Simple multicystic dysplastic kidney disease: end points for subspecialty follow-up

Abstract

Simple multicystic dysplastic kidney (MCDK) disease, defined as unilateral MCDK without other genitourinary tract involvement, portends an excellent prognosis. Nevertheless, its long-term management remains undefined. This study aims to provide subspecialty discharge recommendations for these patients. We identified eighty patients with simple MCDK disease by renal ultrasound between 1996 and 2006. Their charts were reviewed for growth of the contralateral kidney, involution of the MCDK, and incidence of complications, specifically hypertension, chronic renal insufficiency (CRI), urinary tract infection (UTI), and malignancy. Mean follow-up was 5 years. At approximately 1 year, 59% of unaffected kidneys were hypertrophied (>or=95th percentile for age/height) and 100% were >50th percentile. With continued follow-up, 80.3% of unaffected kidneys were hypertrophied. Likewise, at 1 year, 71.2% of MCDKs assessed were either involuting or had disappeared; on further follow-up, this increased to 89.6%. No patient had hypertension, CRI, or malignancy. Four patients (5%) developed nonrecurrent UTIs, none leading to renal scarring or growth impairment. These data suggest that subspecialty follow-up may be discontinued once contralateral hypertrophy and ipsilateral involution occur, assuming that the patient has not experienced hypertension, CRI, or UTI. These criteria are often met by 1 year of age, which would preclude repeated visits, uncomfortable investigations, and unnecessary costs.

Long-term risk of chronic kidney disease in unilateral multicystic dysplastic kidney

“…However, children with involuted MCDK are rarely followed into adulthood to assess GFR, proteinuria, or hypertension [40]. Some authors have suggested that follow-up is not necessary if there is involution of MCDK, contralateral renal hypertrophy, and normal renal function by the first year of life [41]. Our study indicates that children with contralateral abnormalities are at risk for developing decreased kidney function.…”

Unilateral multicystic dysplastic kidney: does initial size matter?

“…Weinstein et al followed 80 MCDK patients for a mean of 5 years and asserted that the favourable criteria of contralateral hypertrophy, ipsilateral involution and freedom from hypertension, chronic renal insufficiency or urinary tract infection are often met by 1 year of age. Discharge from subspecialty follow-up at this time would preclude repeated visits, uncomfortable investigations and unnecessary costs [23]. Our proposed schedule of follow-up should minimise such legitimate concerns, but a longer follow-up will be required in the majority of cases as only 35 % of patients in our series had involuted completely by 2 years, 47 % by 5 years and 62 % by 10 years.…”

Sonographic long-term study: paediatric growth charts for single kidneys

“…In contrast, Godbole et al 29 state that the routine estimation of GFR is not required in the follow-up of children undergoing unilateral nephrectomy for benign disease if the contralateral kidney appears normal on imaging. Weinstein et al 30 even suggest that specific nephrological follow-up in children with MCDK could be ceased as soon as the length of the contralateral kidney has reached or grown beyond the 95% CI.…”