Early diagnosis of solitary functioning kidney: comparing the prognosis of kidney agenesis and multicystic dysplastic kidney.

BACKGROUND: Individuals with congenital solitary functioning kidney (SFK) are at an increased risk of kidney damage. According to some studies, the risk is higher in unilateral kidney agenesis (UKA) than in unilateral multicystic dysplastic kidney (UMCDK). We hypothesized that with early detection of children with UKA and UMCDK, there would be no difference in the presence of hypertension, proteinuria, and reduced glomerular filtration rate (GFR) between UKA and UMCDK. METHODS: Based on a long-term follow-up protocol, we evaluated a cohort of 160 children followed from birth for SFK (84 with UKA and 76 with UMCDK) detected by prenatal or routine neonatal ultrasound screening. Hypertension, proteinuria, and reduced GFR were monitored as markers of kidney damage. We compared the characteristics and outcomes of the subgroups of children with UKA and UMCDK. RESULTS: GFR was reduced in 42 (26.2%) children, of whom 41 showed only mild reduction. Hypertension and proteinuria were found in 22 (13.8%) and 14 (8.8%) children, respectively. Combined kidney damage was present in 57 (35.6%) children. The UMCDK and UKA subgroups differed in GFR at final examination, with UMCDK patients being significantly more likely to have normal GFR compared to UKA patients (82% vs. 67%; p = 0.039). CONCLUSIONS: One third of the children showed signs of SFK damage, albeit mild. Patients with UKA had reduced GFR significantly more often than those with UMCDK, but did not differ in the rates of hyperfiltration injury or congenital anomalies of the kidneys and urinary tract (CAKUT) in SFK.

Pathophysiological clinical features of an infant with hypertension secondary to multicystic dysplastic kidney: a case report.

BACKGROUND: The association of hypertension with congenital renal hypoplasia has been established. We report a case of an infant who underwent nephrectomy for hypertension. CASE PRESENTATION: Magnetic resonance imaging for the mother revealed fetal renal masses, and fetal multicystic dysplastic kidney was suspected. Following birth, the baby developed hypertension. Numerous investigations revealed that the left kidney was non-functional, and she was initiated on benazepril hydrochloride. However, because the drug response was poor, the left kidney was removed at the age of 7 months. Examination of the renal specimen revealed abrupt transition from normal to atrophic cortex with lobar atrophy and cysts. Tubular atrophy, marked abnormal blood vessels with wall thickening, gathered immature glomeruli, and parenchymal destruction were observed. Renin was partially localized in the proximal tubules and the parietal epithelium of the Bowman's capsule in the immature glomeruli. We speculated that an abnormal vascular structure and irregular renin localizations may be the cause of hypertension. Serum renin and aldosterone levels gradually reduced post-surgery, reaching normal levels on the 90th postoperative day. A long follow-up is needed due to the possibility of the child developing hypertension in the future. CONCLUSION: This is a case of an infant with MCDK, which discusses the clinicopathological features based on the pathophysiological analysis, including renin evaluation.

Voiding Cystourethrogram in Children With Unilateral Multicystic Dysplastic Kidney: Is It Still necessary?

OBJECTIVE: To evaluate the value of the voiding cystourethrogram (VCUG) in children with multicystic dysplastic kidney (MCDK) who have a normal versus abnormal contralateral kidney and bladder ultrasound (US), and assess the risk of having vesicoureteral reflux (VUR) or urinary tract infection (UTI) based on the US results. METHODS: A retrospective chart review including children with unilateral MCDK with postnatal US and VCUG available at our institution between January 2008 and September 2017 was performed. Analysis was done to find association between abnormal contralateral US and contralateral VUR and UTI. RESULTS: One hundred and fifty-six children were analyzed; 118(75.6%) patients had a normal contralateral kidney US, while 38(24.4%) had abnormal US. The rate of severe contralateral VUR (grade IV and V) was 2 (1.7%) and 5 (13.2%) in children with normal and abnormal contralateral US, respectively. The risk analysis demonstrated a significant association between severe VUR on the contralateral kidney and an abnormal contralateral US (odds ratio = 7.73; 95%CI: 1.43-41.81; P = 0.018) and no significant association with UTI (odds ratio = 1.58; 95%CI: 0.50-4.94; P = 0.435). CONCLUSION: Our data suggests, the rate of severe contralateral VUR in children with unilateral MCDK and normal contralateral kidney is low. VCUG should be considered for infants with proven MCKD and alterations on the contralateral kidney on US. Following patients with MCDK and normal contralateral kidney without the use of VCUG is a reasonable approach, unless there is development of signs and symptoms of recurrent UTI or deterioration of the renal function. We found that abnormal contralateral kidney US was associated with severe VUR.

