Multicystic dysplastic kidney detected by prenatal ultrasonography: natural history and conservative management

Conservative management of multicystic dysplastic kidney (MCDK) without nephrectomy has recently been advocated. The purpose of this study was to determine the clinical course of conservatively managed unilateral MCDK detected prenatally. Between 1991 and 2001, ten children (three boys and seven girls) with unilateral MCDK detected by prenatal ultrasonography (US) were prospectively followed at our institution. At birth, US confirmed the prenatal findings in all cases. All patients underwent voiding cystourethrography, intravenous pyelography, and radionuclide scans. Postnatal follow-up US examinations were performed every 3 months until patients were 5 years old and annually from then forward. The mean age at diagnosis during the prenatal period was 29 weeks of gestation (range 21-38 weeks). Median follow-up time was 42 months (range 17-125 months). Follow-up US was performed in eight children; three (38%) showed partial resolution, three (38%) complete resolution, and two (24%) no change in cyst size. The mean age at complete resolution of the lesion was 23 months (range 9-33 months). No children developed hypertension or tumors, and all maintained normal growth. In the present study, the natural history of MCDK was benign, and serial US monitoring showed that the affected kidneys frequently showed resolution with time. The results of this study support the conclusion that a nonsurgical approach for patients with MCDK is advisable.     

微创开放切口肾切除术治疗儿童多房性肾囊性变

目的总结微创开放切口肾切除术治疗小儿多房性肾囊性变(MCDK)的初步经验。方法回顾性分析2008年5月-2010年10月本院连续开展的微创开放切口肾切除术治疗小儿MCDK 15例的临床资料。患儿均为单侧MCDK,均经CT、放射性核素显像和超声检查确诊。对侧功能肾脏未发现异常。男12例,女3例;右侧5例,左侧10例。手术均经腹膜后间隙完成。取腰肋部开放切口,长度1.5～2.0 cm(平均1.7 cm)。手术时年龄3个月～5.6岁(平均2.4岁)。手术时间30～45 min(平均34.6 min)。所有手术术中估计出血量<5 mL。术后静脉予抗生素预防感染2～4 d。结果本组手术均成功。患儿术后住院2～4 d(平均2.8d)。全部患儿术后随访未发现术后并发症。结论微创开放切口肾切除术治疗儿童MCDK可以达到通过开放切口实现微创治疗的目的。本方法手术时间短,美容效果好,术后住院时间短,且安全、有效,容易开展。     

Multicystic dysplastic kidney detected by fetal sonography: conservative management and follow-up

The most common cystic lesion recognized antenatally is multicystic dysplastic kidney (MCDK). Recently, conservative management without nephrectomy has been advocated. The purpose of this study was to report our experience in the conservative management of unilateral MCDK. Between 1989 and 1997, 20 children with MCDK detected by prenatal ultrasonography (US) were prospectively followed. At birth, US confirmed the prenatal findings in all cases. All patients were submitted to radioisotope scans and a micturating cystogram. Follow-up US examinations were performed annually. Mean age at diagnosis during the prenatal period was 31 weeks of gestation (range 24–38). Median follow-up time was 33 months (range 7–91). Follow-up US was performed in 19 children; 13 (68%) showed partial involution, 4 (21%) complete involution, and 2 (11%) an increase in unit size. The mean age at complete or partial involution of the lesion was 18 months. No children developed hypertension or tumors, and all maintained normal growth. In conclusion, the natural history of MCDK is usually benign, and serial US examinations show that affected kidneys frequently show involution with time. Accepted: 14 November 1999     

Nephrectomy for multicystic dysplastic kidney and renal hypodysplasia in children: where do we stand?

Objectives

Little is reported in literature regarding correct management of benign lesions of the kidney. The aim of our study is to present a series of total and partial nephrectomies performed in the last 5 years and to discuss indications.

Materials and methods

Patients with benign lesions who underwent nephrectomy and partial nephrectomy at our institution in the period 2003–2008 were retrospectively included in the study. Notes were carefully reviewed and demographic data, symptoms onset, preoperative diagnosis, investigations, medical and/or surgical treatment, postoperative complications and definitive histological reports were collected.

