| Abstract|| |
We reviewed 71 cases of children and adolescents with nephrolithiasis over a 9 year period (1982-1991). The mean age was 12.3 years. The male: female ratio was 2.5:1. Twelve patients (16.9%) had bilateral stones. Fifteen patients (21%) had documented urinary tract infection. Escherichia coli was the most common organism growing in the urine cultures. Five patients had metabolic abnormalities and four had genitourinary developmental anomalies. Of the 45 calculi recovered for analysis, 17 (37.8%) were predominantly calcium oxalate, 14 (31.1%) were mixed calcium oxalate and uric acid stones, two (4.4%) were uric acid, two (4.4%) were calcium phosphate, two (4.4%) were cystine and eight (17.8%) were struvite stones. Four patients passed their stones spontaneously. Forty-eight underwent open surgery, with complete stone clearance in 45 patients. Two patients needed nephrectomy, seven had their stones removed by endourological procedures, nine patients were referred to other centers for extra corporeal shock wave lithotripsy, while two did not need any intervention. After the initial hospitalization, 57 patients continued follow up for a mean period of 3.3 years. Of them sixteen patients (28.1%) had recurrence of stone disease. We conclude that renal stone disease in children in our area was not uncommon. The majority were calcium oxalate stones. The clinical manifestations were not specific. Open surgery was needed in the majority of patients. Due to significant recurrence rate, long term follow-up was essential. Follow up by a pediatric nephrologists and/or urologist would be advisable.
Keywords: Nephrolithiasis, Children, Calcium, Oxalate, Uric acid, Cystine.
|How to cite this article:|
Al-Rasheed S, Al Jurayyan NA, Al Nasser MN, Al-Mugeiren MM, Al-Salloum AA, Petterson BA. Nephrolithiasis in Children and Adolescents in the South Western Region of Saudi Arabia. Saudi J Kidney Dis Transpl 1995;6:396-9
|How to cite this URL:|
Al-Rasheed S, Al Jurayyan NA, Al Nasser MN, Al-Mugeiren MM, Al-Salloum AA, Petterson BA. Nephrolithiasis in Children and Adolescents in the South Western Region of Saudi Arabia. Saudi J Kidney Dis Transpl [serial online] 1995 [cited 2020 Aug 12];6:396-9. Available from: http://www.sjkdt.org/text.asp?1995/6/4/396/40556
| Introduction|| |
The incidence and composition of urinary stones have geographic variation ,, . Diet, urinary tract infection, metabolic disorders, and underlying anatomical abnormalities may be significant aetiological factors in renal stone formation in children  . Nephrolithiasis is highly prevalent disease in adults in Saudi Arabia, where calcium oxalate and uric acid are the commonest constituents ,, . In children, the infective stones are more prevalent in the United Kingdom, whereas stones secondary to metabolic disorders are seen more in the United States of America , . There are only few studies in children from countries neighboring Saudi Arabia , . In this study we attempt to evaluate the clinical pattern, the outcome and the possible aetiological factors leading to renal stone diseases in children and adolescents in a major referral center in Saudi Arabia.
| Materials and Methods|| |
King Fahad Hospital is the main referral center for Al Baha area in the South Western region of Saudi Arabia and has a large referring area. The total number of patients admitted to the hospital below the age of 18 years, during a 9 year period from July 1982 to end of June 1991, was 57051 patients. Of them the charts of 71 patients, who presented with nephrolithiasis, were reviewed. Patients with only bladder stones were excluded. The patients were admitted for initial evaluation and therapy and subsequently followed up as outpatients in the hospital or referred to other tertiary care centers in the Kingdom where different therapeutic modalities were available. Data extracted from the records included age, sex, presenting symptoms and signs, family history, laboratory data, radiological investigations, the mode and outcome of therapy and the duration of follow up. The pertinent laboratory data included the result of midstream clean catch urinalysis, urine culture (more than 100,000 colonies per/ml were considered positive), serum electrolytes, total CO2, serum calcium, phosphorus, magnesium, uric acid, alkaline phosphatase and parathormone levels. Twenty-four hour urine collection was undertaken for evaluation of calcium in 39 patients; phosphorus, uric acid, oxalate and creatinine in 28 patients, and cystein in 6 patients. Chemical analysis of stones was done when available. These tests were done using the standard laboratory methods. All patients had intravenous pyelography with and without renal and bladder ultrasound and micturating cystourethrography as clinically indicated.
| Results|| |
The patients admitted with nephrolithiasis comprised (0.0012%) of the total pediatric admissions; 61 were Saudi and 10 were non Saudi. There were 51 males and 20 females (male to female ratio 2.5:1). Ages ranged from 1.5 to 18 years, with a mean of 12.3 years. Two patients had a positive family history of nephrolithiasis. The principal presenting symptom in 56 patients was abdominal or flank pain, which lasted for a few days in some patients to several years in others. The majority did not complain of typical renal colic as seen in adults. The frequency of other presenting manifestations is shown in [Table - 1].
