0022-534 7/79/1214-0480$2. 00/0 Vol. 121, April Printed in U.S.A.
THE JOURNAL OF UROLOGY
Copyright© 1979 by The Williams & Wilkins Co.
UNUSUAL ASPECTS OF URINARY CALCULI IN CHILDREN ROBERT J. REINER, R. LAWRENCE KROOVAND
AND
ALAND. PERLMUTI'ER
From the Department of Urology, Wayne State University School of Medicine and the Department of Pediatric Urology, Children's Hospital of Michigan, Detroit, Michigan
ABSTRACT
Urinary calculous disease is unusual in children in the United States. During the last 5 years (1972 to 1977) we have examined and treated 35 children with urinary calculi. The predisposing factors to calculus formation have been established in 20 children. Metabolic screening, although mandatory, has proved unrewarding in the evaluation of children with urinary calculi. Obstructive uropathy, immobilization, urinary stasis and infection, previously undiagnosed urologic anomalies, steroid therapy, milk-alkali syndrome, iatrogenic disease and endemic disease have contributed to stone formation. The management of children with urinary calculi generally parallels that of adults but reflects a need for caution when performing transurethral extraction oflower ureteral calculi. Reduction in dairy product intake, fluid diuresis and frequent changes in position may provide adequate prophylaxis against urinary calculi in children who must be immobilized. Urinary calculous disease in children is uncommon in the United States. The etiology is varied and relates to metabolic disease, renal tubular disorders, diet, urinary stasis, obstruction and infection. During the last 5 years (1972 to 1977) we have diagnosed and treated 35 children with urinary calculi, including 11 in the last year. Herein we will outline and discuss some of the more unusual aspects of calculous disease as encountered in our group of children. MATERIALS AND METHODS
Of the 35 children with a discharge diagnosis of urinary calculous disease 29 had sufficient data available for comprehensive review. There were 21 boys and 8 girls, ranging in age from 2 to 17 years. Of the children 28 were white and 1 was black. The presentation of urinary calculi in children may be typical, with ureteral colic, nausea, vomiting or hematuria, or it may be insidious resulting in a delayed or missed diagnosis. A 2-year-old boy with vague non-specific right abdominal pain had a normal appendix removed. Postoperatively, the abdominal pain persisted. Finally, when he was 6 years old uroradiographic evaluation demonstrated a calculus in the distal right ureter and the long-standing symptoms resolved after right ureterolithotomy. Calculous disease also may be associated with previously undiagnosed urologic anomalies. A 9-year-old girl spontaneously passed a calculus. Evaluation revealed a dysmorphic left kidney with a ureteropelvic junction obstruction. A pyeloplasty was done and no additional stones have formed during the 1 year since the operation. A second child with a ureteropelvic junction obstruction had a calculus in the anomalous kidney for which pyelolithotomy and pyeloplasty also were curative. An 11-year-old girl with recurrent urinary infection had a solitary right kidney and multiple calculi that appeared to be located within a bladder diverticulum. At operation the calculi were found in a large ectopic ureterocele draining a dysplastic left kidney. N ephroureterectomy and ureterocelectomy were curative. A 10-year-old boy had a ureteral calculus impacted in the distal end of an adynamic megaureter. The calculus was removed at the time of ureteral tapering and reimplantation. A child with a minor ventriculoseptal defect spontaneously passed a ureteral calculus. Uroradiographic Accepted for publication August 18, 1978. Read at annual meeting of American Urological Association, Washington, D. C., May 21-25, 1978.
