DOES EVERY PATIENT WITH URETEROPELVIC JUNCTION OBSTRUCTION NEED VOIDING CYSTOURETHROGRAPHY?

0022-5347/01/1656-2305/0 THE JOURNAL OF UROLOGY® Copyright © 2001 by AMERICAN UROLOGICAL ASSOCIATION, INC.®

Vol. 165, 2305–2307, June 2001 Printed in U.S.A.

DOES EVERY PATIENT WITH URETEROPELVIC JUNCTION OBSTRUCTION NEED VOIDING CYSTOURETHROGRAPHY? YOUNG SIG KIM, SUNG HOON DO, CHANG HEE HONG, MYUNG JOON KIM, SEUNG KANG CHOI AND SANG WON HAN From the Departments of Urology and Radiology, Yonsei University College of Medicine, Seoul, Korea

ABSTRACT

Purpose: Voiding cystourethrography is routinely recommended to detect vesicoureteral reflux in children with ureteropelvic junction obstruction. Vesicouretral reflux coexisting with primary ureteropelvic junction obstruction is usually of low grade and resolves spontaneously after pyeloplasty, whereas pseudo ureteropelvic junction obstruction and obstruction secondary to high grade reflux usually present with a dilated ureter that is easily detected on real-time ultrasonography. We assessed the role of voiding cystourethrography in children with ureteropelvic junction obstruction by retrospectively evaluating the incidence and natural history of coexisting vesicourethral reflux. Materials and Methods: We reviewed the records of 106 children younger than 15 years who underwent pyeloplasty for ureteropelvic junction obstruction at our hospital between January 1990 and December 1998. A patient who had initially undergone antireflux surgery later underwent pyeloplasty for newly developed secondary obstruction was not included in the analysis. The diagnosis of ureteropelvic junction obstruction was based on ultrasonography and diuretic renography. Preoperative voiding cystourethrography was performed in all patients to detect vesicourethral reflux. We categorized reflux as low grade if the ureters were not dilated and as high grade if the ureters were dilated and tortuous. Results: There were 89 boys and 17 girls who underwent 115 pyeloplasties, including 9 who underwent bilateral pyeloplasty. Mean patient age at surgery was 27.4 months (63 infants, 6 between 1 and 2 years old, and 37 older than 2 years). Of these 106 patients 85 had unilateral (left side 64, right side 21) and 21 had bilateral ureteropelvic junction obstruction. Vesicourethral reflux was documented in 19 ureters of 12 children. Of the 85 cases of unilateral ureteropelvic junction obstructions 10 had vesicourethral reflux, which was bilateral 6, ipsilateral in 2 and contralateral in 2. Of the 21 cases of bilateral obstructions 2 had reflux, which was bilateral in 1 and was unilateral in 1. Reflux was low grade reflux in 6 and high grade in 6 cases. All low grade reflux disappeared spontaneously at an average period of 4.2 months (range 2 to 10) after pyeloplasty. All 6 patients with high grade reflux subsequently underwent antireflux surgery because of breakthrough urinary tract infection in 2 and persistent in 4 at an average of 36 months (range 3 to 112) after pyeloplasty. All high grade reflux coexisting with ureteropelvic junction obstruction was easily detected on real-time ultrasonography. Conclusions: Low grade reflux coexisting with ureteropelvic junction obstruction spontaneously disappeared after pyeloplasty, and all high grade reflux coexisting with obstruction was easily detected on ultrasonography using real-time mode. Therefore, we believe that indication for voiding cystourethrography in children with ureteropelvic junction obstruction should be limited to those with dilated ureters on ultrasonography. KEY WORDS: vesico-ureteral reflux, ultrasonography, ureter

Approximately 9% to 14% of patients with ureteropelvic junction obstruction have vesicoureteral reflux,1, 2 which can affect renal function and change the treatment plan. Therefore, voiding cystourethrography is usually recommended in children with ureteropelvic junction obstruction to detect the possible coexistence of vesicourethral reflux. However, because many series included pseudo or secondary obstruction due to high grade reflux, the true incidence of primary coexisting ureteropelvic junction obstruction and vesicourethral reflux might be less than previously reported. Moreover, vesicourethral reflux coexisting with primary ureteropelvic junction obstruction is usually of low grade and spontaneously resolves after correction of obstruction. Secondary or pseudo obstruction due to high grade reflux presents as a dilated and tortuous ureter that is easily detected on abdominal ultrasonography using real-time mode. In this context it

may be reasonable to limit the indication for voiding cystourethrography in children with ureteropelvic junction obstruction to those who show dilated ureters on ultrasonography. We assessed the need for voiding cystourethrography in children with ureteropelvic junction obstruction by retrospectively evaluating the incidence and natural history of coexisting vesicourethral reflux.

