Renal outcome in patients with complex anorectal malformations

Abstract

Introduction: Anorectal malformations (ARMs) are one of the most frequent congenital malformations in pediatric surgery. Its estimated incidence ranges between 1 in 2000 and 1 in 5000 live newborns approximately. The aim of the work is to present the associated urinary anomalies and functional renal outcomes in patients with worse prognosis anorectal malformations treated in our department Material and methods: A retrospective review of the patients operated at our center with complex anorectal malformations was performed, including urological abnormalities and long-term renal follow-up. Collected data included the type of urinary abnormality, classified as high or low, renal function (glomerular filtration rate and blood creatinine level), the presence of chronic kidney failure (CKD), the need for surgery to correct the urinary abnormality, the need for kidney transplantation and complications and long-term results. Results: A total of 55 patients were included, 32 girls and 23 boys. Mean age at the time of corrective surgery for the anorectal malformation was 9 months (SD 2.18). The mean follow-up of the patients was 13 years (SD 7.01). Sixty-nine per cent of the patients presented some urological anomaly, being more frequent in the cloacal group. Renal structural abnormalities were found in 22 (40%) of 55 patients. They were identified in 11 (47%) cloacal patients, being the most frequent renal dysplasia (n=7; 32%), followed by position abnormalities in 3. Regarding the lower urinary tract anomalies, it was described in 32 (58%) patients. In the cloacal group, the incidence was 65%, being the most frequent vesicoureteral reflux (n = 14, 60%) as well as in the group of patients with a fistula to the prostatic urethra and in the group with exstrophies of the cloaca (n = 3, 42%). Regarding the rest of the lower urinary tract anomalies, the general incidence of anatomic bladder anomalies (bladder diverticulum, patent urachus) was 15%. As a pathology related to the upper urinary tract: primary obstructive megaureter 5%, ureterocele 1% and posterior urethral valves 1%. Conclusions: Patients with complex anorectal malformations have a significant risk for renal impairment. Adequate screening, high level of suspicion, treatment and long term follow up of any associated urinary anomaly in patients with complex anorectal malformations is essential to preserve renal function and prevent CKD. Care by a multidisciplinary team and adequate transition to adulthood is essential to optimize the medical management of patients and long-term outcomes.