Predictive factors of ultrasonographic involution of prenatally detected multicystic dysplastic kidney

Approach to the postnatal sonographic evaluation of prenatally detected abdominopelvic cysts

Prenatally detected abdominal and pelvic masses are commonly cystic in morphology and usually seen on mid-trimester sonography. Sonography is the favored imaging modality for the postnatal evaluation of these lesions in newborns, given its availability, low cost, lack of ionizing radiation, lack of sedation, and high spatial resolution in small patients. The differential diagnosis of abdominopelvic cystic masses in newborns is broad given that they can arise from many organs and may have overlapping features on imaging. This article illustrates an approach to the postnatal sonographic evaluation of prenatally detected cystic abdominal and pelvic masses based on their anatomic location and distinctive sonographic characteristics, which can aid in an accurate diagnosis and guide appropriate management.

Prenatal diagnosis and outcome of unilateral multicystic kidney

We reviewed the records of 144 patients. The mean gestational age at first US diagnosis was 27.5 ± 4.3 weeks. An anomaly of the contralateral kidney was detected in 25% of cases. An extrarenal anomaly was detected in 13.8%. Karyotype analysis was performed in 16.6% of cases and revealed trisomy 18 in 2 cases with extrarenal defects. Karyotype analysis was normal in all the patients who had isolated multicystic dysplastic kidney (MCDK). The diagnostic accuracy of prenatal ultrasound was 92.2%. Contralateral kidney anomaly was detected 33.9% of patients, and half of these were vesicoureteral reflux. Antihypertensive therapy was required in 2.6% of cases. Nephrectomy was performed in 8%, and partial or total involution of MCDK was achieved in 33.9% of patients. MCDK can be accurately diagnosed by prenatal sonography, and prognosis depends on extrarenal and contralateral renal abnormalities. In isolated cases, require of surgery is rare, and serial follow-up is suggested to determine involution.Impact statementWhat is already known on this subject? Multicystic dysplastic kidney (MCDK) is one of the most renal anomalies and is associated with numerous renal and extrarenal abnormalities. It can lead to severe consequences in the neonatal period.What do the results of this study add? The accuracy of prenatal ultrasonography is excellent for detecting MCDK. In isolated unilateral cases, chromosomal aberrations are low, and the majority of them involute spontaneously. A periodic follow-up of the contralateral kidney is mandatory due to an increased risk of an anomaly. Genital anomaly risk is increased in males.What are the implications of these findings for clinical practice and/or further research? Detailed evaluation and follow-up of the contralateral kidney are crucial for counselling in isolated cases. Karyotype analysis in isolated unilateral MCDK is debateable. Postnatal prognosis is encountering, and the majority of patients have no requirement of surgery.

Multicystic dysplastic kidney - treat each case on its merits

OBJECTIVES

To assess outcomes of unilateral multicystic dysplastic kidney (MCDK) managed at an Australasian centre over a 15 year period. To assess if MCDK involution could be predicted based on change noted between first two postnatal ultrasound scans 6 months apart.

SUBJECTS AND METHODS

A retrospective study was performed.

RESULTS

One-hundred-and-six cases of unilateral MCDK were studied. Eighty-four of these presented antenatally. Twenty-two MCDK cases presented postnatally. Urological anomalies associated with MCDK included vesicoureteric reflux (VUR), ureterocele and contralateral pelviureteric junction obstruction (PUJO). Children undergoing surgical intervention for these anomalies were offered concurrent MCDK nephrectomy. Morbidity associated with MCDK under surveillance included febrile culture-positive urinary tract infection in 20 cases (20.7%), hypertension in four (3.7%) and Wilms' tumor in one (0.9%). Thirty-six cases (34%) underwent complete involution, 32 (30.2%) were in the process of involuting and 38 cases (35.8%) underwent nephrectomy because of failure of involution or associated morbidity. If the MCDK reduced in cranio-caudal interpolar length by 20% or more between the first postnatal USS and the next one 6 months later, then it was very likely to involute spontaneously. If the MCDK did not reduce in cranio-caudal interpolar length by 20% between the first postnatal scan and the next one 6 months later, then it was highly likely to fail to involute, and in our study, correlated with the outcome of nephrectomy.