MATERIALS AND METHODS

We reviewed the records and imaging studies of all 106 patients younger than 15 years who underwent pyeloplasty for ureteropelvic junction obstruction at our hospital between January 1990 and December 1998. A patient who initially had undergone antireflux surgery and later underwent pyeloplasty because of a newly developed secondary ureteropel-

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vic junction obstruction was not included in the analysis. The diagnosis of ureteropelvic junction obstruction was based on real-time abdominal ultrasonography and diuretic renography using diethylenetriaminepentaacetic acid. When the results of the diuretic renogram were equivocal, a Whitaker test was occasionally performed. Preoperative voiding cystourethrography was done in all patients to detect for vesicourethral reflux. The grading system for primary reflux is only applicable if reflux is the only cause of the dilated collecting system, and it cannot be graded in the presence of ureteropelvic junction obstruction. Therefore, reflux coexisting with ureteropelvic junction obstruction was categorized as low grade if the ureters were of normal size, and high grade if they were dilated and tortuous. We differentiated true and pseudo obstruction due to reflux using either diuretic renography or the Whitaker test. Patients with true ureteropelvic junction obstruction initially underwent dismembered pyeloplasty, and were followed with abdominal ultrasonography and diuretic renography. Voiding cystourethrography and urine culture were added at followup in patients who initially had vesicourethral reflux. RESULTS

There were 89 boys and 17 girls who underwent 115 pyeloplasties, including 9 who underwent bilateral pyeloplasty due to bilateral ureteropelvic junction obstruction (see table). Mean patient age at surgery was 27.4 months (range 7 days to 15 years, 63 infants, 6 between 1 and 2 years old, and 37 older than 2 years). Of the 106 patients 85 had unilateral (left side 64, right side 21) and 21 had bilateral ureteropelvic junction obstruction. Vesicourethral reflux was documented in 19 ureters of 12 (11.3%) children. Of the 85 cases with unilateral ureteropelvic junction obstruction 10 (11.8%) had vesicourethral reflux, which was low grade in 6 and high grade in 4, and bilateral in 6, ipsilateral in 2 and contralateral in 2 preoperatively. Of the 21 cases with bilateral ureteropelvic junction obstruction 2 (9.5%) had high grade vesicourethral reflux, which was bilateral in 1 and unilateral in 1 preoperatively. Reflux was documented in 9 (14.3%) of the 63 infants (low grade in 4 ureters and high grade (5.4%) in 6), 1 (16.7%) of the 6 patients between 1 and 2 years old (low grade) and 2 of the 37 older than 2 years (low grade in 1 and high grade in 1). Of the 12 (11.3%) children who had vesicourethral reflux coexisting with ureteropelvic junction obstruction, 6 (5.7%) had low grade and 6 high grade reflux. All of the low grade reflux spontaneously resolved within an average of 4.2 months (range 2 to 10) after pyeloplasty. All 6 patients with high grade reflux subsequently underwent antireflux surgery because of breakthrough urinary tract infection in 2 and persistent reflux in 4 at an average of 36 months (range 3 to 112 months) after pyeloplasty. All high grade reflux cases had dilated and tortuous ureters that were easily detected on real-time abdominal ultrasonography. Of the 94 patients who

Distribution of vesicoureteral reflux in patients with ureteropelvic junction obstruction

No. pts. Low grade reflux: Ipsilat. Contralat. Bilat. High grade reflux: Ipsilat. Unilat. Contralat. Bilat. Totals

