| Abstract|| |
The objective of the study is to review the indications for nephrectomy in children. This study was conducted in the Division of Pediatric Surgery at the King Hussein Medical Center, Amman, Jordan, between the years 1997 and 2009. The medical records of 119 of 141 patients who underwent nephrectomy were reviewed. The patients included 67 males and 52 females, and their ages ranged from two months to 13 years. The study patients underwent simple or radical nephrectomy or nephron-sparing surgery during the 13-year period. They were studied with regard to gender, age, indication for nephrectomy, morbidity and mortality. The indications for nephrectomy were divided into benign and malignant conditions. Of the 119 nephrectomies performed, 49 patients (41.2%) had malignant conditions and 70 (58.8%) had a benign etiology. In the benign group, 23.5% of the patients underwent nephrectomy for complicated vesicoureteric reflux, urinary tract stones or infection (1.6%). Other conditions in this group included ureterocele, posterior urethral valve, etc. Benign conditions and ureterocele necessitating nephrectomy were predominant in female patients, while pelvi-ureteric junction obstruction was predominant in males. The malignant lesions necessitating nephrectomy included Wilms tumor and neuroblastoma. The over-all mortality rate was nil in the absence of malignancy. Obstructive nephropathy was the main cause of nephrectomy in this series, followed by malignancy of the kidney. It remains to be seen whether better management will reduce the incidence of nephrectomies in preventable cases. It is also important that children with a solitary functioning kidney have long-term follow-up.
|How to cite this article:|
Daradka I. Indications for nephrectomy in children: A report on 119 cases. Saudi J Kidney Dis Transpl 2012;23:1221-6
| Introduction|| |
The indications for nephrectomy differ between the pediatric and the adult patient populations. While vesico-ureteric reflux (VUR) is the leading indication for nephrectomy in children, malignancy is the leading cause in adults.  Pediatric urology is very dependent upon radiographic imaging as the genitourinary tract is internally located. Advances in various imaging modalities such as ultrasonography, nuclear medicine, voiding cystography, computerized tomography (CT) and magnetic resonance imaging (MRI) have aided in our ability to visualize and evaluate the genitourinary tract better. ,
Simple nephrectomy is a standard therapeutic urological procedure in patients with an ireversibly damaged kidney due to chronic infection, obstruction, calculus disease, pyelonephritis, reflux or congenital dysplasia. The decision for performing nephrectomy is mainly based on the results of renal ultrasonography and radionuclide scans. ,,
In some infection-related diseases, nephrectomy can be avoided if the diagnosis is made early and adequate treatment is instituted, although when there is severe deterioration of renal function as seen in some congenital and acquired disorders, nephrectomy becomes necessary. 
The recognition, of late, that the pediatric kidney has a remarkable ability to recover its function after reconstructive surgery has led to a more conservative approach thereby reducing the incidence of nephrectomy in children.  Although radical nephrectomy is the standard treatment for localized renal carcinoma with a normal contra-lateral kidney, there is a growing interest in the use of nephronsparing surgery for selected patients. ,
The goal should be to document and categorize those cases that will impact the health of the infants and children, with timely referral to a pediatric surgeon and possible intervenetion to minimize adverse outcomes, particularly in the cases in whom nephrectomy can be avoided. ,
| Patients and Methods|| |
The files of 119 of 141 patients, aged two months to 13 years who underwent radical or partial nephrectomy during a 13 years period from January 1997 to December 2009, were reviewed. Data extracted included gender, age, affected side, clinical presentation, indication for nephrectomy, mortality and morbidity. The indication for nephrectomy was divided into benign and malignant conditions. All patients underwent urine analysis and blood biochemistry investigations and renal ultrasound and/or isotope scans to evaluate the function of the kidneys that were labeled for nephrectomy. Patients with benign conditions were treated with nephrectomy. Patients with renal cancer were treated either with immediate radical nephrectomy or they underwent an initial trucut biopsy followed by pre-operative chemotherapy.
