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

Clinical Characteristics and Outcomes of Children with Unilateral Multicystic Dysplastic Kidney: A Cohort Study

OBJECTIVES

To study the clinical profile and outcomes of children with unilateral multicystic dysplastic kidney (MCDK).

METHODS

We assessed the clinical features and extrarenal manifestations in children with unilateral MCDK. These children were followed up to ascertain involution, compensatory hypertrophy and progression of chronic kidney disease (CKD) stage.

RESULTS

We enrolled 106 children with unilateral MCDK which was detected antenatally in 98 (92.4%), while evaluating for urinary tract infection in three (2.8%), and incidentally in five (4.7%) children. Abnormalities in the contralateral kidney and extrarenal manifestations at initial presentation were detected in 30 (28.3%) and 15 (14.2%), respectively. At a median (IQR) follow-up of 60 (32, 87) months, 34 (32.1%) children demonstrated complete involution of the MCDK, while 72 (67.9%) showed compensatory hypertrophy in the contralateral kidney. The median age at involution of MCDK was 48.5 (33, 86.5) months. Twenty-two (20.7%) children had non-regression of MCDK, and two (1.9%) underwent nephrectomy. Eight (7.5%) children developed hypertension and two children were detected to have proteinuria. One child, each, progressed to CKD stage 2 and stage 3a; and another child (0.9%) progressed to end stage kidney disease. None of the patients developed malignant transformation.

CONCLUSIONS

Majority of cases (92.4%) of MCDK had been detected antenatally. The rate of involution was 32.1% at a median follow-up of 60 months. Although, 28.3% of cases of MCDK had abnormalities in the contralateral kidney, progression of CKD to a higher stage occurred only in three (2.8%) cases.

Outcomes of solitary functioning kidneys-renal agenesis is different than multicystic dysplastic kidney disease

BACKGROUND

Multicystic dysplastic kidney (MCDK) disease and unilateral renal agenesis (URA) are well-known causes of a solitary functioning kidney (SFK) and are associated with long-term kidney injury. The aims of this study were to characterize the natural history of SFK at our center, define the risk factors associated with chronic kidney injury, and identify distinguishing features between URA and MCDK that predict outcome.

METHODS

This was a retrospective cohort study of 230 SFK patients. We compared MCDK (n=160) and URA (n=70) according to clinical features at diagnosis and kidney outcomes over follow-up. Univariate and multivariate binary regression analysis was used to determine independent risk factors for chronic kidney injury, defined as the composite outcome of hypertension, proteinuria, or chronic kidney disease (eGFR <60 mL/min/1.73m²).

RESULTS

URA had a higher prevalence of comorbid genetic syndromes (15 vs. 6%, p=0.04), non-renal anomalies (39 vs. 11%, p<0.001), and congenital anomalies of the kidney and urinary tract (CAKUT) (51 vs. 26%, p<0.001) than MCDK. Over follow-up, URA experienced more hypertension (19 vs. 3%, p=0.002), proteinuria (12 vs. 3%, p=0.03), and the composite outcome (19 vs. 6%, p=0.003) than MCDK. Independent risk factors for chronic kidney injury included CAKUT (OR 5.01, p=0.002) and URA (OR 2.71, p=0.04).

CONCLUSIONS

In our population, URA was more likely to have associated syndromes or anomalies, and to have worse outcomes over time than MCDK. URA diagnosis was an independent risk factor for chronic kidney injury. Our results will be used to develop a standardized clinical pathway for SFK management. A higher resolution version of the Graphical abstract is available as Supplementary information.

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.

Investigating the use of ultrasonography for the antenatal diagnosis of structural congenital anomalies in low-income and middle-income countries: a systematic review

BACKGROUND

Congenital anomalies are the fifth leading cause of under-5 mortality globally. The greatest burden is faced by those in low/middle-income countries (LMICs), where over 95% of deaths occur. Many of these deaths may be preventable through antenatal diagnosis and early intervention. This systematic literature review investigates the use of antenatal ultrasound to diagnose congenital anomalies and improve the health outcomes of infants in LMICs.