No. Unilat. Obstruction

No. Bilat. Obstruction

85

21

1 2 3

– – –

1

– 1

– 3

1

10

2

had ureteropelvic junction obstruction without reflux, 22 (23.4%) had positive urine culture without urinary tract infection symptoms. Among the 12 patients who had ureteropelvic junction obstruction coexisting with vesicourethral reflux 10 (83.3%) had positive urine culture but only 2 had febrile urinary tract infection symptom. DISCUSSION

The exact overall incidence of vesicourethral reflux in normal children is unknown because it is difficult to screen normal children with voiding cystourethrography due to its invasive nature, radiation exposure, expense and postprocedure urinary tract infection rate that would be high without antibiotics. Jones and Headstream reported reflux in 1% of normal hospitalized children spanning a wide age range.3 Lich et al noted reflux in 7.8% of newborns,4 whereas Peters et al observed no reflux on suprapubic punch cystography in premature infants.5 Haberlik reported a 10.5% incidence of grade 2 or less reflux in children with a normal urinary tract and no prior urinary tract infection.6 Zerin et al noted an overall incidence of vesicourethral reflux of 38% in patients with prenatal hydronephrosis.7 The incidence of reflux in children with ureteropelvic junction obstruction is approximately 9% to 14%, including pseudo or secondary obstruction due to high grade reflux. On the other hand, there was no increased risk of obstruction in patients with reflux when all grades of reflux were included, while those with compared to those without high grade reflux had a significantly increased risk of obstruction.8 Of our 106 children with ureteropelvic junction obstruction 12 (11.3%) had vesicourethral reflux, which was low grade in 6 and high grade in 6. There is no evidence that the incidence of vesicourethral reflux, especially low grade reflux (5.7%) not easily detected on ultrasonography, coexisting with ureteropelvic junction obstruction is high compared to the incidence of reflux in normal children. Hollowell et al reported that most low grade reflux associated with ureteropelvic junction obstruction resolves spontaneously,1 which was confirmed by our results. Teele et al demonstrated that reflux occurs into unused ureters such as those in patients with urinary diversion, renal transplantation, renal agenesis or dysplasia, and suggested that it can resolve spontaneously when urine can flow freely down the ureter.9 However, the rate of spontaneous resolution of low grade reflux was the same for ureters ipsilateral and contralateral to the pyeloplasty, and our results agree. This phenomenon indicates that spontaneous resolution of low grade reflux is not totally attributed to the secondary effect of pyeloplasty. Large scale, prospective studies have confirmed that most grade I to III primary vesicourethral reflux resolves with somatic growth in time.10 –12 Reported overall resolution rates are approximately 80%, 60% and 50% for grades I, II and III, respectively. Resolution may take many years and sometimes it does not occur until adolescence. Skoog et al reported that grades II and III reflux resolve in an average of 1.97 and 1.56 years, respectively.10 In our series low grade reflux coexisting with ureteropelvic junction obstruction spontaneously resolved within an average of 4.2 months after pyeloplasty. We believe that not only the natural history of reflux, but also the secondary effect of pyeloplasty might help spontaneously resolve reflux coexisting with ureteropelvic junction obstruction in such a relatively short time. To date the primary diagnostic tool for vesicourethral reflux has been voiding cystourethrography. However, it is an invasive and unpleasant procedure, and ultrasonography has been performed instead. Detection of grade III to V vesicourethral reflux on real-time ultrasonography was first reported as an alternative to voiding cystourethrography by Hofmann.13 Schneider et al noted that grade III reflux or higher was detected in 100% of

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30% of children evaluated for proved urinary infection and 26% to 46% of the siblings of patients with reflux,15–17 we recommend voiding cystourethrography in those cases. Our data also confirm that children with than those without urinary tract infection have a higher incidence of vesicourethral reflux. REFERENCES

Diagram of easy approach to cases of vesicoureteral reflux coexisting with ureteropelvic junction obstruction. UTI, urinary tract infection. VUR, vesicouretheral reflux. VCUG, voiding cystourethrography.