Antenatally detected ureterocele: Associated anomalies and postnatal prognosis.

OBJECTIVE: We purposed to review prenatal diagnoses of ureterocele, to determine the sonographic findings and additional abnormalities, and to illustrate the pregnancy outcomes of these patients. MATERIAL AND METHODS: We reviewed the records of 24 patients with the diagnosis of ureterocele in our referral center between January 2010-March 2017. Prenatal sonographic findings, antenatal course, and postnatal follow-up were obtained. RESULTS: The mean gestational age at first US diagnosis was 24.5 ± 2.9 weeks. 13 (54.1%) of fetuses were female, and 11 (45.9%) were male. Ureterocele was associated with the duplex kidney in 17 (70.8%), MCDK in 5 (20.8%) and hydronephrosis with a single system in 1 (4.2%) and pelvic kidney in 1 (4.2%) fetuses. Postnatal follow-up was achieved in 22 of 24 (91.6%) cases, and mean follow-up interval was 56 ± 14.2. Months. The diagnosis of ureterocele was confirmed in 22 (91.6%) cases postnatally. 15 of 22 (68%) cases were classified as extravesical ureterocele, and 7 (32%) cases were intravesical ureterocele. Postnatal confirmation of duplex kidney achieved in 16 of 17 (94.1%) patients. 17 (77.2%) patients were required surgical intervention, and 5 (22.8%) cases were managed conservatively. 15 of 16 (93.7%) cases who were diagnosed duplex kidney underwent surgery however 2 of 5 (40%) cases which were confirmed MCDK required an operation. Cystoscopic ureterocele incision was the initial approach for the surgical management and performed all of the cases which required surgery. It was curative in 10 of 17 (58.8%) patients and 7 (41.2%) cases needed to further operations. Ureteroselectomy and common-sheath ureteroneocystostomy was performed in 5 (29.1%) cases and. 2 (%11.7%) cases underwent partial nephrectomy. CONCLUSION: Ureterocele can be accurately diagnosed by prenatal sonography, and it is a significant clue for the diagnosis of a duplex kidney. Postnatal prognosis depends on associated anomaly and presence of reflux and upper pole function.

Predictors of poor neonatal outcomes in prenatally diagnosed multicystic dysplastic kidney disease.

OBJECTIVE: Multicystic dysplastic kidney (MCDK) is one of the most common anomalies detected by prenatal ultrasound. Our objective was to identify factors associated with severe adverse neonatal outcomes of prenatally diagnosed MCDK STUDY DESIGN: A retrospective review of prenatally diagnosed MCDK (1 January 2009 to 30 December 2014) from a single academic center was conducted. The primary outcome was death or need for dialysis among live-born infants. Associations between prenatal characteristics and outcome were analyzed by Fisher's exact test and Mann-Whitney test. RESULTS: A total of 53 cases of prenatally suspected MCDK were included, of which 46 cases were live-born and confirmed postnatally (38 survivors, 8 non-survivors). Prenatally diagnosed extrarenal anomalies, bilateral MCDK, contralateral renal anomalies, and anhydramnios were significantly associated with death or need for dialysis (all p < 0.0001). CONCLUSIONS: Prenatally identified findings are associated with adverse neonatal outcome, and can guide counseling and management planning. In the absence of significant associated findings, prenatally diagnosed unilateral MCDK has a benign neonatal course.

Natural History of Contralateral Hypertrophy in Patients with Multicystic Dysplastic Kidneys.

