Nephrectomy for multicystic dysplastic kidneys: a new therapeutic option

Retrospective evaluation of the pediatric multicystic dysplastic kidney patients: experience of two centers from southeastern Turkey

Background/aim

The objective of this study is to determine the clinical features of unilateral multicystic dysplastic kidney (MCDK) patients.

Materials and methods

The demographic, clinical, laboratory, and radiologic features of MCDK patients at Diyarbakır Children’s Hospital and Diyarbakır Gazi Yaşargil Training and Research Hospital between January 2008-June 2019 were retrospectively evaluated.

Results

A total of 111 [59 (53.2%) male and 52(46.8%) female] patients with MCDK were followed for a mean period of 41.89 ± 32.03 months. MCDK was located on the left and right sides in 46 (41.4%) and 65 (58.6%) of the children, respectively (p > 0.05). A total of 87 (78.4%) patients had antenatal diagnosis. The mean age at diagnosis was 13.7 ± 34.2 months. Of the 49 voiding cystourethrogram (VCUG)-performed patients, vesicoureteral reflux was detected in 11 patients (22.4%). Other associated urological anomalies in the patients were detected in 12 (10.8%) patients. On Tc-99m dimercaptosuccinic acid (DMSA) scintigraphy which was performed in all patients showed scarring in four children. Eight patients had history of UTI (7.2%). Renal failure, hypertension, and proteinuria were diagnosed in three children (2.7%). Sixty-nine (62%) patients developed compensatory hypertrophy.

Conclusion

All cases should be followed up closely and VCUG should be reserved for patients with recurrent UTI and other urological problems indicated by ultrasonography and abnormal DMSA scan results.

Trends in surgical management of multicystic dysplastic kidney at USA children's hospitals

INTRODUCTION AND OBJECTIVE

Multicystic dysplastic kidney (MCDK) is a congenital renal cystic disease often incidentally diagnosed in children. Historically, children with MCDK underwent early nephrectomy because of concerns for the development of hypertension or malignancy. Over the last decade, management recommendations have not supported routine early surgical removal of MCDK. The study authors sought to determine the current trends in the use of nephrectomy for MCDK in US children's hospitals because national practice patterns have not been investigated.

METHODS

A population-based retrospective cohort study using the Pediatric Health Information System (PHIS) was conducted. The study population was comprised of patients aged 0-18 years with a diagnosis of MCDK (International Classification of Diseases-9th revision, code 753.19) admitted to the inpatient department of the study hospital between January 2006 and September 2015. Patients with additional renal anomalies including polycystic kidney, medullary cystic kidney, and medullary sponge kidney were excluded, as were patients treated in a hospital that did not contribute data to the PHIS continuously throughout the study period. Trends in the annual proportion of nephrectomies performed were analyzed among admissions in the study population, along with patient clinical and demographic information.

RESULTS

A total of 3792 MCDK admissions, in 34 hospitals, were included in the study. Overall, 569 nephrectomies were performed during the study period. The proportion of nephrectomy decreased annually by 9.2% on average, from 22.1% in 2006 to 7.3% in the first 3 quarters of 2015. No significant trends were observed in the annual number of overall MCDK admissions or patient age at procedure among patients who had a nephrectomy. Among nephrectomies, 84.2% were open and 15.8% were minimally invasive procedures (laparoscopic non-robotic, 10% and robotic, 5.8%). The proportion of minimally invasive nephrectomies increased annually by 13.7%, from 8% in 2006 to 29% in 2015.

DISCUSSION

Trends in the use of nephrectomy for MCDK at a national level have not been previously reported. This study is limited by the use of inpatient discharge data, which did not allow estimating the true rate of nephrectomy in patients born with MCDK.

CONCLUSIONS

During the study period, there has been a decrease in the use of nephrectomy for MCDK in pediatric hospitals, along with a concurrent increase in utilization of minimally invasive techniques to perform nephrectomies. These results suggest that in general, urologists at freestanding children's hospitals are heeding recommendations for observation and against routine early surgical removal of these kidneys; although trends in the use of nephrectomy varied between hospitals, there is room for continued improvement in following these recommendations.

Indications and relative renal function for paediatric nephrectomy over a 20-year period

BACKGROUND

The indications for partial or total nephrectomy for urological reasons are not clearly documented in the paediatric surgical literature and there are only a limited number of publications on this subject.

PURPOSE

In order to clarify the situation in our centre, we reviewed our own indications for nephrectomy over a 20-year period.

METHODS

Medical records of patients who underwent nephrectomy for urological and oncological causes between May 1990 and October 2010 at our centre were retrospectively reviewed. Indications for nephrectomy were noted. Renal function was noted for urological cases.

RESULTS

A total of 357 nephrectomies were undertaken; out of these, 241 cases were for urological causes and 116 for oncological reasons. The majority of total nephrectomies were performed for multicystic dysplastic kidneys, reflux nephropathy, pelvi-ureteric junction obstruction and dysplasia. Eighty-seven patients exhibited no function at the time of nephrectomy. Of the remainder, 17 had <5% function, 18 had 5-10% function, 5 had 10-15% function and 2 patients had 15-20% function.

CONCLUSIONS

This is the largest series of nephrectomies in the paediatric surgery literature to date. The majority of nephrectomies were undertaken for urological conditions with relative renal function of <10% and could not have been usefully preserved in situ. We suggest that kidneys with >10% function should not be routinely removed.

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.

Management and etiology of the unilateral multicystic dysplastic kidney: a review

In children, unilateral multicystic dysplastic kidney (MCDK) is one of the most frequently identified urinary tract abnormalities. A variety of proposed etiologies has been associated with the underlying pathogenesis of MCDK. These include genetic disturbances, teratogens, in utero infections, and urinary outflow tract obstruction. From 5-43% of the time, MCDK has associated genito-urinary anomalies, both structural and functional in nature. A review of the literature reveals that involution rates are reported to be 19-73%, compensatory hypertrophy of the contralateral kidney occurs from 24-81% of the time, and estimated glomerular filtration rates (GFRs) (by the Schwartz formula) range from 86-122 ml/min per 1.73 m(2) body surface area. Most authors suggest serial ultrasonography to monitor contralateral growth, routine blood pressure monitoring, and a serum creatinine monitoring algorithm. The risk of hypertension in those with MCDKs does not appear to be greater than that of the general population, and the rates of malignant transformation of MCDK are small, if at all increased, in comparison with those in the general population. If the patient develops a urinary tract infection or has abnormalities of the contralateral kidney, shown on ultrasound, a voiding cystourethrogram is recommended. Finally, the body of literature does not support the routine surgical removal of MCDKs.

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.