Nephrocalcinosis and Renal Dysfunction in Pediatric Intestinal Failure

Background: Outcomes of pediatric intestinal failure (PIF) have improved recently, with other comorbidities, such as increased echogenicity/nephrocalcinosis on ultrasound (US) in long‐term survivors now evident. We evaluated the significance of nephrocalcinosis over time in PIF and its impact on renal function. Methods: Retrospective analysis on a cohort of PIF patients was performed. Presence of nephrocalcinosis and/or increased renal echogenicity (identified on US), estimated glomerular filtration rate (eGFR; ml · min −1  · 1.73 m − 2), renal tubular function, PN volume (ml · kg −1  · day −1 ) and PN exposure time (hours/day) were reviewed annually over a follow‐up period of 2 years. Outcomes in the nephrocalcinosis versus normal US groups were compared. Results: Forty patients (28 boys, median age 2.7 years) were followed for 2 years. Fifteen (38%) had either increased echogenicity or nephrocalcinosis (group 1) at initial US. US were normal in the remaining 25 (62%) on initial assessment (group 2). eGFR did not differ between group 1 and group 2 at baseline (118 vs 133, P  = 0.51) and year 2 (130 vs 131, P  = 1.00). The percentage of patients with abnormal markers of tubular function was similar in both groups at year 2 (high urine calcium: creatinine 33 versus 30, P  = 0.83; high urine calcium: citrate 39 versus 42, P  = 0.87; low urine citrate: creatinine 15 versus 17, P  = 1.00; high urine oxalate: creatinine 39 versus 25, P  = 0.77). Conclusions: A large proportion of PIF patients with a history of parenteral nutrition (PN) exposure have nephrocalcinosis and/or increased echogenicity on US. Over a 2‐year follow‐up period, however, these abnormalities had no impact on eGFR or renal tubular function.