Non-surgical management of multicystic dysplastic kidney

Ultrasound and magnetic resonance imaging features of fetal urogenital anomalies: A pictorial essay

This pictorial essay focuses on ultrasound (US) and magnetic resonance imaging (MRI) features of fetal urogenital anomalies. Fetal urogenital malformations account for 30%-50% of all anomalies discovered during pregnancy or at birth. They are usually detected by fetal ultrasound exams. However, when ultrasound data on their characteristics is insufficient, MRI is the best option for detecting other associated anomalies. The prognosis highly depends on their type and whether they are associated with other fetal abnormalities.

The Outcome of Multicystic Dysplastic Kidney Disease Patients at King Abdulaziz Medical City in Riyadh

Background Multicystic dysplastic kidney (MCDK) is a type of kidney dysplasia consisting of many irregular, various-sized cysts divided by dysplastic renal tissue, which negatively impacts kidney function. MCDK is one of the most common renal congenital disorders seen in antenatal ultrasounds. The typical prognosis of MCDK is complete or partial involution that starts antenatally and continues postnatally. The aim of the study was to shed light on the overall outcome of patients with MCDK. Methods We retrospectively collected data on MCDK patients from 2016 until 2022 at King Abdulaziz Medical City, Ministry of National Guard Health Affairs in Saudi Arabia, Riyadh. The data included the recording of epidemiological data, radiological and laboratory reports, and the presence of urological or non-urologically associated anomalies. Results A total of 57 patients with MCDK were reviewed. Seven of them were excluded due to the diagnosis of bilateral MCDK, which was incompatible with life. Of the remaining 50 patients, the right kidney was affected in 52% of them. Most patients were diagnosed antenatally (98%). The mean duration of follow-up for the study was 48 months. Vesicoureteral reflux (VUR) was detected in 22% of the total sample. Overall, 90% of the patients underwent kidney involution. A small percentage had genitourinary anomalies (20%), while a larger percentage (48%) had extrarenal abnormalities. Conclusion Multicystic dysplastic kidney disease is relatively common in children. The prognosis is affected by the presence of genitourinary and non-genitourinary anomalies. Patients have an overall good prognosis with conservative management. Antenatal screening, diagnosis, and long-term nephrological follow-up are essential for the optimal management of patients.

Associated Anomalies and Complications of Multicystic Dysplastic Kidney

BACKGROUND

To assess multicystic dysplastic kidneys (MCDK) in children, their complications and associated congenital genitourinary anomalies.

METHODS

Children with unilateral MCDK, evaluated between 2012 and 2020, were analyzed. In this retrospective study, data were obtained from electronic and paper health care records.

RESULTS

There were 80 children included. Follow-up time was 8.0 +/- 5.2 years (mean +/- standard deviation). None of them had hypertension. In total, 43.8% of the children had associated congenital genitourinary anomalies, most commonly cryptorchidism and vesicoureteral reflux (VUR), and 6.3% of these children had chromosomopathy. All of them had normal kidney function except one child with dysplasia of the contralateral kidney. Urinalysis was normal in 90% of children. Extrarenal malformations occurred in 22.5% of them. We observed spontaneous involution of MCDK in 38.8% of children in the observed period. Nephrectomy was performed in 12.5% of children, at an average age of 2.0 years.

CONCLUSIONS

Children with a unilateral MCDK have a very good prognosis if the contralateral kidney is normal. Associated congenital genitourinary anomalies are common. Cryptorchidism was found to be the most common associated anomaly among boys, which is unique for this study. Most of these children do not suffer from hypertension, kidney dysfunction or other complications.

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.

Retrospective evaluation of the pediatric multicystic dysplastic kidney patients: experience of two centers from southeastern Turkey

Background/aim

The objective of this study is to determine the clinical features of unilateral multicystic dysplastic kidney (MCDK) patients.

Materials and methods

The demographic, clinical, laboratory, and radiologic features of MCDK patients at Diyarbakır Children’s Hospital and Diyarbakır Gazi Yaşargil Training and Research Hospital between January 2008-June 2019 were retrospectively evaluated.