PURPOSE: We evaluated predictive factors for compensatory hypertrophy and renal outcomes in a large cohort of patients with multicystic dysplastic kidneys. MATERIALS AND METHODS: We conducted a retrospective review from 1997 to 2016. Contralateral kidney and multicystic dysplastic kidney length were recorded from all ultrasounds as well as creatinine when available. We used generalized estimating equations to determine predictors of contralateral kidney length. RESULTS: A total of 443 children with multicystic dysplastic kidneys were identified based on sonographic findings and lack of function on nuclear scan. Average followup was 3.2 years (IQR 1.5 to 5.7). Median time to involution in patients diagnosed before age 2 years was 5.5 years (95% CI 3.8-7.0). In all patients the median time to contralateral hypertrophy was 2.7 years (95% CI 2.2-3.3), and 90% of patients manifested contralateral hypertrophy by 10 years. After adjusting for age, gender, multicystic dysplastic kidney side and cohort status for each year of involution after age 2 years, the contralateral kidney grows 0.35 cm longer (95% CI 0.01-0.68, p = 0.04) compared to cases without involution. Patients with contralateral hypertrophy had greater creatinine clearance at followup (83 vs 61 ml per minute, p = 0.07), although this finding was not statistically significant due to limited data. CONCLUSIONS: The majority of children with multicystic dysplastic kidneys will have contralateral hypertrophy by age 3 years. Multicystic dysplastic kidney involution predicts contralateral kidney growth rate after age 2 years. A small cohort of patients with multicystic dysplastic kidneys will not exhibit contralateral hypertrophy and may be at risk for renal insufficiency.

Unilateral multicystic renal dysplasia: Prenatal diagnosis on ultrasound.

Multicystic renal dysplasia (MCRD) is the most common cause of abnormally enlarged kidney, diagnosed on antenatal ultrasound examination. It is an abnormality of the embryonic development in which the renal parenchyma is substituted by nonfunctioning renal tissue made up of cysts which do not communicate with each other. Vesicoureteric reflux (VUR), pelviureteric junction obstruction, vesicoureteric junction obstruction, and ureterocele are the most commonly seen abnormalities in contralateral kidney. Here, we report a case of prenatal diagnosis of unilateral MCRD with VUR in contralateral kidney. In conclusion, we want to emphasize optimal use of ultrasound imaging to detect such abnormalities as early as possible to guide the proper management.

Outcomes of Pyeloplasty in Very Poorly Functioning Kidneys: Examining the Myths.

OBJECTIVE: To assess the perioperative complications and functional midterm outcomes after pyeloplasty for poorly functioning kidneys due to ureteropelvic junction obstruction. PATIENTS AND METHODS: We retrospectively analyzed patients who underwent pyeloplasty for primary ureteropelvic junction obstruction in very poorly functioning kidneys in terms of split renal function of ≤20% or estimated glomerular filteration rate of ≤20 mL/minute. Perioperative complications and postoperative outcomes in terms of symptomatic improvement and functional stabilization or recovery were assessed. RESULTS: A total of 32 patients with estimated glomerular filteration rate ≤20 mL/minute or split function ≤20% underwent pyeloplasty since January 2010. All patients were followed for a mean period of 26.8 months and none required reintervention for obstructive drainage, deteriorating function, or intractable pain. One patient had persistent pain requiring analgesics and overall success rate (defined as nonobstructive pattern, no deterioration in split function, and no persistent symptoms) was 93.7%. Thirteen patients (40.6%) showed significant improvement in renal function (>5% over preoperative), and in all except 1 (3.1%) case there was no further deterioration of function. CONCLUSION: Pyeloplasty provides high rates of morphological and functional success even in very poorly functioning renal units. There is a possibility of functional recovery in one-third of patients, and in most of the rest, there is no further deterioration.

Functional Results of Laparoscopic Pyeloplasty in Children: Single Institute Experience in Long Term.

