Unilateral Multicystic Dysplastic Kidney Management: A National Survey.

Risks of contralateral kidney abnormalities and chronic kidney disease necessitate follow-up for unilateral multicystic dysplastic kidneys (MCDK). A nationwide survey of senior UK pediatricians was conducted. Of the 60 responses obtained, 62% routinely perform a dimercaptosuccinic acid scan to confirm diagnosis. Eight percent routinely perform a cystogram to investigate contralateral vesicoureteric reflux. Sixty-two percent would routinely measure renal function (frequency ranging from once only to "every 2 years"). Twenty-five percent recalled MCDK nephrectomy being performed within the previous 5 years. Respondents voiced concerns that national guidance may result in an overcautious approach but could balance consensus and safe variation, and offer families choice and reassurance. The mean estimated cost of follow-up from birth to 18 years ranged from £258 to £3854. Results demonstrate significant variation in management, highlighting the need for a clear pathway to decrease unwanted variability and to ensure those at high risk of renal sequelae are recognized early, without undue investigatory burden.

Neonatal multicystic dysplastic kidney with mass effect: A systematic review.

INTRODUCTION: Multicystic Dysplastic Kidney (MCDK) is a common cause of palpable abdominal mass in a neonate, yet reports are few of resultant life-threatening extrinsic compression. This systematic review is the first to review all known neonatal MCDK cases complicated by external compression due to mass effect. Our aim is to foster communication about these unusual cases to inform management of future comparable cases. METHODS: This systematic review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Medical Subject Headings (MeSH) were used to search PubMed through June 8, 2021 as follows: ((((Polycystic Kidney Diseases/complications [MeSH Terms]) OR (Multicystic Dysplastic Kidney/complications [MeSH Terms])) AND (Humans [MeSH Terms]) AND (Infant, Newborn [MeSH Terms]) AND (Case Reports [Publication Type]) AND (("multicystic dysplastic kidney") OR ("multicystic kidney")))) OR ((unusual respiratory distress in newborn [Title]) AND (kidney)) OR (large MCDK). Resulting papers were screened and included if they reported neonatal MCDK complicated by external compression by mass effect. Excluded papers lacked an MCDK diagnosis, a neonatal patient, or clear indication of mass effect. Salient data was extracted from each case for comparison. RESULTS: Of 51 papers screened, seven met inclusion criteria, presenting eight neonatal MCDK patients exhibiting varied combinations of symptoms secondary to external compression, including respiratory distress, gastrointestinal obstruction, and contralateral ureteral obstruction. All eight cases, ultimately managed with neonatal nephrectomy, had positive outcomes. Unreported and undiagnosed cases are not included in this review, making it susceptible to publication bias. CONCLUSIONS: Large neonatal MCDK is typically managed conservatively, however it can be complicated by external compression due to mass effect. In this scenario, nephrectomy is a reasonable and definitive treatment. Less invasive management options may exist, e.g., aspiration with sclerotherapy. Communication about exceptional cases like these should be encouraged even when outcomes are poor.

Evidence-based treatment of multicystic dysplastic kidney: a systematic review.

OBJECTIVES: There is a lack of a standardised protocol for the investigation and non-operative management of paediatric multicystic dysplastic kidney (MCDK). Institutional protocols for non-operative management remain essentially ad hoc. The primary outcome of this systematic review is to establish the incidence of hypertension associated with an MCDK. The secondary outcome is to determine the malignancy risk associated with an MCDK. The tertiary outcome is to assess the rate of MCDK involution. Subsequent to these, an evidence-based algorithm for follow-up is described. METHODOLOGY: A systematic review of all relevant studies published between 1968 and April 2017 was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies were identified by specific inclusion and exclusion criteria, all of which included data relevant to the primary, secondary and tertiary outcomes. Hypertension was defined as systolic blood pressure greater than the 95th centile for gender, age and height centile. Subset analysis was performed for hypertension associated with an MCDK. RESULTS: The primary outcome measure revealed a 3.2% (27/838) risk of developing hypertension associated with an MCDK. The secondary outcome measure noted a 0.07% malignancy risk (2/2820). The tertiary outcome measure established that 53.3% (1502/2820) had evidence of involution of the dysplastic kidney. A total of 44 cohort studies (2820 patients) were analysed. CONCLUSION: Given the low risk of hypertension and malignancy, which is similar to the general population, the current conservative non-operative pathway is an appropriate management strategy. An algorithm to help support clinicians with ongoing management is proposed.

Clinical features of children with multicystic dysplastic kidney.