Results

Forty procedures were performed. Twelve patients were preoperatively diagnosed of having multicystic dysplastic kidney (MCDK), which was confirmed in 10, whereas the remaining 28 patients of having severe dysplasia or hypodysplasia. Thirty-four patients underwent total nephrectomy, six underwent partial nephrectomy. Histopathological analysis confirmed segmental or complete abnormalities of the involved kidney in all cases. No malignancies were detected.

Discussion

Our study confirmed the extremely low malignancy rate of MCDK and hypodysplastic kidneys. The 20% mismatch of pre- and post-operative diagnosis suggests a common aetiology and shared therapeutic strategies for MCDK and hypodysplasia. At present, there is no consensus regarding correct indications for nephrectomy in paediatric age. As nephrectomy seems not to provide any advantage over preservation, but surgical and anesthesiological risks, we should be prudent in preserving every asymptomatic poorly or non-functioning kidneys maintaining a strict follow-up. Randomised controlled studies on larger multicentric series are strongly warranted to define this topic.     

Involution of multicystic dysplastic kidney: Is it predictable?

ObjectiveTo evaluate the clinical course of multicystic dysplastic kidney (MCDK) and to reveal any criteria indicating spontaneous involution.Material methodsHospital records of patients with MCDK followed in two different institutions in 1994–2009 were reviewed and data were analyzed regarding involution.ResultsRecords 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%.ConclusionReviewing 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.     

Renal dysplasia in infants: Apperance on99mTc DMSA scintigraphy

Infantile renal dysplasias, including multicystic dysplastic kidneys (MCDK), are reported rarely to accumulate radiopharmaceuticals on renal scintigraphy.^99mTc DMSA is a highly sensitive tracer for detecting functioning renal cortical tissue and may be more suited to studying renal dysplasia than^99mTc DTPA. We reviewed the ultrasound studies and^99mTc DMSA scintigrams of 42 infants (age range 1–12 months) with known or suspected MCDK. Overall, uptake on^99mTc DMSA scintigraphy was evident in 6/41 (15%) dysplastic kidneys. Of the 18 patients who underwent nephrectomy, histopathological examination revealed that uptake correlated closely with the presence of mature renal cortical tissue in the affected kidney. Our study shows that a small, but significant number of MCDK will show low-grade uptake on DMSA scintigraphy. This finding may be relevant given the reliance placed on renal scintigraphy in planning treatment for infants with suspected MCDK, particularly with the increasing trend for the non-operative management of this condition.     

A spectrum of segmental multicystic renal dysplasia

Background. Multicystic renal dysplasia (MCDK) is a common anomaly well described in the literature, but less well described when involving only a portion of a kidney. Objective. To present the imaging spectrum, natural history and associated anomalies of six kidneys with segmental MCDK. Materials and methods. Five children with segmental MCDK (one with bilateral segmental MCDK) referred to our hospital between 1989 and 1996 were reviewed. All had at least one ultrasound examination. Four had a voiding cystogram and three had renal scintigraphy. Results. Four children had antenatal diagnosis of cystic renal abnormality. In two, with obvious duplex kidneys and associated ureteroceles, the diagnosis of upper moiety MCDK was obvious either antenatally or immediately postnatally. In the other three there were diagnostic difficulties. One patient had bilateral widespread cysts obscuring the functioning renal portions. Another presented in utero with a large ureterocele and a cystic upper pole that had involuted by birth. The fifth had a nephrectomy at 3 years for a multiloculated cystic mass. Varying degrees of involution occurred in the five kidneys seen early. Reflux was demonstrated into the ipsilateral functioning lower moiety and midpole. Conclusion. In these children as in other studies, the commonest presentation of segmental MCDK is in the upper pole of a duplex kidney associated with a ureterocele at the end of the atretic ureter. Atypical segmental MCDK may present a diagnostic dilemma and should be included in the differential diagnosis of multiloculated cystic masses and cystic kidneys. Received: 16 June 1998 Accepted: 16 November 1998     

Unilateral multicystic dysplastic kidney: the case for nephrectomy

Management of unilateral multicystic dysplastic kidneys (MCDK) presents physicians and surgeons with a significant dilemma. Recent studies have indicated that the incidence of short term complications of MCDK is low and many authors have recommended conservative non-operative treatment. Surgery has been proposed by some because of the potential complications of hypertension, infection, and malignant change. Three children with hypertension secondary to MCDK seen at this institution in the past four years, one of whom had been discharged from follow up as a result of 'disappearance' of the cystic kidney on ultrasound examination, are reported. We believe that the risks of hypertension secondary to MCDK have been understated, and that based on the conclusions of these studies, many children may be receiving suboptimal follow up. We currently favour elective nephrectomy as the treatment of choice for this lesion.     

