Trends in surgical management of multicystic dysplastic kidney at USA children's hospitals.

INTRODUCTION AND OBJECTIVE: Multicystic dysplastic kidney (MCDK) is a congenital renal cystic disease often incidentally diagnosed in children. Historically, children with MCDK underwent early nephrectomy because of concerns for the development of hypertension or malignancy. Over the last decade, management recommendations have not supported routine early surgical removal of MCDK. The study authors sought to determine the current trends in the use of nephrectomy for MCDK in US children's hospitals because national practice patterns have not been investigated.

METHODS: A population-based retrospective cohort study using the Pediatric Health Information System (PHIS) was conducted. The study population was comprised of patients aged 0-18 years with a diagnosis of MCDK (International Classification of Diseases-9th revision, code 753.19) admitted to the inpatient department of the study hospital between January 2006 and September 2015. Patients with additional renal anomalies including polycystic kidney, medullary cystic kidney, and medullary sponge kidney were excluded, as were patients treated in a hospital that did not contribute data to the PHIS continuously throughout the study period. Trends in the annual proportion of nephrectomies performed were analyzed among admissions in the study population, along with patient clinical and demographic information.

RESULTS: A total of 3792 MCDK admissions, in 34 hospitals, were included in the study. Overall, 569 nephrectomies were performed during the study period. The proportion of nephrectomy decreased annually by 9.2% on average, from 22.1% in 2006 to 7.3% in the first 3 quarters of 2015. No significant trends were observed in the annual number of overall MCDK admissions or patient age at procedure among patients who had a nephrectomy. Among nephrectomies, 84.2% were open and 15.8% were minimally invasive procedures (laparoscopic non-robotic, 10% and robotic, 5.8%). The proportion of minimally invasive nephrectomies increased annually by 13.7%, from 8% in 2006 to 29% in 2015.

DISCUSSION: Trends in the use of nephrectomy for MCDK at a national level have not been previously reported. This study is limited by the use of inpatient discharge data, which did not allow estimating the true rate of nephrectomy in patients born with MCDK.

CONCLUSIONS: During the study period, there has been a decrease in the use of nephrectomy for MCDK in pediatric hospitals, along with a concurrent increase in utilization of minimally invasive techniques to perform nephrectomies. These results suggest that in general, urologists at freestanding children's hospitals are heeding recommendations for observation and against routine early surgical removal of these kidneys; although trends in the use of nephrectomy varied between hospitals, there is room for continued improvement in following these recommendations.