CONCLUSION

Although MCDK is a benign condition, it should be carefully investigated and followed-up, as involution may not occur in over a third. In some cases, morbidity may occur. Each case of MCDK should be managed on its own merits.

LEVEL OF EVIDENCE

Level II - Prognosis study, Retrospective.

[Prenatal diagnosis of multicystic dysplastic kidney: about 18 cases]

Multicystic dysplastic kidney (MCDK) is the most common Congenital Abnormalities of Kidney and Urinary Tract (CAKUT) in clinical practice. Its etiology and pathogenesis are still controversial and obstruction is a generally accepted causative assumption. Obstetric ultrasound is the gold standard for prenatal diagnosis and for the detection of other associated malformations. Prenatal management is based on ultrasound monitoring of pregnancy, of the disease, of the occurrence of other anomalies and of the amount of amniotic fluid. This study aims to report our experience in the Department of Gynecology-Obstetrics 2 at the University Hospital Hassan II-Fez in order to clarify the epidemiology of MCDK, highlight the role of obstetric ultrasound in positive and etiological diagnosis while describing the various sonographic appearances. It is essential to schedule for screening tests during pregnancy in order to assess the evolution of the disease diagnosed in the prenatal period, to implement a strategy in postpartum care and to establish a prognosis.

A clinical predictive model of renal injury in children with congenital solitary functioning kidney

BACKGROUND

Solitary functioning kidney (SFK) is an important condition in the spectrum of congenital anomalies of the kidney and urinary tract. The aim of this study was to describe the risk factors for renal injury in a cohort of patients with congenital SFK.

METHODS

In this retrospective cohort study, 162 patients with SFK were systematically followed up (median, 8.5 years). The primary endpoint was time until the occurrence of a composite event of renal injury, which includes proteinuria, hypertension, and chronic kidney disease (CKD). A predictive model was developed using Cox proportional hazards model and evaluated by c statistics.

RESULTS

Among 162 children with SFK included in the analysis, 132 (81.5%) presented multicystic dysplastic kidney, 20 (12.3%) renal hypodysplasia, and 10 (6.2%) unilateral renal agenesis. Of 162 patients included in the analysis, 10 (6.2%) presented persistent proteinuria, 11 (6.8%) had hypertension, 9 (5.6%) developed CKD stage ≥ 3, and 18 (11%) developed the composite outcome. After adjustment by the Cox model, three variables remained as independent predictors of the composite event: creatinine (HR, 3.93; P < 0.001), recurrent urinary tract infection (UTI) (HR, 5.05; P = 0.002), and contralateral renal length at admission (HR, 0.974; P = 0.002). The probability of the composite event at 10 years of age was estimated as 3%, 11%, and 56% for patients assigned to the low-risk, medium-risk, and high-risk groups, respectively (P < 0.001).

CONCLUSION

Our findings have shown an overall low risk of renal injury for most of infants with congenital SFK. Nevertheless, our prediction model enabled the identification of a subgroup of patients with an increased risk of renal injury over time.

Cystic Diseases of Childhood: A Review

Renal cystic lesions are considered the most common abnormality associated with the kidneys. Most renal cysts are usually uncomplicated simple cysts that are not life-threatening; however, fatal renal cystic diseases can develop from these space-occupying lesions. Although renal cystic diseases are similar in presentation, they possess distinct features, variable prognoses, and complications later in life. Early identification and effective management of these respected diseases has led to longer survival rates and better quality of life. The purpose of this review is to provide a comprehensive analysis of the most prevalent cystic diseases of the pediatric population in hopes to aid in early distinction and appropriate treatment.

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.

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.

Early risk factors for neonatal mortality in CAKUT: analysis of 524 affected newborns

BACKGROUND

Congenital abnormalities of the kidney and urinary tract (CAKUT) are significant causes of morbidity. The aim of the study was to determine predictive factors of mortality in newborns with CAKUT.

