Upside-down kidney placement: An alternative in pediatric renal transplantation

Review - Renal transplantation for congenital urological diseases

INTRODUCTION

Congenital Anomalies of the Kidney and Urinary Tract (CAKUT) are structural disorders originating prenatally and present at birth. Affecting 4.2 to 1000 per 10,000 births globally, CAKUT includes conditions like posterior urethral valves, cloacal anomalies, and reflux nephropathy. These anomalies can lead to chronic kidney disease (CKD) or end-stage kidney disease (ESKD) in children, necessitating renal replacement therapy or transplantation.

OBJECTIVES

This article aims to provide an updated perspective on pediatric kidney transplantation for children with CAKUT, emphasizing pre-transplant evaluation and management to optimize long-term outcomes.

METHODS

A comprehensive urologic evaluation is essential for children with ESKD being considered for kidney transplantation. Key pre-transplant investigations include kidney/bladder ultrasound (US), voiding cystourethrogram (VCUG), uroflowmetry, and urodynamics (UDS)/video-urodynamics (VUDS). Non-operative interventions such as pharmacotherapy and clean intermittent catheterization (CIC) are also considered. Surgical interventions, like augmentation cystoplasty or continent catheterizable channels, are evaluated based on individual patient needs.

RESULTS

Kidney/bladder US and VCUG provide essential anatomical information. UDS offers comprehensive functional data, identifying hostile bladders needing pre-transplant optimization. Non-surgical measures like anticholinergics and CIC improve bladder function, while surgical options enhance compliance and capacity. Concurrent interventions during transplantation are feasible but require careful consideration of risks and benefits.

DISCUSSION

Children with CAKUT undergoing kidney transplantation exhibit comparable or better graft survival rates than those without CAKUT. However, those with lower urinary tract obstructions (LUTO) may have poorer long-term outcomes. UDS is crucial for evaluating bladder function pre-transplant, guiding the need for interventions. Long-term monitoring for urinary tract infections (UTIs) and bladder dysfunction is essential.

CONCLUSION

Optimal outcomes in pediatric kidney transplantation for CAKUT patients require thorough pre-transplant evaluation and management, particularly for those with LUTO. Multidisciplinary approaches ensure careful monitoring and timely interventions, improving graft survival and quality of life for these patients.

Assessing the role of upside-down (inverted) renal allografts in pediatric kidney transplantation: a propensity-score matched analysis

OBJECTIVE

To evaluate the implications of inverted (upside-down) kidney configuration in pediatric renal transplantation employing a comparative analysis with at least 1-year follow-up.

METHODS

Patients who underwent kidney transplantation at our institution between January 2011 and June 2021 were reviewed. Patients who had an inverted renal transplant were propensity-score matched (PSM) in 1:2 ratio with those who had traditional orientation transplant. The outcomes assessed included delayed graft function (DGF), urine leak, lymphocele, rejection, allograft calculus, ureteric stricture, and nadir creatinine.

RESULTS

A total of 24 patients with inverted orientation were identified. Following PSM, 41 patients were matched, with exclusions due to incompatible propensity scores. Baseline characteristics were appropriately matched, and no significant differences were noted between the two groups. There were no differences in: delayed graft function (0/24 vs. 3/41, p = 0.290), urine leak (3/24 vs. 2/41, p = 0.350), lymphocele (2/24 vs. 4/41, p = 1.000), rejection (3/24 vs. 5/41, p = 1.000), graft calculus (2/24 vs. 0/41, p = 0.133), and ureteric stricture (0/24 vs. 2/41, p = 0.527). The two cases of renal calculus seen in the inverted transplant group occurred on post-operative day 13 and 1584, both were managed without complications. There was no difference in nadir creatinine (median 34umol/L IQR23-57 vs. 35 umol/L IQR 20-50, p = 0.624) or time to nadir creatinine (8 days IQR 6-12 vs. 8 days IQR 7-28, p = 0.315).

CONCLUSION

Inverting a renal allograft does not appear to significantly contribute to increased risk of post-operative adverse outcomes. When aiming to achieve the best anatomical placement to secure a comfortable vascular anastomosis, inverting the allograft should be considered.

Ultrashort anisoperistaltic end-to-side ureteroureterostomy in renal transplantation

The improvement of surgical techniques in kidney transplantation aims to reduce the incidence of post-transplant complications, contributing to the reduction of hospital stay, related costs, morbidity and mortality, in addition to improving the quality of life of patients. The choice of the best technique is influenced by several factors and the most common technique for urinary tract reconstruction in transplants is performed with implantation of the ureter of the graft in the caudal position, with the anastomosis performed in the bladder. However, the kidney pole can be inverted and the graft ureter anastomosis can be performed directly on the recipient's ureter, facilitating venous and ureteral anastomoses and reducing urological complications.

Anastomose uretero-ureteral término-lateral anisoperistáltica ultracurta no transplante renal

RESUMO O aprimoramento das técnicas cirúrgicas no transplante renal tem o objetivo de reduzir a incidência de complicações pós-transplante, contribuindo com a redução do tempo de internamento hospitalar, os custos relacionados, a morbidade e a mortalidade, além de melhorar a qualidade de vida dos pacientes. A escolha da melhor técnica é influenciada por diversos fatores e a técnica mais comum de reconstrução do trato urinário nos transplantes é a realizada com implante do ureter do enxerto na posição caudal, com a anastomose feita na bexiga. No entanto, pode-se inverter o polo do rim, posicionando o polo inferior cranialmente e realizar a anastomose do ureter do enxerto diretamente no ureter do receptor, facilitando a anastomose ureteral e diminuindo as complicações urológicas.