At hospitalization, 40 patients had significant pyuria and microscopic haematuria in their urinalyses. Fifteen patients (21%) had positive urine culture; 9 with E. coli, 3 with Pseudomonas aeruginosa, 2 with Klebsiella and one with proteus.
All but one patient had normal serum biochemical evaluations. He presented with a high urea, creatinine and uric acid due to acute renal failure secondary to bilateral pelviureteric junction obstruction by stones.
Twelve patients (16.9%) had bilateral stones in their kidneys and/or ureters, while the rest had unilateral stone disease. The site of the calculi is shown in [Table - 2]. Forty-five stones were analyzed chemically. Most stones were a mixture of two or more compounds [Table - 3], calcium oxalate was the commonest compound. There were 2 cystine stones and 2 uric acid/urate stones.
Four identifiable factors were felt significant in the pathogenesis of calculi in our patients. Fifteen patients had urinary tract infection. Four patients had genitourinary development anomalies. Five patients had metabolic abnormalities; one had hypercalcuria, one had hyperoxaluria, one had hyperuricosuria and two had cystinuria. Forty eight cases (67%) were considered idiopathic. The majority of the idiopathic group did not have extensive metabolic workup.
Four patients passed their stones spontaneously or during medical therapy. However, 48 patients underwent surgery in the form of nephropyelolithotomy or ureterlithotomy, all were rendered stone free except in three patients left with small residual stones. Two patients underwent nephrectomy, 9 were referred to other centers for extracorporeal shock wave lithotripsy, 7 had their stones removed by endourological procedures, while two patients had small stones and were asymptomatic, so they had no intervention.
Fourteen patients were lost to follow-up following their initial hospitalization. However, 57 patients had a follow-up period from 6 months to 9 years with a mean of 3.3 years. During the follow-up period, 16 patients (28%) demonstrated recurrence of the stone disease in the same site of the previously removed one. The majority were small in size and were asymptomatic. Only 5 patients with recurrent stones were referred to other centers for extracorporeal shock wave lithotripsy and subsequently lost to follow-up.
| Discussion|| |
The incidence of urinary stone disease in children and adolescents in Saudi Arabia is not known. The observed incidence in our study was 1.2 per 1000 pediatric hospital admissions. This incidence was higher than the one reported from North America or Europe ,, . Male predominance in our study was not a unique finding, since it was observed by others ,, .
Abdominal pain was the commonest presenting symptom but the typical renal colic pain, as seen in adults, was not a major presenting symptom except in few patients above the age of 15 years. This has been attributed to the elasticity of the walls of the urinary tract and the relatively greater width of the ureters in children , . Due to the lack of specificity of symptoms of renal stones, the possibility of their presence should be included in the differential diagnosis of abdominal pain in children.
Urinary tract infection was diagnosed only in 15 patients and the commonest organism was E. coli. Only one urine culture grew proteus, which was contrary to the experience of others ,, . Most of our patients were referred from primary care centers without full report of the types of infection they had in the past. The limited preoperative hospital stay and the fact that none of the stones were sent for culture were contributing factors to our failure to identify proteus infection.
After detailed metabolic evaluation, we were able to identify only 5 patients (7%) with predisposing metabolic factors. Many of our patients had either bilateral or multiple stones or recurrent stone formation, which were reported previously to be highly associated with underlying metabolic disorder  .
Metabolic causes of stone formation have been found in 33% of patients from North America and in 12.3% of patients from Europe  . Diagnosing an underlying metabolic disorder in our patients could have been better if all patients were systematically studied, as advocated by Paulson et al.  and Laufer and Boichis  .
The majority of stones were densely radiopaque and calcium oxalate either in pure form or mixed with other chemicals was the commonest compound. Similar observations were made from studies done in the Middle East ,, . Uric acid was found to be the major component mixed with calcium oxalate in 14 patients and in pure form in 2 patients. The same observation was also made on adult stone formers in Saudi Arabia, a wealthy country with hot dry climate  . The average dietary consumption of animal protein and purine is among the highest in the world. Such factors lead to formation of low urine volume which is more acidic with high insoluble substrate that tends to precipitate and cause stone formation  . Most of our patients were treated surgically with excellent results. Only three patients were left with small residual fragments. It has been our experience as well as others that such small residual fragments do not necessarily cause either symptoms or stone recurrence  .
Two patients with calculus pyohydronephrosis underwent nephrectomy because of irreparable damage. The previously reported incidence of nephrectomy for stone disease in children was 7%  . Basaklar and Kale  reported on 196 patients with 9.6% nephrectomy rate. In our series the rate was 2.8%.
We conclude that renal stone disease in children in our area was not uncommon. The majority were calcium oxalate stones. The clinical manifestations were not specific. Open surgery was needed in the majority of patients. Due to significant recurrence rate, long term follow-up was essential. Follow up by a paediatric nephrologist and/or urologist would be advisable.
| Acknowledgment|| |
We would like to thank Mrs. Vangie S. Walz for secretarial assistance.
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Department of Pediatrics, College of Medicine, King Saud University, P.O. Box 2925, Riyadh 11461
[Table - 1], [Table - 2], [Table - 3]