Results

A total of 111 [59 (53.2%) male and 52(46.8%) female] patients with MCDK were followed for a mean period of 41.89 ± 32.03 months. MCDK was located on the left and right sides in 46 (41.4%) and 65 (58.6%) of the children, respectively (p > 0.05). A total of 87 (78.4%) patients had antenatal diagnosis. The mean age at diagnosis was 13.7 ± 34.2 months. Of the 49 voiding cystourethrogram (VCUG)-performed patients, vesicoureteral reflux was detected in 11 patients (22.4%). Other associated urological anomalies in the patients were detected in 12 (10.8%) patients. On Tc-99m dimercaptosuccinic acid (DMSA) scintigraphy which was performed in all patients showed scarring in four children. Eight patients had history of UTI (7.2%). Renal failure, hypertension, and proteinuria were diagnosed in three children (2.7%). Sixty-nine (62%) patients developed compensatory hypertrophy.

Conclusion

All cases should be followed up closely and VCUG should be reserved for patients with recurrent UTI and other urological problems indicated by ultrasonography and abnormal DMSA scan results.

Renal cystic diseases during the perinatal and neonatal period

Renal cystic diseases are a clinically and genetically diverse group of renal diseases that can manifest in utero, infancy, or throughout childhood and adulthood. These diseases may be unilateral or bilateral with a single cyst or multiple cysts, or with increased echogenicity of the renal cortex without macroscopic cysts. Certain cystic renal diseases are life-threatening, with many developing chronic kidney and hepatic disease if not recognized early enough. Therefore, due to the prevalence and life-altering complications of this specific group of diseases in vulnerable populations, it is crucial for clinicians and healthcare providers to have an overall understanding of cystic diseases and how to pre-emptively detect and manage these conditions. In this review, we discuss in detail the epidemiology, genetics and pathophysiology, diagnosis, presentation, and management of numerous genetic and sporadic renal cystic diseases, such as polycystic kidney disease, multicystic dysplastic kidney, and calyceal diverticula, with an emphasis on prenatal care and pregnancy counseling.

[Kidney Cysts and Cystic Nephropathies in Children - A Consensus Guideline by 10 German Medical Societies]

This consensus-based guideline was developed by all relevant German pediatric medical societies. Ultrasound is the standard imaging modality for pre- and postnatal kidney cysts and should also exclude extrarenal manifestations in the abdomen and internal genital organs. MRI has selected indications. Suspicion of a cystic kidney disease should prompt consultation of a pediatric nephrologist. Prenatal management must be tailored to very different degrees of disease severity. After renal oligohydramnios, we recommend delivery in a perinatal center. Neonates should not be denied renal replacement therapy solely because of their age. Children with unilateral multicystic dysplastic kidney do not require routine further imaging or nephrectomy, but long-term nephrology follow-up (as do children with uni- or bilateral kidney hypo-/dysplasia with cysts). ARPKD (autosomal recessive polycystic kidney disease), nephronophthisis, Bardet-Biedl syndrome and HNF1B mutations cause relevant extrarenal disease and genetic testing is advisable. Children with tuberous sclerosis complex, tumor predisposition (e. g. von Hippel Lindau syndrome) or high risk of acquired kidney cysts should have regular ultrasounds. Even asymptomatic children of parents with ADPKD (autosomal dominant PKD) should be monitored for hypertension and proteinuria. Presymptomatic diagnostic ultrasound or genetic examination for ADPKD in minors should only be done after thorough counselling. Simple cysts are very rare in children and ADPKD in a parent should be excluded. Complex renal cysts require further investigation.

"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.

Trends in surgical management of multicystic dysplastic kidney at USA children's hospitals

INTRODUCTION AND OBJECTIVE

Multicystic dysplastic kidney (MCDK) is a congenital renal cystic disease often incidentally diagnosed in children. Historically, children with MCDK underwent early nephrectomy because of concerns for the development of hypertension or malignancy. Over the last decade, management recommendations have not supported routine early surgical removal of MCDK. The study authors sought to determine the current trends in the use of nephrectomy for MCDK in US children's hospitals because national practice patterns have not been investigated.

