy (p = 0.028). 2 of 2 gastric augments developed malignancy, one of which was cause of death. Graft failure rate was 22% in both the PUV group and matched cohort, with median interval times to failure of 6.7 years and 3.7 years, respectively (p = 0.71). There were no differences in eGFR at follow-up time points between the PUV and matched cohort.

CONCLUSIONS

Patients with PUV represent a spectrum of disease with heterogeneous management before and after kidney transplant. Overall, graft function outcomes were similar when compared to matched cohort without lower urinary tract dysfunction. Patients on CIC had higher rates of UTI but without impact on graft function. Gastric augmentation cystoplasty should be avoided given risk for malignancy. Guidelines to standardize evaluation and management would be helpful for patient care and outcomes.

Renal transplantation in pediatric recipients: Considerations and preoperative assessment strategies

INTRODUCTION AND OBJECTIVE

Renal transplantation in the pediatric population differs from adults in many aspects. This review will focus on the unique issues of the pediatric recipient.

MATERIAL AND METHODS

A narrative review on the scarce literature regarding preoperative evaluation before kidney transplantation of the paediatric recipient with an educational focus was conducted. The literature search allowed for identification of publications in English from January 2000 to October 2022. Published studies were identified by searching the following electronic databases: PubMed (MEDLINE), WHO/UNAIDS, Google-Scholar, Semantic-Scholar and Research Gate. For efficiency and reliability, recent randomized controlled trials, meta-analyses, high quality systematic reviews and large well-designed studies were used if available. Internet searches were conducted for other relevant information (definitions, policies or guidelines).

RESULTS

Management of congenital urogenital anomalies and lower urinary tract dysfunction along with optimal pediatric urological preoperative assessment for renal transplantation in children is addressed in the light of the available literature. Furthermore, particular considerations including pre-emptive transplantation, transplantation of an adult-size kidney into an infant or small child is discussed.

CONCLUSIONS

Outcomes of RT in children have shown progressive improvement over the past 15 years. Transplantation with living related donor gives the best results and pre-emptive transplantation provides with benefits of avoiding dialysis. Surgical and medical considerations in both the pre-transplant and post-transplant management of the pediatric kidney recipient are extremely crucial in order to achieve better short and long-term results.

Paediatric kidney transplantation: Towards a framework for pretransplant urological evaluation

The role of the urologist in paediatric kidney transplantation has evolved alongside advances in management for the various causes of end-stage kidney disease. Improvements in antenatal intervention and postnatal care have seen children with increasingly complex urological anomalies survive until transplant. Once solely responsible for the oversight of a child's surgical care, the paediatric urologist now works within a multidisciplinary transplant team, alongside transplant surgeons, paediatric nephrologists, transplant coordinators, psychologists, social workers, and transitional care specialists. We sought to identify available pretransplant evaluation frameworks to guide urological preparation and decision-making. Drawing from available evidence and reflecting on multi-institutional experience, we propose a streamlined approach to urologic assessment, which recognises that optimal transplant outcomes in this heterogenous cohort require lower urinary tract dysfunction to be carefully defined preoperatively.

Impact of native nephrectomy on hypertension outcomes in pediatric kidney transplant recipients: a 10-year institutional experience

OBJECTIVE

To assess the role native nephrectomy (NN) in hypertension-related outcomes for pediatric patients undergoing renal transplantation (RT).

METHODS

Renal transplants (RT) performed at our institution between 2006 and 2015 were reviewed. RT recipients who underwent NN were compared to those who did not. Primary outcomes were hypertension-related: use/number of medications pre-/post-transplant and hypertension-related readmissions. Secondary outcomes were 1-year outcomes of: readmissions, eGFR, Clavien-Dindo classification ≥ 3 complications, and graft loss.

RESULTS

135 patients were evaluated. 24 underwent NN (Group 1) and 111 did not (Group 2). Baseline characteristics were similar between Groups 1 and 2. The majority of NN indications were hypertension (10/39 kidneys) and proteinuria (12/39 kidneys). There were no differences in use/number of anti-hypertensive medications pre- or post-transplant. However, between Group 2 and subgroup of patients who underwent NN for hypertension, a significant difference was seen in medication use/numbers but not post-transplant. Number of readmissions due to hypertension was similar (7.2% vs. 12.5%). The only difference in secondary outcomes was higher readmission rates with bacterial infections for group 1 (45.8% vs. 23.4%, p = 0.041).

CONCLUSION

NN, when offered to patients at higher risk of post-RT hypertension, may allow high-risk patients to achieve similar hypertension outcomes as those at lower risk.

Pediatric kidney transplantation, a technical update

PURPOSE OF REVIEW

Pediatric kidney transplantation is the definitive therapy for infants and children suffering from renal failure. It is a distinct endeavor demanding specialized care for optimal results. This includes a dedicated preoperative workup accounting for unique predisposing urologic conditions, specialized surgical techniques, and careful hemodynamic monitoring and maintenance.

RECENT FINDINGS

Historically, size-matched renal allografts from pediatric donors to pediatric recipients suffered from poor outcomes. Advances in surgical technique performed at high volume centers have shown that these operations can be performed safely, helping expand the donor pool for these patients. Concurrently, transplantation of increasingly small for size infants with complex medical and surgical backgrounds has become a reality.

SUMMARY

On a policy front, efforts to expand access to size-matched organs, combined with advances in medical management and immunosuppression have seen pediatric renal transplantation reach new heights. Now, these breakthroughs are heightened by the ability to transplant such organs into the smallest infants. The net result will be diminished transplant waiting times and, accordingly, improved quality of life and longevity for children suffering from renal failure.