Multicystic Renal Dysplasia Treatment & Management

Updated: Jun 22, 2020
  • Author: Agnieszka Swiatecka-Urban, MD, FASN, FAAP; Chief Editor: Craig B Langman, MD  more...
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Medical Care

The role of nephrectomy in multicystic dysplasia of the kidney (MCDK) is controversial. Prior to the availability of modern ultrasonography, nephrectomy was often required to establish the diagnosis. A survey by Bloom et al revealed that 65% of pediatric urologists recommended nephrectomy for multicystic dysplastic kidney, compared with more recent data that indicated only 40% of pediatric urologists recommend nephrectomy. [20, 22]  A retrospective cohort study showed that the use of nephrectomy for MCDK in pediatric hospitals decreased from 22.1% in 2006 to 7.3% in 2015. [1]

The traditional reasons to consider nephrectomy are to treat or prevent abdominal or flank pain, urinary tract infection (UTI), hypertension, or renal malignancy. If a child has significant abdominal or flank discomfort that can be attributed to the pressure effects of multicystic dysplastic kidney, the abnormal kidney should be removed.

If a child has evidence of a UTI, consider a nephrectomy only if the UTI involves the kidney with multicystic dysplastic kidney. The presence of ipsilateral vesicoureteral reflux (VUR), pyelonephritis in the contralateral kidney, or recurrent episodes of cystitis are not sufficient justification for a nephrectomy in multicystic dysplastic kidney. If a child has hypertension, consider a nephrectomy only if the hypertension can be shown to be due to the kidney with multicystic dysplastic kidney.

The presence of a renal malignancy is an indication for nephrectomy.

The main controversy regarding the indications for nephrectomy is whether this procedure prevents a renal malignancy. Determining whether a renal malignancy is present in individuals with multicystic dysplastic kidney might be difficult. The retroperitoneal location precludes physical detection of a small mass, and the lack of urine output from the affected kidney does not allow for cytologic examination. The evidence for the presence of a renal malignancy must be based on diagnostic imaging changes, and because cysts can be noted in renal malignancy, differentiation might be difficult.

Beckwith's mathematical analysis does not recommend nephrectomy based on the calculated incidence of Wilms tumor, but the calculation does not consider the incidence of renal carcinoma. [30] Whether the risk of renal malignancy in those individuals who show involution is different compared with the risk in those who do not is unknown.

Some concern surrounds the possibility that the intervening stroma of a kidney affected by multicystic dysplastic kidney might not undergo complete involution and might provide a focus for malignant degeneration. However, no increased risk of Wilms tumor has been demonstrated in patients with multicystic dysplastic kidney. A systemic review of 26 studies demonstrated no cases of Wilms tumor in 1041 children with unilateral multicystic dysplastic kidney. [31] These data are consistent with an earlier study by the American Multicystic Kidney Disease Registry that found no cases of renal neoplasia in 260 patients with multicystic dysplastic kidney. [32]

Some authors recommend nephrectomy only in patients who do not show involution over a defined period, such as the first 5 years of life. Because the peak incidence of Wilms tumor is in infancy and declines after age 5 years, this approach seems less scientific.

Individuals with multicystic dysplastic kidney should undergo renal ultrasonography every 6-12 months until age 5 years or until involution is noted.

Individuals with multicystic dysplastic kidney and contralateral VUR should receive antibiotic prophylaxis during infancy and early childhood, the ages during which the risk of scarring due to pyelonephritis is highest. Miller et al reported on 75 children with multicystic dysplastic kidney. [40] Nineteen (26%) had VUR. After a median follow-up of 4.4 years, spontaneous resolution occurred in 89% of patients with grades I and II VUR, compared with only 50% of patients with grades III and IV VUR (P = .14). The presence of VUR did not affect the sonographically measured growth of the contralateral kidney.

Lifetime follow-up is required whether or not involution has occurred or a nephrectomy has been performed because long-term studies of patients with a single kidney report hypertension in 27-47% of patients, proteinuria in 23-47% of patients, and renal insufficiency in 3-13% of patients. Sporadic clinical reports have documented the development of proteinuria and focal glomerulosclerosis in patients with a single kidney.

Follow-up should include routine and ambulatory measurement of the blood pressure, urinalysis, and periodic assessments of kidney filter function. The presence of associated urinary and nonurinary abnormalities might require specific follow-up.

Consultations with a pediatric nephrologist and a pediatric urologist should be obtained.


Surgical Care

Nephrectomy for multicystic dysplastic kidney is conventionally done as an inpatient procedure. However, outpatient nephrectomy has been reported through a 2.5-cm incision without the need for overnight hospitalization. The role of laparoscopic nephrectomy for multicystic dysplastic kidney is controversial. [41]  However, Brown et al found that the proportion of minimally invasive nephrectomies for multicystic dysplastic kidney has steadily grown each year, from 8% in 2006 to 29% in 2015. [1]


Diet and Activity

A diet that minimizes salt and protein intake to the recommended daily requirements for age is recommended for all patients with only one functional kidney.

Lifestyle recommendations for patients with only one functional kidney include maintaining a thin body habitus and daily aerobic exercise.