METHODS

All 29,653 consecutive newborns hospitalized in a tertiary neonatal unit between 1996 and 2006 were evaluated. The main outcome was neonatal mortality. The variables analyzed as risk factors were maternal age, first pregnancy, low birth weight (LBW), prematurity, oligohydramnios, and CAKUT associated with other malformations (Associated CAKUT).

RESULTS

CAKUT was detected in 524 newborns, with an overall prevalence of 17.7 per 1,000 live births. A total of 325 (62%) cases were classified as urinary tract dilatation, 79 (15.1%) as renal cystic disease, and 120 (22.9%) as other subgroups. In the urinary tract dilatation subgroup, independent risk factors for early mortality were Associated CAKUT [odds ratio (OR) 20.7], prematurity (OR 4.5) LBW (OR 3.8), oligohydramnios (OR 3.0), and renal involvement (OR 3.0). In the renal cystic disease subgroup, two variables remained associated with neonatal mortality: LBW (OR 12.3) and Associated CAKUT (OR 21.4).

CONCLUSION

The presence of extrarenal anomalies was a strong predictor of poor outcome in a larger series of infants with CAKUT.

Urinary levels of TGF β-1 and of cytokines in patients with prenatally detected nephrouropathies

This study aimed to identify noninvasive biomarkers of clinically significant nephrouropathies in patients with antenatal renal and/or urinary tract alterations. Spot-urine levels of interleukin-6 (IL-6), transforming growth factor-β1 (TGF-β1) and tumor necrosis factor-α (TNF-α) were measured in 100 patients with antenatal detected nephrouropathies. Patients were divided in idiopathic hydronephrosis (n = 47), urinary tract malformations (n  = 35), and dysplastic kidneys (n = 18). Urinary concentrations of TGF-β1, IL-6, and TNF-α were compared between groups according to clinical and image findings. Receiver-operating characteristic (ROC) curves were analyzed for the overall diagnostic accuracy of TGF-β1, IL-6, and TNF-α levels in discriminating infants with nephrouropathies. No significant differences in urinary TGF- β1, IL-6, and TNF-α levels were found in the comparison between the groups. TGF-β1 levels tended to be higher in patients with renal hypodysplasia compared to idiopathic hydronephrosis (p = 0.07). Twenty-nine patients had reduced DMSA uptake. In these cases, absolute urinary concentration of TGF-β1 and levels standardized for creatinine were significantly higher than in patients with normal DMSA uptake, while IL6 and TNF-α did not differ between groups. Urinary cytokine measurements were not useful as a screening test for clinically significant nephrouropathies. Conversely, increased concentrations of TGF-β1 pointed out to renal damage as indicated by reduced DMSA uptake.

The Society for Fetal Urology consensus statement on the evaluation and management of antenatal hydronephrosis

The evaluation and management of fetuses/children with antenatal hydronephrosis (ANH) poses a significant dilemma for the practitioner. Which patients require evaluation, intervention or observation? Though the literature is quite extensive, it is plagued with bias and conflicting data, creating much confusion as to the optimal care of patients with ANH. In this article, we summarized the literature and proposed recommendations for the evaluation and management of ANH.

Fetal multicystic kidney disease: Outcome and follow up

Introduction Congenital fetal anomalies are the great problem and one of the main causes of increased perinatal mortality and morbidity. The aim of this study is to determine the outcome of prenataly detected multicystic dysplastic kidney and to point to the necessity of postnatal diagnostic procedures. Material and methods The retrospective-prospective study encompasses 38 cases of the prenatally diagnosed unilateral fetal multicystic dysplastic kidney. The associated anomalies were revealed either by autopsy findings when the pregnancy was terminated, or when the pregnancy continued, by clinical and operative findings the newborns. Results The autopsy finding revealed bilateral multicystic displastic kidney or unilateral mylticystic displastic kidney and the agenesis of the contralateral kidney. The postnatal evaluation of the newborns with unilateral multicistic disease revealed that 84.3% of them had some concomitant anomaly of the urinary tract, most of them had an anomaly of the contralateral kidney (31.4%). The surgery was performed in 73.6% of children, in 17% of children the kidney function deteriorated after the surgery. Conclusion The findings of bilateral multicystic kidney disease and unilateral multicystic kidney disease and anamnion are the indication to terminate the pregnancy. The finding of an isolated unilateral multicystic dysplastic kidney require thorough examination, both prenatally and postnatally. We propose obligatory serial prenatal ultrasound examinations, followed by postnatal ultrasound, isotope scan, and urinary cystourethography.

