Portal de Periódicos da CAPES

Urolithiasis in the Pediatric Age Group

2003; King Faisal Specialist Hospital and Research Centre; Volume: 23; Issue: 3-4 Linguagem: Inglês

10.5144/0256-4947.2003.201

0975-4466

Mohammad Ghafoor, Imran Majeed, Akhtar Nawaz, Ahmed H. Al‐Salem, Anwer Halim,

Gallbladder and Bile Duct Disorders

Brief ReportsUrolithiasis in the Pediatric Age Group Mohammad Ghafoor, MD, FRCS, D. Urol Imran Majeed, MD, FRCS Akhtar Nawaz, MD, FRCS Ahmed Al-Salem, and MD, FRCSI, FACS, FICS Anwer HalimMD, FRCS, PhD Mohammad Ghafoor Correspondence to: Dr. M. Ghafoor P.O. Box 15258 Al-Ain, Abu dhabi UAE From the Department of Urology, Tawam Hospital, Al-Ain, Abu Dhabi, United Arab Emirate , Imran Majeed From the Department of Urology, Tawam Hospital, Al-Ain, Abu Dhabi, United Arab Emirate , Akhtar Nawaz From the Department of Urology, Tawam Hospital, Al-Ain, Abu Dhabi, United Arab Emirate , Ahmed Al-Salem From the Department of Urology, Tawam Hospital, Al-Ain, Abu Dhabi, United Arab Emirate , and Anwer Halim From the Department of Urology, Tawam Hospital, Al-Ain, Abu Dhabi, United Arab Emirate Published Online:1 May 2003https://doi.org/10.5144/0256-4947.2003.201SectionsPDF ToolsAdd to favoritesDownload citationTrack citations ShareShare onFacebookTwitterLinked InRedditEmail AboutIntroductionUrolithiasis is usually considered a disease of adults and is rarely seen in the pediatric age group. However, the incidence as well as the etiology of childhood urolithiasis is variable according to geographical areas. In countries of the Arabian peninsula (Kuwait, United Arab Emirates and Saudi Arabia), it has been estimated that 20% of the men who reach the age of 60 years will have at least one episode in their lives, which is a projected lifetime risk at least 50% higher than the highest corresponding figure in the West.1 In Europe and United States, the reported incidence of urolithiasis in the pediatric age group ranges from 0.13 to 0.94 cases per 1000 hospital admissions, with a predominance of upper urinary tract stones.2 Bladder stones on the other hand are endemic in Southeast Asia, including Thailand3, Indonesia4, and India.5 As industrialization progresses in a geographic area, there tends to be a shift in the incidence of urolithiasis from lower urinary tract to upper urinary tract stones.6 In the United Kingdom and certain European countries, 30 to 90% of stones are infection related7, while in the. United States and Scandinavian countries, metabolic disorders are the most common cause of kidney stones.8During the last two decades, the introduction of extracorporeal Shockwave lithotripsy (ESWL) has revolutionalized the management of urolithiasis. ESWL is now considered a safe, noninvasive and effective method for treatment for urinary tract stones in adults and children.9,10 This report describes our experience in the management of childhood urolithiasis in the United Arab Emirates.PATIENTS AND METHODSThe medical records of 35 children with urolithiasis treated between 1991 and 2001 were retrospectively reviewed. Their ages, sex, presenting symptoms, laboratory and radiological findings, stone composition, underlying pathological factors, mode of treatment and final outcome were noted. The diagnosis of urolithiasis was made by plain abdominal x-ray (kidney-ureter-bladder), intravenous pyelography and/or ultrasound of the urinary tract. A metabolic evaluation, including serum electrolytes, calcium, uric acid, phosphorus, 24-hour urine collection for volume, calcium, and creatinine, was carried out for all patients. In those with suspectedcystine stones a nitroprusside test was done. Hypercalciuria was diagnosed if the amount of calcium in the urine exceeded 4 mg/kg per 24 hours and/or the urinary calcium and creatinine ratio exceeded 0.2.RESULTSOut of 35 children with urolithiasis, 22 (62.8%) were males and 13 (37.2%) were females. Their ages ranged from 6 months to 14 years with a mean age of 8 years. The majority of them presented with flank pain (51.4%) (Table 1). Other presenting symptoms were gross hematuria (20%), recurrent urinary tract infection (20%), non-specific abdominal pain (11.5%), and failure to thrive (5.7%). One patient presented with acute urinary retention due to a stone in