Unilateral multicystic dysplastic kidney: the case for nephrectomy

Accepted 28 August 1996Management of unilateral multicystic dysplastic kidneys (MCDK) presents physicians and surgeons with a significant dilemma. Recent studies have indicated that the incidence of short term complications of MCDK is low and many authors have recommended conservative non-operative treatment. Surgery has been proposed by some because of the potential complications of hypertension, infection, and malignant change. Three children with hypertension secondary to MCDK seen at this institution in the past four years, one of whom had been discharged from follow up as a result of `disappearance'' of the cystic kidney on ultrasound examination, are reported. We believe that the risks of hypertension secondary to MCDK have been understated, and that based on the conclusions of these studies, many children may be receiving suboptimal follow up. We currently favour elective nephrectomy as the treatment of choice for this lesion.     

Multicystic dysplastic kidney: Impact of imaging modality selection on the initial management and prognosis

ObjectiveTo evaluate the impact of imaging modalities on the evaluation and prognosis of children with multicystic dysplastic kidney (MCDK) disease.Patients and methodsA 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.ResultsAt 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.ConclusionsThe 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.     

Does the multicystic dysplastic kidney really involute? The role of the retroperitoneoscopic approach

ObjectiveTo assess the role of video-assisted retroperitoneoscopy in the follow up of multicystic dysplastic kidney (MCDK) that has involuted – disappeared? – on serial renal ultrasonography (US).Patients and methodsProspectively, we performed a retroperitoneoscopy in 14 patients, nine girls and five boys, with unilateral MCDK that had involuted on serial US. MCDK was diagnosed in utero (80%) and confirmed postnatally by US and Tc99m dimercaptosuccinic acid radionuclide scan. Follow up US examinations were performed at 1 month, 5 months and 12 months in the first year of life and every 6 months from then on. US showed complete involution at a mean age of 13 months (range 5–18 months). Retroperitoneoscopy was then indicated, at a mean age of 23 months (range 8–24 months), to confirm the disappearance of the kidney dysplastic remnant.ResultsRetroperitoneoscopy detected persistence of anomalous kidney tissue in 100% of cases. The mean length of the renal remnant was 2 cm (range 1–3.5 cm). Two cases showed a pelvic ectopic location that was not detected by US before involution. The remnant was removed during the same procedure. Anatomo-pathological findings were found to be compatible with dysplastic renal tissue. There were no intra- or postoperative complications. All patients had a mean length of stay of less than 24 h.ConclusionsComplete resolution on US does not mean disappearance of MCDK, as US does not detect renal dysplastic remnants after cyst involution has occurred. The retroperitoneoscopic approach to the renal and pelvic area is a minimally invasive, safe and effective procedure to diagnose and treat the renal dysplastic remnant in US-involuted MCDK.     

Multicystic dysplastic kidney disease and hypertension: clinical and pathological correlation

We report on a child with hypertension secondary to MCDK who underwent an elective retroperitoneoscopic nephrectomy and is normotensive on follow up. We looked at the pathological correlation with respect to the hypertension caused by a non-functioning kidney.     

The impact of vesicoureteral reflux on contralateral renal length in infants with multicystic dysplastic kidney

