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.

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.

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 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.

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.

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.

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.

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.

A girl with Peters plus syndrome associated with myelomeningocele and chronic renal failure.

A girl was born with sclerocornea of the right eye, corneal staphyloma of the left eye and lumbar myelomeningocele. The myelomeningocele was repaired soon after birth. The corneal staphyloma was perforated during infancy. She received keratoplasty and achieved light perception. Her right kidney revealed multicystic dysplasia and was non-functioning at birth. She had neurogenic bladder, and her renal function deteriorated gradually. Peters plus syndrome was diagnosed based on anterior ocular segment anomalies, short stature, developmental delay and characteristic face. Anterior ocular segment anomalies are rare findings, but seem to be occasionally associated with spina bifida and renal anomalies. Myelomeningocele and chronic renal failure in patients with Peters plus syndrome have not been reported to our knowledge.

Non-surgical management of multicystic dysplastic kidney.

OBJECTIVES: To better define the outcome and association of multicystic dysplastic kidney (MCDK) with hypertension, vesico-ureteric reflux (VUR), infection and cancer, as there is no consensus on the management of patients born with MCDK. The risk of cancer has dictated the surgical management of the disease in the past. METHODS: The Medline database was searched for articles published between 1965 and 2006 and written in the English language, and containing the keywords 'multicystic dysplastic kidney'. RESULTS: The inclusion criteria were met by 105 reports that were subsequently analysed. Of MCDK, 60% regress or involute within 3 years. About 25% of patients will have VUR into the contralateral kidney, of which 90% is grade

[Multicystic dysplastic kidney disease: update and information for parents at the time of prenatal diagnosis]. / Dysplasie rénale multikystique: mise au point et information pour les parents lors du diagnostic anténatal.

Multicystic kidney disease (MCKD) is the most common form of Congenital Abnormality of Kidney and Urinary Tract (CAKUT). This anomaly of renal development is characterized by unilateral enlarged cystic formations and fibrous dysplastic parenchyma. The long-term prognosis is usually good; however because of reduced nephron mass, an early prevention of cardiovascular risk and nephrotoxicity is recommended. A lifelong follow-up of blood pressure, serum creatinine and microalbuminuria seems logical as well as in other patients with a single kidney. MCKD is usually diagnosed during pregnancy so that parents often question about long-term prognosis and follow-up. Therefore, we propose an information sheet for parents.

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.

[Spontaneous renal bleeding in a dialysis patient with acquired cystic disease of the kidney: case report and review of the literature]. / Emorragia renale spontanea in paziente in emodialisi per nefropatia cistica acquisita: descrizione di un caso e revisione della letteratura.

The aim of this paper is to describe a rare clinical case of spontaneous haemorrhagic rupture of a multicystic kidney in a patient on haemodialysis for acquired cystic disease. We also discuss current issues about the management of this rare condition, with a short review of the literature.

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.

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.

[Conservative management of multicystic dysplastic kidney: clinical course and ultrasound outcome]. / Tratamento conservador do rim displásico multicístico: curso clínico e ultra-sonográfico.

OBJECTIVE: The aim of this study was to describe the clinical course and ultrasound outcome of prenatally detected multicystic dysplastic kidney. METHODS: Fifty-three children with unilateral multicystic dysplastic kidney detected by prenatal ultrasound between 1989 and 2004 were included in the analysis. All children were submitted to conservative management with follow-up visits every six months. Follow-up ultrasound examinations were performed at six-month intervals during the first two years of life and yearly thereafter. The following clinical parameters were evaluated: blood pressure, urinary tract infection, renal function, and growth. The following ultrasound parameters were evaluated: involution of multicystic dysplastic kidney and contralateral renal growth. RESULTS: The mean follow-up time was 68 months. Two children presented hypertension during follow-up and five had urinary tract infection (only one with recurrent episodes). There was no malignant degeneration of multicystic dysplastic kidney. A total of 334 ultrasound scans were analyzed. US scan demonstrated involution of the multicystic dysplastic kidney in 48 (90%) cases, including complete involution in nine (17%). The involution rate was faster in the first 30 months of life. There was progressive compensatory renal hypertrophy of the contralateral renal unit; the rate of growth was greater in the first 24 months of life. CONCLUSION: The results of prolonged follow-up of children with conservatively managed multicystic dysplastic kidney suggest that clinical approach is safe, the incidence of complications is small, and that there is a clear tendency for multicystic dysplastic kidney to decrease in size. Our data also suggest that the involution rate of multicystic dysplastic kidney as well as the growth of the contralateral kidney is greater in the first 24 months of life.

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.

Follow-up of unilateral multicystic kidney dysplasia after prenatal diagnosis.

OBJECTIVES: Since the introduction of antenatal diagnostic screening, multicystic kidney dysplasia (MCKD) has been diagnosed in 1 of 4300 live births. We analyze our own experience and demonstrate a management regime based on these results and existing studies. METHODS: Retrospective data analysis was carried out in 110 patients, prenatally diagnosed with MCDK. A total of 93 patients with confirmed diagnosis of unilateral MCDK were born alive and followed up in our institutions. RESULTS: A total of 110 unilateral cystic kidneys were prenatally diagnosed; 93 were confirmed postnatally. These children were retrospectively allocated to two treatment groups: 51 were operated upon; 42 were treated conservatively. A micturition cystourethrogram was performed 88 times, yielding 20 pathological findings. Vesicoureteral reflux was identified 11 times (12.5%). Eleven children (12%) had associated non-urological abnormalities. Cardiac and musculoskeletal malformations predominated. After 1995, nephrectomy was performed only when clinically indicated. Thirty-seven children were treated conservatively for between 4 months and 6 years (mean 33 months); 28 dysplastic kidneys exhibited size reduction. Complete involution was noted in 16 of 28 children between 7 and 29 months (mean 16.2 months). CONCLUSION: This study provides evidence that neonatal nephrectomy of unilateral MCDK is rarely required. It also shows that the discussed malformation is not an isolated developmental abnormality. In a high proportion, associated urogenital abnormalities were present and therapeutically relevant, and determined the overall prognosis.