Outcomes of a Cohort of Prenatally Diagnosed and Early Enrolled Patients with Congenital Solitary Functioning Kidney.

PURPOSE

We evaluated the clinical course of patients prenatally diagnosed and enrolled early with congenital solitary functioning kidney, and identified the risk factors for renal injury.

MATERIALS AND METHODS

We retrospectively evaluated 322 patients with congenital solitary functioning kidney according to the inclusion criteria of 1) prenatal diagnosis of solitary kidney; 2) first evaluation at 1 to 3 months of life with confirmation of congenital solitary functioning kidney, and evaluation of possible associated congenital anomalies of the kidney and urinary tract by abdominal ultrasound, renal scintigraphy and cystography; and 3) absence of any condition potentially affecting renal function in the neonatal period as well as absence of renal injury at enrollment (1 to 3 months of life) confirmed by a normal estimated glomerular filtration rate, lack of proteinuria and hypertension. Followup of 306 patients was evaluated.

RESULTS

Median followup was 7.2 years (range 1 to 23) and 1 or more signs of renal injury were found in 12 of 306 patients (3.9%). Considering the entire population the cumulative proportion of patients free from renal injury at 17 years old was 93.7%, vs 81.3% and 95.9% for subjects with and those without congenital anomalies of the kidney and urinary tract of congenital solitary functioning kidney (p <0.001), respectively. Of congenital anomalies of the kidney and urinary tract, congenital solitary functioning kidney resulted in significant risk factors for renal injury (HR 8.75, 95% CI 2.77-27.65).

CONCLUSIONS

In an evaluation of a large cohort of patients enrolled early with congenital solitary functioning kidney with a prenatal diagnosis, excluding those with neonatal onset of renal damage, the prevalence of renal damage was 3.9%. Among congenital anomalies of the kidney and urinary tract, congenital solitary functioning kidney represented the major risk factor.