Purpose. The purpose of our study was to determine the influence of vesicoureteral reflux (VUR) on contralateral renal length in neonates and young infants with unilateral multicystic dysplastic kidney (MCDK). Material and Methods. We reviewed the imaging findings in 48 term neonates and infants (27 boys; 21 girls) who had unilateral MCDK (mean age at diagnosis 0.09 years; range 0–0.64 years). Each had renal ultrasonography (RUS), renal scintigraphy, and voiding cystourethrography before 1 year of age. The diagnosis of MCDK was based on characteristic imaging findings (i. e., an echogenic, cystic kidney at RUS that did not function at scintigraphy). None had contralateral hydronephrosis or cysts. We calculated an age-corrected z-score for contralateral renal length (at RUS) in each patient based on published standards. We examined the effects of gender, ipsilateral or contralateral VUR, and age at RUS on the contralateral renal length using multifactor ANOVA. Results. Nine patients (19 %) had VUR into the contralateral kidney. The refluxing kidneys were significantly shorter (renal length: median 5.1 cm, mean 5.07 cm; z-score: median − 0.43, mean − 0.58) than the nonrefluxing kidneys (renal length: median 6.2 cm, mean 6.08 cm; z-score: median 1.03, mean 1.04; P < 0.001). The contralateral kidney was more than 1 SD longer than the mean for age in none of the 9 patients with VUR on that side. By comparison, the contralateral kidney was more than 1 SD longer than the mean for age in 21 (54 %) of 39 patients with no VUR on that side, and more than 2 SD longer than the mean in 5 (13 %). Conclusion. VUR into the kidney contralateral to a MCDK is associated with smaller size of that kidney during the first year of life. Received: 16 January 1998 Accepted: 13 April 1998     

Contralateral renal abnormalities in multicystic-dysplastic kidney disease.

Multicystic-dysplastic kidney (MCDK) disease has been associated with contralateral genitourinary tract abnormalities; however, neither the nature nor the prevalence of the contralateral renal lesion has been delineated. We retrospectively studied patients with MCDK disease to determine the prevalence of contralateral renal abnormalities and of other urologic anomalies. Forty-nine patients, ranging in age from neonates to 6 years, were examined by renal ultrasonography, excretory urography or nuclear medicine scanning, and voiding cystourethrography; 51% of the patients had an associated urologic abnormality. The abnormality was contralateral to the MCDK in 19 patients (39%), ipsilateral in 3 patients (6%), and involved the bladder wall in 3 patients (6%). The most common contralateral genitourinary tract abnormality was vesicoureteral reflux (18%) followed by ureteropelvic junction obstruction (12%). We conclude that urologic anomalies are common in patients with MCDK disease; contralateral vesicoureteral reflux is the most common abnormality identified.     

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

ObjectiveImaging 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 materialsInstitutional 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.Results301 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.ConclusionAs 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.     

Ultrasound diagnosis of multicystic dysplastic kidney: Is a confirmatory nuclear medicine scan necessary?

ObjectiveIt is critical to differentiate between a multicystic dysplastic kidney (MCDK) and a kidney with severe hydronephrosis as the treatment varies significantly. We designed a study to compare renal ultrasound (RUS) to nuclear medicine (NM) scan in the diagnosis of MCDK, in order to determine if RUS can be used for the definitive diagnosis of MCKD without use of NM scan.Materials and methodsWe performed a retrospective review of children with MCDK, who underwent both a RUS and Tc-99m MAG3 or DMSA scan. We planned to calculate the positive predictive value of an RUS diagnosis of MCDK, using NM scan diagnosis of a nonfunctioning kidney as the gold standard.ResultsThe diagnosis of MCDK was made by RUS in 91 patients, 84 of whom had a normal bladder US. NM confirmed the diagnosis of MCDK in all 84 of these patients (100%).ConclusionWe have demonstrated a high predictive value for RUS in the diagnosis of MCDK. Our data support that in healthy infants with RUS diagnosis of unilateral MCDK and normal bladder US, NM scan may be unnecessary to confirm the diagnosis.     

Unilateral multicystic dysplastic kidney: long term outcomes.

AIMS: To report the long term follow up of children with antenatally detected unilateral multicystic dysplastic kidney (MCDK) with documentation of complications, involution rate with time, and renal function at 10 years. METHODS: Data were retrieved from a prospective regional registry of patients with MCDK between 1985 and 2004. Children were followed using a common protocol of investigation with follow up ultrasound scans (USS) at 2 (165 patients), 5 (117 patients), and 10 years (43 patients). RESULTS: Serial USS showed that 33% of the MCDK kidneys had completely involuted at 2 years of age, 47% at 5 years, and 59% at 10 years. No patients developed hypertension, significant proteinuria, or malignancy, but two developed pelviureteric junction obstruction in the contralateral kidney. Twenty seven of 143 children (19%) had vesicoureteric reflux (VUR) (96% mild to moderate VUR) into the contralateral kidney with no difference in the incidence of urinary tract infections or renal scarring between those with or without VUR. The mean estimated glomerular filtration rate (GFR) was 86.4 ml/min/1.73 m2 (range 48-125) in 31 of 43 patients followed to 10 years. CONCLUSIONS: Conservative management of unilateral MCDK is justified with clinical review and infrequent USS but longer term follow up continues in the 41% still with renal remnants at 10 years and those with impaired GFR. It is suggested that the initial micturating cystogram is deferred unless abnormal USS features are present in the contralateral kidney or ureter.     