OBJECTIVE: The aim of this study was to evaluate the long-term functional outcomes of laparoscopic pyeloplasty (LP) in children for consecutive cases of single institute. MATERIALS AND METHODS: Our laparoscopy database was investigated for children in terms of LP between June 2008 and April 2015. All the patients had ureteropelvic junction obstruction (UPJO) and LP was performed. Demographic data including age, gender, side of UPJO, operation time, estimated blood loss (EBL), hospital stay and complications according to Clavien classifications were recorded. Renal ultrasonography and diethylenetriamine penta-acetate (DTPA) scintigraphies were respectively performed 3, 12 and 24 months after surgery. Statistical analyses were performed and p value was accepted as significant at <0.05. RESULT: Mean follow-up was 34 ± 4.7 months. The mean age was 13 (6-72) months. A total of 153 (110 boys and 43 girls) LP patients enrolled. Of that, 93 (60.78%) LP were in left side and 60 (39.21%) were in right side. Three cases needed open conversation according to difficulties in anastomosis. Aberrant crossing vessel was observed in 12 (7.84%) patients. The mean operation time was 155 ± 21 min and the mean EBL was 22 ± 11.1 ml. The mean hospital stay was 3.4 days. Anastomotic leakage was the common complication (in 13 patients) that was successfully managed conservatively (Clavien 1). Eight patients experienced unsuccessful LP and underwent open pyeloplasty (Clavien 3b). The mean split renal function significantly increased in DTPA scintigraphy in follow-up. The overall success was 91%. CONCLUSIONS: The LP procedure can be an effective and safe surgical method for childhood UPJO, specifically in the experienced hands of pioneer centers.

Multicystic dysplastic kidney: a retrospective study.

OBJECTIVE: To report the renal structural and functional anomalies in children with multicystic dysplastic kidneys. METHODS: Retrospective descriptive analysis of 47 children with multicystic dysplastic kidney seen in a pediatric nephrology unit over a period of 6 years. RESULTS: Antenatal diagnosis of multicystic dysplastic kidney was made in 34 (72.3%) patients. On follow up of 31 children for more than 12 months, 21 (68%) had involution, 4 [13%] had non-regression, and 4 (13%) were nephrectomized. Vesico-ureteric reflux (n=13; 28%) was the commonest renal abnormality. The serum creatinine values were higher (P=0.006) in children with contralateral reflux. Sub-nephrotic proteinuria was noted in 9 (29%) and was significantly associated with complete involution (P=<0.023). None of the patients developed hypertension and 2 (6.4%) had renal failure. CONCLUSIONS: Close nephrological follow-up is needed in children with multicystic dysplasia of kidneys.

Epidermal nevus syndrome and dysplatic kidney disease.

Epidermal nevus syndrome is a rare congenital disorder, characterized by epidermal nevi and multiple organ involvement. Multicystic kidney disease has been very rarely reported in this syndrome. Here is the report of a boy presented with multiple epidermal nevi, cardiac anomaly, seizure attack, hemi hypertrophy, and multicystic dysplastic kidney complicated with Wilms' tumor. According to this association, it is suggested to search for dysplastic kidney disease in patients with neurocutaneous disorders.

Supranormal differential renal function in unilateral hydronephrotic kidney: insights from functional MR urography.

PURPOSE: To retrospectively assess supranormal differential renal function (DRF) in unilateral hydronephrotic kidney by functional MR urography (fMRU). MATERIALS AND METHODS: The ethics committees granted exempt status for this study and also waived the need for informed consent. A retrospective analysis was performed of all patients undergoing fMRU from January 2008 to November 2011. DRF was measured by both the area under the curve method and Rutland-Patlak plot. Glomerular DRF per unit of volume and kidney volumes were analyzed. Kidney volumes were compared with nomograms. RESULTS: Of 170 children, 3 patients (2, 12, and 14 years) with a left ureteropelvic junction obstruction were included. Glomerular DRF per unit of volume was slightly higher on the dilated side but remained within normal range (<55%). Dilated kidney volumes were higher on the dilated side (≥55%). The volumes of nondilated kidneys were within normal range. CONCLUSION: The data support the fact that the dilated kidney was not hyperfunctioning and that the nondilated kidney was not hypofunctioning. Based on these three patients, it could be assumed that supranormal DRF on the dilated side might be explained by a slight kidney volume asymmetry, in association with higher DRF per unit of volume, remaining within normal physiological range. J. Magn. Reson. Imaging 2014;40:577-582. © 2013 Wiley Periodicals, Inc.

Renal functional reserve in children with apparently normal congenital solitary functioning kidney.