480
investigation revealed a solitary right kidney. A child with an omphalocele and exstrophy of the bladder had a calculus in the hydronephrotic solitary right kidney, which was removed at the time of urinary diversion. No followup data are available for either of these latter 2 children. ETIOLOGY
The etiology of the urinary calculi in this group of children has been quite diverse (see figure). Endemic calculi are common in developing nations but uncommon in this country. We have seen 4 children with endemic calculi, all recent emigres from stone-forming countries. Immobilization, urinary stasis and urinary infection, singly or in combination, are known predisposing factors to stone formation and contributed to stone formation in 4 children with myelodysplasia. The addition of steroid therapy or excessive dairy product ingestion to immobilization may further enhance stone formation. Two children receiving steroid therapy for idiopathic thrombocytopenic purpura formed urinary calculi during a brief period of immobilization for treatment of complications from the primary disease. Another child, a voracious milk drinker, had a left ureteral calculus during temporary immobilization after an orthopedic operation. At this time he was hypercalcemic with a serum calcium of 14 mg. per cent. After discontinuing the excessive dairy product intake he became nonnocalcemic and has formed no additional stones during the 2 years offollowup. An additional child, also a compulsive milk drinker but normocalcemic, ceased forming calculi after discontinuing the excessive milk consumption. A 16-year-old boy, immobilized because of extreme bone fragility associated with osteogenesis imperfecta tarda, had numerous calculi. A child with an intestinal malrotation anomaly and volvulus necessitating small bowel resection had the short bowel syndrome and formed a calcium oxalate calculus. A 3-year-old boy had a vesical calculus on a silk suture placed through a bladder ear during high ligation of persistent patent processus vaginalis. A 17-year-old boy had a calculus attached to intraurethral hairs growing from scrotal skin used during repair of a severe hypospadias. TREATMENT AND RESULTS
In most situations the management of children with urinary calculi parallels that of adults. Many calculi will pass spontaneously after a period of observation, while others may require transurethral manipulation or open lithotomy. Three boys, 6, 10 and 14 years old, with lower ureteral
UNUSUAL ASPECTS OF URINARY CALCULI IN CHILDREN MYELODYSPLASIA (4) - - ~;;;;~~~;~;---;:::::-=s=T=E=R=o=10=s==::;-i E..'1.'3 IMMOBILIZATION IMMOBILIZATION ( 3 ) - - IZZl MILK ALKALI MILK ALKALI (2) - - - OSTEOGENESIS IMPERFECTA (I) CONG. ANOMALIES (6)--~:=:=:=:=:==:::i ENDEMIC ORIGIN ( 4 ) - - - >-._-_-_-_-_-_-_-_-_~~ SHORT BOWEL(I) - - IATROGENIC ( 2 ) - - - STEROIDS ( 2 ) - - - - -
2 3 4 5 6 7 8 9 ~ Etiology of urinary calculi in children. Four children with no identifiable predisposing cause for stone formation have been considered idiopathic and are not included.
calculi underwent successful basket extraction of the stones. Of these children 2 had avulsion injuries to the distal ureter treated by prolonged ureteral catheterization in 1 instance and ureteral reimplantation in the other. Convalescence was uneventful. The boy with osteogenesis imperfecta tarda posed a surgical challenge. Because of the rotund body configuration and extreme bone fragility a standard flank approach to the mid ureteral calculus was not possible. An anterior approach was elected. Postoperatively, persistent urinary drainage occurred. Cystoscopy and retrograde catheterization with the attendant risk of bone injury did not seem advisable. The urinary drainage ceased spontaneously after 2 weeks. Followup pyelograms have been satisfactory. Chronic inflammation with long-standing renal stone disease may directly involve adjacent viscera and a difficult nephrectomy may result in injury to these adjacent nonurinary organs. A 6-year-old girl had a colocutaneous fistula after nephrectomy for calculus-induced xanthogranulomatous pyelonephritis. The fistula closed spontaneously in 7 days. DISCUSSION
