Vol. 118, July, Part 1 Printed in U.SA.
THE JOURNAL OF UROLOGY
Copyright© 1977 by The Williams & Wilkins Co.
Pediatric Articles STAGHORN CALCULI IN CHILDREN FRANCIS F. BARTONE*
J. H. JOHNSTON
From the Alder Hey Children's Hospital, Liverpool, England
Nineteen children who underwent extensive nephrotomies and anatrophic nephrotomies for staghorn calculi (bilateral in 4 cases) are presented. Proteus infection was the cause of the calculus in most cases. In the absence of recurrent stones, renal growth and function were excellent postoperatively. Stone recurrence was minimal if all calculi were removed and infection was controlled. Followup ranged from a few months to 13 years. Staghorn calculi, those stones that occupy a major portion of the renal pelvis and invade at least 2 major calices, are uncommon in children. There have been few reports of children with staghorn calculi treated by extensive nephrotomy. 1- 3 Herein we describe 19 children who underwent nephrotomy for staghorn calculi.
Blood pressures were recorded preoperatively in 17 cases and were normal in 16. One child had 1 or 2 readings with a diastolic of 90 mm. Hg. SURGICAL TECHNIQUE
In all cases extensive longitudinal nephrotomies were done to extract the calculi, that is an incision in the kidney parenchyma extending for at least 2 consecutive major calices in the frontal plane. The modification of anatrophic nephrotomy was used in 3 kidneys in 2 patients. In no instance was hypothermia used nor was mannitol infused. The renal pedicle was occluded completely in all instances except in those cases in which anatrophic nephrotomy was performed and the artery only was clamped. In 2 of the latter cases methylene blue was injected intravenously after occluding the posterior branch of the renal artery to delineate the proper plane as described by Glenn. 4 In 1 case the plane was found without the use of dye. (The recommended dose is 2 mg. per kg. in 1 bolus or 50 mg. per M. 2 ) 5 In young children the small size of the structures makes it difficult to enter the plane just anterior to the posterior calices but with patience it can be found.fi Calirrhaphy or calicoplasty was not necessary in any case since there were no instances of infundibular obstruction. X-rays were obtained intraoperatively in all patients to ensure that there were no residual stone fragments.
MATERIALS AND METHODS
There were 14 boys and 5 girls, ranging in age from 1 to 13 years. Of these children 14 were less than 6 years old. Four children underwent bilateral operations; hence, 23 kidneys were observed. Six patients were followed less than 2 years, 9 were followed more than 4 years, 1 was followed for 13 years and 1 was lost to followup. Only 4 children had urinary obstruction, which may have contributed to the formation of calculi. Three patients had neurogenic bladders secondary to myelomeningocele and 1 had a heavily trabeculated bladder of uncertain causation but no upper tract dilatation. One boy had a contralateral duplicated collecting system with hydronephrosis of the lower moiety. He underwent excision of this system after nephrolithotomy. Several children had mild bilateral hydronephrosis, which cleared subsequent to the nephrotomy and cure of infection. Biochemical investigation, including studies of blood and urine for calcium and phosphorous content and amino-aciduria, were all unrewarding. One patient had an abnormal hourly calcium excretion on 1 occasion, although the 24-hour level was normal. One child had defective urinary acidification but no other stigmas of renal tubular acidosis. It seems likely that the tubular defect was the result of parenchymal damage caused by the stones and infection, and was not a primary condition. The only common denominator indicated was urinary infection. Of the 19 children 18 had infected urine, including a Proteus organism being present in pure or mixed cultures in 16 cases, Escherichia coli in 2 and mixed infection in 1. The composition of the calculi was magnesium calcium ammonium phosphate in the majority of instances. The symptoms exhibited by these children varied but generally were those of upper tract infection. It was interesting that in 2 cases the calculi were diagnosed serendipitously.
One residual calculus and 2 recurrences were noted in 3 children and secondary nephrectomies were performed. The recurrences were true recurrences since x-rays immediately postoperatively had not revealed residual calculi. TABLE
1. Preoperative kidney size differences
9.4 7.5 9.8 8.0 9.0 12.5 12.5 Sums 68.7 Means 9.81
9.3 9.0 10.0 9.0 9.0 11.1 12.8 70.2 10.03
Accepted for publication September 17, 1976. *Requests for reprints: Department of Urology, University of Nebraska Medical Center, 42nd and Dewey Ave., Omaha, Nebraska
t = -0.62
Not statistically significant
STAGHORN CALCULI IN CHILDREN
study of the urine for infection indicated that harbored infected urine. Of these patients 2 had bladders but no recurrence of calculi, 1 had a ne,pt1trectcimv and subsequently had sterile urine and 2 had continued without recurrence of calculi. Eleven children did not have infected urine postoperatively and in 3 instances the information was not available. Blood pressure was recorded postoperatively i.n 13 cases. In 2 children mild elevation was noted and in neither instance was further documentation obtained. Thus, there was little evidence of hypertension postoperatively, despite extensive renal and infection, even in the 4 children who had bilateral operations.