METHODS

A population-based retrospective cohort study using the Pediatric Health Information System (PHIS) was conducted. The study population was comprised of patients aged 0-18 years with a diagnosis of MCDK (International Classification of Diseases-9th revision, code 753.19) admitted to the inpatient department of the study hospital between January 2006 and September 2015. Patients with additional renal anomalies including polycystic kidney, medullary cystic kidney, and medullary sponge kidney were excluded, as were patients treated in a hospital that did not contribute data to the PHIS continuously throughout the study period. Trends in the annual proportion of nephrectomies performed were analyzed among admissions in the study population, along with patient clinical and demographic information.

RESULTS

A total of 3792 MCDK admissions, in 34 hospitals, were included in the study. Overall, 569 nephrectomies were performed during the study period. The proportion of nephrectomy decreased annually by 9.2% on average, from 22.1% in 2006 to 7.3% in the first 3 quarters of 2015. No significant trends were observed in the annual number of overall MCDK admissions or patient age at procedure among patients who had a nephrectomy. Among nephrectomies, 84.2% were open and 15.8% were minimally invasive procedures (laparoscopic non-robotic, 10% and robotic, 5.8%). The proportion of minimally invasive nephrectomies increased annually by 13.7%, from 8% in 2006 to 29% in 2015.

DISCUSSION

Trends in the use of nephrectomy for MCDK at a national level have not been previously reported. This study is limited by the use of inpatient discharge data, which did not allow estimating the true rate of nephrectomy in patients born with MCDK.

CONCLUSIONS

During the study period, there has been a decrease in the use of nephrectomy for MCDK in pediatric hospitals, along with a concurrent increase in utilization of minimally invasive techniques to perform nephrectomies. These results suggest that in general, urologists at freestanding children's hospitals are heeding recommendations for observation and against routine early surgical removal of these kidneys; although trends in the use of nephrectomy varied between hospitals, there is room for continued improvement in following these recommendations.

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.

Applicability of Laparoscopic Nephrectomy in the Treatment of Multicystic Dysplastic Kidney: Sorting Out Surgical Indication

Introduction We evaluated the applicability of laparoscopic nephrectomy in the treatment of multicystic dysplastic kidney (MCDK) in children, including procedures performed by resident physicians or trainees in surgical urology. Methods We retrospectively evaluated the medical records of 20 children with MCDK who underwent laparoscopic nephrectomy over a six-year period. Data collected included gender, laterality of the affected kidney, age at the time of surgery, the largest diameter of the multicystic kidney and associated urological diagnoses, surgical, and postoperative data. All surgical procedures were performed transperitoneally. Results The mean age at the time of surgery was 46 months with a slight predominance of girls. The right side was the more affected side, and the average diameter of the affected kidney at the time of surgical excision was 5.8 cm. Other changes in the urinary tract were found in five children. The mean operative time was 133 minutes. On pathological examination, on average, the pieces measured 4.8 cm and weighed 18.1 g. There were no operative complications. The average length of hospital stay was 37.35 hours. Conclusion Laparoscopic nephrectomy was confirmed as an applicable treatment for MCDK. The technique was easy to perform, safe and efficient, even when performed by trainees in pediatric urology.

