UNCOMPLICATED
HYPOSPADIAS AND ANOMALIES
OF UPPER URINARY TRACT Need for Screening? RICHARD ROBERT
McARDLE, LEBOWITZ,
M.D. M.D.
From the Departments of Surgery (Urology) and Radiology, Harvard Medical School and Children’s Hospital Medical Center, Boston, Massachusetts
ABSTRACT -In a series of 200 patients with uncomplicated hypospadias, 6 (3 per cent) had an anomaly of the upper urinary tract. However, even this lowjigure is an overestimate of the usefulness of the intravenous pyelogram as a screening procedure since none of the patients has had related symptoms and none has required treatment for his anomaly. The implication of this review is that the intravenous urogram is not a necessary part of the evaluation, for management purposes, of the asymptomatic patient with uncomplicated hypospadias. Occasionally, some interesting information may be obtained.
Previous studies attempting to define the incidence of anomalies of the upper urinary tract in patients with uncomplicated hypospadias have been inaccurate or misleading and have often included unimportant minor renal variants and acquired kidney conditions, thus suggesting that the screening intravenous urogram (intravenous pyelogram) is crucial in the management of these patients. l-5 We have attempted to define the role of screening intravenous urography more accurately in asymptomatic patients with uncomplicated hypospadias. Method
and Results
The records of 355 boys who had undergone repair of hypospadias from 1964 through 1974 at Children’s Hospital Medical Center were reviewed. All patients who would have had intravenous urography whether or not they had hypospadias, for example, patients with anorectal malformations, congenital asymmetry or abdominal masses were (hemihypertrophy), excluded. Of the remaining 351patients with uncomplicated hypospadias 200 had intravenous urograms for review. Table I lists the locations of the urethral meatus in the 200 patients with un-
712
complicated hypospadias who had intravenous pyelograms and the 151 who did not. Only 6 of the 200 patients (3 per cent) had an anomaly of the upper urinary tract. None has required treatment for his anomaly. A brief discussion of these 6 patients with anomalies follows. Case abstracts Case 1. A two-and-one-half-year-old boy was seen in 1968 for evaluation of ambiguous genitalia. He had penoscrotal hypospadias, bilateral undescended testicles, a bifid scrotum, and a Screening intravenous right inguinal hernia. urography showed absence of the left kidney and TABLE I. Location of urethral meatus in uncomplicated hypospadias
Location
-Intravenous Performed*
Subcoronal Penile Penoscrotal
60 (30.0) 105 (52.5) 33 (16.5)
Perineal TOTALS
2 ( 1.0) zoo
*Figures in parentheses
UROLOGY
represent
PyelographyNot Performed* 49 (32.0) 59 (39.1) 42 (27.8) 1 ( 0.6) 151 per cent.
/ MAY1975 / VOLUMEV,
NUMBER5
FIGURE 1. Radiographs of upper urinary tract anomalies. (A) Case 1. Solitary right pelvic kidney. (B) Case 2. Right pelvic kidney. (C) Case 3. Horseshoe kidney.
a nondilated nonobstructed right pelvic kidney (Fig. 1A). Case 2. In a boy eight years of age with Klinefelter’s syndrome and subcoronal hypospadias, symptomatic Klebsiella urinary tract infection developed in 1968, three weeks following the second stage of repair of hypospadias which included ten days of tubed suprapubic bladder drainage. Because of the infection, intravenous urography was done and showed a normal left kidney and a nonobstructed nondilated right pelvic kidney. Voiding cystourethrography at this time showed grade 2A reflux into the right pelvic kidney. 6 Cystoscopy was normal. Repeat voiding cystourethrography after successful treatment of the infection showed that the reflux had disappeared. Subsequent intravenous urograms have continued to show the normal left and normal right pelvic kidney (Fig. 1B). Case 3. This boy was first seen in 1956 at two years of age with penoscrotal hypospadias, bifid scrotum, and right inguinal hernia. Not until four-and-one-half years of age, when dysuria developed, did he have intravenous urography which showed a horseshoe kidney. Cultures of the urine were negative. Subsequent intravenous urograms have continued to show the nonobstructed nondilated collecting systems of the horseshoe kidney (Fig. 1C). Case 4. A boy four years of age was admitted in 1973 with penoscrotal hypospadias and right in-
