Unilateral multicystic dysplastic kidney

[Developmental abnormalities of the kidney]

Les anomalies du développement rénal sont fréquentes chez le fœtus et correspondent à un défaut des étapes de la néphrogenèse. La plupart d’entre elles ont une évolution favorable, mais la gravité potentielle de certaines malformations rend leur dépistage et leur prise en charge précoce essentiels. Le dépistage de ces anomalies repose sur l’échographie fœtale. L’échographie devra préciser le pronostic de l’anomalie en recherchant des critères de gravité, tels qu’une atteinte rénale bilatérale, une altération de la quantité de liquide amniotique, témoin d’une altération de la fonction rénale fœtale, ou encore l’existence d’atteintes extra-rénales associées. Dans les cas les plus sévères, une prise en charge dans un centre pluridisciplinaire de diagnostic prénatal (CPDPN) est indispensable. Les anomalies du développement rénal peuvent être isolées ou s’inscrire dans le cadre d’un syndrome poly-malformatif. L’apport de la génétique dans la compréhension de ces anomalies est d’une aide considérable.

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.

Diagnostic accuracy of midtrimester antenatal ultrasound for multicystic dysplastic kidneys

OBJECTIVES

To establish the diagnostic accuracy of obstetric ultrasound at a tertiary fetal medicine center in the prenatal detection of unilateral and bilateral multicystic dysplastic kidney (MCDK) in fetuses in which this condition was suspected, and to undertake a systematic review of the relevant literature.

METHODS

This was a retrospective observational study of all cases referred to a regional tertiary fetal medicine unit due to suspicion of either unilateral or bilateral MCDK between 1997 and 2015. Diagnosis was confirmed by postnatal ultrasound reports or postmortem examination. The accuracy of prenatal ultrasound in the diagnosis of MCDK was calculated. Using a systematic search strategy we also performed a review of the literature regarding the prenatal diagnosis and diagnostic accuracy of MCDK.

RESULTS

We included 144 women in our analysis; 37 (25.7%) opted for pregnancy termination (TOP) (due to unilateral MCDK with additional abnormalities, suspected bilateral MCDK or severe obstructive uropathy). Complete pre- and postnatal data were available in 126 pregnancies, including 104 livebirths, 19 TOPs with postmortem findings available and three intrauterine fetal deaths. Two infants died shortly after birth (due to known bilateral MCDK or known cranial vault defect). The overall number of cases of MCDK confirmed postnatally was 100; of these, 98 were diagnosed prenatally (true positive), while two were thought to be hydronephrosis prenatally (false negative) and the diagnosis of MCDK was made after birth. In nine cases, the initial antenatal diagnosis of suspected MCDK was revised, either later in pregnancy (n = 2) or postnatally (n = 7) (false positive). Overall, the diagnostic accuracy in our population for the use of antenatal ultrasound to detect MCDK was 91.3%, while that reported in the existing literature was found to range from 53.3% to 100%. MCDK was isolated in the majority (71%) of cases, while in 29% of cases it was found to be associated with other renal and extrarenal fetal abnormalities.

CONCLUSIONS

Antenatal ultrasound had a diagnostic accuracy of about 91% in the prediction of postnatal MCDK and can therefore be used to guide antenatal counseling. However, prenatal or postnatal revision of the diagnosis occurred in about 7% of cases and parents should be counseled appropriately. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Congenital Anomalies of the Kidney and Urinary Tract (CAKUT)

Congenital anomalies of the kidneys and urinary tract (CAKUT) are found in 3-6 out of 1.000 of the newborns, or according to some statistics they are represented in 0.5% of all pregnancies. Congenital abnormalities of the kidneys and urinary tract present a family of diseases of various anatomic spectrum, including renal anomalies, and anomalies of the bladder and urethra. The study was retrospective-prospective which means that it included newly diagnosed patients suffering from CAKUT, as well as those patients with already diagnosed and well defined CAKUT on the basis of imaging studies which have been processed according to the protocol for this study.

