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IS PRIMARY OBSTRUCTIVE MEGAURETER REPAIR AT RISK FOR CONTRALATERAL REFLUX?
0022-5347/00/1643-1061/0 THE JOURNAL OF UROLOGY® Copyright © 2000 by AMERICAN UROLOGICAL ASSOCIATION, INC.®
Vol. 164, 1061–1063, September 2000 Printed in U.S.A.
IS PRIMARY OBSTRUCTIVE MEGAURETER REPAIR AT RISK FOR CONTRALATERAL REFLUX? PAOLO CAIONE, NICOLA CAPOZZA, LAURA ASILI, ALBERTO LAIS
AND
ENNIO MATARAZZO
From the Division of Pediatric Urology, Department of Surgery, “Bambino Gesu`” Children’s Hospital, Research Institute, Rome, Italy
ABSTRACT
Purpose: Contralateral vesicoureteral reflux occurs after successful unilateral reflux repair in a significant proportion of patients without correlation to the surgical approach. Unilateral congenital obstructive megaureter was compared to primary vesicoureteral reflux with regard to the risk of onset of contralateral reflux after unilateral ureteral reimplantation. Materials and Methods: Unilateral congenital obstructive megaureter was diagnosed in 58 consecutive patients 2 to 10 years old (mean age 3.2). Cross-trigonal ureteroneocystostomy was performed in 57 cases and longitudinal ureteral reimplantation, according to the PolitanoLeadbetter technique was done in 1. Longitudinal tapering according to Hendren was performed in 44 ureters, and the Kalicinski folding was used to repair 11 ureters. All patients underwent serial renal ultrasound, diethylenetetraminepentaacetic acid nuclear scan, excretory urogram and voiding cystourethrogram. The control group was composed of 98 age matched children with unilateral vesicoureteral reflux who underwent unilateral reimplantation with or without tapering. Fisher’s exact test and Student’s t test were used for statistical analysis. Results: Followup ranged from 1 to 5 years. All patients in both groups underwent a voiding cystourethrogram at 6 months, and renal ultrasound at 3, 6 and 12 months postoperatively. Grade 2 reflux developed in 1 study group patient after contralateral Kalicinski ureteral folding and cross-trigonal reimplantation (1.7%). In the control group new onset contralateral reflux developed in 11 cases (11.2%). The difference was statistically significant (p ⬍0.005, Fisher’s exact test p ⫽ 0.033). Conclusions: Ureteral reimplantation for unilateral congenital obstructive megaureter is not correlated with the development of contralateral reflux. The occurrence of contralateral reflux after successful unilateral reflux repair is high (11.2%), and is not correlated with age, sex and technique of reimplantation or tapering. These results support the hypothesis that the functional anatomy of the trigone is preserved in congenital obstructive megaureter but is impaired on both sides in cases of unilateral vesicoureteral reflux. The surgical management of unilateral primary vesicoureteral reflux and congenital obstructive megaureter should be differentiated based on these results. KEY WORDS: ureter; bladder, replantation; vesico-ureteral reflux; ureteral obstruction
The onset of de novo contralateral reflux after successful unilateral repair of primary vesicoureteral reflux occurs in 10% to 27% of cases.1–5 The development of postoperative contralateral reflux is independent of age, sex, and technique of reimplantation and ureteral tapering, and involves intravesical, extravesical and endoscopic approaches.5, 6 To date no attention has been paid to congenital obstructive megaureter in regard to the occurrence of contralateral reflux after unilateral reimplantation with or without ureteral tapering. We performed a retrospective longitudinal study comparing unilateral congenital obstructive megaureter with unilateral primary vesicoureteral reflux treated with similar surgical procedures. MATERIALS AND METHODS
Unilateral congenital obstructive megaureter was diagnosed in 58 consecutive patients 2 to 10 years old (mean age 3.2) during the last 5 years. All patients underwent preoperative serial renal ultrasound, diethylenetetraminepentaacetic acid nuclear scan, excretory urogram and at least 1 voiding cystourethrogram to rule out vesicoureteral reflux. Crosstrigonal ureteroneocystostomy was performed in 57 cases and longitudinal ureteral reimplantation, according to the Politano-Leadbetter technique was done in 1. A dilated distal