Our treatment of 7 patients per year with urinary calculi exceeds that of 5 per year in 20 years at the Mayo Clinic, 1 and 2.5 per year seen by Paulson and associates 2 at Duke during a 22-year span. Bennett and Colodny, 3 and Johnston and McKendrick4 have each reported larger series. Reports from endemic stone-forming areas, such as Turkey, Israel and India, reflect a more frequent occurrence. 4 The reasons for a more frequent diagnosis of childhood urinary calculi in the Detroit area are uncertain. We are not in a stone-belt community and our adult population does not have a similarly increased frequency of urinary calculi. Despite a large regional black population, only 1 child in our series was black, a finding similar to that of Troup and associates. 5 We have seen no metabolic calculi during the period under discussion. The 4 endemic calculi in our series occurred in immigrants. This is not surprising, since Detroit is an ethnic community with emigres from many endemic stone-forming areas. Immobilization promotes urinary stasis and calcium mobilization from the bone. The addition of excessive dairy food product intake or steroid therapy may contribute further to stone formation in immobilized children. We recommend a reduction in dairy product intake, liberal fluid intake and frequent position changes to minimize the risk of urinary calculi in children who must be immobilized. Metabolic causes of stone formation in children are uncommon and metabolic screening in those children with urinary calculi seen at our hospital has been unrewarding. Bartone and Johnston arrived at a similar conclusion after evaluation of 19 children with staghorn calculi. 6 However, we do obtain
481
base line serum calcium, phosphorus, uric acid and nitroprusside screening for cystine to rule out the possibility of metabolic etiology. Stones that are retrieved are sent for x-ray diffraction and chemical analysis to provide a rationale for postoperative care and for possible prophylaxis against subsequent stone formation. Calcium oxalate stones are common in adults after intestinal bypass procedures for treatment of morbid obesity. Bypass of the terminal ileum alters oxalate metabolism, contributing to stone formation. 7 This would appear to be the mechanism of calculus formation in the child with the short bowel syndrome after extensive small bowel resection for volvulus. Iatrogenic calculi are generally preventable. Extension of the bladder into a congenital inguinal hernia is not uncommon and should be recognized easily when performing high ligation of a persistent processus vaginalis during hernia repair in infants. 8 Formation of calculi on intraurethral hairs can be minimized by avoiding the use of hair-bearing skin or by careful depilation when it is necessary to use scrotal skin, especially when such an operation is done after puberty. While Paulson and associates 2 were unable to demonstrate a cause for stone formation in 79 per cent of the children they reviewed, we believe that we have identified predisposing factors to stone formation in 20 of the 29 children reviewed (69 per cent) including 9 with multiple factors (see figure). The complications encountered during management of the calculi in this series are not unique. However, our experience with basket extraction of lower ureteral calculi reflects a need for caution in pediatric transurethral stone manipulation. Smaller basket extractors, such as 4 and 5F, are now available and should be used for such procedures. However, even with the smaller instruments the ureter of the child is more delicate and even more vulnerable to injury than that of the adult. REFERENCES
1. Malek, R. S.: Urolithiasis. In: Clinical Pediatric Urology. Edited by P. P. Kelalis and L. R. King. Philadelphia: W. B. Saunders Co., p. 865, 1976. 2. Paulson, D. F., Glenn, J. F., Hughes, J., Roberts, L. C. and Coppridge, A. J.: Pediatric urolithiasis. J. Urol., 108: 811, 1973. 3. Bennett, A. H. and Colodny, A. H.: Urinary tract calculi in children. J. Urol., 109: 318, 1973. 4. Johnston, J. H. and McKendrick, T.: Urinary calculus disease. In: Reviews in Pediatric Urology. Edited by J. H. Johnston and W. E. Goodwin. New York: American Elsevier Publishing Co., Inc., 1974. 5. Troup, C. W., Lawnicki, C. C., Bourne, R. B. and Hodgson, N. B.: Renal calculus in children. J. Urol., 107: 306, 1972. 6. Bartone, F. F. and Johnston, J. H.: Staghorn calculi in children. J. Urol., 118: 76, 1977. 7. Hoffmann, A. F., Tacker, M. M., Fromm, H., Thomas, P. J. and Smith, L. H.: Acquired hyperoxaluria and intestinal disease. Mayo Clin. Proc., 48: 35, 1973. 8. Allen, R. P. and Condon, V. R.: Transitory extraperitoneal hernia of the bladder in infants (bladder ears). Radiology, 77: 979, 1961. EDITORIAL COMMENT Based on observations in recent years pediatric urolithiasis is either increasing in incidence or is becoming increasingly recognized as a distinct entity. Although often of little help a metabolic evaluation is still mandatory in this population so that disorders such as cystinuria, hyperoxaluria and hypercalciuria may be detected. A full radiological and physiological evaluation of the urinary tract also is necessary to detect congenital anomalies and disorders of bladder function that could predispose to stone formation. Martin I. Resnick Section of Urology Bowman Gray School of Medicine Winston-Salem, North Carolina
THE JOURNAL OF UROLOGY
Copyright© 1979 by The Williams & Wilkins Co.