BACKGROUND: To evaluate the clinical features of patients with multicystic dysplastic kidney (MCDK). METHODS: The medical files of children diagnosed with MCDK between January 2008 and November 2015 were retrospectively reviewed. The demographic, clinical, laboratory and radiological data were evaluated. RESULTS: Of 128 children with MCDK enrolled in the study, 82 (64.1%) were male, and 46 (35.9%) were female (P < 0.05). MCDK were located on left and right sides in 66 (51.6%) and 62 children (48.4%), respectively (P > 0.05). Antenatal diagnosis was present in 64 patients (50%). The mean age at diagnosis was 2.8 ± 2.7 years (range, 0-8 years), and follow-up duration was 4.5 years. Fifteen patients (20.8%) had vesicoureteral reflux. Of these, four underwent endoscopic surgical correction. Other associated urological anomalies were ureteropelvic junction obstruction (n = 6), hypospadias (n = 1), and kidney stones (n = 1). On technetium-99 m dimercaptosuccinic acid scintigraphy, which was performed in all patients, no significant association between grade of reflux and presence of scarring was seen. Hypertension was diagnosed only in one child (0.8%) who required antihypertensive treatment. The prevalence of unilateral undescended testicle in children aged <1 year in the 82 male patients was 4.9%. Seventy-six patients (59.4%) developed compensatory hypertrophy in the contralateral kidney during a 1 year follow-up period. Of the total, only seven children (5.5%) had undergone nephrectomy. CONCLUSIONS: MCDK follows a benign course with relatively few sequelae, and therefore these patients should be closely followed up and conservatively managed.

The molecular biology of pelvi-ureteric junction obstruction.

Over recent years routine ultrasound scanning has identified increasing numbers of neonates as having hydronephrosis and pelvi-ureteric junction obstruction (PUJO). This patient group presents a diagnostic and management challenge for paediatric nephrologists and urologists. In this review we consider the known molecular mechanisms underpinning PUJO and review the potential of utilising this information to develop novel therapeutics and diagnostic biomarkers to improve the care of children with this disorder.

Unilateral multicystic renal dysplasia: Prenatal diagnosis on ultrasound.

Multicystic renal dysplasia (MCRD) is the most common cause of abnormally enlarged kidney, diagnosed on antenatal ultrasound examination. It is an abnormality of the embryonic development in which the renal parenchyma is substituted by nonfunctioning renal tissue made up of cysts which do not communicate with each other. Vesicoureteric reflux (VUR), pelviureteric junction obstruction, vesicoureteric junction obstruction, and ureterocele are the most commonly seen abnormalities in contralateral kidney. Here, we report a case of prenatal diagnosis of unilateral MCRD with VUR in contralateral kidney. In conclusion, we want to emphasize optimal use of ultrasound imaging to detect such abnormalities as early as possible to guide the proper management.

Is it Always Necessary to Treat an Asymptomatic Hydronephrosis Due to Ureteropelvic Junction Obstruction?

The postnatal treatment of asymptomatic unilateral hydronephrosis due to ureteropelvic junction obstruction remains controversial, and the timing of and indications for surgical intervention are continuously debated. There is no consensus on the best follow-up during expectant management. The various modalities and parameters have been discussed along with their pros and cons and an attempt has been made to clear up the controversies.

Conservative Management of Segmental Multicystic Dysplastic Kidney in Children.

OBJECTIVE: To assess the clinical characteristics and natural course of segmental multicystic dysplastic kidney (MCDK). METHODS: We retrospectively analyzed the medical records of 40 patients (43 renal units) diagnosed as having segmental MCDK between January 2002 and June 2014. Segmental MCDK was classified as typical when it was localized to the upper pole of a duplex collecting system, and otherwise as atypical. We investigated involution, associated anomalies requiring surgery, and complications of segmental MCDK. RESULTS: Of 43 renal units, 23 were typical and 20 were atypical. During 71.5 (interquartile range: 37.5-84.1) months of median follow-up period, complete and partial involution were observed in 48% and 26% of the typical group and 30% and 35% of the atypical group, respectively. In the typical group, involution was complete significantly earlier (P = .048) and ipsilateral anomalies were more frequently observed (P = .002). The initiation point of involution and contralateral anomalies were not different in the two groups. Hypertension developed in 1 case with contralateral MCDK and 1 case with contralateral renal agenesis. CONCLUSION: Segmental MCDK is not a rare disease entity, and conservative treatment appears to be sufficient with thorough follow-up, including regular monitoring of blood pressure and renal function, and with ultrasonography.

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.

The natural history of the multicystic dysplastic kidney--is limited follow-up warranted?