patients using real-time sonography.14 We categorized reflux as low grade if the ureters were not dilated, and high grade if the ureters were dilated and tortuous. All of the high grade reflux cases had dilated and tortuous ureters that were easily detected on real-time ultrasonography but low grade reflux was not. The figure provides an easy approach to the problem. If ultrasonography shows ureteral dilatation in a child with ureteropelvic junction obstruction, voiding cystourethrography should be performed to rule out other accompanying conditions, especially high grade reflux. If no ureteral dilatation is shown on ultrasonography, reflux is usually absent or of low grade. To diagnose low grade reflux in a patient who might need prophylactic antibiotics remains a problem. However, considering the fact that most low grade reflux disappears within a short time after pyeloplasty, grade II reflux or less in a child may be physiological. Since the incidence of low grade reflux in patients with ureteropelvic junction obstruction does not seem to be higher than in the normal pediatric population and considering possible harm that might be caused by the procedure, we believe that performing voiding cystourethrography in all patients with ureteropelvic junction obstruction to detect low grade reflux is unwarranted. However, because vesicourethral reflux is found in 20% to

1. Hollowell, J. G., Altman, H. G., Snyder, H. M. et al: Coexisting ureteropelvic junction obstruction and vesicoureteral reflux: diagnostic and therapeutic implications. J Urol, 142: 490, 1989 2. Maizels, M., Smith, C. K. and Firlit, C. F.: The management of children with vesicoureteral reflux and ureteropelvic junction obstruction. J Urol, 131: 722, 1984 3. Jones, B. W. and Headstream, J. W.: Vesicoureteral reflux in children. J Urol, 80: 114, 1958 4. Lich, R., Jr., Howerton, L. W., Jr., Goode, L. S. et al: The ureterovesical junction of the newborn. J Urol, 92: 436, 1964 5. Peters, P. C., Johnson, D. E. and Jackson, J. H.: The incidence of vesicoureteral reflux in the premature child. J Urol, 97: 259, 1967 6. Haberlik, A.: Detection of low-grade vesicoureteral reflux in children by color Doppler imaging mode. Pediatr Surg Int, 12: 38, 1997 7. Zerin, J. M., Ritchey, M. L. and Chang, A. C. H.: Incidental vesicoureteral reflux in neonate with antenatally detected hydronephrosis and other renal abnormalities. Radiology, 187: 157, 1993 8. Bomalaski, M. D., Hirschl, R. B. and Bloom, D. A.: Vesicoureteral reflux and ureteropelvic junction obstruction: association, treatment options and outcome. J Urol, 157: 969, 1997 9. Teele, R. L., Lebowitz, R. L. and Colodny, A. H.: Reflux into the unused ureter. J Urol, 115: 310, 1976 10. Skoog, S. J., Belman, A. B. and Majd, M.: A nonsurgical approach to the management of primary vesicoureteral reflux. J Urol, 138: 941, 1987 11. Tamminen-Mobius, T., Brunier, E., Ebel, K. D. et al: On behalf of the international reflux study in children: cessation of vesicoureteral reflux for 5 years in infants and children allocated to medical treatment. J Urol, 148: 1662, 1992 12. Goldraich, N. P. and Goldraich, I. H.: Followup of conservatively treated children with high and low grade vesicoureteral reflux: a prospective study. J Urol, 148: 1688, 1992 13. Hofmann, V.: Ultraschalldiagnostik beim vesico-ureteralen reflux im kindesalter. Z Urol Nephrol, 74: 249, 1981 14. Schneider, K., Jablonski, C., Kohn, M. et al: Screening for vesicoureteral reflux in children using real-time sonography. Pediatr Radiol, 14: 400, 1984 15. White, R. H. R.: Management of urinary tract infection. Arch Dis Child, 62: 421, 1987 16. Noe, H. N.: The long-term results of prospective sibling reflux screening. J Urol, 148: 1739, 1992 17. Connolly, L. P., Treves, S. T., Connolly, S. A. et al: Vesicoureteral reflux in children: incidence and severity in siblings. J Urol, 157: 2287, 1997

DISCUSSION

Dr. Moneer Hanna. Just a word of caution about voiding cystourethrography and the ureteropelvic junction. I perform voiding cystourethrography routinely. In some cases a grade I becomes grade II or III because as you repair the ureteropelvic junction, the reflux extends above the obstructed junction. Therefore, we would place this child on continuous antibiotics even if the ureter is not dilated. I think it is wiser to keep doing voiding cystourethrography.