UROLOGY
/ MAY 1975 / VOLUMEV,
NUMBER5
guinal hernia. At herniorraphy a right streak gonad was noted. Screening intravenous urography revealed a nonobstructed, nondilated horseshoe kidney made up of the right kidney and the lower pole of a duplex left collecting system with a bifid ureter (Fig. 2A). He has had no upper urinary tract problems. Case 5. A boy was first seen at five days of age in 1961 because of penoscrotal hypospadias and bifid scrotum. Screening intravenous urography revealed a left duplex collecting system with a bifid ureter. In 1968 repeat intravenous urography showed that the upper pole calyces and ureter had become mildly dilated. Voiding cystourethrography was negative. At cystoscopy the single left ureteral orifice was catheterized, and retrograde pyelography, under fluoroscopic control, showed that the point of junction of the left ureters was 1.5 cm. above the bladder (Fig. 2B). Ureteroureteral reflux was seen. One urinary infection was successfully treated, and the patient has remained asymptomatic. Case 6. A boy with noncommunicating hydrocephalus was first seen in 1959 at four years of age because of midshaft hypospadias and bilateral undescended testicles. Screening intravenous urography showed duplex collecting systems bilaterally, but there was no obstruction or parenchymal loss. The degree of duplication has never been ascertained, but the left ureters are separate at least into the true pelvis. There have been no
713
FIGURE 2. (A) Case 4. Horseshoe kidney (arrows); left duplex collecting system and bifid ureter with junction at level of fourth and f&h lumbar vertebrae (arrow). (B) Case 5. Left duplex collecting system with bi$d ureter. Junction 1.5 cm. above bladder (arrow) (retrograde pyelogram).
urologic problems, and the intravenous pyelogram has shown no change except for normal growth (Fig. 3).
included. Not only are they not upper tract anomalies, and hence not demonstrable during conventional intravenous urography, they are an expected part of the complex of anomalies as-
Comment Our review has shown a low prevalence (3 per cent) of upper urinary tract anomalies in patients with uncomplicated hypospadias. This is analogous to the recent report of Watson, Lennox, and Gangai’ in which prior figures on the prevalence of associated upper urinary tract anomalies in patients with undescended testicles were refuted. Prior studies
This low prevalence contrasts with five prior studies which have reported the association between upper tract anomalies and hypospadias. I-’ Unfortunately, these prior studies have been incomplete and at times misleading. Nonexistent entities such as bladder neck obstruction or contracture have been included.* Patients whose only problem was reflux have been included without information as to the presence or absence of infection. Since in many patients reflux is related to infection, this most often is an acquired condition rather than a congenital anomaly. Examples of enlarged utricles have often been
714
FIGURE 3. tems.
Case 6. Bilateral duplex collecting sys-
UROLOGY
/ MAY1975 I VOLUMEV,
NUMBER5
sociated with hypospadias.g Insignificant variants such as minor degrees of rotation, duplication, or lobulation have also been included as anomalies in past reports. Smyth and Forsythe4 reported that 15 per cent of 60 patients with hypospadias had associated anomalies. These, however, included instances of ureteral reflux, enlarged utricles, and “bladder neck obstruction.” Feltonl reported a 9 per cent prevalence in 45 patients. Included were several instances of minor ureteral dilatation which required no treatment. No mention was made as to the presence of infection or the fullness of the bladder, both of which often lead to transient ureteral dilatation. l”,il Kennedy,’ too, included bladder neck obstruction and ureteral reflux as anomalies. Willis, Brannan, and Ochsner5 reported a prevalence of 14.5 per cent in 96 patients, but some of the patients had other congenital anomalies and hence would not qualify as patients with “uncomplicated” hypospadias. In addition, bladder neck contracture, lobulated kidneys, minor rotational and duplication variants, and dilated ureters were included, without further evaluation. Neyman and Schirmer3 reported a prevalence of 16 per cent in 34 patients but included bladder neck obstruction and reflux.