OBJECTIVE: The aim of the study was to investigate renal functional reserve (RFR) and to assess its relationship with serum cystatin C and blood pressure in children with apparently normal congenital solitary functioning kidney (SFK). MATERIAL AND METHODS: RFR was obtained from the difference of endogenous creatinine clearance (CrCs) before and after a meat-free oral protein load (OPL) in the patients who were pre-treated with cimetidine. Serum cystatin C and urinary protein excretion were determined before and after OPL. RESULTS: Among 22 patients (13 boys), aged 9.5 ± 4.3 years, 72.7% had increased serum cystatin C, and 54.5% had decreased RFR. Following OPL, CrCs and urine creatinine increased, while serum creatinine and cystatin C remained unchanged. The multiple regression analysis demonstrated that cystatin C could predict more than 90% of RFR variability. CONCLUSION: Half of the patients with apparently normal SFK had decreased RFR. Serum cystatin C is one of the best predictors of RFR.

Multicystic dysplastic kidney: four-year evaluation.

OBJECTIVE: Multicystic dysplastic kidney is a relatively common developmental abnormality in infants and children. Additional abnormalities like vesicoureteral reflux, ureteropelvic junction obstruction, and ureterovesical junction obstruction may accompany multicystic dysplastic kidney. In this article, we reviewed the pathogenesis, diagnosis, associated urinary tract anomalies and results of management of multicystic dysplastic kidney in the light of the literature. MATERIAL AND METHOD: We retrospectively assessed 20 children with unilateral multicystic dysplastic kidney between January 2005 and December 2009. Mean duration of follow-up was 35 ± 8.7 months. All children with multicystic dysplastic kidney underwent nephrectomy. Patient characteristics, the pathology findings, associated urinary tract anomalies and results of management were reviewed. RESULTS: Abdominal ultrasound, voiding cystourethrography and renal scintigraphy revealed vesicoureteral reflux in 3 (15%) children, ureteropelvic junction obstruction in 3 (15%) children, and a duplex system in the contralateral kidney in 1 (5%) child. Blood pressure values, serum urea, creatinine and urinalysis were within normal range in all children during follow-up. CONCLUSION: A conservative approach to children with multicystic dysplastic kidney has been advocated, but surgical removal is also another management modality on the basis of risk of hypertension, mass effect, potential for malignant change, and cost of repeated ultrasound examination.

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.

Long-term risk of chronic kidney disease in unilateral multicystic dysplastic kidney.

The clinical spectrum of renal dysplasia includes the non-functioning multicystic dysplastic kidney (MCDK). We report our experience of the outcome of unilateral MCDK and its contralateral kidney in 101 children with the diagnosis of MCDK from 1985 to 2009. Data collected included urine protein/creatinine ratio, estimated GFR (eGFR), blood pressure, surgical intervention, renal length and abnormalities of the contralateral kidney, and the involution rate. There was a predominance of left-sided MCDK. Diagnosis was made prenatally in 86.7%. Contralateral abnormalities included vesicoureteral reflux (16.8%), UPJ obstruction (4.1%), and megaureter (2.4%). Complete involution of MCDK occurred within 5 years in 60%. Compensatory hypertrophy of the contralateral kidney to >97% occurred in 74.1%. Nephrectomy was performed in 19.8%. There was an increased risk of chronic kidney disease (CKD) stage ≥ 2, and hypertension in those with contralateral abnormalities (p<0.0001; p<0.001 respectively). In those without contralateral abnormalities, hyperfiltration with mean eGFR of 149 ± 13 ml/min/1.73 m(2) was seen in 32% and proteinuria in 9.8%. There was a significantly inverse relationship between proteinuria and eGFR (p<0.0001). In conclusion, children with contralateral abnormalities are at risk for developing decreased kidney function, whereas a substantial number of patients with no obvious contralateral abnormalities have markers of renal injury. Therefore, systematic follow-up of all patients is recommended.

Antenatal detection of pelviureteric junction stenosis: main controversies.