ureter was tapered in 54 cases. Longitudinal tapering according to Hendren7 was performed in 44 ureters, and the Kalicinski folding8 was used to repair 11 ureters. No tapering was required in 3 ureters. The control group included 98 patients 1 to 12 years old (mean age 2.9) with unilateral primary reflux ranging from grade 2 to 5 according to the International Reflux Classification. Grade 3 and 4 reflux was present in 85 cases. Preoperative evaluation included renal ultrasound, dimercaptosuccinic acid scan and at least 2 voiding cystourethrograms. The second voiding cystourethrogram was performed 1 year after a trial of antimicrobial prophylaxis. Contralateral vesicoureteral reflux was not recognized in any patient. All patients underwent ipsilateral antireflux surgery, including cross-trigonal ureteroneocystostomy in 86, longitudinal Politano-Leadbetter reimplantation in 8 and Glenn-Anderson trigonal advancement in 4. Longitudinal modeling of wide ureters was performed in 21 cases, including ureteral tapering in 13 and ureteral folding in 8. Preoperative cystoscopy was not performed and there was no history consistent with dysfunctional voiding in either group. Postoperative followup included serial renal ultrasound at 3, 6 and 12 months, voiding cystourethrogram every 6 months and nuclear renal scan at 1 year. All procedures were performed by the same pediatric urology staff. Statistical
1061
1062
PRIMARY OBSTRUCTIVE MEGAURETER REPAIR
analysis was performed with chi-square and Fisher’s exact tests. RESULTS
Followup ranged from 1 to 5 years in the control and study groups. Contralateral reflux developed postoperatively in 1 of the 58 patients with congenital obstructive megaureter (1.7%). This patient was a 3-year-old boy who had undergone Kalicinski longitudinal folding for a grossly dilated left ureter and cross-trigonal left ureteroneocystostomy. The postoperative voiding cystourethrogram showed right grade 2 vesicoureteral reflux that was successfully treated with the endoscopic subureteral injection of cross-linked collagen.9 New onset vesicoureteral reflux developed in the ureter opposite the reimplantation site in 11 of the 98 control group cases (11.2%). Contralateral reflux was grade 2 in 6 cases and grade 3 in 5 (see table). No postoperative ipsilateral vesicoureteral reflux was detected in the congenital obstructive megaureter group, and 2 cases of reflux, which was grade 2 in 1 and grade 3 in 1, occurred in the control group. The occurrence of contralateral de novo reflux was significantly different between the 2 groups (p ⬍0.005, Fisher’s exact test p ⫽ 0.033). DISCUSSION
Congenital obstructive megaureter or primary obstructive megaureter refers to large ureters with intrinsic obstruction of the ureterovesical junction or more frequently in the nearby ureteral segment. Congenital distal ureteral stricture, ureteral valves or more often a distal adynamic segment has been reported to cause congenital obstructive megaureter.10 Histological studies using light microscopy and electron microscopy have predominantly shown hypoplasia and atrophy of the ureteral muscle, and an increased amount of collagen between muscle cells with abnormal cellto-cell contact.11–13 As a consequence ureteral peristalsis is disrupted and noneffective.14 Congenital obstructive megaureter affects more males and the left ureter, and is unilateral in approximately 75% of cases.10 Surgical correction of congenital obstructive megaureter should be reserved for cases with proved obstruction of ureteral urinary flow by excretory urography or diethylenetetraminepentaacetic acid/mercaptoacetyltriglycine renal nuclear scan. Specific surgical indications include progressive loss of parenchymal function, significant delayed washout, increasing upper tract dilatation and/or symptomatic megaureter (urinary tract infections, stone disease, persistent flank pain and hematuria). In 1969 Hendren developed the tapering technique of wide ureters7 and in 1977 Kalicinski et al proposed a simplified technique of ureteral modeling with longitudinal folding of the ureteral wall.8 The tapered megaureter is suitable for
Contralateral vesicoureteral reflux after unilateral reimplantation No. Study Group (congenital obstructive megaureter) Total cases Lt. ureter Rt. ureter Cross-trigonal reimplantation Longitudinal Politano-Leadbetter repair Glenn-Anderson advancement Ureteral tapering (Hendren) Ureteral folding (Kalicinski) No ureteral modeling New contralat. reflux (%) Ipsilat. persistent reflux *Reflux was grade 2 in 6 cases and grade 3
58 42 16 57 1 – 47 11 3 1 (1.7%) – in 5.
