Multicystic dysplastic kidney detected by prenatal ultrasonography: conservative management

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

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

Posterior Urethral Valve and Prenataly Resolved Multicystic Dysplastic Kidney

Multicystic dysplastic kidney is a rare congenital anomaly of the kidney and urinary tract. The association with the posterior urethral valve is also very rare. Here we present a patient with both entities and prenatal resolution of the cysts.A 10-week old baby was referred for nephrourological work up due to prenatal diagnosis of the left multicystic kidney. He had serial US scans during the pregnancy. Immediately before delivery the cysts were not seen (prenatal resolution). There were no extrarenal anomalies. The first postnatal ultrasound scan revealed normal sized right kidney without dilatation of the pelvicalyceal system. The bladder had normal thickness of the wall. Technetium-99m dimercaptosuccinic acid scan showed no activity on the left side, and the right kidney appeared normal. At two months of age, a poor urinary steam was observed and additional urologic work up was indicated on clinical suspicion of PUV. Voiding urethrocystography revealed posterior urethral valve and the baby underwent cytoscopic valve resection.Conclusion: We present a rare association of two congenital anomalies of the kidney and urinary tract with prenatal involution of the multicystic dysplastic kidney that is extremely rare event as seen in our case. Presence of posterior urethral valve must be suspected in a male baby with a poor urinary stream even when his ultrasound scan of urinary system appears normal.

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.

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.

Postnatal evaluation of infants with an abnormal antenatal renal sonogram

PURPOSE OF REVIEW

Antenatally detected renal abnormalities are frequently encountered. Recommended postnatal evaluation of these infants has evolved to minimize invasive testing while maximizing detection of significant abnormalities.

RECENT FINDINGS

There is a low rate of detectable renal abnormalities in infants with a normal postnatal sonogram at 4-6 weeks of age. Routine prophylactic antibiotics are not indicated in infants with isolated antenatal hydronephrosis. Infants with a multicystic dysplastic kidney and a normal contralateral kidney on renal ultrasound do not require further evaluation. Parents of these children should be counseled on symptoms of urinary tract infections to allow prompt diagnosis.

SUMMARY

All infants with abnormalities on antenatal sonogram should undergo postnatal evaluation with a sonogram after birth and at 4-6 weeks of age. Further evaluation can be safely limited when the postnatal sonogram is normal at 6 weeks of age.

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.