1567 Management of unilateral multicystic dysplastic kidney (MCDK) in the UK: a national survey

Abstract

<h3>Background</h3> Follow-up for unilateral MCDK is recommended due to its risk of contralateral kidney abnormalities and long-term sequelae. However, there is currently no national or international consensus on management strategies for this group of children and young people. Varying practice between and within departments may have negative consequences including performance of unnecessary investigations, parental anxiety or late recognition of chronic kidney disease progression in those at risk. <h3>Objectives</h3> To review the current evidence and explore variation in management strategies amongst paediatricians looking after children and young people with unilateral MCDK. <h3>Methods</h3> A nationwide online survey was performed using a 10-item survey with multiple choice and free text between August 2020 to December 2020. The survey was open to tertiary paediatric nephrology and general paediatric consultants who care for these patients. <h3>Results</h3> A total of 60 responses were obtained, two-thirds of whom were paediatric nephrologists. 62% routinely perform a DMSA scan to confirm the diagnosis (Paediatric Nephrologists(58%); SPIN paediatricians(67%); Non-SPIN paediatricians(80%)). 8% routinely perform an MCUG to investigate for contralateral vesico-ureteric reflux (VUR) (Paediatric Nephrologists(13%); SPIN paediatricians(0%); Non-SPIN paediatricians(0%)). Thematic analysis of free-text answers supported these findings. A total of 62% of respondents stated the need for routine renal function assessment even in the absence of indication. The frequency of blood sampling ranged from once only(62%) to ‘every two years’ until transfer to adult services. Referral to assess for nephrectomy for lack of involution was stated by 7%. Thresholds quoted were: ‘still present at 3/4 years’; ‘still present at 5 years’; ‘3cm at 5 years’; and ‘6cm at 6 years’. 25% of respondents recalled nephrectomy of an MCDK in the previous five years. Quoted indications for nephrectomy of the MCDK were: hypertension(5), large size(4, 1 with symptoms), lack of involution(3), urinary tract infections (1), surgical decision (1), previous sibling died from malignancy (1). The survey also revealed divergent opinions over creation and implementation of a national guidance for management of MCDK, mainly due to concerns around overcautious management. However an evidence-based national guidance that could (1) balance between consensus and safe variation and (2) offer families both choice and reassurance, was cited as potentially beneficial. Estimated costs from birth to adulthood(18 years) in those with uncomplicated MCDK were calculated from the respondents’ free-text answers. 53 (88%) respondents’ answers were detailed enough and suitable for this analysis. Mean estimated costs were £1,962 (range: £258 - £3,854). Although the average costs were greater for general paediatricians compared to paediatric nephrologists, this was not statistically significant (£1,950 SD± £871 versus £1,485 SD± £829). <h3>Conclusions</h3> Management of children and young people with unilateral MCDK varies nationally. Review of current evidence suggests this variation extends globally. There is increasing consensus for avoiding invasive testing and taking a more pragmatic approach, but the risks of hypertension and progression to chronic kidney disease remain a concern in some, highlighting the need for a clear pathway to ensure those at high-risk of renal sequelae are recognised early and followed-up appropriately.