[Renal position and fusion anomalies]

To analyse kidney position and fusion anomalies, as well as associated urinary tract and extra-renal pathologies in a cohort from a tertiary hospital.

The medical records of 84 children with renal ectopia (RE) and horseshoe kidney (HK) in our hospital from 1999 to 2010 were retrospectively reviewed.

Prenatal diagnosis was made in 53 patients (63.09%). Of the 84 patients surveyed 35 had unilateral simple renal ectopia (SRE), 1 had bilateral SRE; 2 had crossed renal ectopia (CRE) without fusion, 17 had CRE with fusion, and 29 had HK. Average age was 30 days at diagnosis (IQR: 0-12 months). In the individuals with renal ectopia (RE), the incidence of associated urinary tract pathologies was 20.23% in the ectopic kidney (EK) (17 out of 84) and 17.85% in the contralateral kidney (CK) (15 out of 84). The most frequent urological pathology was vesico-ureteral reflux (VUR), 4 individuals had multicystic dysplastic kidneys (MCDK). In 4 patients renal agenesis was detected in the CK. In patients with HK, the incidence of associated urinary tract pathologies was 16.66% (14 out of 84), and the most frequent associated urological anomaly was also VUR. Of the 84 patients 21(25.45%) had extra-renal pathology. Anomalies of the skeletal system were detected in 9/84(10.71%), genital anomalies 5/84 (5.95%), cardiac anomalies 3/84 (3.57%), and digestive disease 1/84 (1.19%). Facial malformations were noted in 3/84 patients (3.57%), endocrine disorders 2/84 (2.38%), and 8/84 children (9.52%) suffered from polymalformative syndrome. During follow-up, the most frequent complication of the urinary tract was infection, observed in 10/84 patients (11.91%).

When renal ectopia or horseshoe kidney is detected, associated renal and urinary anomalies and structural extra-renal malformations should be evaluated. Patients need long-term follow-up and should be examined regularly for potential complications.