METHODS

A systematic literature review was conducted using three search strings: (1) structural congenital anomalies; (2) LMICs; and (3) antenatal diagnosis. The search was conducted on the following databases: Medline, Embase, PubMed and the Cochrane Library. Title, abstract and full-text screening was undertaken in duplicate by two reviewers independently. Consensus among the wider authorship was sought for discrepancies. The primary analysis focused on the availability and effectiveness of antenatal ultrasound for diagnosing structural congenital anomalies. Secondary outcomes included neonatal morbidity and mortality, termination rates, referral rates for further antenatal care and training level of the ultrasonographer. Relevant policy data were sought.

RESULTS

The search produced 4062 articles; 97 were included in the review. The median percentage of women receiving an antenatal ultrasound examination was 50.0% in African studies and 90.7% in Asian studies (range 6.8%-98.8%). Median detection rates were: 16.7% Africa, 34.3% South America, 34.7% Asia and 47.3% Europe (range 0%-100%). The training level of the ultrasound provider may affect detection rates. Four articles compared morbidity and mortality outcomes, with inconclusive results. Significant variations in termination rates were found (0%-98.3%). No articles addressed referral rates.

CONCLUSION

Antenatal detection of congenital anomalies remains highly variable across LMICs and is particularly low in sub-Saharan Africa. Further research is required to investigate the role of antenatal diagnosis for improving survival from congenital anomalies in LMICs.

PROSPERO REGISTRATION NUMBER

CRD42019105620.

A meta-analysis of the incidence and fate of contralateral vesicoureteral reflux in unilateral multicystic dysplastic kidney

INTRODUCTION

Multicystic dysplastic kidney (MCDK) is the most common type of renal cystic disease. It is associated with urinary tract abnormalities in the contralateral kidney in up to 30% of cases, most commonly vesicoureteral reflux (VUR).

OBJECTIVES

The objective of this study was to describe the incidence and selected issues in management and evolution for each VUR grade in the contralateral kidney of patients with unilateral MCDK, in order to strengthen the scientific basis regarding the need for voiding cystourethrography (VCUG) screening.

METHODS

A comprehensive search of standard and gray literature was performed. Full-text screening, data abstraction, and quality appraisal were conducted in duplicates. Included studies reported a primary diagnosis of unilateral MCDK with contralateral VUR determined by VCUG. Articles had to include a distribution of VUR grade to meet the eligibility criteria.

RESULTS

From 698 retrieved articles, 37 studies enrolling 2057 patients were analyzed. Of the patients, 80% were male; 50% had left unilateral MCDK; and 87% were diagnosed prenatally. A total of 1800 patients had VCUG, of whom 303 had VUR (weighted proportion: 17%; 95% confidence interval [CI]: 14-20%). Weighted proportions of VUR were 9%, 7%, and 17% for grades I-II, III-V, and I-V, respectively. Of the patients, 99% (95% CI: 97-100%) were on continuous antibiotic prophylaxis (CAP) and 18% (95% CI: 8-37%) had urinary tract infections (UTIs), with a higher rate of UTIs (23% vs 10%) in patients with dilating (grades III-V) VUR, over a mean follow-up of 40 months. In patients with dilating VUR, reflux resolved or downgraded to grade I in 52% (95% CI: 37-67%) of patients, and 32% (95% CI: 19-49%) had surgical correction of VUR.

CONCLUSIONS

Among patients with unilateral MCDK, 17% have VUR in the contralateral kidney, 41% of which is dilating VUR. Of the cases with dilating VUR, half will resolve or downgrade to grade I during follow-up; 23% will develop a UTI despite CAP; and one-third will undergo ureteral re-implantation. While many physicians may thus choose to forego routine VCUG screening of the single functional kidney, shared decision-making with the patient's caregivers is currently recommended, where the risks and benefits of the different approaches can be discussed. The data from this analysis can help inform the discussions.

