Involution of multicystic dysplastic kidney: is it predictable?

Outcome of children with multicystic dysplastic kidney: Does involved side matter?

BACKGROUND

Multicystic dysplastic kidney (MCDK) is a common anomaly detected on antenatal ultrasound. We aimed to assess the profile of children with MCDK and to investigate whether the involved side has any effect on outcome.

METHODS

Thirty-nine patients with MCDK and 20 controls were enrolled. Patients who estimated glomerular filtration rate (eGFR) values over 90 mL/min/1.73 m2 were compared with controls. Comparison was made between the involved sides.

RESULTS

MKDB was right-sided in 20 (51.3%) and left-sided in 19 (48.7%) patients. 33.3% had additional urinary tract abnormality, 10.2% had systemic abnormality. 82% showed contralateral kidney enlargement. 48.7% involuted, 17.9% underwent nephrectomy. 35.8% suffered from urinary tract infection (UTI). 5.1% had renal scarring (RS). 30% developed microalbuminuria. 12.8% complicated with hypertension. 17.9% progressed to chronic kidney disease (CKD). Hypertension was independent risk factor for developing CKD. Blood pressure, cystatin C and urine microalbumin/creatinine levels were increased, and eGFR values were decreased in patients compared to controls. No significant difference was found between the two sides for rates of involution, UTI, RS, nephrectomy, and additional abnormality. Cystatin C levels were higher on the right than left sides (p = .033).

CONCLUSION

Children with MCDK predispose to renal deterioration even at normal eGFR values. Although cystatin C levels tended to increase in right-sided patients, the involved side seemed to have no significant effect on renal outcome. Hypertension was main determinant for progression to CKD in MCDK.

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.

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.

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.

Applicability of Laparoscopic Nephrectomy in the Treatment of Multicystic Dysplastic Kidney: Sorting Out Surgical Indication

Introduction We evaluated the applicability of laparoscopic nephrectomy in the treatment of multicystic dysplastic kidney (MCDK) in children, including procedures performed by resident physicians or trainees in surgical urology. Methods We retrospectively evaluated the medical records of 20 children with MCDK who underwent laparoscopic nephrectomy over a six-year period. Data collected included gender, laterality of the affected kidney, age at the time of surgery, the largest diameter of the multicystic kidney and associated urological diagnoses, surgical, and postoperative data. All surgical procedures were performed transperitoneally. Results The mean age at the time of surgery was 46 months with a slight predominance of girls. The right side was the more affected side, and the average diameter of the affected kidney at the time of surgical excision was 5.8 cm. Other changes in the urinary tract were found in five children. The mean operative time was 133 minutes. On pathological examination, on average, the pieces measured 4.8 cm and weighed 18.1 g. There were no operative complications. The average length of hospital stay was 37.35 hours. Conclusion Laparoscopic nephrectomy was confirmed as an applicable treatment for MCDK. The technique was easy to perform, safe and efficient, even when performed by trainees in pediatric urology.

Multicystic Dysplastic Kidney and Sonography

Multicystic dysplastic kidney is a congenital anomaly that can affect the kidneys. It is generally unilateral and is characterized by multiple noncommunicating cysts in the renal parenchyma. This disease usually results in an enlarged, nonfunctioning kidney in the neonate. Recent advances in diagnostic medical imaging, especially in sonography, have enabled earlier detection of this disease, created better management and treatment options, and resulted in improved outcomes for patients. This case study demonstrates the use of early detection with sonography and the utilization of it for follow-up care. Sonography is ranked as the imaging modality of choice for patients with a clinical condition of renal failure and has the potential for an improved outcome for patients.

The natural history of the multicystic dysplastic kidney--is limited follow-up warranted?

OBJECTIVE

Imaging of patients with multicystic dysplastic kidney (MCDK) has increased over the past three decades. This increased use of imaging has provided additional insights into the natural history of MCDK. The present study looked at this data for predictors of involution and associated anomalies.

METHODS AND MATERIALS

Institutional review board approval was obtained for this retrospective study. The University of Michigan Departments of Urology and Radiology records were searched to identify unilateral MCDK patients during 1980-2012. Available clinical, radiological and surgical records were reviewed, and pertinent data were recorded. The log-rank test and a Cox proportional regression analysis were performed to identify predictors of MCDK involution. Probability of involution over time was assessed using Kaplan-Meier methodology.

RESULTS

301 unilateral MCDKs were identified; 195 (64.8%) were detected antenatally. Of the MCDKs found, 136 (45.2%) were in girls; 160 (53.2%) were right-sided. Mean size at baseline was 5.0 ± 0.2 cm (Mean ± SE). Associated abnormalities included: contralateral ureteropelvic junction obstruction (n = 10; 3.3%); contralateral ureterovesical junction obstruction/primary megaureter (n = 6; 2.0%); ipsilateral VUR (n = 21; 7.0%); contralateral VUR (n = 63; 20.1%); and renal fusion anomaly (n = 4; 1.3%). The cumulative probability of involution was: 9.8% at one year, 38.5% at five years, and 53.5% at ten years of age. Baseline MCDK size was the only significant predictor of involution at bivariate (p < 0.0001) and multivariate (p < 0.0001; HR 0.58 [95% CI: 0.49, 0.69]) analyses. No MCDK developed malignancy during the follow-up period.

CONCLUSION

As many MCDKs eventually involute and the risk of associated malignancy appears to be very low, there is no absolute indication for nephrectomy. Based on the data and other recent studies, it is believed that pediatric MCDK patients with no other urologic abnormalities can safely tolerate more limited urological and radiological follow-up.