Embryologic
correlation
The fact that significant anomalies of the upper urinary tract are uncommon in patients with uncomplicated hypospadias should not be surprising. The critical events in the development of a normal kidney occur during the fifth to seventh intrauterine weeks. The appearance of the ureteric bud from the mesonephric duct takes place at the end of the fourth week, and the growing ureter meets the nephrogenic blastema in the fifth week. The ascent of the kidney occurs during the sixth to eighth intrauterine weeks.g These are the times at which anomalies of number, rotation, and position should occur. Hypospadias, however, which results from failure of the urethral folds to form throughout their length (or if they have formed, to close distally), occurs at or later than the eighth week, that is, after the time when upper urinary anomalies would be expected to develop. g This is in distinction to the abnormal developmental events that are thought to be related to the anorectal malformations (imperforate anus) which occur during the sixth and seventh weeks and helps to explain the well-documented observation that there is a
UROLOGY
I
MAY 1975 / VOLUME
V, NUMBER
5
high prevalence of associated upper urinary tract anomalies in patients with imperforate anus. 12*13 Comparisons
with normal
population
It would be useful to be able to compare our 3 per cent prevalence of upper tract anomalies in patients with hypospadias with the number of anomalies in the “normal” population. However, an accurate figure of upper tract anomalies in the “normal” population is difficult to obtain. Although Dees14 noted a developmental anomaly of the kidney or ureter in 9.6 per cent of 1,410 consecutive intravenous urograms, many of the patients had the study performed because they had urinary tract symptoms, or anomalies in other organ systems, making it more likely that they would have a urinary tract anomaly. Several minor variants were also included. Thus this figure is an overestimate of the number of anomalies in a “normal” population. Rubenstein, Meyer, and Bernstein I5 estimated the number of unsuspected upper urinary tract anomalies to be 7 per cent in their unselected autopsy series. This is also an overestimate when compared with a “normal” population. Felton’s’ estimate of 2 per cent (3 of 152) is an overestimate in that one of the anomalies found was in a patient with Fanconi’s anemia which itself is associated with a high prevalence of renal anomalies. I6 Another abnormality (dilated ureters) may have been acquired, not congenital. A more accurate estimate of the number of significant anomalies in the “normal” population will be the topic of a future article. Among the 6 patients with renal anomalies in our series, 2 (1 per cent) had horseshoe kidneys. Estimates of the prevalence of horseshoe kidney range from 1 in 352 (0.3 per cent) to 1 in 1,800 (0.1 per cent). ” We found 2 patients with some degree of collecting system duplication. Estimates are that this occurs with a prevalence of from 0.6 to 4.0 per cent. 14,18There were 2 patients with a pelvic kidney. The prevalence of pelvic kidney is estimated to be 1 in 800 (0.1 per cent). lg Signijkance
of anomalies
The significance of an anomaly is difficult to define. Donahue, Utley, and Maling20 have defined significance as “a major abnormality. . . resulting in significant loss of renal substance, or requiring correction for conservation of the renal substance.” Using these criteria, none of our cases would be considered significant. However, it may be of interest to know that a patient has a solitary, pelvic, horseshoe, or duplex kidney.
715
None ofour patients has had symptoms related to the anomaly, and none required treatment. 300 Longwood Avenue Boston, Massachusetts 02115 (DR. LEBOWI’IZ) ACKNOWLEDGMENT. Our appreciation to John Kirkpatrick, M.D., N. Thorne Griscom, M.D., Arnold Colodny, M.D., Seymour Grufferman, M.D., and Ms. Andrea Kelton for their help in preparing this report. References 1. FELTON, L. M.: Should intravenous pyelography be a routine procedure for children with cryptorchism or hypospadias? J. Ural. 81: 335 (1959). 2. KENNEDY, P. S., JR.: Hypospadias: a twenty year review of 489 cases, ibid. 85: 814 (1961). 3. NEYMAN, MM.A., and SCHIRMER, H. K. A.: Urinary tract evaluation in hypospadias, ibid. 94: 439 (1965). 4. SWYTH, B. T., and FORSYTHE, I. W.: Hypospadias and associated anomalies ofthe genitourinary tract, ibid. 82: 109 (1959). 5. WILLIS, c., BRANNAN, W., and OCHSNER, M.: Hypospadias and associated anomalies, South. Med. J. 60: 969 (1967). 6. COLODNY, A. H., and LEBOWITZ, R. L.: A plea for grading vesicoureteric reflux, Urology 4: 357 (1974). 7. WATSON, R. A., LENNOX, K. W., and GANGAI, M. P.: Simple cryptorchidism: the value of the excretory urogram as a screening method, J. Ural. 111: 789 (1974). 8. WILLIAMS, D. I.: The ureter, the urologist and the paediatrician, Proc. R. Sot. Med. 63: 35 (1970). 9. GRAY, . W., and SKANDALAKIS,J. E. : Embryology for Surgeons, Philadelphia, W. B. Saunders Company, 1972, pp. 443, 595, 625.
