Outcome and cost analysis of operative versus nonoperative management of neonatal multicystic dysplastic kidneys

Reducing Unnecessary Imaging in Children With Multicystic Dysplastic Kidney or Solitary Kidney

BACKGROUND AND OBJECTIVES

Children with isolated unilateral multicystic dysplastic kidney (MCDK) or congenital solitary kidney (CSK) undergo serial renal ultrasonography with variable frequency until they are transitioned to adult care. A growing body of literature suggests the value of frequent ultrasonography in this population is limited, providing no benefit to overall outcomes. Despite emerging evidence, ultrasound remains overused, resulting in avoidable health care expenditures and unnecessary use of resources. With our initiative, we aimed to improve quality of care by reducing avoidable ultrasounds in these children.

METHODS

This was a single-center, prospective, interrupted time series of children <18 years with ultrasound-confirmed isolated unilateral MCDK or CSK in the outpatient nephrology clinic to evaluate the effect of a decision-making algorithm on the proportion of children receiving an avoidable ultrasound. An algorithm depicting a consensus, evidence-based protocol for managing pediatric MCDK or CSK was refined through content expert feedback and usability testing to standardize frequency of ultrasonography. Ultrasounds were deemed necessary after birth, at 6 months, and at 2, 5, 10, and 15 years. Differences pre- and postintervention were determined by using a U chart and t and F tests for significance.

RESULTS

The algorithm resulted in a 47% reduction (P < .001) in the proportion of avoidable ultrasounds ordered in children with MCDK and CSK. This reduction was sustainable over a 6-month period and would result in at least $46 000 annual savings.

CONCLUSIONS

Introduction of a clinical decision-making algorithm was associated with a reduction in avoidable ultrasound testing. Improving adherence across providers may allow for an even more pronounced reduction.

Association of Wilms tumor in multicystic dysplastic kidneys: case report and review of the literature

Multicystic dysplastic kidney is a rare urinary anomaly characterized by multiple non-communicating cysts resulting in a non-functional kidney. In addition to association with hypertension and contralateral renal anomalies, children with multicystic dysplastic kidney have an increased risk of Wilms tumor. Cohort studies and systematic reviews are hampered in estimating the true risk of this association due to the rarity and infrequent reporting of the condition. We present a case of a 2-year-old male child with an antenatal diagnosis of multicystic dysplastic kidney undergoing surveillance ultrasonography who presented with a symptomatic Wilms tumor.

Level of evidence: Not applicable for this multicentre audit.

"Watch and Wait" Strategy for Multicystic Dysplastic Kidney (MCDK): Status Survey of Perceptions, Attitudes, and Treatment Selection in Chinese Pediatric Urologists and Pediatric Surgeons

To investigate the perceptions, attitudes, and treatment selection of Chinese pediatric urologists and pediatric surgeons regarding a "watch and wait" strategy for multicystic dysplastic kidney (MCDK). We used a cross-sectional survey in this study. We sent the questionnaire to pediatric urologists and pediatric surgeons to capture their views via the "Questionnaire Star" online survey platform between November and December 2019. The questionnaire contained the basic information and surgical experiences of the respondent, respondents' awareness regarding the counseling of prenatally-diagnosed MCDK and the treatment of MCDK, and respondents' knowledge regarding the imaging modalities, frequency, and duration of follow-up. Of the 200 questionnaires we sent, we received 151 responses. Of those 151 complete responses, most respondents were women (n = 104, 68.9%), pediatric urologists (n = 78, 51.6%), and practicing with at least 5 years of surgical experience (n = 112, 74.2%); 11.9% reported >20 years' experience. Eighty-two surgeons (54.3%) provided positive counseling for prenatally-diagnosed MCDK. Ninety-nine surgeons (65.6%) advocated conservative management for MCDK, and only 14.8% of respondents suggested limiting the use of radiographic evaluation for MCDK. Surgeons working in academic teaching facilities and those from East China were more likely to select a "watch and wait" strategy. Chinese pediatric urologists and pediatric surgeons have inadequate knowledge of the "watch and wait" strategy for MCDK. An expert consensus on the strategy of "watch and wait" for MCDK in China is urgently needed to promote the application of this non-surgical treatment mode in clinical practice. A larger sample size is required to fully identify the current opinion of Chinese pediatric urologists and pediatric surgeons regarding the management of MCDK.