Seventy patients were operated for a benign disease while 49 underwent nephrectomy for malignant disease. The operative approach in our series was trans-peritoneal in all the study patients.
| Results|| |
During the 13 years' study period, 119 nephrectomies were performed. Sixty-seven patients (56.3%) were male and 52 (43.7%) were female (male:female ratio 1.2:1). Age of the patients ranged from two months to 13 years.
Of the 119 nephrectomies, 70 (58.8%) were performed for benign conditions while 49 patients (41.2%) had malignancy. Patients with benign and malignant conditions presented with varied clinical patterns [Table 1]. In patients with benign conditions, 28 (23.5%) had poor function with split function being <10% or non-functioning kidney, caused by VUR.
Neglected pelvi-ureteric junction (PUJ) obstruction was noted in 18 patients (15%). The mean age of the patients with VUR was 4.9 years (range one to 13 years) and 6.8 years (4 months to 13 years) in patients with PUJ [Figure 1]. Other benign conditions where nephrectomy was indicated included ureterocele (6.9%), duplicate kidney and/or ureters (6.2%) and posterior urethral valves (PUV, 2.3%). Benign conditions necessitating nephrectomy were pre-dominant in female patients, while PUJ was prominent in males. One patient each underwent nephrectomy for life-threatening hemorrhage during nephrolithotomy, bladder extrophy, horseshoe kidney and multicyctic dysplastic kidney. Two patients underwent nephrectomy for renal hydatid cyst and xanthogranulomatous pyelonephritis (XLP) associated with renal stones.
|Figure 1: The mean age of the study patients in years at the time of undergoing nephrectomy and the causes.|
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In the malignant group, 35 patients (29.4%) had Wilms tumor; their age ranged between two months and 12 years (mean age 3.6 years). Three of these patients had bilateral tumor and underwent nephrectomy on one side and nephron-sparing surgery on the other. Fourteen patients (11.7%) had neuroblastoma; their age ranged from three months to three years (mean age 1.6 years). They all underwent trans-peritoneal nephrectomy because of renal involvement.
Wilms tumor was more common in males (19 males versus 16 females), while no such gender difference was noted in patients with neuroblastoma (M:F, 8:6). There was no predilection to any particular side in the malignant group, while benign lesions occurred mostly (58%) on the right side. The mean age of patients with nephrectomy for benign conditions was 4.8 years (range two months to 13 years).
The number of nephrectomies performed had increased two-fold in the last four years (n = 67) in comparison with the years 2001-2004 (n = 34) for both benign and malignant groups [Figure 2]. The mortality rate was nil in the benign group, while it was 2.5% in the malignant group. Three patients died in the immediate post-operative period. Data on mortality in the other patients in the malignant group is not known because they are on follow-up with the oncology department following surgery.
|Figure 2: The number of nephrectomies performed over the years (male– female– benign– malignant).|
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| Discussion|| |
The incidence of nephrectomy performed for congenital diseases is presently about 10% among the newborn; thus, early detection of the disease remains unsatisfactory because of the atypical course and absence of pathognomonic symptoms.  Among older children, the incidence of nephrectomy for acquired disorders is 1.4%, while it is 56% for congenital disease.  In our study, the rate was 1.6% and 57.2%, respectively, similar to that in the literature.
An increasing number of neonatal uropathies including VUR are detected by ultrasonography; Berrocal showed that VUR was present in 25.7% of mild hydronephrotic kidneys and 26.3% of cases with normal-sized kidneys contralateral to the hydronephrotic ones. 
In our series, the youngest patient was two months old; the mean age was 4.8 years in the benign group, 3.8 years in patients with Wilms tumor and 1.6 years for neuroblastoma [Figure 1]. Wilms tumor was the leading indication for nephrectomy (29.4%), followed by VUR (23.5%). In the benign group, nephrectomy was performed due to loss of kidney function in the majority, most of whom had grade IV-V VUR, followed by PUJO, ureterocele, duplex, PUV and others [Figure 2].
Conditions such as urinary tract obstruction and VUR can prevent normal renal development and cause renal injury. Early diagnosis of PUJO and prompt intervention is mandatory to prevent or minimize renal damage. , VUR, which was the most common benign condition needing nephrectomy, was mainly seen in female patients, followed by uretero-pelvic obstruction (UPO), which was seen more frequently in males.