716
10. BERDON, W. E., and BAKER, D. H.: The significance of a distended bladder in the interpretation of intravenous pyelograms obtained on patients with “hydronephrosis,” Am. J. Roentgenol. Radium Ther. Nucl. Med. 120: 402 (1974). 11. LEBOWITZ, R. L., ~~~COLODNY, A. H.: Urinary tract infection in children, Crit. Rev. Clin. Radial. Nucl. Med. 4: 457 (1974). 12. BERDON, W. E., et al. : The association of lumbosacral spine and genitourinary anomalies with imperforate anus, Am. J. Roentgenol. Radium Ther. Nucl. Med. 98: 181 (1966). 13. CARLTON, C. E., HARBERG, F. J., and FRY, F. M.: Urologic complications of imperforate anus, J, Ural. 109: 737 (1973). 14. DEES, J. E.: The, clinical importance of congenital anomalies of the upper urinary tract, ibid. 46: 659 (1941). 15. RUBENSTEIN, M., MEYER, R., and BERNSTEIN, J. : Congenital abnormalities of the urinary system, J. Pediatr. 58: 356 (1961). 16. MINAGI, H., and STEINBACH, H. L.: Roentgen appearance of anomalies associated with hypoplastic anemias of childhood: Fanconi’s anemia and congenital hypoplastic anemia, Am. J. Roentgenol. Radium Ther. Nuc1. Med. 97: 100 (1966). 17. K~~LLN, C. P., BOATMAN, J. D., SCHMIDT, J. D., and FLOCKS, R. H.: Horseshoe kidney: a review of 105 patients, J. Ural. 107: 203 (1972). 18. HARTMAN, G. W., and HODSON, C. J.: The duplex kidney and related abnormalities, Clin. Radial. 20: 387 (1969). 19. CAMPBELL, M. F. : Urology, 2nd ed., Philadelphia, W. B. Saunders Company, 1963, chaps. 33, 34, 35. 20. DONAHUE, R. E., UTLEY, W. L. F., and MALING, T. M.: Excretory urography in asymptomatic boys with cryptorchidism, J. Ural. 109: 912 (1973).
UROLOGY
/
MAY 1975 /
VOLUME V, NUMBER 5
HYPOSPADIAS AND ANOMALIES
OF UPPER URINARY TRACT Need for Screening? RICHARD ROBERT
McARDLE, LEBOWITZ,
M.D. M.D.
From the Departments of Surgery (Urology) and Radiology, Harvard Medical School and Children’s Hospital Medical Center, Boston, Massachusetts
ABSTRACT -In a series of 200 patients with uncomplicated hypospadias, 6 (3 per cent) had an anomaly of the upper urinary tract. However, even this lowjigure is an overestimate of the usefulness of the intravenous pyelogram as a screening procedure since none of the patients has had related symptoms and none has required treatment for his anomaly. The implication of this review is that the intravenous urogram is not a necessary part of the evaluation, for management purposes, of the asymptomatic patient with uncomplicated hypospadias. Occasionally, some interesting information may be obtained.
Previous studies attempting to define the incidence of anomalies of the upper urinary tract in patients with uncomplicated hypospadias have been inaccurate or misleading and have often included unimportant minor renal variants and acquired kidney conditions, thus suggesting that the screening intravenous urogram (intravenous pyelogram) is crucial in the management of these patients. l-5 We have attempted to define the role of screening intravenous urography more accurately in asymptomatic patients with uncomplicated hypospadias. Method
and Results
The records of 355 boys who had undergone repair of hypospadias from 1964 through 1974 at Children’s Hospital Medical Center were reviewed. All patients who would have had intravenous urography whether or not they had hypospadias, for example, patients with anorectal malformations, congenital asymmetry or abdominal masses were (hemihypertrophy), excluded. Of the remaining 351patients with uncomplicated hypospadias 200 had intravenous urograms for review. Table I lists the locations of the urethral meatus in the 200 patients with un-
712
complicated hypospadias who had intravenous pyelograms and the 151 who did not. Only 6 of the 200 patients (3 per cent) had an anomaly of the upper urinary tract. None has required treatment for his anomaly. A brief discussion of these 6 patients with anomalies follows. Case abstracts Case 1. A two-and-one-half-year-old boy was seen in 1968 for evaluation of ambiguous genitalia. He had penoscrotal hypospadias, bilateral undescended testicles, a bifid scrotum, and a Screening intravenous right inguinal hernia. urography showed absence of the left kidney and TABLE I. Location of urethral meatus in uncomplicated hypospadias
Location
-Intravenous Performed*
Subcoronal Penile Penoscrotal
60 (30.0) 105 (52.5) 33 (16.5)
Perineal TOTALS
2 ( 1.0) zoo
*Figures in parentheses
UROLOGY
represent
PyelographyNot Performed* 49 (32.0) 59 (39.1) 42 (27.8) 1 ( 0.6) 151 per cent.