[Association of fetal unilateral multicystic kidney disease with other urinary tract anomalies]

BACKGROUND/AIM

Multicystic dysplastic kidney represents a disorder in the fetus development presented prenatally of postnatally, this deserving special attention due to a risk of additional anomalies in children with this disorder. The aim of this study was to determine the incidence and type of common anomalies of the urinary system in the prenatal diagnosis of unilateral multicystic dysplastic kidney, and point out the necessity of postnatal diagnostic procedures in order to evaluate the state of the urinary system.

METHODS

This retrospective-prospective study encompassed 38 cases of prenatally diagnosed unilateral fetal multicystic dysplastic kidney, presented to the Council for Fetal Anomalies from the Institute for Gynecology and Obstetrics of the Clinical Centre of Serbia and the University Children's Clinic within a three-year period. Associated anomalies were revealed by autopsy findings when pregnancy was terminated, ie resumed with clinical and operative findings of born children.

RESULTS

In every case of terminated pregnancy and death after birth the autopsy revealed additional renal or exstrarenal anomaly which were not prenataly detected. Postnatal evaluation of survived children with unilateral multicistic disease revealed that 31.4% of them have an anomaly of the contralateral kidney, 26.3% anomaly of the ipsilateral side, 13.2% anomaly of the lower portions of the urinary system and the same percent an additional extrarenal anomaly. The surgery was performed in 73.6% of children, more than half of the interventions were related to extrarenal anomaly. In 17% of children the kidney function was deteriorated after surgery.

CONCLUSION

Children suffering from unilateral multicystic dysplastic kidney have a greater chance of exhibiting an anomaly of the contralateral kidney and the urinary system in general. Therefore, they require thorough examination, both prenatally and postnatally. We propose obligatory serial professional prenatal ultrasound examinations, followed by postnatal ultrasound, isotope scan, and we especially emphasize the need for performing urinary cystouretherography, bearing in mind the high incidence of the vesicoureteral reflux of the contralateral kidney. In addition to nephrectomy, cytoscopy and colposcopy also need to be performed for the purpose of discovering possible hidden anomalies of the urogenital system.

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.

Unilateral multicystic dysplastic kidney: single-center experience

Multicystic dysplastic kidney (MCDK) is one of the most common renal abnormalities in children. The aim of our study was to evaluate the clinical course and outcome of patients with MCDK. Ninety pediatric patients with unilateral MCDK followed by the Pediatric Nephrology Department of Bakirkoy Maternity and Children's Hospital between 1990 and 2007 were included in this retrospective study. The dimercaptosuccinic acid radionuclide scan revealed no function in MCDK in all of our patients. Voiding cystourethrogram was performed in all patients. Twenty patients (22.2%) had abnormalities in the contralateral kidney. Nephrectomy was performed in 41 patients (45.5%). Twelve patients had undergone routine nephrectomy before 1996. Since then, patients have been followed up conservatively, and nephrectomy has been performed only when indicated. Indication of nephrectomy was arterial hypertension in 16 patients (23.1%), recurrent urinary tract infection (UTI) in 11 (15.9%), and severe abdominal pain in two (2.8%). Hypertension was noted within the first year of life in all patients except two. MCDK completely involuted in 39.3% within 48 months. There was no malignant transformation, proteinuria, or renal failure. In conclusion, hypertension is often noticed in infants with MCDK. Uninephrectomy leads to normalization. However, prospective studies are needed to exclude a spontaneous improvement of hypertension.