the urethra. The distribution of the stones in the urinary tract was as follows: 19 had kidney stones, 13 had ureteric stones, two had bladder stones and one had a urethral stone. Five (14.3%) patients had associated anatomic anomalies of the urinary tract, including pelviureteric junction obstruction in two, and bilateral duplex system, horseshoe kidney and ectopia vesica in one each (Table 2). Nine (25.7%) children had underlying metabolic disorders including idiopathic hypercalciuria in 5 patients and 4 had renal tubular acidosis, Donohue syndrome, lactase deficiency and intestinal epithelial dysplasia in one each (Table 2). None of our patients had hyperuricosuria or cystinuria. Urinary tract infections were present in 14 (40%) patients and the most common causative pathogen was E. coli followed by Pseudomonas.Table 1. Presenting symptoms in 35 pediatric patients with urolithiasis.Table 1. Presenting symptoms in 35 pediatric patients with urolithiasis.Table 2. Pathology associated with renal tract stones.Table 2. Pathology associated with renal tract stones.Associated hydronephrosis was present in 10 patients. A JJ stent was inserted in 8 of them (22.9%) prior to the commencement of ESWL. One patient with bilateral hydronephrosis had bilateral nephrostomies placed prior to ESWL therapy while the other patient with hydronephrosis received in-situ ESWL treatment.The different modalities of treatment in relation to site and size of stone are shown in Table 3. Twenty (57%) patients were treated with ESWL with an overall clearance rate of 95%. In fourteen (70%) patients, the stones were cleared after a single ESWL treatment session while 5 (14.3%) patients required multiple treatment sessions (range 2 to 6) for complete stone clearance. ESWL therapy failed in one patient with a bladder stone, who had surgical repair for bladder extrophy, due to difficulty in localizing the stone. His stone was removed through open cystolithotomy. Endoscopic removal of a lower ureteric stone was attempted in one patient but this failed due to technical reasons and thestone was removed through open surgery. A total of 6 (17%) patients, including one each with failed ESWL and endoscopic removal, had open surgery for their stones. Ten (28.6%) patients with stones less than 10 millimeters in size passed the stones spontaneously with conservative hydrotherapy and analgesia. These included small ureteric stones in 8, small bilateral kidney stones in medullary sponge kidneys on one patient, and a stone at the external urethral meatus in one patient with that was removed with a pair of forceps. Four of our patients had bilateral renal stones. One patient had multiple bilateral small stones in medullary sponge kidneys with tubular acidosis that were treated medically with spontaneous passage of stones. Another patient with bilateral small kidney stones passed the stones spontaneously from one side and after ESWL therapy on the other side. A third patient had a horseshoe kidney with stones in both moieties, and was treated by open pyelithotomy. Afourth patient with bilateral kidney stones had bilateral hydronephrosis associated with lactase deficiency. He had bilateral nephrostomies and ESWL therapy to both kidneys at different treatment sessions with complete stone clearance. Five of the recovered stones were sent for chemical analysis; three of them were calcium oxalate and two were magnesium ammonium phosphate (struvite) stones. On follow-up, ranging from 1 to 3 years (mean 2.3 years) post-treatment, there was no apparent recurrence in any of our patients.Table 3. Treatment summary for 35 pediatric patients with urolithiasis.Table 3. Treatment summary for 35 pediatric patients with urolithiasis.DISCUSSIONThe etiology and location of urinary tract stones in children varies in different parts of the world. In North American and certain European countries, stones tend to be located in the upper urinary tract6 and are largely of calcium oxalate or struvite in composition, while in certain parts of Southeast Asia lower urinary tract stones predominate.3,4,5 The high incidence of these stones in endemic areas is attributed predominantly to a cereal-based, low-protein diet as well as a high incidence of urinary tract infection, whereas