The data on kidney length, as measured from the radiograms, were analyzed to determine whether an inhibited renal growth. Eleven children were rnore than 1 year with data on renal size. Because the best control for each operated kidney is the contralateral unoperated kidney 2 subjects who underwent bilateral operation had to he excluded from analysis. Two additional subjects were excluded from analysis because data of kidney length at the time operation were not available. Thus, 7 subjects were auan,,.,cu Table 1 shows the analysis of kidney length at the time of operation. The mean length of operated kidneys was 9.8 cm., which was 0.2 cm. smaller than the mean unoperated (10.0 cm.). This difference was not statistically M,;1111.,cacuc, since p equals 0.05 (t equals minus 0.62). At followup, hP1c.ul/ Pn 1 and 13 years postoperatively, operated and unoperated kid· neys had grown to 10.8 and 11.4 cm., respectively (table 2) The difference in size between operated and unoperated kidneys at the time of followup was not statistically significant, since the level p equals 0.05 (t equals minus 2.08). The average growth for the operated kidneys was 1.0 cm. and for unoperated kidneys it was 1.4 cm. (table 3). This difference in using a paired t statistic was not statistically significant, since the level p equals 0.05 (t equals minus 0.66). Because of the small sample size neither the average 1.0 cm. growth of the operated kidney nor the 1.4 cm. growth of the kidney was found to be statistically significant, since p 0
2. Postoperative kidney size di1rerences
10.0 8.3 13.0 12.2 11.8 12.5 12.0 79.8 11.4
7.8 13.0 12.2 11.4
10.2 11.5 75.5 10.79
0.05. Not statistically significant TABLE
3. Kidney growth differences
0 0.3 3.2
0.7 -0.7 3.0 3.2 2.8 1.4 -0.8
Not statistically significant
In summary, the operated kidneys were smaller, than their non-operated counterparts at the time of operation and did grow but to a lesser degree by the time of followup. length for each of 9 children who underwent unilateral nephrotomies and in whom the kidneys could be measured postoperatively was likewise compared with the expected of a kidney for a child of the same age as compiled by u,,~~·va and associates.' As seen in figure 1, the operated kidneys did grow but at a slightly slower rate than their unoperated mates. In a further comparison, again using the data of Hodson and associates,7 the renal length of operated and unoperated kidneys was compared to the expected renal length for children of similar ages. All kidneys measured were found to be withm 2½ deviations of the mean, which is within the normal range (fig. 2). 7
Ml/IN KllllHY SIHS
(BEfORt vs I\FHR SURG[RY) AI/G PUllOD Of fOllOW UP 5.83 YRS.
Fm. 1. Grnwth curves of non-operated and operated kidneys compared to predicted growth curve as estimated by Hodson and associates. 7
BARTONE AND JOHNSTON
KIDNEY LENGTH (cm) AFTER SURGERY
AGE FIG. 2. Renal length of operated and non-operated kidneys compared to estimates of renal size based on age according to Hodson and asso-
FIG. 3. Pt. N. T. A, straight x-ray in 1968 shows left staghorn calculus. B, excretory urogram (IVP) in 1968 reveals caliceal and ureteral dilatation preoperatively. C, IVP in 1975, 7 years postoperatively. Note regularity of renal architecture and excellent renal growth.
Of further interest is the excellent preservation of renal architecture that was found in many cases. Two such examples are shown in figures 3 and 4 with followups of 7 and 13 years, respectively. DISCUSSION
Because most children have intrarenal pelves it is difficult to remove every particle of calculus by extended pyelolithot-
FIG. 4. Pt. G. C. A, straight x-ray in 1959 shows right staghorn calculus. B, IVP in 1959 reveals caliceal and ureteral dilatation preoperatively. C, IVP in 1972, 13 years postoperatively. Note excellent renal growth and preservation of architecture.