/ MAY1975 / VOLUMEV,
NUMBER5
FIGURE 1. Radiographs of upper urinary tract anomalies. (A) Case 1. Solitary right pelvic kidney. (B) Case 2. Right pelvic kidney. (C) Case 3. Horseshoe kidney.
a nondilated nonobstructed right pelvic kidney (Fig. 1A). Case 2. In a boy eight years of age with Klinefelter’s syndrome and subcoronal hypospadias, symptomatic Klebsiella urinary tract infection developed in 1968, three weeks following the second stage of repair of hypospadias which included ten days of tubed suprapubic bladder drainage. Because of the infection, intravenous urography was done and showed a normal left kidney and a nonobstructed nondilated right pelvic kidney. Voiding cystourethrography at this time showed grade 2A reflux into the right pelvic kidney. 6 Cystoscopy was normal. Repeat voiding cystourethrography after successful treatment of the infection showed that the reflux had disappeared. Subsequent intravenous urograms have continued to show the normal left and normal right pelvic kidney (Fig. 1B). Case 3. This boy was first seen in 1956 at two years of age with penoscrotal hypospadias, bifid scrotum, and right inguinal hernia. Not until four-and-one-half years of age, when dysuria developed, did he have intravenous urography which showed a horseshoe kidney. Cultures of the urine were negative. Subsequent intravenous urograms have continued to show the nonobstructed nondilated collecting systems of the horseshoe kidney (Fig. 1C). Case 4. A boy four years of age was admitted in 1973 with penoscrotal hypospadias and right in-
UROLOGY
/ MAY 1975 / VOLUMEV,
NUMBER5
guinal hernia. At herniorraphy a right streak gonad was noted. Screening intravenous urography revealed a nonobstructed, nondilated horseshoe kidney made up of the right kidney and the lower pole of a duplex left collecting system with a bifid ureter (Fig. 2A). He has had no upper urinary tract problems. Case 5. A boy was first seen at five days of age in 1961 because of penoscrotal hypospadias and bifid scrotum. Screening intravenous urography revealed a left duplex collecting system with a bifid ureter. In 1968 repeat intravenous urography showed that the upper pole calyces and ureter had become mildly dilated. Voiding cystourethrography was negative. At cystoscopy the single left ureteral orifice was catheterized, and retrograde pyelography, under fluoroscopic control, showed that the point of junction of the left ureters was 1.5 cm. above the bladder (Fig. 2B). Ureteroureteral reflux was seen. One urinary infection was successfully treated, and the patient has remained asymptomatic. Case 6. A boy with noncommunicating hydrocephalus was first seen in 1959 at four years of age because of midshaft hypospadias and bilateral undescended testicles. Screening intravenous urography showed duplex collecting systems bilaterally, but there was no obstruction or parenchymal loss. The degree of duplication has never been ascertained, but the left ureters are separate at least into the true pelvis. There have been no
713
FIGURE 2. (A) Case 4. Horseshoe kidney (arrows); left duplex collecting system and bifid ureter with junction at level of fourth and f&h lumbar vertebrae (arrow). (B) Case 5. Left duplex collecting system with bi$d ureter. Junction 1.5 cm. above bladder (arrow) (retrograde pyelogram).
urologic problems, and the intravenous pyelogram has shown no change except for normal growth (Fig. 3).
included. Not only are they not upper tract anomalies, and hence not demonstrable during conventional intravenous urography, they are an expected part of the complex of anomalies as-
Comment Our review has shown a low prevalence (3 per cent) of upper urinary tract anomalies in patients with uncomplicated hypospadias. This is analogous to the recent report of Watson, Lennox, and Gangai’ in which prior figures on the prevalence of associated upper urinary tract anomalies in patients with undescended testicles were refuted. Prior studies
This low prevalence contrasts with five prior studies which have reported the association between upper tract anomalies and hypospadias. I-’ Unfortunately, these prior studies have been incomplete and at times misleading. Nonexistent entities such as bladder neck obstruction or contracture have been included.* Patients whose only problem was reflux have been included without information as to the presence or absence of infection. Since in many patients reflux is related to infection, this most often is an acquired condition rather than a congenital anomaly. Examples of enlarged utricles have often been
714
FIGURE 3. tems.