Nuclear Medicine in Pediatric Nephro-Urology: An Overview

In the context of ante-natally diagnosed hydronephrosis, the vast majority of children with a dilated renal pelvis do not need any surgical treatment, as the dilatation resolves spontaneously with time. Slow drainage demonstrated at Tc-99m-mercaptoacetyltriglycine (MAG3) renography does not necessarily mean obstruction. Obstruction is defined as resistance to urinary outflow with urinary stasis at the level of the pelvic-ureteric junction (PUJ) which, if left untreated, will damage the kidney. Unfortunately this definition is retrospective and not clinically helpful. Therefore, the identification of the kidney at risk of losing function in an asymptomatic patient is a major research goal. In the context of renovascular hypertension a DMSA scan can be useful before and after revascularisation procedures (angioplasty or surgery) to assess for gain in kidney function. Renal calculi are increasingly frequent in children. Whilst the vast majority of patients with renal stones do not need functional imaging, DMSA scans with SPECT and a low dose limited CT can be very helpful in the case of complex renal calculi. Congenital renal anomalies such as duplex kidneys, horseshoe kidneys, crossed-fused kidneys and multi-cystic dysplastic kidneys greatly benefit from functional imaging to identify regional parenchymal function, thus directing further management. Positron emission tomography (PET) is being actively tested in genito-urinary malignancies. Encouraging initial reports suggest that F-18-fluorodeoxyglucose (FDG) PET is more sensitive than CT in the assessment of lymph nodal metastases in patients with genito-urinary sarcomas; an increased sensitivity in comparison to isotope bone scans for skeletal metastatic disease has also been reported. Further evaluation is necessary, especially with the promising advent of PET/MRI scanners. Nuclear Medicine in paediatric nephro-urology has stood the test of time and is opening up to new exciting developments.

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.

Neonatal polycystic kidney disease

This article provides an up-to-date comprehensive review and summary on neonatal polycystic kidney disease (PKD) with emphasis on the differential diagnosis, clinical manifestations, diagnostic techniques, and potential therapeutic approaches for the major causes of neonatal PKD, namely hereditary disease, including autosomal recessive and autosomal dominant PKD and nonhereditary PKD, with particular emphasis on multicystic dysplastic kidney. A brief overview of obstructive cystic dysplasia and simple and complex cysts is also included.

Nephrectomy for Non-neoplastic Kidney Diseases

This review discusses the pathology of non-neoplastic kidney disease that pathologists may encounter as nephrectomy specimens. The spectrum of pediatric disease is emphasized. Histopathologic assessment of non-neoplastic nephrectomy specimens must be interpreted in the clinical context for accurate diagnosis. Although molecular pathology is not the primary focus of this review, the genetics underlying several of these diseases are also touched on.

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.

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.

Unilateral multicystic dysplastic kidney: does initial size matter?

BACKGROUND

We report the long-term follow-up of children with antenatally detected unilateral multicystic dysplastic kidney (MCDK) who were followed between 1985 and 2009.

METHODS

Involution rates were documented over time based on the initial size of the MCDK, as documented on postnatal ultrasound (USS), as well as long-term complications and renal function.

RESULTS

In 323 patients (182 male), 10 % of MCDK had involuted, as evidenced on the first postnatal USS, with survival function analysis showing the probability of complete involution to be 35 % in 249 patients by 2 years of age, 47 % in 180 patients by 5 years of age and 62 % in 94 patients by 10 years of age. There was a significant difference in the involution rates of MCKD at the 10-year follow-up between MCDK with an initial size of >5 cm versus MCDK with an initial size of ≤5 cm (p < 0.0001). No patients in the whole cohort developed sustained hypertension or malignancy during a median follow-up of 10.1 years (range 0.3-15.4 years). Median estimated glomerular filtration rate (eGFR) in 76 patients (7 at 5 years, 69 at 10 years) was 93 ml/min/1.73 m(2) (range 46-175 ml/min/1.73 m(2)), with 40 (53%) having an eGFR of between 90 and 140 ml/min/1.73 m(2). Twenty-three (30 %) of the 76 patients at 10 years had normal eGFR (90-140 ml/min/1.73 m(2)) as well as complete involution of the MCDK, compensatory hypertrophy of the contralateral kidney, no proteinuria and no hypertension.

CONCLUSIONS

Larger MCDK at birth are less likely to involute during the first decade of life. However, conservative management remains justified due to the lack of complications. A minority of patients fulfil current criteria for discharge from specialty follow-up at 10 years.