UNUSUAL ASPECTS OF URINARY CALCULI IN CHILDREN ROBERT J. REINER, R. LAWRENCE KROOVAND
AND
ALAND. PERLMUTI'ER
From the Department of Urology, Wayne State University School of Medicine and the Department of Pediatric Urology, Children's Hospital of Michigan, Detroit, Michigan
ABSTRACT
Urinary calculous disease is unusual in children in the United States. During the last 5 years (1972 to 1977) we have examined and treated 35 children with urinary calculi. The predisposing factors to calculus formation have been established in 20 children. Metabolic screening, although mandatory, has proved unrewarding in the evaluation of children with urinary calculi. Obstructive uropathy, immobilization, urinary stasis and infection, previously undiagnosed urologic anomalies, steroid therapy, milk-alkali syndrome, iatrogenic disease and endemic disease have contributed to stone formation. The management of children with urinary calculi generally parallels that of adults but reflects a need for caution when performing transurethral extraction oflower ureteral calculi. Reduction in dairy product intake, fluid diuresis and frequent changes in position may provide adequate prophylaxis against urinary calculi in children who must be immobilized. Urinary calculous disease in children is uncommon in the United States. The etiology is varied and relates to metabolic disease, renal tubular disorders, diet, urinary stasis, obstruction and infection. During the last 5 years (1972 to 1977) we have diagnosed and treated 35 children with urinary calculi, including 11 in the last year. Herein we will outline and discuss some of the more unusual aspects of calculous disease as encountered in our group of children. MATERIALS AND METHODS
Of the 35 children with a discharge diagnosis of urinary calculous disease 29 had sufficient data available for comprehensive review. There were 21 boys and 8 girls, ranging in age from 2 to 17 years. Of the children 28 were white and 1 was black. The presentation of urinary calculi in children may be typical, with ureteral colic, nausea, vomiting or hematuria, or it may be insidious resulting in a delayed or missed diagnosis. A 2-year-old boy with vague non-specific right abdominal pain had a normal appendix removed. Postoperatively, the abdominal pain persisted. Finally, when he was 6 years old uroradiographic evaluation demonstrated a calculus in the distal right ureter and the long-standing symptoms resolved after right ureterolithotomy. Calculous disease also may be associated with previously undiagnosed urologic anomalies. A 9-year-old girl spontaneously passed a calculus. Evaluation revealed a dysmorphic left kidney with a ureteropelvic junction obstruction. A pyeloplasty was done and no additional stones have formed during the 1 year since the operation. A second child with a ureteropelvic junction obstruction had a calculus in the anomalous kidney for which pyelolithotomy and pyeloplasty also were curative. An 11-year-old girl with recurrent urinary infection had a solitary right kidney and multiple calculi that appeared to be located within a bladder diverticulum. At operation the calculi were found in a large ectopic ureterocele draining a dysplastic left kidney. N ephroureterectomy and ureterocelectomy were curative. A 10-year-old boy had a ureteral calculus impacted in the distal end of an adynamic megaureter. The calculus was removed at the time of ureteral tapering and reimplantation. A child with a minor ventriculoseptal defect spontaneously passed a ureteral calculus. Uroradiographic Accepted for publication August 18, 1978. Read at annual meeting of American Urological Association, Washington, D. C., May 21-25, 1978.