Case 6. Bilateral duplex collecting sys-
UROLOGY
/ MAY1975 I VOLUMEV,
NUMBER5
sociated with hypospadias.g Insignificant variants such as minor degrees of rotation, duplication, or lobulation have also been included as anomalies in past reports. Smyth and Forsythe4 reported that 15 per cent of 60 patients with hypospadias had associated anomalies. These, however, included instances of ureteral reflux, enlarged utricles, and “bladder neck obstruction.” Feltonl reported a 9 per cent prevalence in 45 patients. Included were several instances of minor ureteral dilatation which required no treatment. No mention was made as to the presence of infection or the fullness of the bladder, both of which often lead to transient ureteral dilatation. l”,il Kennedy,’ too, included bladder neck obstruction and ureteral reflux as anomalies. Willis, Brannan, and Ochsner5 reported a prevalence of 14.5 per cent in 96 patients, but some of the patients had other congenital anomalies and hence would not qualify as patients with “uncomplicated” hypospadias. In addition, bladder neck contracture, lobulated kidneys, minor rotational and duplication variants, and dilated ureters were included, without further evaluation. Neyman and Schirmer3 reported a prevalence of 16 per cent in 34 patients but included bladder neck obstruction and reflux.
Embryologic
correlation
The fact that significant anomalies of the upper urinary tract are uncommon in patients with uncomplicated hypospadias should not be surprising. The critical events in the development of a normal kidney occur during the fifth to seventh intrauterine weeks. The appearance of the ureteric bud from the mesonephric duct takes place at the end of the fourth week, and the growing ureter meets the nephrogenic blastema in the fifth week. The ascent of the kidney occurs during the sixth to eighth intrauterine weeks.g These are the times at which anomalies of number, rotation, and position should occur. Hypospadias, however, which results from failure of the urethral folds to form throughout their length (or if they have formed, to close distally), occurs at or later than the eighth week, that is, after the time when upper urinary anomalies would be expected to develop. g This is in distinction to the abnormal developmental events that are thought to be related to the anorectal malformations (imperforate anus) which occur during the sixth and seventh weeks and helps to explain the well-documented observation that there is a
UROLOGY
I
MAY 1975 / VOLUME
V, NUMBER
5
high prevalence of associated upper urinary tract anomalies in patients with imperforate anus. 12*13 Comparisons
with normal
population
It would be useful to be able to compare our 3 per cent prevalence of upper tract anomalies in patients with hypospadias with the number of anomalies in the “normal” population. However, an accurate figure of upper tract anomalies in the “normal” population is difficult to obtain. Although Dees14 noted a developmental anomaly of the kidney or ureter in 9.6 per cent of 1,410 consecutive intravenous urograms, many of the patients had the study performed because they had urinary tract symptoms, or anomalies in other organ systems, making it more likely that they would have a urinary tract anomaly. Several minor variants were also included. Thus this figure is an overestimate of the number of anomalies in a “normal” population. Rubenstein, Meyer, and Bernstein I5 estimated the number of unsuspected upper urinary tract anomalies to be 7 per cent in their unselected autopsy series. This is also an overestimate when compared with a “normal” population. Felton’s’ estimate of 2 per cent (3 of 152) is an overestimate in that one of the anomalies found was in a patient with Fanconi’s anemia which itself is associated with a high prevalence of renal anomalies. I6 Another abnormality (dilated ureters) may have been acquired, not congenital. A more accurate estimate of the number of significant anomalies in the “normal” population will be the topic of a future article. Among the 6 patients with renal anomalies in our series, 2 (1 per cent) had horseshoe kidneys. Estimates of the prevalence of horseshoe kidney range from 1 in 352 (0.3 per cent) to 1 in 1,800 (0.1 per cent). ” We found 2 patients with some degree of collecting system duplication. Estimates are that this occurs with a prevalence of from 0.6 to 4.0 per cent. 14,18There were 2 patients with a pelvic kidney. The prevalence of pelvic kidney is estimated to be 1 in 800 (0.1 per cent). lg Signijkance
of anomalies
The significance of an anomaly is difficult to define. Donahue, Utley, and Maling20 have defined significance as “a major abnormality. . . resulting in significant loss of renal substance, or requiring correction for conservation of the renal substance.” Using these criteria, none of our cases would be considered significant. However, it may be of interest to know that a patient has a solitary, pelvic, horseshoe, or duplex kidney.
