Vesicoureteral reflux into small kidney: diagnostic and therapeutic paradigm

The causes of renal size reduction in children by 20 percent or more from the age norm include abnormalities of urodynamics of upper (UUT) and lower (LUT) urinary tract, combined with vesicoureteral reflux (VUR) and infra-vesical obstruction (IVO). Several issues regarding diagnosis and choice of treatment in children with small kidneys depending on the severity of functional abnormalities and the presence of comorbidities still remain controversial. 101 children with small kidneys accounting for 3.1% of the entire number of urologic patients admitted to the clinic were followed for 25 years. 78 (77.2%) patients were simultaneously diagnosed as having ipsilateral vesicoureteral reflux (VUR) (2.4% of the total number of hospitalized children). Moreover, contralateral VUR was found in 63% of patients. In 5.1% of children, anomalies of the contralateral kidney were identified: lumbar dystopia (3.8%), duplication of the renal pelvis and ureter (1.3%). Combination with IVO was found in 25.5% of cases. 75 (96%) children with vesicoureteral reflux into the small kidney were operated on. Reconstructive plastic surgery was made in 72 (92%) those patients. Indications for conservative management were identified in patients with intermittent VUR of I-II degree into small kidney or both kidneys. In case of detection of IVO, initial surgery was carried out to eliminate the obstruction. Conservative therapy was aimed at getting rid of the inflammatory process, restoring the function of kidney and bladder, and at the treatment of concomitant vulvovaginitis. In the absence of positive results of 6-8 months of conservative treatment or in case of the negative clinical course, the operation was considered justified. Indications for antireflux surgery were the failure of conservative therapy for intermittent VUR into small kidney or both kidneys, the presence of VUR of III-V degree into one or both kidneys. In cases of bilateral VUR antireflux surgery was performed simultaneously. Indications for nephrureterectomy were complete loss of kidney function, a combination of several unfavorable prognostic signs, namely a significant reduction of the renal size (renal area less than 30% ofthe age norm); severely impaired kidney function (reduced contribution to the total accumulation of up to 10% or less); the presence of ultrasonic and radiographic evidence of secondary shrinkage; pronounced abnormalities of UUT urodynamics; failure of treatment of frequent and severe pyelonephritis exacerbations. It is shown that VUR is often combined with a decreased renal size, creating difficulties in selecting treatment tactics and determining the prognosis of the disease further. The proper strategy is to prevent disease progression and reduce the need for organ-removal surgery in children.

small kidney, vesicoureteral reflux, children