Indications and relative renal function for paediatric nephrectomy over a 20-year period

BACKGROUND

The indications for partial or total nephrectomy for urological reasons are not clearly documented in the paediatric surgical literature and there are only a limited number of publications on this subject.

PURPOSE

In order to clarify the situation in our centre, we reviewed our own indications for nephrectomy over a 20-year period.

METHODS

Medical records of patients who underwent nephrectomy for urological and oncological causes between May 1990 and October 2010 at our centre were retrospectively reviewed. Indications for nephrectomy were noted. Renal function was noted for urological cases.

RESULTS

A total of 357 nephrectomies were undertaken; out of these, 241 cases were for urological causes and 116 for oncological reasons. The majority of total nephrectomies were performed for multicystic dysplastic kidneys, reflux nephropathy, pelvi-ureteric junction obstruction and dysplasia. Eighty-seven patients exhibited no function at the time of nephrectomy. Of the remainder, 17 had <5% function, 18 had 5-10% function, 5 had 10-15% function and 2 patients had 15-20% function.

CONCLUSIONS

This is the largest series of nephrectomies in the paediatric surgery literature to date. The majority of nephrectomies were undertaken for urological conditions with relative renal function of <10% and could not have been usefully preserved in situ. We suggest that kidneys with >10% function should not be routinely removed.

Multicystic dysplastic kidney: our experience in non-surgical management

INTRODUCTION

Although multicystic dysplastic kidney (MDK) is a common renal anomaly, the management of this condition remains controversial. The purpose of this study was to focus on its regression by ultrasound (US) scan for MDK managed conservatively.

MATERIALS AND METHODS

Between 1990 and 2010, 50 children with MDK were retrospectively studied. All patients were submitted to radioisotope scan to confirm the diagnosis, and a micturating cystogram to exclude other uropathies.

RESULTS

Of the 50 patients, 19 underwent nephrectomy, and the other 31 were conservatively managed with clinical and US scan follow-up. The mean follow-up time (range 6 months to 11 years) in the non-operated group was 6.2 years. Of the 31 children with nonsurgical management, 17 (54.8%) showed total involution on US scan, 7 (22.6%) showed a partial regression, and 7 (22.6%) were unchanged at the time of this study. The mean time to complete disappearance on US scan was 2.5 years (1-4 years). No children developed hypertension or tumors.

DISCUSSION

The natural history of MDK is usually benign, but patients must have long-term follow-up with US scan. In addition, many studies confirmed that the disappearance of it on a US scan does not mean a total involution of the affected kidney. We recommend a strict follow-up even when US scan shows an undetectable kidney.

Prenatal diagnosis: what do we know of long-term outcomes?

Although prenatal diagnosis has been a prominent feature of Paediatric Urology for more than two decades the published literature has been largely characterized by studies reporting short to medium-term follow up. This deficiency is now being addressed by the growing availability of published and unpublished long-term outcome data for a range of prenatally detected anomalies. This review analyses the evidence on long-term outcomes which is provided by studies with mean or median follow- up exceeding 5 years, with particular emphasis on the small number of studies reporting follow -up at 10 years and beyond. The natural history and outcome of conservatively managed uropathies is considered in conjunction with an appraisal of evidence- based indications for surgical intervention. This review evaluates the relative benefits and drawbacks of prenatal diagnosis for children and their parents and also considers the impact of prenatal diagnosis on the delivery of Paediatric Urological services and specialist training.

Nephrectomy for multicystic dysplastic kidney and renal hypodysplasia in children: where do we stand?

OBJECTIVES

Little is reported in literature regarding correct management of benign lesions of the kidney. The aim of our study is to present a series of total and partial nephrectomies performed in the last 5 years and to discuss indications.

MATERIALS AND METHODS

Patients with benign lesions who underwent nephrectomy and partial nephrectomy at our institution in the period 2003-2008 were retrospectively included in the study. Notes were carefully reviewed and demographic data, symptoms onset, preoperative diagnosis, investigations, medical and/or surgical treatment, postoperative complications and definitive histological reports were collected.