480
investigation revealed a solitary right kidney. A child with an omphalocele and exstrophy of the bladder had a calculus in the hydronephrotic solitary right kidney, which was removed at the time of urinary diversion. No followup data are available for either of these latter 2 children. ETIOLOGY
The etiology of the urinary calculi in this group of children has been quite diverse (see figure). Endemic calculi are common in developing nations but uncommon in this country. We have seen 4 children with endemic calculi, all recent emigres from stone-forming countries. Immobilization, urinary stasis and urinary infection, singly or in combination, are known predisposing factors to stone formation and contributed to stone formation in 4 children with myelodysplasia. The addition of steroid therapy or excessive dairy product ingestion to immobilization may further enhance stone formation. Two children receiving steroid therapy for idiopathic thrombocytopenic purpura formed urinary calculi during a brief period of immobilization for treatment of complications from the primary disease. Another child, a voracious milk drinker, had a left ureteral calculus during temporary immobilization after an orthopedic operation. At this time he was hypercalcemic with a serum calcium of 14 mg. per cent. After discontinuing the excessive dairy product intake he became nonnocalcemic and has formed no additional stones during the 2 years offollowup. An additional child, also a compulsive milk drinker but normocalcemic, ceased forming calculi after discontinuing the excessive milk consumption. A 16-year-old boy, immobilized because of extreme bone fragility associated with osteogenesis imperfecta tarda, had numerous calculi. A child with an intestinal malrotation anomaly and volvulus necessitating small bowel resection had the short bowel syndrome and formed a calcium oxalate calculus. A 3-year-old boy had a vesical calculus on a silk suture placed through a bladder ear during high ligation of persistent patent processus vaginalis. A 17-year-old boy had a calculus attached to intraurethral hairs growing from scrotal skin used during repair of a severe hypospadias. TREATMENT AND RESULTS
In most situations the management of children with urinary calculi parallels that of adults. Many calculi will pass spontaneously after a period of observation, while others may require transurethral manipulation or open lithotomy. Three boys, 6, 10 and 14 years old, with lower ureteral
UNUSUAL ASPECTS OF URINARY CALCULI IN CHILDREN MYELODYSPLASIA (4) - - ~;;;;~~~;~;---;:::::-=s=T=E=R=o=10=s==::;-i E..'1.'3 IMMOBILIZATION IMMOBILIZATION ( 3 ) - - IZZl MILK ALKALI MILK ALKALI (2) - - - OSTEOGENESIS IMPERFECTA (I) CONG. ANOMALIES (6)--~:=:=:=:=:==:::i ENDEMIC ORIGIN ( 4 ) - - - >-._-_-_-_-_-_-_-_-_~~ SHORT BOWEL(I) - - IATROGENIC ( 2 ) - - - STEROIDS ( 2 ) - - - - -
2 3 4 5 6 7 8 9 ~ Etiology of urinary calculi in children. Four children with no identifiable predisposing cause for stone formation have been considered idiopathic and are not included.
calculi underwent successful basket extraction of the stones. Of these children 2 had avulsion injuries to the distal ureter treated by prolonged ureteral catheterization in 1 instance and ureteral reimplantation in the other. Convalescence was uneventful. The boy with osteogenesis imperfecta tarda posed a surgical challenge. Because of the rotund body configuration and extreme bone fragility a standard flank approach to the mid ureteral calculus was not possible. An anterior approach was elected. Postoperatively, persistent urinary drainage occurred. Cystoscopy and retrograde catheterization with the attendant risk of bone injury did not seem advisable. The urinary drainage ceased spontaneously after 2 weeks. Followup pyelograms have been satisfactory. Chronic inflammation with long-standing renal stone disease may directly involve adjacent viscera and a difficult nephrectomy may result in injury to these adjacent nonurinary organs. A 6-year-old girl had a colocutaneous fistula after nephrectomy for calculus-induced xanthogranulomatous pyelonephritis. The fistula closed spontaneously in 7 days. DISCUSSION