omy. This deserves emphasis. Even such enthusiastic advocates of extensive pyelolithotomy as Singh and associates prefer nephrotomy for the removal of staghorn calculi in children. 8 In comparing our review with similar studies in the British literature we agree with Williams and associates in regard to the incidence and cause of upper tract calculi in children in
STAGHORN CALCULI IN CHILDREN
Western Europe and England. 1' Renal calculi are not uncommon and are largely of the upper tract infective type. This type of disease is rare in Scandinavia and North America. Since infections are just as frequent in these countries, there must be other factors involved in causing childhood urolithiasis. In urinary infections in children in the United States, Proteus accounts for no more than 1 to 2 per cent. Neverthethere are still many examples of such infections without complicating stone, particularly with the neuropathic bladder of myelomeningocele. 111 We also agree with Williams and associates that the yield of metabolic diagnosis from screening children with renal calculi and Proteus infection is small. 11 The whole problem of calculous disease in children in Great Britain contrasts markedly with the North American experience. Besides noting that calculous disease is much rarer in children on the North American continent, we should also realize that obstruction plus infection accounted for 34 to 67 per cent of instances of calculi in various reported series in the United States and that the incidence of metabolic causes ranged around 15 per cent, much higher than in the reported British series. 12- 14 The low recurrence rate in our series compares to that reported by Smith and Boyce of 15 recurrences in 100 consecutive cases in adults undergoing anatrophic nephrotomy.li Our series emphasizes their contention that removal of all fragments of calculi and eradication of infection postoperatively are the most important factors in the prevention of recurrence. Postoperative renal function and growth also compared fadespite the fact that hypothermia was not used and the renal vein and artery were clamped together. We believe this is explained by the fact that the pedicle was clamped for less than half an hour in almost all instances, for it is thought that a warm ischemia time of more than 1 hour would cause significant deterioration of renal function. 1., It is recommended that hypothermia and mannitol infusion be used whenever extensive nephrotomy is contemplated by anyone who cannot be reasonably certain to keep the ischemia time less than 1 hour. The other important factor that may have contributed to such excellent renal growth and function postoperatively may be the fact that these were all young children. Lyon, in a review of children with renal growth arrest secondary to infection and reflux, noted that in 26 of 32 cases renewed growth and development of the affected kidneys occurred when infection and reflux were eradicated. Our series adds further credence to his observation."' Drs. K Patil and G. Fleischli provided statistical interpretation of the data. REFERENCES
1. Williams, D. I., Barratt, T. M., Eckstein, H.B., Kohlinsky, S. M., Newns, G. H., Polani, P. E. and Singer, J. D.: Urology in
Childhood. New York: Springer-Verlag, vol. 15, suppl., 1974. Johnston, J. H. and Goodwin, W. E.: Reviews in Pediatric Urology. Amsterdam: Excerpta Medica, p. 370, 1974.
3. Middleton, R. G. and Marshall, V. F.: Complete nephrolithotomy for staghorn calculi in children. J. 776, 1971. 4. Glenn, J. F.: Urologic Surgery, 2nd ed. New York: Harper Row, Publishers, Inc., p. 180, 1975. 5. Shirkey, H. C.: Pediatric Therapy, 4th ed. St. Louis: The C. V. Mosby Co., p. 125, 1972. 6. Smith, M. J. V. and Boyce, W. H.: Anatrophic nephrotomy plastic calyrhaphy. J. Urol., 99: 521, 1968. 7. Hodson, C. J., Drewe, J. A., Kam, M. N. and size in normal children. A radiographic study Arch. Dis. Child., 37: 616, 1962. 8. Singh, M., Tresidder, G. C. and Blandy, J.: The results of removal of staghorn calculi by extended omy without cooling or renal artery occlusion. 43: 658, 1971. 9. Williams, D. I., Barratt, T. M., Eckstein, H.B., Kohlinsky, S, M., Newns, G. H., Polani, P. E. and Singer, J. D.: Urology in Childhood. New York: Springer-Verlag, vol. 15, suppl., p. 281, 1974. 10. Williams, D. I., Barratt, T. M., Eckstein, H.B., Kohlinsky, M., Newns, G. H., Polani, P. E. and Singer, J, D.: Urology in Childhood. New York: Springer-Verlag, vol. 15, suppl., p, 1974. 11. Williams, D. I., Barratt, T. M., Eckstein, H.B., Kohlinsky, M., Newns, G. H., Polani, P. E. and Singer, J. D.: Childhood. New York: Springer-Verlag, vol. 15, suppl., p. 1974. 12. Wenzl, J. E., Burke, E. C., Stickler, G. B. and Utz, D. C,. Nephrolithiasis and nephrocalcinosis in children. Pediatrii::s, 41: 57, 1968. 13. Bass, H. N. and Emanuel, B.: Nephrolithiasis in childhood. Urol., 95: 749, 1966. 14. Bennett, A. H. and Colodny, A. H.: Urinary tract calculi 111 children. J. Urol., 109: 318, 1973. 15. Metzner, P. J. and Boyce, W. H.: Simplified renal an adjunct to conservative renal surgery. Brit. J. 1972. 16. Lyon, R.. P.: Renal arrest. J. Urol., 109: 707, 1973. COMMENT We have not been able to establish a safe period for normothermic ischemia. The functional changes in animals and the ultrastructurn.l alterations in human biopsies have led us to the assumption that renal damage commences with ischemia and assumes a degree of significant cell death or acute tubular necrosis in the normothermic ischemic kidneys within 10 to 20 minutes. 1961 we had had access to electron microscopy and biopsy material from kidneys with all the modern drugs and methodology for remtl preservation but without the clinical knowledge that such kidneys can recover, I feel certain that we would not have underta.ken hypothermic renal surgery at that time. The development of typical acute renal tubular necrosis after warm ischemia times of 30 to 40 minutes in adult patients undergoing an operation on a solitary kidney prompted the initial use of hypothermia in this institution, The 15 years of experience have convinced us of the value of hypothermia, as well as the many other ancillary techniques for the ervation of structure and function during renal ischemia of whatever duration. William H. Boyce Bowman Gray School Winston-Salem,