OBJECTIVE: Imaging of patients with multicystic dysplastic kidney (MCDK) has increased over the past three decades. This increased use of imaging has provided additional insights into the natural history of MCDK. The present study looked at this data for predictors of involution and associated anomalies. METHODS AND MATERIALS: Institutional review board approval was obtained for this retrospective study. The University of Michigan Departments of Urology and Radiology records were searched to identify unilateral MCDK patients during 1980-2012. Available clinical, radiological and surgical records were reviewed, and pertinent data were recorded. The log-rank test and a Cox proportional regression analysis were performed to identify predictors of MCDK involution. Probability of involution over time was assessed using Kaplan-Meier methodology. RESULTS: 301 unilateral MCDKs were identified; 195 (64.8%) were detected antenatally. Of the MCDKs found, 136 (45.2%) were in girls; 160 (53.2%) were right-sided. Mean size at baseline was 5.0 ± 0.2 cm (Mean ± SE). Associated abnormalities included: contralateral ureteropelvic junction obstruction (n = 10; 3.3%); contralateral ureterovesical junction obstruction/primary megaureter (n = 6; 2.0%); ipsilateral VUR (n = 21; 7.0%); contralateral VUR (n = 63; 20.1%); and renal fusion anomaly (n = 4; 1.3%). The cumulative probability of involution was: 9.8% at one year, 38.5% at five years, and 53.5% at ten years of age. Baseline MCDK size was the only significant predictor of involution at bivariate (p < 0.0001) and multivariate (p < 0.0001; HR 0.58 [95% CI: 0.49, 0.69]) analyses. No MCDK developed malignancy during the follow-up period. CONCLUSION: As many MCDKs eventually involute and the risk of associated malignancy appears to be very low, there is no absolute indication for nephrectomy. Based on the data and other recent studies, it is believed that pediatric MCDK patients with no other urologic abnormalities can safely tolerate more limited urological and radiological follow-up.

Multicystic dysplastic kidney: Impact of imaging modality selection on the initial management and prognosis.

OBJECTIVE: To evaluate the impact of imaging modalities on the evaluation and prognosis of children with multicystic dysplastic kidney (MCDK) disease. PATIENTS AND METHODS: A retrospective analysis of all children with MCDK diagnosed from 2004 until 2012 was performed. The study included 63 patients for whom all postnatal imaging modalities were available: renal bladder ultrasound (RBUS), dimercaptosuccinic acid scan (DMSA) and voiding cystourethrogram (VCUG). Cases with major congenital abnormalities or incomplete data were excluded. Abnormalities in the contralateral kidney and the fate of MCDK were also addressed. RESULTS: At diagnosis, the average age was four-and-a-half months. The majority of cases were detected antenatally (87%). Postnatal RBUS and DMSA scans established the diagnosis of MCDK in 92% and 98% of patients, respectively. DMSA showed photopenic areas in the contralateral kidneys in 10% of patients; all of them had hydronephrosis and were confirmed to have vesicoureteral reflux (VUR). Contralateral VUR was detected in 16 patients; 63% of them had hydronephrosis. After a mean follow-up of three-and-a-half years, involution occurred in 62% of patients and the involution rate was inversely proportional to the initial size. CONCLUSIONS: The classical appearance of MCDK on RBUS was sufficient to establish the diagnosis in most patients. DMSA scan was more accurate in confirming the diagnosis and evaluating the contralateral kidney. Selective screening for VUR in patients with contralateral hydronephrotic kidney should be considered.

Pelvi-Ureteric Junction Obstruction at Red Cross Children's Hospital, Cape Town: a Six Year Review.

INTRODUCTION: Congenital abnormalities of the kidney and urinary tract (CAKUT) are significant causes of end stage renal disease (ESRD) in children. Some of these abnormalities, when identified early, are amenable to treatment. In developing countries, very few published reports exist concerning the pattern and scope of CAKUT in childhood. METHODS: This is a retrospective review of all patients with confirmed Pelvi-Ureteric Junction (PUJ) obstruction who were diagnosed antenatally with hydronephrosis between Jan 2002 and Dec 2007 at the Red Cross Children's Hospital, Cape Town. The clinical course of every patient was reviewed for a twelve-month period after confirmation of the diagnosis. RESULTS: One hundred patients, 80 males and 20 females, were included in the analysis. Thirty-two children (32%) had bilateral PUJ obstruction while the rest had unilateral involvement of the left (40%) or right (28%) kidney; overall, 132 kidneys were affected. mild, moderate and severe pelvic dilatation was present in 44.7%, 36.4% and 18.9% of affected kidneys respectively. One child required nephrostomy during the first day of life while eighteen children were treated by pyeloplasty. Urinary tract infection was confirmed in eleven children. At 12 months of follow-up, 83 affected kidneys (62.9%) demonstrated spontaneous resolution of PUJ obstruction while 14 (18.5%) kidneys improved after surgical intervention. Spontaneous resolution occurred more often in kidneys with mild to moderate pelvic dilatation. CONCLUSION: Spontaneous resolution of the PUJ obstruction occurred in a substantial proportion of children by twelve months of follow-up and complete resolution is more likely in mild to moderate dilatation.