Our treatment of 7 patients per year with urinary calculi exceeds that of 5 per year in 20 years at the Mayo Clinic, 1 and 2.5 per year seen by Paulson and associates 2 at Duke during a 22-year span. Bennett and Colodny, 3 and Johnston and McKendrick4 have each reported larger series. Reports from endemic stone-forming areas, such as Turkey, Israel and India, reflect a more frequent occurrence. 4 The reasons for a more frequent diagnosis of childhood urinary calculi in the Detroit area are uncertain. We are not in a stone-belt community and our adult population does not have a similarly increased frequency of urinary calculi. Despite a large regional black population, only 1 child in our series was black, a finding similar to that of Troup and associates. 5 We have seen no metabolic calculi during the period under discussion. The 4 endemic calculi in our series occurred in immigrants. This is not surprising, since Detroit is an ethnic community with emigres from many endemic stone-forming areas. Immobilization promotes urinary stasis and calcium mobilization from the bone. The addition of excessive dairy food product intake or steroid therapy may contribute further to stone formation in immobilized children. We recommend a reduction in dairy product intake, liberal fluid intake and frequent position changes to minimize the risk of urinary calculi in children who must be immobilized. Metabolic causes of stone formation in children are uncommon and metabolic screening in those children with urinary calculi seen at our hospital has been unrewarding. Bartone and Johnston arrived at a similar conclusion after evaluation of 19 children with staghorn calculi. 6 However, we do obtain
481
base line serum calcium, phosphorus, uric acid and nitroprusside screening for cystine to rule out the possibility of metabolic etiology. Stones that are retrieved are sent for x-ray diffraction and chemical analysis to provide a rationale for postoperative care and for possible prophylaxis against subsequent stone formation. Calcium oxalate stones are common in adults after intestinal bypass procedures for treatment of morbid obesity. Bypass of the terminal ileum alters oxalate metabolism, contributing to stone formation. 7 This would appear to be the mechanism of calculus formation in the child with the short bowel syndrome after extensive small bowel resection for volvulus. Iatrogenic calculi are generally preventable. Extension of the bladder into a congenital inguinal hernia is not uncommon and should be recognized easily when performing high ligation of a persistent processus vaginalis during hernia repair in infants. 8 Formation of calculi on intraurethral hairs can be minimized by avoiding the use of hair-bearing skin or by careful depilation when it is necessary to use scrotal skin, especially when such an operation is done after puberty. While Paulson and associates 2 were unable to demonstrate a cause for stone formation in 79 per cent of the children they reviewed, we believe that we have identified predisposing factors to stone formation in 20 of the 29 children reviewed (69 per cent) including 9 with multiple factors (see figure). The complications encountered during management of the calculi in this series are not unique. However, our experience with basket extraction of lower ureteral calculi reflects a need for caution in pediatric transurethral stone manipulation. Smaller basket extractors, such as 4 and 5F, are now available and should be used for such procedures. However, even with the smaller instruments the ureter of the child is more delicate and even more vulnerable to injury than that of the adult. REFERENCES
1. Malek, R. S.: Urolithiasis. In: Clinical Pediatric Urology. Edited by P. P. Kelalis and L. R. King. Philadelphia: W. B. Saunders Co., p. 865, 1976. 2. Paulson, D. F., Glenn, J. F., Hughes, J., Roberts, L. C. and Coppridge, A. J.: Pediatric urolithiasis. J. Urol., 108: 811, 1973. 3. Bennett, A. H. and Colodny, A. H.: Urinary tract calculi in children. J. Urol., 109: 318, 1973. 4. Johnston, J. H. and McKendrick, T.: Urinary calculus disease. In: Reviews in Pediatric Urology. Edited by J. H. Johnston and W. E. Goodwin. New York: American Elsevier Publishing Co., Inc., 1974. 5. Troup, C. W., Lawnicki, C. C., Bourne, R. B. and Hodgson, N. B.: Renal calculus in children. J. Urol., 107: 306, 1972. 6. Bartone, F. F. and Johnston, J. H.: Staghorn calculi in children. J. Urol., 118: 76, 1977. 7. Hoffmann, A. F., Tacker, M. M., Fromm, H., Thomas, P. J. and Smith, L. H.: Acquired hyperoxaluria and intestinal disease. Mayo Clin. Proc., 48: 35, 1973. 8. Allen, R. P. and Condon, V. R.: Transitory extraperitoneal hernia of the bladder in infants (bladder ears). Radiology, 77: 979, 1961. EDITORIAL COMMENT Based on observations in recent years pediatric urolithiasis is either increasing in incidence or is becoming increasingly recognized as a distinct entity. Although often of little help a metabolic evaluation is still mandatory in this population so that disorders such as cystinuria, hyperoxaluria and hypercalciuria may be detected. A full radiological and physiological evaluation of the urinary tract also is necessary to detect congenital anomalies and disorders of bladder function that could predispose to stone formation. Martin I. Resnick Section of Urology Bowman Gray School of Medicine Winston-Salem, North Carolina
![[Urinary calculi in children in Burkina Faso: about 67 cases].](/assets/img/hold.png)