Co-existence of UPO and uretero-vesical junction stenosis was seen in two patients and PUJ obstruction with ureterocele was seen in one patient; in the latter case, the diagnosis was initially missed and pyeloplasty was performed, followed by excision of the ureterocele and re-implantation of the ureter a few months later.
Poorly functioning pole moieties occur more often in those with a complete duplex-system anomaly. , Duplication anomalies usually cause UPJ obstruction at the lower pole. In these cases, co-existence of VUR should always be considered. , In our series, 6.7% of the patients had duplex system and VUR was the most common associated anomaly; four of these patients underwent hemi-nephrectomy of the upper moiety, which was non-functional on radionuclide scan.
Regarding ureteral duplications and ureteroceles, difficulties remain concerning early diagnosis and referral of patients. Ureterocele presents as part of a duplex or a single system. The co-existing VUR is generally seen in the lower ipsilateral moiety or in the contralateral kidneys. , In patients with a ureterocele, the long-term efficacy of treatment depends on the patients' age at surgery, position of the ureterocele, a duplex system, pre-operative and post-operative reflux and the need for additional operations. , Ureteroceles were seen in eight of our patients (7.5%), all of whom were females.
The delay between diagnosis and the onset of symptoms is common, particularly in the female patients. This may be attributed to older practices, wherein investigations were performed after the first episode of urinary infection in males, but only after two or more episodes in females. It is also possible that there is a bias toward earlier diagnosis among boys due to the greater seriousness of their clinical status. ,
Posterior urethral valve is the most common cause of lower urinary tract obstruction in male neonates; the significance of this obstruction depends on the secondary effects on the bladder, ureter and kidneys.  It is the cause of renal insufficiency in approximately 10-15% of children undergoing renal transplant, and nearly one-third of patients with PUV progress to end-stage renal disease over the course of 10-15 years. , Treatment of PUV requires active management from infancy into adulthood to avoid progressive dysfunction and deterioration of both the upper and lower urinary tracts. ,, PUV was seen in three of our patients who underwent nephrectomy.
Xanthogranulomatous pyelonephritis is a rare inflammatory disease accounting for 0.8% of chronic pyelonephritis with underlying stone. , It is known that untreated infections can allow XGP to develop, and XGP must be considered in the differential diagnosis of renal neoplasms in childhood, particularly cystic Wilms tumor. ,
Patients with malignant tumors are treated either with immediate radical nephrectomy or undergo an initial biopsy followed by pre-operative chemotherapy.  Appropriate chemotherapy and conservative nephron sparing can achieve good results with preservation of adequate renal function. , In our study, 49 patients had malignancy, of whom 46 patients underwent unilateral radical trans-peritoneal nephrectomy and a nephron-sparing procedure was performed in the three patients with bilateral Wilms tumor. Complete excision of primary tumors was not always feasible in patients with neuroblastomas. Patients with malignancy were followed-up post-operatively by our pediatric oncologists.
Despite the whole range of technical and technological advances made in preserving renal tissue, the total number of nephrectomies performed in our department has increased in the last four years in comparison with the years 1997-2000 [Figure 2].
The removal of one kidney leads to structural and functional changes in the remaining kidney. ,,, It is important that the children who have a solitary functioning kidney have longterm follow-up until they reach adulthood because they could experience subtle renal deterioration at that time or later in adult life.  Also, it is necessary to draw the attention of professionals in the areas of obstetrics, pediatrics and primary health care to the necessity of early investigation of children suspected to have urological malformations or who present with UTI. 
In many infection-related diseases, nephrectomy can be avoided with early diagnosis and adequate treatment. Obstructive nephropathy was the main indication for nephrectomy in this series, followed by malignancy of the kidney. It remains to be seen whether more effort for management of infection will reduce the incidence of nephrectomies in the future.
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Consultant of Pediatric Surgery, King Hussein Medical Center/Queen Rania Hospital for Children, P.O. 541767, Amman
[Figure 1], [Figure 2]