[Multicystic dysplastic kidney disease: update and information for parents at the time of prenatal diagnosis]

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.

Prenatally detected ureteropelvic junction obstruction: clinical features and associated urologic abnormalities

Urologic congenital anomalies associated with ureteropelvic obstruction (UPJO) have been previously characterized; however, less data are available regarding these associations in a prenatally diagnosed population. A retrospective study was conducted to evaluate significant clinical features and urological anomalies associated with prenatally diagnosed UPJO. The records of 143 children with prenatally diagnosed hydronephrosis secondary to UPJO were retrospectively reviewed. The gender, side of obstruction, degree of hydronephrosis, associated clinical features, and urological anomalies were noted. Hundred and forty-three children (M/F = 2.7) with a total of 198 affected renal units (RU) presenting with unilateral (61%) or bilateral (39%) UPJO were enrolled. In cases of unilateral obstruction, the left side was affected in 60 children (68%). The grade of hydronephrosis was Grade 1 in 56 RU (28%), Grade 2 in 51 RU (26%), Grade 3 in 50 RU (25%) and Grade 4 in 41 RU (21%). Associated clinical features included prematurity (n = 7, 4.9%), twinning (n = 5, 3.5%) and presentation with renal failure (RF) (n = 2). Excluding contralateral UPJO, other urologic anomalies were encountered in 29 patients (20.3%). Associated vesicoureteral reflux (VUR) was encountered in 11 patients (7.7%, M/F = 2.7). Pyeloplasty was required more often in children with associated VUR (54.5 vs. 18.2%) (P = 0.01). Contralateral multicystic dysplastic kidney (MCDK) was encountered in six patients (M/F = 2), one of whom presented with RF. One child carried the diagnosis of Schinzel-Giedion syndrome (SGS), demonstrating severe developmental and neurological disorders and bilateral hydronephrosis. The more frequent occurrence of UPJO in males with predominantly left-sided location, association with VUR and MCDK, and increased frequency of bilaterality in our prenatally diagnosed patients were similar to historical reports. In addition, prematurity and twinning were independently associated with UPJO. The higher rate of pyeloplasty in patients with associated reflux warrants further investigation.

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 <or=3. The risk of urinary tract infection appears to be associated with VUR or coexistent abnormalities rather than the MCDK. The risk of hypertension is no greater than that in the general population and nephrectomy is usually not curative. The overall risk of Wilms' tumour developing in a MCDK is <1 in 2000. All reported Wilms' tumours were identified before 4 years of age and 70% presented as a palpable mass.

CONCLUSIONS

Published reports support the non-surgical management of MCDK. Common practice has been to remove palpable or growing MCDKs, although these represent a very small fraction of MCDKs. In theory, ultrasonographic surveillance until 4 years old might allow the earlier detection of a Wilms' tumour, and decrease the intensity of chemotherapy and improve prognosis. Previous reports do not prove or disprove this concept, and the appropriate frequency of surveillance is not evident.

Ultrasound progression of prenatally detected multicystic dysplastic kidney

OBJECTIVES

To evaluate the sonographic involution of prenatally detected multicystic dysplastic kidney (MCDK).

METHODS

A total of 53 children with unilateral MCDK detected by prenatal ultrasonography between 1989 and 2004 were included in this analysis. All children received conservative management with follow-up visits every 6 months. Follow-up ultrasound examinations were performed at 6-month intervals during the first 2 years after birth and yearly thereafter. A linear mixed effect model was constructed, including MCDK length as the dependent variable and body size parameters and contralateral renal dimensions as independent variables.

RESULTS

The mean follow-up time was 68 months. A total of 334 ultrasound scans were analyzed. The ultrasound scan demonstrated partial or total involution of the MCDK in 48 cases (91%). A consistent negative correlation was found among MCDK length, patient age, and body size parameters. As a whole, the MCDK length reduction was estimated to be 0.29 mm/mo. The rate of reduction was not constant over time and was intense during the first 30 months of age. According to the regression model, MCKD reduced in length by 0.80 mm/mo during the first 30 months of age, 0.26 mm between 30 and 84 months old, and 0.30 mm in children older than 84 months.

