Allograft Vesicoureteral Reflux after Kidney Transplantation

Abstract

Allograft vesicoureteral reflux (VUR) is a leading urological complication of kidney transplantation. Despite the relatively high incidence, there is a lack of consensus regarding VUR risk factors, impact on renal function, and management. Dialysis vintage and atrophic bladder have been recognized as the most relevant recipient-related determinants of post-transplant VUR, whilst possible relationships with sex, age, and ureteral implantation technique remain debated. Clinical manifestations vary from an asymptomatic condition to persistent or recurrent urinary tract infections (UTIs). Voiding cystourethrography is widely accepted as the gold standard diagnostic modality, and the reflux is generally graded following the International Reflux Study Committee Scale. Long-term transplant outcomes of recipients with asymptomatic grade I-III VUR are yet to be clarified. On the contrary, available data suggest that symptomatic grade IV-V VUR may lead to progressive allograft dysfunction and premature transplant loss. Therapeutic options include watchful waiting, prolonged antibiotic suppression, sub-mucosal endoscopic injection of dextranomer/hyaluronic acid copolymer at the site of the ureteral anastomosis, and surgery. Indication for specific treatments depends on recipient’s characteristics (age, frailty, compliance with antibiotics), renal function (serum creatinine concentration < 2.5 vs. ≥ 2.5 mg/dL), severity of UTIs, and VUR grading (grade I-III vs. IV-V). Current evidence supporting surgical referral over more conservative strategies is weak. Therefore, a tailored approach should be preferred. Properly designed studies, with adequate sample size and follow-up, are warranted to clarify those unresolved issues.

Diagnostic and therapeutic management of vesico‐ureteral reflux in pediatric kidney transplantation—Results of an online survey on behalf of the European Society for Paediatric Nephrology

“…20 Therefore, these findings represent the most common indications for screening of VUR in the native kidneys of renal transplant candidates and to the renal allograft. 2,20,21 Surprisingly, almost one third of the centers perform routine VUR screening for all renal transplant candidates independent from given clinical risk factors, which is worth questioning with regard to benefit/risk assessment and costs. 22 The steadily improving body of evidence for treatment of VUR has critically scrutinized the effectiveness of non-surgical and surgical intervention to prevent renal function deterioration following fUTI.…”

“…3 The lack of well-designed studies in the population of renal transplant patients with VUR prevents to draw firm conclusions on the best diagnostic and therapeutic strategy. 2,3 Surveys may serve as an advantageous method to collect data of a large sample in a time efficient manner to develop a better understanding of the field of interest. Furthermore, they often represent a major driving force for developing consensus statements, particularly if evidence is scarce and practice patterns seem to vary considerably.…”

“…Although data are conflicting regarding the impact of vesico-ureteral reflux (VUR) on renal transplant function, febrile urinary tract infections (fUTI) associated with VUR in the renal allograft still remain an important morbidity factor in pediatric kidney transplantation (KTx). 1,2 Pre-existing VUR in the native kidneys, bladder dysfunction, and urological technical challenges contribute to the reported high prevalence rates of VUR up to 58% in pediatric renal transplant recipients. 3 The lack of well-designed studies in the population of renal transplant patients with VUR prevents to draw firm conclusions on the best diagnostic and therapeutic strategy.…”

Clinical and Surgical Challenges in Kidney Transplantation: Toward a Personalized Approach?

“…Consolidated knowledge and evidence-based care constantly mutate to adapt new scientific advances to old and emerging clinical or surgical challenges. Necessarily, the progressive changes in our praxis contribute to addressing the issues we face every day, from the well-established [ 1 , 2 , 3 ] to the uncommon ones [ 4 ], as well as to the unprecedented crisis caused by the ongoing SARS-CoV-2 pandemic [ 5 ].…”

“…Prof. Ponticelli produced an elegant review on new-onset diabetes mellitus after renal transplantation, offering a practical and ready-to-use guide for the management of this frequent yet difficult to handle medical complication [ 1 ]. Brescacin et al diligently explored past and present knowledge on renal allograft vesicoureteral reflux, highlighting the limited evidence that is available and the need for a more rigorous approach in future studies [ 2 ]. In their contribution, Moroni and colleagues described how the fate of patients with ANCA-associated vasculitis and chronic kidney disease has changed dramatically over the last decade.…”