Congenital anomalies of kidney and hand: a review

‘Acro-renal syndrome’ refers to co-occurrence of congenital renal and limb anomalies. The term acro-renal syndrome was coined by Curran et al. in 1972 though Dieker and Opitz were the first to report this phenomenon in three male patients in 1969. The common limb defects include oligodactyly, ectrodactyly, syndactyly or brachydactyly anomalies of the carpal and tarsal bones and the common renal anomalies observed are unilateral renal agenesis (URA), bilateral renal hypoplasia, ureteric hypoplasia, hydroureteronephrosis and duplication abnormalities. The acro-renal syndrome as originally described is rare, reported only in ∼20 patients in the international literature. We report a 23-year-old male patient with renal anomalies in the form of absent right kidney, left-sided vesicoureteric reflux (VUR) and skeletal anomalies viz short radius, absent first metacarpal ray in left hand and left undescended testis, consistent with Dieker's type acro-renal syndrome. Apart from the classical acro-renal syndrome, several anomalies of acro-renal patterns and the abnormal gene loci involved are described in the literature. This article is a comprehensive review of the development of kidneys, types of acro-renal syndromes, congenital anomalies of the kidney and urinary tract (CAKUT), syndromes associated with combined limb and renal anomalies, and anomalies associated with URA.

Unilateral multicystic dysplastic kidney: a meta-analysis of observational studies on the incidence, associated urinary tract malformations and the contralateral kidney

BACKGROUND

Many papers are published on cohorts with unilateral multicystic dysplastic kidney (MCDK) patients, but show variable results as to the incidence of associated urinary tract abnormalities. The objective of this study was to describe the status of the urinary tract, including contralateral hypertrophy and malformations, in patients with unilateral MCDK based on a meta-analysis of the literature, taking into account the timing of diagnosis (pre- versus postnatal) as a possible source of bias.

METHODS

A systematic review of the scientific literature in English was conducted using PubMed and Embase. A meta-analysis was performed with the studies that were identified using our reproducible search.

RESULTS

Based on analysis of the data in 19 populations, the overall incidence of unilateral MCDK is 1 in 4300 with an increasing trend over the years. A total of 67 cohorts with over 3500 patients with unilateral MCDK were included in the meta-analysis. Fifty-nine percent of patients were male and the MCDKs were significantly more often found on the left side (53.1%). Associated anomalies in the solitary functioning kidney were found in 1 in 3 patients, mainly vesicoureteric reflux (VUR, in 19.7%). In patients with VUR, 40% have severe contralateral VUR, defined as grade III-V. Contralateral hypertrophy, present in 77% of patients after a follow-up of at least 10 years, showed a trend to be less pronounced in patients with VUR. Timing of the diagnosis of MCDK did not essentially influence the results.

CONCLUSIONS

These aggregate results provide insight into the incidence, demographic data and associated anomalies in patients with unilateral MCDK. One in three patients with unilateral MCDK show anomalies in the contralateral, solitary functioning kidney. However, studies into the long-term consequences of these anomalies are scarce.

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.

Perspectives on human perinatal renal tract disease

Perinatal renal tract disease is the main cause of end-stage renal failure in children. The diagnosis also includes many disorders of lesser severity, which may cause morbidity, such as hypertension, in later life. There remain uncertainties in the accuracy of some fetal diagnoses, and the life-time outcomes of children born with renal tract disease, who survive the neonatal period, are not known. There is a need for prospective trials to establish the efficacy, if any, with regard to protection of long-term kidney function of existing 'therapies', such as prenatal surgical decompression and postnatal drugs, which might slow the progression of renal failure. Specific drugs, which may block the growth of renal cysts, are being tested in humans. Advances in genetics are uncovering specific mutations in some children with renal tract malformations, providing parent and carers with explanations for the occurrence of such diseases.

[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.