in the United States and Scandanavian countries, metabolic disorders are the most common cause of renal stones.8 Urolithiasis is common in Middle Eastern countries including the UAE and represents one of the major urological problems that cause significant morbidity, including end-stage renal disease.1The etiology of urinary lithiasis in children, like that in adults, is diverse. Urinary stones are usually divided into primary and secondary. Primary calculi are mainly of renal origin with underlying metabolic causes, while secondary stones develop around a foreign body in the urinary tract or as a result of chronic obstruction and infection. In our series, one bladder stone developed in a neobladder after surgical repair for bladder extrophy. Developmental anomalies of the urinary tract predispose to urolithiasis by prompting stasis and infection. This was the case in five (14.3%) of our patients who had underlying urinary tract anomalies. The most common metabolic disorder in association with calcium urolithiasis, in both children and adults is idiopathic hypercalciuria.15 Idiopathic hypercalciuria is a familial disorder that appears to be an autosomal dominant trait.16 The prevalence of idiopathic hypercalciuria in asymptomatic children with urolithiasis has been reported as high as 6.2% and up to 70% have a family history of urolithiasis.17 Five (14.3%) of our patients had idiopathic hypercalciuria which was the main metabolic disorder associated with urolithiasis in our series.Childhood urolithiasis is more common in males with a reported male:female ratio varying from 1.2:1 to 3:1 in different series.11,12 In our study, the male:female ratio was 1.7:1. The distribution of stones in the urinary tract in our series was comparable to that from other developed countries and 91.4% of the stones were upper urinary tract stones. Oneof our patients presented with a stone in the urethra, probably of upper urinary tract origin and only one patient presented with a primary bladder stone. The reported incidence of urinary tract infection in children with urolithiasis varies from 9% to 80%.13,14 In our series, 14 (40%) patients had proven associated urinary tract infections. The clinical presentation of childhood urolithiasis is different from that of adults. Classic flank pain may not be seen in children, especially in those less than 5 years of age. In our series, flank pain was the main presenting symptom.Treatment modalities for urolithiasis in children are similar to those for adults. These include conservative management in the hope of spontaneous stone clearance, noninvasive therapy like ESWL, minimally invasive procedures like endoscopic manipulation or percutaneous nephrolithothomy and open surgery. Spontaneous passage of urinary stones in childhood has been reported to occur in 8% to 50% of cases.11,18 In our study, 10 of 35 (28.6%) patients with stones less than 10 millimeters passed their stones spontaneously. This included one patient with bilateral kidney stones and renal tubular acidosis treated with medical therapy, and 8 patients with small ureteric stones passed spontaneously while one had a stone in the anterior urethra that was removed manually.ESWL is a safe, non-invasive and effective primary treatment modality for renal and ureteric stones in children.9,10 A stone clearance rate ranging from 79% to 98.5% has been reported with minimal short-term complications.9,19,20 In our series, 20 (57.2%) children were treated with ESWL, with an overall clearance rate of 95% and no morbidity.Endoscopic stone manipulation is a well-established modality of treatment for lower ureteric stones in adults and recently for children. This is especially so following the development of newer smaller diameter scopes and the introduction of the holmium laser. These developments minimize the risk of reflux and trauma to the urinary tract.21 Endoscopy was tried in one of our patients with lower ureteric stone, but failed due to technical reasons. Percutaneous nephrolithotomy is preferred for large stones and hard stones like cystine stones, which respond poorly to ESWL.Surgical lithotomy has traditionally been the most common form of therapy for urinary tract stones. However, this is not the case today because