Although renography has been used for half a century to evaluate the function of the infant kidney, there are still important disagreements among the specialists involved in this particular pathology. Each department of nuclear medicine has his own way to acquire and process a renogram; to interpret the obtained images, curves, and quantitative parameters; and to make recommendations for the referring physician. The urologist has his or her part of responsibilities because the decision for operating or not operating varies from one center to another and is generally determined by a series of unproven assumptions. The aim of the present work is to focus on the main controversies involving both the nuclear medicine physician and the urologist. Concerning the technique of renography. The bladder catheter, systematically recommended in different centers, can best be replaced in most of the cases by a much less-invasive procedure, namely the acquisition and processing of late postmicturition (PM) posterect images. The change of patient's position contributes strongly to the renal washout. Intravenous hydration is used to standardize the level of hydration. However, the patients, in most of the cases, are in good health, and adequate oral hydration is sufficient. Even if hydration was not ideal when the procedure began, the administration of furosemide and the late PM images will result in a very good drainage of a normal kidney. Any renal tracer with high extraction rate is adequate, but diethylene triamine pentaacetic acid ((99m)Tc-DTPA) does not allow a precise estimation of differential function in children younger than 6 months. The moment of furosemide injection (F0, F+20, F-15) does not influence the quality of the final renal washout, and the F0 procedure is recommended in cases of known hydronephrosis because it shortens the time of acquisition on the gamma camera and allows the simultaneous injection of both the tracer and the diuretic. Background correction remains controversial among nuclear medicine physicians. Including in the background area some liver and spleen activity, which are responsible for an important part of the extrarenal activity within the renal area, will improve the quality of the renogram curve, suppressing almost completely the initial vascular phase. The supporters of the Rutland-Patlak (R-P) fit for calculating differential function state that the vascular component is eliminated better than with use of the classical integral method. However, this method is based on a slope, with counting statistics being rather poor in infants with immature function. In most of the cases, the integral method will provide robust results. Determination of the same differential function by the use of both methods increases the level of confidence of the final results. It is generally admitted that the first renogram in children with antenatally detected hydronephrosis should be performed at approximately 1 month of age. However, there is a tendency to start earlier, and even in the first days of life, in case of huge hydronephrosis. The renogram should be repeated in case of significant hydronephrosis, significant increase of dilation, poor response to furosemide, or low initial differential function. Moderate dilation associated with normal differential function can probably be monitored by ultrasound alone. T(½) of the diuretic curve is an empiric parameter that does not take into account the bladder emptying and the change of patient's position. Output efficiency (OE) and normalized residual activity (NORA), measured on the late PM and posterect images, represent physiological parameters not dependent on the input function of the considered kidney and can be used whatever the moment of furosemide injection. There is presently no way to quantitatively measure cortical transit in antenatally detected pelviureteric junction syndrome; all methods are limited by the slight kidney motion related to respiratory movements and by the almost-complete superimposition between cortical area and collecting system. The best approach probably is a visual estimation. Concerning the position of the urologist. The main controversy is related to the definition of obstruction and the indication for surgery. Neither the degree of hydronephrosis nor the impairment of differential function and/or the quality of the response to furosemide can define which kidney is in danger of further deterioration. Alternatively, these parameters are unable to predict for which kidneys an improvement of differential function can be expected because of a pyeloplasty. It has not been excluded, according to recent published work, that cortical transit could be a better predictive factor of the risk of a conservative attitude or the benefits of a surgical procedure, but this procedure has still to be confirmed.

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.

Hypertension and microalbuminuria in children with congenital solitary kidneys.

AIM: According to the hyperfiltration hypothesis, a low nephron endowment will lead to hyperfiltration in the remaining glomeruli and is associated with systemic hypertension, proteinuria and glomerulosclerosis. Being born with one functioning kidney instead of two, for instance because of unilateral renal agenesis or multicystic dysplastic kidney, is a cause of congenital renal mass reduction. METHODS: In order to study the effect of congenital renal mass reduction on renal function and blood pressure, a retrospective chart review of 66 patients at the Pediatric Renal Center of the VU University Medical Center was performed. As intrauterine growth restriction is associated with a low nephron endowment, the additional effect of birthweight was also studied. RESULTS: A total of 50% of patients with congenital renal mass reduction is found to be hypertensive, using anti-hypertensive drugs, and/or having microalbuminuria (>20 mug/min). Patients born small for gestational age have significantly smaller kidneys and lower estimated glomerular filtration rate than patients with a normal birthweight. CONCLUSIONS: We conclude that microalbuminuria and/or hypertension is present in 50% of patients with congenital solitary kidneys, which warrants a systematic follow-up of blood pressure, proteinuria and renal function in all patients with congenital solitary functioning kidneys, especially in patients with a low birthweight.