CONCLUSIONS

Our results suggest a clear tendency of MCDK to decrease in size, with the rate of the involution greater during the first 30 months than the rate in older children.

Natural history of patients with multicystic dysplastic kidney-what followup is needed?

PURPOSE

Most clinicians recommend followup with annual ultrasound for patients with multicystic dysplastic kidney. The aim of this study was to determine whether followup ultrasound provides any clinical benefit.

MATERIALS AND METHODS

We retrospectively reviewed the charts of 73 patients who were diagnosed with multicystic dysplastic kidney between October 1991 and August 2005. Data were analyzed with respect to patient characteristics and followup information.

RESULTS

We identified 61 patients (43 boys and 18 girls) with adequate followup. A total of 49 patients (80%) were diagnosed prenatally and 12 (20%) postnatally. Associated urological anomalies were noted in 16 patients (26%). Median followup was 2.6 years (range 6 months to 37.5 years). Ultrasound examinations showed complete involution in 25 patients (41%) and partial regression in 18 (30%). The size of the multicystic dysplastic kidney increased in 1 patient (1.6%) and was unchanged in 17 (28%) without any pathological manifestations. Median age at complete involution was 2.1 years (range 36 days to 13.7 years). Patients with contralateral compensatory hypertrophy had more rapid complete involution. Urinary tract infection developed in 6 patients, of whom 1 was ultimately found to have reflux and 1 had ureteropelvic junction obstruction.

CONCLUSIONS

In our patients with unilateral multicystic dysplastic kidney ultrasound provided little clinically important information. Our data and a review of the literature suggest that once the diagnosis is made, no urological followup is needed. The primary care provider should monitor patients with multicystic dysplastic kidney for hypertension, abdominal mass and urinary tract infection.

Urological anomalies in children with renal agenesis or multicystic dysplastic kidney

This study aimed to determine the frequency of associated urological abnormalities in children with unilateral renal agenesis (RA) or multicystic dysplastic kidney (MCDK). In total, 38 children (10 girls, 28 boys) were studied: 21 with RA and 17 with MCDK. In 14 children (37%) anomalies of the urinary tract were suspected prenatally in ultrasound studies. In the remaining 24 children the diagnosis of RA/MCDK was made postnatally: in 13 (34%) in the first 7 days of life, in 11 (29%) at the age of 8 days to 34 months, mean 10.6+/-8.05 months. Voiding cystourethrography was done in 36 (95%) children, the isotopic 99mTc-EC/DMSA scan of the kidney in 29 (67%), and urography in 8. Urological anomalies were present in 11 (29%) children: in 7 (33%) with RA and in 4 (24%) with MCDK. Vesicoureteral reflux was diagnosed in 8 children: grade II in 4, III in 3, and IV in 1 (in 1 child to duplicated, in 1 to ectopic kidney); ureterovesical junction obstruction in 2 (9.5%); and ureteropelvic junction obstruction in 1 (4.8%). Among them, 2 children demanded surgery on the contralateral urinary tract: pyeloplasty in 1, antireflux procedure in 1; while 9 children were treated conservatively. Compensatory hypertrophy of the contralateral kidney was found in 90% of children. Thus due to an increased risk of pathological changes in the single functioning kidney, lifelong nephrological care is recommended in patients with unilateral RA/MCDK.

Perinatal assessment of hereditary cystic renal diseases: the contribution of sonography

The aims of this review article were to clarify the steps that may lead to a proper diagnosis of fetal and neonatal renal cystic diseases. All the hereditary cystic diseases are reviewed and a classification is proposed. The various sonographic patterns that can be used to ascertain the diagnosis are also reviewed. Finally, tables with differential diagnoses are presented to help the reader in the work-up of such pathologies.