715
None ofour patients has had symptoms related to the anomaly, and none required treatment. 300 Longwood Avenue Boston, Massachusetts 02115 (DR. LEBOWI’IZ) ACKNOWLEDGMENT. Our appreciation to John Kirkpatrick, M.D., N. Thorne Griscom, M.D., Arnold Colodny, M.D., Seymour Grufferman, M.D., and Ms. Andrea Kelton for their help in preparing this report. References 1. FELTON, L. M.: Should intravenous pyelography be a routine procedure for children with cryptorchism or hypospadias? J. Ural. 81: 335 (1959). 2. KENNEDY, P. S., JR.: Hypospadias: a twenty year review of 489 cases, ibid. 85: 814 (1961). 3. NEYMAN, MM.A., and SCHIRMER, H. K. A.: Urinary tract evaluation in hypospadias, ibid. 94: 439 (1965). 4. SWYTH, B. T., and FORSYTHE, I. W.: Hypospadias and associated anomalies ofthe genitourinary tract, ibid. 82: 109 (1959). 5. WILLIS, c., BRANNAN, W., and OCHSNER, M.: Hypospadias and associated anomalies, South. Med. J. 60: 969 (1967). 6. COLODNY, A. H., and LEBOWITZ, R. L.: A plea for grading vesicoureteric reflux, Urology 4: 357 (1974). 7. WATSON, R. A., LENNOX, K. W., and GANGAI, M. P.: Simple cryptorchidism: the value of the excretory urogram as a screening method, J. Ural. 111: 789 (1974). 8. WILLIAMS, D. I.: The ureter, the urologist and the paediatrician, Proc. R. Sot. Med. 63: 35 (1970). 9. GRAY, . W., and SKANDALAKIS,J. E. : Embryology for Surgeons, Philadelphia, W. B. Saunders Company, 1972, pp. 443, 595, 625.
716
10. BERDON, W. E., and BAKER, D. H.: The significance of a distended bladder in the interpretation of intravenous pyelograms obtained on patients with “hydronephrosis,” Am. J. Roentgenol. Radium Ther. Nucl. Med. 120: 402 (1974). 11. LEBOWITZ, R. L., ~~~COLODNY, A. H.: Urinary tract infection in children, Crit. Rev. Clin. Radial. Nucl. Med. 4: 457 (1974). 12. BERDON, W. E., et al. : The association of lumbosacral spine and genitourinary anomalies with imperforate anus, Am. J. Roentgenol. Radium Ther. Nucl. Med. 98: 181 (1966). 13. CARLTON, C. E., HARBERG, F. J., and FRY, F. M.: Urologic complications of imperforate anus, J, Ural. 109: 737 (1973). 14. DEES, J. E.: The, clinical importance of congenital anomalies of the upper urinary tract, ibid. 46: 659 (1941). 15. RUBENSTEIN, M., MEYER, R., and BERNSTEIN, J. : Congenital abnormalities of the urinary system, J. Pediatr. 58: 356 (1961). 16. MINAGI, H., and STEINBACH, H. L.: Roentgen appearance of anomalies associated with hypoplastic anemias of childhood: Fanconi’s anemia and congenital hypoplastic anemia, Am. J. Roentgenol. Radium Ther. Nuc1. Med. 97: 100 (1966). 17. K~~LLN, C. P., BOATMAN, J. D., SCHMIDT, J. D., and FLOCKS, R. H.: Horseshoe kidney: a review of 105 patients, J. Ural. 107: 203 (1972). 18. HARTMAN, G. W., and HODSON, C. J.: The duplex kidney and related abnormalities, Clin. Radial. 20: 387 (1969). 19. CAMPBELL, M. F. : Urology, 2nd ed., Philadelphia, W. B. Saunders Company, 1963, chaps. 33, 34, 35. 20. DONAHUE, R. E., UTLEY, W. L. F., and MALING, T. M.: Excretory urography in asymptomatic boys with cryptorchidism, J. Ural. 109: 912 (1973).
UROLOGY
/
MAY 1975 /
VOLUME V, NUMBER 5