No. Control Group (primary vesicoureteral reflux) 98 46 52 86 8 4 13 8 – 11 (11.2%)* 3
effective ureteroneocystostomy using standard ureterovesical reimplantation techniques. The results are good with a success rate of 90% to 95% regardless of the ureteroneocystostomy techniques.15 In our experience results of ureteral reimplantation for primary vesicoureteral reflux have been satisfactory,16 and we have achieved similar results with surgical repair of obstructive unilateral congenital obstructive megaureter. The effects on the contralateral ureter differ grossly after surgical repair for congenital obstructive megaureter than for unilateral primary vesicoureteral reflux. The incidence of newly diagnosed contralateral reflux postoperatively for unilateral primary reflux is significant. Warren et al reported the development of contralateral reflux in 15% to 20% of patients after unilateral reimplantation.1 Parrott and Woodard,2 and more recently Diamond et al4 confirmed that these data do not seem to be influenced by intravesical repair, extravesical repair or endoscopic treatment. Diamond et al reported that high grade vesicoureteral reflux and a duplex system were important risk factors for contralateral reflux.4 In our series we found an overall 11.2% incidence of de novo contralateral reflux without a statistically significant difference between surgical technique or grade of reflux.17 We proposed a simple and effective solution, contralateral ureteral meatal advancement, to prevent postoperative de novo contralateral reflux.17 This procedure is easy to perform during ipsilateral reimplantation, allows marginal invasiveness and prevents contralateral reflux. Contralateral ureteral meatal advancement avoids systematic standard bilateral surgery in all cases of unilateral vesicoureteral reflux2 or the “wait and see” approach. Our results indicate that vesicoureteral reimplantation for unilateral primary congenital obstructive megaureter does not cause de novo contralateral reflux in a significant number of cases. We only observed 1 case of grade 2 contralateral reflux in a 3-year-old child who had undergone ureteral folding and cross-trigonal ureteroneocystostomy. This unique onset of contralateral postoperative reflux is difficult to explain but we postulate that trigone distortion secondary to the cross-trigonal reimplantation was a predominant factor. This newly developed reflux was successfully treated with endoscopic subureteral injection of bovine cross-linked collagen. Our results indicate that congenital obstructive megaureter is different than primary vesicoureteral reflux, and the occurrence rate of secondary contralateral reflux is significantly higher in cases of primary reflux independent of age, sex and repair technique. Of our 98 control group patients 11 (11.2%) had contralateral postoperative reflux despite close attention to detect any sign of bilateral involvement before performing unilateral reimplantation. Two main hypotheses have been proposed with regard to the pathophysiology of contralateral reflux after primary vesicoureteral reflux repair. Iatrogenic distortion of the contralateral trigone has been described as a result of ipsilateral surgical correction6 but it does not explain the onset of contralateral reflux also reported after endoscopic treatment. Similarly, elimination of the pop-off valve mechanism as a result of surgical correction of the refluxing ureter has been advocated4 but we equally observed development of secondary contralateral reflux regardless of primary reflux grade. Our results confirm the hypothesis that the functional anatomy of the trigone is normal in cases of primary nonrefluxing megaureter, whereas the ureterovesical junctions appear bilaterally impaired in cases of vesicoureteral reflux. Thus, contralateral reflux is unlikely to occur after congenital obstructive megaureter repairs. In cases of primary vesicoureteral reflux contralateral reflux is probably a result of primitive trigonal impairment, which is associated with the weakness of both ureterovesical junctions rather than the effect of bladder fiber distortion during ureteral reimplantation or elimination of the pop-off valve mechanism.