Large Multicystic Dysplastic Kidney Mimicking a Large Cystic Renal Neoplasm

Multicystic Dysplastic Kidney (MCDK) is one of the most common renal conditions seen in paediatric population. The natural history typically involves involution and many of the patients with unilateral disease may actually never become symptomatic. The initial evaluation is usually done on Ultrasonography (USG) while cross-sectional imaging and nuclear scan are reserved for diagnostic dilemmas. Management is conservative and surgery is done for selected patients with symptomatic cysts or suspicion of neoplasm. We present an interesting case of MCDK in a nine-month-old female hypertensive child presenting with a large abdominal mass increasing in size with imaging features similar to cystic neoplasm and managed with nephrectomy.

Proximal ureteral atresia, a rare congenital anomaly-incidental finding: a case report

Ureteral atresia is a rare disease usually associated with a non-functioning dysplastic kidney. The condition may be unilateral or bilateral; focal, short or long and may involve any part of the ureter. Association with other urinary anomalies is rare. We report the case of a 10-month-old boy with prenatal diagnosis of multicystic right kidney. This suspicion was confirmed after birth by ultrasound and static scintigraphy; a right vesicoureteral reflux (VUR) was recorded at cystography. The boy presented a regular renal function but was hospitalized twice for suspected pyelonephritis between the 8th and the 10th month of life and were recorded occasional mild changes in blood pressure. Antibiotic prophylaxis was administered until surgery. When he was 10-month underwent retroperitoneoscopy to perform a nephroureterectomy finding a complete atresia of the upper third of the ureter with the blind end at the level of the uretero-pelvic-junction. The programmed surgery was performed. By a revision of literature, only few cases of imperforate distal ureter have been described. This condition is associated with a kidney dysplasia. The atresia of the ureter with no signs of infection in the dysplastic kidney may be unknown up to adulthood or throughout one's life. Prognosis usually depends on the severity of the obstruction.

Update on Multicystic Dysplastic Kidney

Multicystic dysplastic kidney (MCDK) is the most common cause of cystic disease in children. It is characterized by multiple non-communicating cysts of varying sizes with no identifiable normal renal parenchyma. The incidence ranges from 1 in 1000 to 4300 live births, and it is one of the most commonly detected anomalies on prenatal ultrasound. MCDK has been shown to follow a benign course with relatively few sequelae and therefore should be managed conservatively. Currently, the key clinical questions revolve around the detection of anomalies in the contralateral kidney and follow-up imaging. The recent literature suggests that very limited radiographic evaluation of the MCDK is needed. The use of voiding cystourethrogram or nuclear medicine renal scans should be directed by any abnormalities on renal ultrasound or the development of urinary tract infections.

Unilateral multicystic dysplastic kidney: long term outcomes

AIMS

To report the long term follow up of children with antenatally detected unilateral multicystic dysplastic kidney (MCDK) with documentation of complications, involution rate with time, and renal function at 10 years.

METHODS

Data were retrieved from a prospective regional registry of patients with MCDK between 1985 and 2004. Children were followed using a common protocol of investigation with follow up ultrasound scans (USS) at 2 (165 patients), 5 (117 patients), and 10 years (43 patients).

RESULTS

Serial USS showed that 33% of the MCDK kidneys had completely involuted at 2 years of age, 47% at 5 years, and 59% at 10 years. No patients developed hypertension, significant proteinuria, or malignancy, but two developed pelviureteric junction obstruction in the contralateral kidney. Twenty seven of 143 children (19%) had vesicoureteric reflux (VUR) (96% mild to moderate VUR) into the contralateral kidney with no difference in the incidence of urinary tract infections or renal scarring between those with or without VUR. The mean estimated glomerular filtration rate (GFR) was 86.4 ml/min/1.73 m2 (range 48-125) in 31 of 43 patients followed to 10 years.