Outcome of Multi-Cystic Dysplastic Kidneys in Children

Background:

Renal cystic diseases are important causes of chronic kidney disease (CKD).

Objectives:

We report the pattern of renal cystic disease in children and evaluate the outcome of children with multicystic dysplastic kidney (MCDK).

Patients and Methods:

Retrospective study of all children with cystic kidney diseases at King Abdulaziz University hospital from 2006 to 2014.

Results:

Total of 55 children (30 males); 25 MCDK, 22 polycystic kidney diseases (PKD), 4 nephronophthises and 4 renal cysts. Consanguinity was positive in 96.2%. MCDK and simple renal cyst patients had good renal function while PKD and nephronophthisis developed renal impairment. Most MCKD were diagnosed ante-natally, 16 of them were followed up for 3.4 (1.97) year. Their last creatinine was 33.9 (13.5) umol/L. MCDK was spontaneously involuted at mean age of 2.6 (1.3) years in 56%.

Conclusions:

MCDK is the commonest cystic renal disease and diagnosed ante-natally in the majority of cases. It has a good prognosis.     

Unilateral multicystic dysplastic kidney: long term outcomes

Aims

To report the long term follow up of children with antenatally detected unilateral multicystic dysplastic kidney (MCDK) with documentation of complications, involution rate with time, and renal function at 10 years.

Methods

Data were retrieved from a prospective regional registry of patients with MCDK between 1985 and 2004. Children were followed using a common protocol of investigation with follow up ultrasound scans (USS) at 2 (165 patients), 5 (117 patients), and 10 years (43 patients).

Results

Serial USS showed that 33% of the MCDK kidneys had completely involuted at 2 years of age, 47% at 5 years, and 59% at 10 years. No patients developed hypertension, significant proteinuria, or malignancy, but two developed pelviureteric junction obstruction in the contralateral kidney. Twenty seven of 143 children (19%) had vesicoureteric reflux (VUR) (96% mild to moderate VUR) into the contralateral kidney with no difference in the incidence of urinary tract infections or renal scarring between those with or without VUR. The mean estimated glomerular filtration rate (GFR) was 86.4 ml/min/1.73 m² (range 48–125) in 31 of 43 patients followed to 10 years.

Conclusions

Conservative management of unilateral MCDK is justified with clinical review and infrequent USS but longer term follow up continues in the 41% still with renal remnants at 10 years and those with impaired GFR. It is suggested that the initial micturating cystogram is deferred unless abnormal USS features are present in the contralateral kidney or ureter.     

Uterus didelphys with unilateral vaginal atresia: multicystic dysplastic kidney is the precursor of ��renal agenesis�� and the key to early diagnosis of this genital anomaly

Background

Uterus didelphys with obstructed hemivagina (UDWOH) and ipsilateral renal agenesis is a distinct but rare entity.

Objective

To demonstrate the association between UDWOH and a multicystic dysplastic kidney (MCDK) in neonates. To demonstrate the usefulness of sonography with vaginal fluid instillation in the early and reliable diagnosis of this genital anomaly in girls with MCDK.

Materials and methods

Our patients were five female neonates with a MCDK, which had been detected in utero. We performed sonography of the internal genitalia in all patients before and after filling the vagina with saline.

Results

In all five girls, sonographic examination revealed uterus didelphys with obstruction of the vagina ipsilateral to the MCDK. In three girls, a dilated ureter originating from the MCDK and extending to the level of the vagina could be clearly demonstrated, with one of these including the ureteric insertion into the atretic vagina.

Conclusion

MCDK is key to the early diagnosis of UDWOH and will facilitate the provision of appropriate treatment. The neonatal period provides a unique opportunity for detecting uterine anomalies by sonography. An MCDK usually involutes and eventually mimics renal agenesis later in life.