Vesicoureteral Reflux in the Transplanted Kidney – Risk and Prognostic Factors: A Single-center Experience

Aims: To evaluate the impact of vesicoureteral reflux in transplanted kidneys, identify its possible risk factors and define its clinical consequences in a public transplant center.

Study Design: Retrospective study.

Place and duration of the study: Division of Urology, Department of Surgery; Radiology Department and Medical Clinical Department, Campinas State University, between September 2019 and October 2020.

Methodology: We analyzed data from patients who underwent kidney transplantation and progressed to kidney failure requiring dialysis due to graft failure. Preoperative evaluation for the new transplant included voiding cystourethrography and ultrasonography of the urinary tract. Twenty-six patients were selected between 2008 and 2018, in whom the preoperative voiding cystourethrography identified vesicoureteral reflux to the previously transplanted kidney. The patients were divided into 2 groups, low-grade and high-grade reflux. The Fisher and Mann-Whitney tests were used for statistical analysis, with a significance level set at 5%.

Results: Twenty-six patients were included, with a mean age of 47.8 years, of whom 73.1% were male. The graft had a similar survival, regardless of the degree of vesicoureteral reflux that the transplant presented. The longer the duration of ischemia, the greater the chance of developing high-grade reflux. A correlation was also found between weight gain and high grades of reflux. No relationship was found between the surgical transplant technique and the prevalence of vesicoureteral reflux, or the presence of bacteriuria, the etiology of renal failure, the duration of pre-transplantation dialysis and the age of the patient.

Conclusions: The presence of vesicoureteral reflux has no negative impact on renal graft function. There are indications that higher patient weight and prolonged organ ischemia can lead to the occurrence of higher-grade reflux.