CONCLUSIONS

Conservative management of unilateral MCDK is justified with clinical review and infrequent USS but longer term follow up continues in the 41% still with renal remnants at 10 years and those with impaired GFR. It is suggested that the initial micturating cystogram is deferred unless abnormal USS features are present in the contralateral kidney or ureter.

Outcome and cost analysis of laparoscopic or open surgery versus conservative management for multicystic dysplastic kidney

PURPOSE

To determine whether laparoscopic nephrectomy (LN), open nephrectomy (ON), or observation (OB) is most efficient for managing multicystic dysplastic kidney (MCDK).

METHODS

We performed a retrospective review of the management of our 12-year clinical experience of 32 MCDK patients to analyze the estimated total cost (ETC) of various treatment options and compare them with respect to survival, development of hypertension, and postoperative cosmetic appearance, to determine the most efficient treatment option.

RESULTS

There were 12 cases in the LN group, 6 in the ON group, and 14 in the OB group. ETC was lower for ON than for LN. But the length of preoperative observation and length of follow-up after spontaneous regression greatly affected ETC. If MCDK cases were observed > 5 years with standard investigations performed regularly, ETC was higher for the OB group than for the LN group. In 6/14 (42.9%) of OB cases, MCDK resolved within 5 years, and this subgroup had the lowest ETC up to the time of this review. Six cases initially in the OB group were managed surgically (4 by LN and 2 by ON) in accordance with parental requests, and ETC in these cases was highest. All cases are well after a mean follow-up of 5.7 years, without any impairment of renal function, or hypertension.

CONCLUSION

The decision to operate after lengthy observation increases costs. Overall, the most efficient surgical technique for managing MCDK was LN because of greater patient satisfaction with postoperative cosmesis. We recommend MCDK be treated by LN after a short period of observation.

Risk of hypertension with multicystic kidney disease: a systematic review

BACKGROUND

Children with multicystic kidney disease (MCKD) are increasingly managed conservatively, and are followed up throughout childhood because of the risk of hypertension highlighted in some reports. With this risk still poorly defined, the strategy and the duration of follow up do not seem to be based on evidence.

METHODS

Systematic review of the literature for all published cohort studies (prospective and retrospective) of children diagnosed to have unilateral MCKD and managed conservatively. Exclusion criteria were bilateral MCKD, and nephrectomy (not for hypertension) during the follow up period. For children with MCKD, the probability of developing hypertension during the follow up period was estimated.

RESULTS

From 29 reviewed studies, six cases of hypertension developed in 1115 eligible children. The mean probability of a child with unilateral MCKD developing hypertension was therefore 5.4 per 1000 (95% CI estimated at 1.9 to 11.7 per 1000).

CONCLUSION

Although the risk of hypertension in MCKD is low, the results of this study do not allow firm recommendations on the frequency and duration of blood pressure measurement follow up for these children. Large prospective cohort studies with a very long duration of follow up are needed.

Predictive factors of ultrasonographic involution of prenatally detected multicystic dysplastic kidney

OBJECTIVE

To evaluate possible predictive factors of involution on ultrasonography (US) or disappearance of a prenatally detected multicystic dysplastic kidney (MCDK).

PATIENTS AND METHODS

Forty-five children with unilateral MCDK detected by prenatal ultrasonography between 1989 and 2002 were analysed. All patients except one had (99m)Tc isotopic scintigraphy to confirm the absence of renal function in the MCDK. All children were managed conservatively with follow-up visits every 6 months, with US 6-monthly during the first 2 years of life and yearly thereafter. Survival was analysed using the Kaplan-Meier method to evaluate the involution of the MCDK, with differences between subgroups assessed using the two-sided log-rank test. Cox's regression model was applied for the multivariate analysis.

RESULTS

The mean (range) follow-up was 50 (12-167) months; in all, 279 ultrasonograms were taken, the mean (range) number per patient being 6 (3-10). US showed partial involution of the MCDK in 30 (67%) cases and complete involution in nine (20%). The absolute MCDK length remained almost unchanged in six children (13%). Univariate analysis showed that four variables were possibly associated with complete involution of the MCDK (gender, impalpable kidney, renal length at admission using two thresholds, 62 and 78 mm). After adjusting by Cox's model only a renal length at diagnosis of <62 mm remained associated with complete involution (relative risk 8, 95% confidence interval 0.98-68; P = 0.05).