RESULTS

Forty procedures were performed. Twelve patients were preoperatively diagnosed of having multicystic dysplastic kidney (MCDK), which was confirmed in 10, whereas the remaining 28 patients of having severe dysplasia or hypodysplasia. Thirty-four patients underwent total nephrectomy, six underwent partial nephrectomy. Histopathological analysis confirmed segmental or complete abnormalities of the involved kidney in all cases. No malignancies were detected.

DISCUSSION

Our study confirmed the extremely low malignancy rate of MCDK and hypodysplastic kidneys. The 20% mismatch of pre- and post-operative diagnosis suggests a common aetiology and shared therapeutic strategies for MCDK and hypodysplasia. At present, there is no consensus regarding correct indications for nephrectomy in paediatric age. As nephrectomy seems not to provide any advantage over preservation, but surgical and anesthesiological risks, we should be prudent in preserving every asymptomatic poorly or non-functioning kidneys maintaining a strict follow-up. Randomised controlled studies on larger multicentric series are strongly warranted to define this topic.

Multicystic dysplastic kidney in children--a need for conservative and long term approach

OBJECTIVE

We retrospectively studied our cases of Multicystic Dysplastic Kidney (MCDK). The review was aimed at identifying the pattern of the disease in Indian Scenario and the required management thereof.

METHODS

We studied the clinical, radiological and nuclear scan findings of 22 patients with unilateral MCDK. They were diagnosed and/or treated in our unit from 1999 to 2007. The diagnosis was achieved by Ultrasound and further confirmed by DMSA scans. Other ancillary investigations like Micturating cystourethrogram were done if indicated. These patients were followed and followup investigations consisted of renal ultrasound, blood pressure measurement, and urinalysis and blood biochemistry

RESULTS

A total of 22 patients (18 boys and 4 girls) with unilateral MCDK were investigated and followed for a mean period of 41 months. MCDK was detected on antenatal ultrasound only in 12(55%) and postnatally in 10(45%) babies. Mean age for postnatal diagnosis was 20 months. Follow up ultrasound revealed complete involution of MCDK in 3 patients and partial regression in 11 patients. The size of dysplastic kidney was unchanged in 4 patients and a further 4 patients underwent nephrectomy. Indications of nephrectomy were parental anxiety in 2, hypertension in 1 and palpable mass in 1.

CONCLUSION

Large proportion (45%) of patients in presented series are diagnosed post natally contrary to western world where more than 80% are diagnosed antenatally. Uncomplicated isolated MCDK carry good prognosis with nephrectomy required in only a few patients. Association with other urological anomalies in ipsilateral/contralateral genitourinary tract is important to identify as they have worse outcome in terms of ultimate renal function. All patients with simple/complex unilateral MCDK should be advised long term follow up for the possible development of hypertension and/or hyper infiltration injury.

Management and etiology of the unilateral multicystic dysplastic kidney: a review

In children, unilateral multicystic dysplastic kidney (MCDK) is one of the most frequently identified urinary tract abnormalities. A variety of proposed etiologies has been associated with the underlying pathogenesis of MCDK. These include genetic disturbances, teratogens, in utero infections, and urinary outflow tract obstruction. From 5-43% of the time, MCDK has associated genito-urinary anomalies, both structural and functional in nature. A review of the literature reveals that involution rates are reported to be 19-73%, compensatory hypertrophy of the contralateral kidney occurs from 24-81% of the time, and estimated glomerular filtration rates (GFRs) (by the Schwartz formula) range from 86-122 ml/min per 1.73 m(2) body surface area. Most authors suggest serial ultrasonography to monitor contralateral growth, routine blood pressure monitoring, and a serum creatinine monitoring algorithm. The risk of hypertension in those with MCDKs does not appear to be greater than that of the general population, and the rates of malignant transformation of MCDK are small, if at all increased, in comparison with those in the general population. If the patient develops a urinary tract infection or has abnormalities of the contralateral kidney, shown on ultrasound, a voiding cystourethrogram is recommended. Finally, the body of literature does not support the routine surgical removal of MCDKs.