Developmental pathology of congenital kidney and urinary tract anomalies

Congenital anomalies of the kidneys or lower urinary tract (CAKUT) are the most common causes of renal failure in children and account for 25% of end-stage renal disease in adults. The spectrum of anomalies includes renal agenesis; hypoplasia; dysplasia; supernumerary, ectopic or fused kidneys; duplication; ureteropelvic junction obstruction; primary megaureter or ureterovesical junction obstruction; vesicoureteral reflux; ureterocele; and posterior urethral valves. CAKUT originates from developmental defects and can occur in isolation or as part of other syndromes. In recent decades, along with better understanding of the pathological features of the human congenital urinary tract defects, researchers using animal models have provided valuable insights into the pathogenesis of these diseases. However, the genetic causes and etiology of many CAKUT cases remain unknown, presenting challenges in finding effective treatment. Here we provide an overview of the critical steps of normal development of the urinary system, followed by a description of the pathological features of major types of CAKUT with respect to developmental mechanisms of their etiology.

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.

Minimally invasive open nephrectomy on children with multicystic dysplastic kidney

The aim of the study was to summarize the preliminary experience of minimally invasive open nephrectomy operation on children with multicystic dysplastic kidney (MCDK). A retrospective review was performed on the clinical materials of the 15 children that had accepted consecutive minimally invasive open nephrectomies during the previous 2 years. The enrolled children were diagnosed with unilateral MCDK under computed tomography, emission computerized tomography and ultrasound and no anomaly in the contralateral functioning kidney was found. Of the 15 children, 12 were boys and 3 were girls, with 5 cases on the right and 10 cases on the left. Operations were completed at the retroperitoneal space in order to open an incision on the waists and ribs of the children, the length of which ranged from 1.5 to 2.0 cm (average 1.7 cm). The age of the children at operation ranged from 3 months to 5.6 years old, with an average of 2.4 years old. Surgery lasted for 30–50 min, with an average of 34.6 min. The estimated blood loss of each child was <5 ml. After operation, prophylactic intravenous antibiotics were administered for 2–4 days to prevent infection. All of the operations proved very successful. Following surgery the children were hospitalized for 2–4 days for observation, with an average of 2.8 days. No complications occurred during the follow-up period. In conclusion, minimally invasive open nephrectomy is effective for children with MCDK. The procedure is superior with regard to operative time, cosmesis, and length of stay. It is a safe and effective treatment choice for patietns with MCDK and can be easily performed on children.

Single center experience in patients with unilateral multicystic dysplastic kidney

OBJECTIVE

To determine the clinical features, long-term outcomes, and additional urological anomalies of patients treated for multicystic dysplastic kidney (MDK).

MATERIALS AND METHODS

Patients with MDK who were followed between January 2004 and October 2012 were reviewed retrospectively. Demographic, clinical, laboratory, and radiological data were evaluated.

RESULTS

A total of 68 patients with MDK were followed for a mean period of 46.8 ± 32.4 months. MDK was detected by antenatal ultrasound in 64 (94.1%) of the patients. Ten patients had (14.7%) additional urological anomalies in contralateral kidney. Vesicoureteral reflux was found in five patients (7.3%). Other urological anomalies were megaureter (two), cortical renal cyst (two), ureteropelvic junction obstruction (one), and renal ectopy (one). Urinary tract infection was detected in 14 (20.5%) patients. Four (5.9%) patients had hypertension. Compensatory hypertrophy was detected in 29 (42.6%) patients. Eight (11.8%) of these 29 patients had glomerular hyperfiltration and three (4.4%) of these eight patients also had proteinuria. Follow-up ultrasound revealed complete involution in 19 (35.8%) patients. Nephrectomy was performed in 15 (22.0%) patients. Indications of nephrectomy were, recurrent urinary infection (four), hypertension (three), ureterocele (two), renal calculi (one), flank pain (one), hematuria (one), persistent large cystic kidney (three), and atypical US findings (two).

CONCLUSION

In patients with MDK, depending on the clinical, laboratory, and radiological findings, appropriate timing of operation by multidisciplinary approach is important for early detection and treatment of any possible complications.