indications for open surgical intervention are few. Indications for open surgical intervention include associated congenital anomalies, which can be corrected at the same time, persistent UTI with the continued presence of the stone as well as intractable pain. In our study, 6 of 35 patients (17%) had open surgical procedures for urolithiasis, including 2 vesicolithotomies, 1 ureterolithotomy and 3 nephrolithotomies.In conclusion, urolithiasis in the pediatric age group is not a rare problem in United Arab Emirates. Anatomic anomalies and metabolic disorders are the two important etiological factors for childhood urolithiasis. Like in adults, ESWL remains the first line of treatment for urolithiasis in children. Open surgery on the other hand is reserved for stones with an underlying anatomical anomaly requiring surgical correction at the same time or large and hard stones that are not suitable for ESWL. The introduction of improved and smaller diameter scopes has made endoscopic retrieval of stones, especially those in the lower ureter, an increasingly common treatment modality.ARTICLE REFERENCES:1. Robertson et al.. Renal stone in the Middle East. In: Hatano et al.. Nephrology. 1999; 1:815–22. Google Scholar2. Polinsky MS, Kaiser BA, Bauarte HJet al.. "Renal stones and hypercalciurea" . Adv Pediatr. 1993; 40:353–384. Google Scholar3. Nimmannit S, Malasit P, Susaengrat W. et al.. "Prevalence of endemic distal renal stones in the Northeast of Thailand" . Nephron. 1996; 72:604–10. Google Scholar4. Talut K, Rizal A, Brokid JG. et al.. "The endemic bladder stones of Indonesia – epidemiology and clinical features" . Br J Urol. 1976; 48:617–21. Google Scholar5. Hari P, Bagga A, Vasudev V. et al.. "Etiology of nephrolithiasis in North Indian children" . Pediatr Nephrol. 1995; 9:474–5. Google Scholar6. Sutor DJ, Wooly SE, Illingworth JJ. "A geographical and historical survey of the composition of urinary stones" . Br J Urol. 1974; 46:393–407. Google Scholar7. Stapleton FB. "Nephrolithiasis in children" . Pediatr Rev. 1989; 11:21–30. Google Scholar8. Barratt TM. Urolithiasis and Nephrocalcinosis. In: Holliday MA, Barratt TM, Avner ED.Eds. Pediatric Nephrology, 3rd ed.Baltimore: Williams and Wilkins. 1994;1070–1080. Google Scholar9. Onuora CV, Koko AH, Al-Turki M, Al-Jawini N. "Extracorporeal shock wave lithoripsy in children" . Ann Saudi Med. 2001; 21(1-2):97–9. Google Scholar10. Lottmann HB, Archambaud F, Traxer O, Mercier-Pageyral and Helal B. "The efficacy and parenchymal consequences of extracorporeal shock wave lithotripsy in infants" . BJU Int. 2000; 85:311–15. Google Scholar11. Choi H, Synder HM, Duckett JW. "Urolithiasis in childhood. Current management" . J Pediatr Surg. 1987; 22:158–164. Google Scholar12. Malek RS, Kelalis P. "Pediatric nephrolithiasis" . J Urol. 1975; 113:545–551. Google Scholar13. Paulson DF, Glenn JF, Huges J. et al.. "Pediatric urolithiasis" . J Urol. 1972; 108:811–14. Google Scholar14. Borgmann V, Nagel R. "Urolithiasis in childhood" . Urol Int. 37:198–204. Google Scholar15. Coe FL, Favus MJ. Disorders of stone formation. In: Brenner BM, Rector FC (eds). The kidney. Saunders, Philadelphia, 1986;1043–1442. Google Scholar16. Coe FL, Parks JH, Moor ES. "Familial idiopathic hypercalciuria in children" . N Engl J Med. 1979; 300:337–40. Google Scholar17. Moor ES, Coe FL, McMann BJ. et al.. "Idiopathic hypercalciuria in children: prevalence and metabolic characteristics" . J Pediatr. 1978; 92:906–10. Google Scholar18. Churchill DN, Maloney CM, Nolan R. et al.. "Pediatric Urolithiasis in the 1970s" . J Urol. 1980; 123:237–8. Google Scholar19. Longo Ja, Netto NR. "Extracorporeal Shock Wave Lithoripsy in children" . Urology. 1995; 46:550–2. Google Scholar20. Vandeursen H, Devos P, Baert I. "Electromagnetic extracorporeal shock wave lithortipsy in children" . J Urol. 1991; 145:1229–1231. Google Scholar21. Thomas R, Ortenberg J, Lee BR. et al.. "Safety and efficacy of pediatric ureteroscopy for management of calculous disease" . J Urol. 1993; 149:1082–1084. Google Scholar Previous article Next article FiguresReferencesRelatedDetails Volume 23, Issue 3-4May-July 2003 Metrics History Accepted1 January 2003Published online1 May 2003 InformationCopyright © 2003, Annals of Saudi MedicinePDF download