The antenatally detected pelvi-ureteric junction stenosis: advances in renography and strategy of management.

This review includes an analysis of new developments in the field of renography, the predictive factors suggesting the need for pyeloplasty in cases of pelvi-utereric stenosis detected antenatally and integration of the pelvi-ureteric junction stenosis within the framework of antenatally detected hydronephrosis.

Short- and middle-term continuous use of cinacalcet in children on peritoneal dialysis.

BACKGROUND: Secondary hyperparathyroidism (HPT) constitute a high-turnover bone disease, manifested by elevated parathyroid hormone. Cinacalcet, belonging to calcimimetics, has been shown to be promising in the control of secondary HPT with limited data in children. OBJECTIVE: To evaluate the safety and efficacy of cinacalcet in children on peritoneal dialysis (PD) with secondary HPT. METHODS: Four patients on PD with severe secondary HPT, uncontrolled with phosphorus dietary restrictions combined with phosphate binders and analog of 1,25 vitamin D3 received cinacalcet. RESULTS: After cinacalcet treatment, in two of four patients, we found a serum intact parathyroid hormone (iPTH) level reduction by more than 70% at 4 weeks and more than 60% at 3 or more than 6 months. Nevertheless, in the other two patients, a transient reduction of iPTH was found in 4 weeks and an increase in 3 or more months, who were finally treated with surgical parathyroidectomy. During cinacalcet treatment, no adverse events were noted. CONCLUSION: Cinacalcet may be a safe and effective treatment for PD patients with secondary HPT, although surgical parathyroidectomy cannot be avoided in certain cases.

Involution of multicystic dysplastic kidney: is it predictable?

OBJECTIVE: To evaluate the clinical course of multicystic dysplastic kidney (MCDK) and to reveal any criteria indicating spontaneous involution. MATERIAL METHODS: Hospital records of patients with MCDK followed in two different institutions in 1994-2009 were reviewed and data were analyzed regarding involution. RESULTS: Records of 96 patients were reviewed, of whom 46 were diagnosed antenatally and followed for more than 1 year. Fourteen patients had undergone nephrectomy. There was one case of hypertension which resided with nephrectomy. There was no malignancy. Involution rate was 53.6% (15/28) for right-sided and only 16.7% (3/18) for left-sided kidneys. The initial size of the kidney was found to be another predictive parameter for involution. Initial sizes of 43 (15 involuted and 28 non-involuted) kidneys were documented. Mean standard deviation score for involuting and non-involuting kidneys was -3.19 and 3.12, respectively. The chance of involution for a large kidney on the left was zero; however, involution risk for a small right-sided kidney was 67%. CONCLUSION: Reviewing a 15-year period of our patient records conveyed data supporting current literature mainly encouraging non-operative management of MCDK. Further studies are required; however, our two objective indicators, the initial size and side of dysplastic kidney, may contribute to the management.

Conservative management of pelvi-ureteric junction obstruction (PUJO): is it appropriate and if so what duration of follow-up is needed?

OBJECTIVE: • To establish whether it is safe to manage minimally symptomatic and asymptomatic pelvi-ureteric junction obstruction (PUJO) conservatively. PATIENTS AND METHODS: • In all, 50 patients with PUJO diagnosed with dynamic renography, and monitored with at least two renograms. RESULTS: • In all, 19 patients were totally asymptomatic, while 31 patients had minimal symptoms at time of diagnosis. • The mean follow-up was 53 months. • During the course of follow-up 10 of the 50 patients deteriorated. • All patients who had asymptomatic renographic deterioration, deteriorated within 2 years of diagnosis. • Eight of the 10 patients that deteriorated needed pyeloplasty and two nephrectomy. CONCLUSIONS: • Conservative management of patients with minimally symptomatic and asymptomatic PUJO is safe. • Discharging patients could be considered at 2 years from diagnosis, if they remain renographically stable and asymptomatic or minimally symptomatic.