Lower urinary tract dysfunction is still underestimated in pediatric kidney transplants despite underlying cause of renal failure

C.M.H.H.T Bootsma-Robroeks, L.L. de Wall, W. Feitz, E.A.M. Cornelissen

Thursday 14 march 2019

13:25 - 13:27h at Tropentheater

Categories: Klinisch/Basaal, Parallelsessie

Parallel session: Parallelsessie XV – Basaal / Klinisch 2

Background: Pediatric kidney graft survival has been significantly improved over the years with a current mean survival of 15-20 years. Several factors, like lower urinary tract dysfunction, are associated with a negative graft survival. Its prevalence however is largely unknown in the pediatric population. This study evaluates the prevalence of lower urinary tract dysfunction in our transplanted children. Results were compared between children with a nephrologic versus urologic origin of chronic kidney failure.

Methods: A single centre analysis of all pediatric kidney transplants performed between 2005 and 2018. Characteristics of donor and recipient, origin of kidney failure, voiding-, drinking-, and bowel habits were documented and evaluated using frequency voiding charts, standardized medical forms and uroflowmetry. Lower urinary tract dysfunction was defined as an expected bladder capacity for age (EBC) >130%, residual urinary volumes >10% of EBC, recurrent urinary tract infections, abnormal daytime voiding pattern (less than 4 times or over 11 times), intermittent uroflowmetry and concomitant occurrence of constipation according to the Rome III classification.

Results: A total of 65 pediatric transplants are currently still under close pediatric follow-up and were available for evaluation (male:female = 39:26). Five patients were not yet potty trained. Overall lower urinary tract dysfunction was present in 32 out of 65 patients (49%) and significantly more present in the urologic group (N=12, 75%) versus the nephrologic group (N=20, 46%), p=0.044. Mean maximum bladder capacity was not significantly different between the groups, respectively 403ml in the nephrogenic group and 450ml in the urologic group, p=0.58. In both groups mean daytime voiding frequency was 7 times (2-13) with an abnormal pattern in four patients. A significant residual volume of urine and intermittent flowmetry were not different between the groups, respectively 38% (N=6/16) in the urologic group versus 18% (N=9/49) in the nephrogenic group, p=0.198. Overall constipation was rarely seen (N=3). Recurrent urinary tract infections were present in 13 nephrogenic patients (30%) versus 6 urologic patients (40%), p=0.643.

Conclusions: Lower urinary tract dysfunction is as common in the nephrologic patients as in the urologic patients. This emphasizes a thorough evaluation and treatment if indicated in all kidney transplanted patients in order to optimize transplant survival.