CONCLUSION

These results suggest that only a renal length of <62 mm on initial US was predictive of complete involution of the MCDK during the follow-up.

Risk of Wilms' tumour with multicystic kidney disease: a systematic review

BACKGROUND

Children with multicystic kidney disease (MCKD) are increasingly managed conservatively and are followed up throughout childhood because they are perceived to be at increased risk of developing Wilms' tumour. With this risk still poorly defined and somewhat controversial, the strategy and the duration of follow up do not seem to be based on evidence.

METHODS

Systematic review of the literature for all published cohort studies (prospective and retrospective) of children diagnosed to have unilateral MCKD and managed conservatively.

EXCLUSION CRITERIA

bilateral MCKD, nephrectomy (not for malignancy) during the follow up period. We estimated for children with MCKD the probability of developing Wilms' tumour during the follow up period, with 95% CI using the Poisson distribution.

RESULTS

From 26 reviewed studies, no cases of Wilms' tumour developed in 1041 eligible children. The mean probability of a child with unilateral MCKD to develop Wilms' was therefore nil, with a 97.5% upper CI estimated at 0.0035 (or 3.5 per 1000 children).

CONCLUSION

The development of a national or a European registry for children with MCKD would increase the precision of their risk estimate to develop Wilms' tumour. In the meantime, there is no evidence to support any of the different modalities for following up these children by ultrasound, if indeed such a strategy is necessary.

Unilateral multicystic dysplastic kidney: experience in children

OBJECTIVES

To report a retrospective study of unilateral multicystic dysplastic kidneys (MCDK) in children, assessing the contralateral kidneys and urinary tract, the functional consequences, and the urological and nephrological management and outcome, as unilateral MCDK is the most common cause of renal cystic disease in children, and malformations of the contralateral urinary tract and kidney (pelvi-ureteric obstruction, megaureter, reflux, renal dysplasia) have been reported.

PATIENTS AND METHODS

The study included 97 patients (60 boys, 37 girls) with MCDK seen between 1985 and 1998; 82 were diagnosed in utero by ultrasonography (US). After birth, the diagnosis was verified by US, renal scanning (in 93) or intravenous urography (in four), and 89 (92%) had voiding cysto-urethrography (VCUG). Of the 97 children, 87 (90% had a mean (range) follow-up of 44.3 (15-115) months.

RESULTS

The MCDK was removed in 17 children; the follow-up of 75 children (five lost to follow-up) showed total involution of the MCDK in 25%, shrinkage in 60% and a stable size in 15%. None had any sign of malignancy. The contralateral kidney showed anomalies in 19 of 97 children (20%); 12 had a dilated renal pelvis (two with megaureter), six had a high echogenicity of the contralateral kidney (one had reflux, and two also pelvic dilatation). In only four of the 89 children was reflux found by VCUG; 16 of the 19 anomalies were detected by US. Five children needed surgery on the contralateral urinary tract (three a pyeloplasty, and one each a pyeloplasty plus ureteroneocystostomy, and an antireflux procedure). Of the contralateral kidneys 43% showed compensatory hypertrophy. There was mild renal insufficiency in three children; renal function seemed to be slightly impaired in many. Five infants had hypertension (four with spontaneous resolution) caused by renal scarring after pyelonephritis or inborn dysplasia of the contralateral kidney. There were symptomatic urinary tract infections in seven children.

CONCLUSION

US can be used safely to diagnose unilateral MCDKs and malformations of the contralateral urinary tract and kidney. In cases where US of the dysplastic kidney remains uncertain renal scintigraphy is necessary to detect the lack of renal function. The low rate of reflux makes routine VCUG unnecessary if the contralateral upper urinary tract and kidney appear to be normal on US. Nephrectomy of the dysplastic kidney in typical cases is also unnecessary. A long-term nephro-urological follow-up of children with MCDK is recommended.