PRIMARY OBSTRUCTIVE MEGAURETER REPAIR CONCLUSIONS
Based on these results and the pathophysiology of secondary vesicoureteral reflux, management of the contralateral ureter should be differentiated when treating congenital obstructive megaureter and primary vesicoureteral reflux. In cases of reflux bilateral involvement must be carefully ruled out and contralateral ureteral meatal advancement should be routinely performed to prevent contralateral reflux.17 In cases of primary unilateral congenital obstructive megaureter no surgery of a normal appearing, opposite ureter is warranted. REFERENCES
1. Warren, M. M., Kelalis, P. P. and Stickler, G. B.: Unilateral ureteroneocystostomy: the fate of contralateral ureter. J Urol, 107: 466, 1972 2. Parrott, T. S. and Woodard, J. R.: Reflux in opposite ureter after successful correction of unilateral vesicoureteral reflux. Urology, 7: 276, 1976 3. Ahmed, S. and Tan, H.: Complications of transverse advancement ureteral reimplantation. J Urol, 127: 970, 1982 4. Diamond, D. A., Rabinovitz, R., Hoenig, D. M. et al: The mechanism of new onset contralateral reflux following unilateral ureteroneocystostomy. J Urol, part 2, 156: 665, 1996 5. Hoenig, D. M., Diamond, D. A., Rabinovitz, R. et al: Contralateral reflux after unilateral ureteral reimplantation. J Urol, 156: 196, 1996 6. Kumar, R. and Puri, P.: Newly diagnosed contralateral reflux following successful unilateral endoscopic correction. Is it due to “pop-off valve” mechanism? Pediatrics, part 2, 98: 617, abstract 56, 1996
1063
7. Hendren, W. H.: Operative repair of megaureter in children. J Urol, 101: 491, 1969 8. Kalicinski, Z. H., Kansy, J., Kotarbinska, B., et al: Surgery of megaureters. Modification of Hendren’s operation. J Pediatr Surg, 12: 183, 1977 9. Caione, P., Capozza, N., Nappo, S. et al: Vesico-ureteral reflux in children: update on diagnosis and treatment. Acta Urol Ital, 11: 397, 1997 10. Noe, H. N.: The wide ureter. In: Adult and Pediatric Urology. Edited by J. Y. Gillenwater, J. T. Grayhack, S. S. Howards et al. Chicago: Year Book Medical Publishers, Inc., chapt. 49, p. 1653, 1987 11. McLaughlin, A. P., III, Pfister, R. C. and Leadbetter, W. F.: The pathophysiology of primary megaloureter. J Urol, 109: 805, 1973 12. Pagano, F. and Passerini, G.: Primary obstructed megaureter. Br J Urol, 49: 469, 1977 13. Tokunaka, S., Koyanagi, T., Tsuji, I. et al: Histopathology of the nonrefluxing megaureter: a clue to its pathogenesis. J Urol, 127: 238, 1982 14. Sripathi, V., King, P. A., Thompson, M. R. et al: Primary obstructive megaureter. J Pediatr Surg, 26: 826, 1991 15. Parrott, T. S., Woodard, J. R. and Wolpert, J. J.: Ureteral tailoring: a comparison of wedge resection with infolding. J Urol, 144: 328, 1990 16. Caione, P., Capozza, N., De Gennaro, M. et al: Il reflusso vescicoureterale: quale spazio per la chirurgia oggi? Ital J Pediatr, 16: 372, 1990 17. Caione, P., Capozza, N., Lais, A. et al: Contralateral ureteral meatal advancement in unilateral antireflux surgery. J Urol, 158: 1216, 1997
DISCUSSION
Dr. Mark Zaontz. You made a comment that despite all of the different techniques you used with the unilateral reimplantations you had a fairly high rate of contralateral reflux recurrence. In what percentage of those cases did reflux resolve spontaneously? We presented a paper here 2 years ago using the extravesical technique and, while we had a small percentage of contralateral reflux, by just simply observing these patients the reflux usually resolved. Dr. Paolo Caione. Regarding contralateral reflux, in the literature there is no technique that is free of the this complication, including extravesical detrusorrhaphy. Contralateral reflux can disappear but not always and sometimes we have to do something. We used to treat it endoscopically if the reflux did not resolve spontaneously within 2 or 3 years. If we open the bladder for intravesical reimplantation, we advance the contralateral orifice. We have had no complications with this technique and no contralateral defects. It is very simple and easy. Dr. Peter Frey. You mentioned that contralateral reflux is managed initially with endoscopic treatment but you did not show us any results. In our series contralateral reflux occurred initially in less than 3% of the cases and it was of low grade. Doctor Caione. Our presentation was not on contralateral reflux, but on megaureters, and our message was not to touch the trigone in the congenital, primary obstructive megaureter. This is different from what we see in cases of unilateral or bilateral primary reflux. If we inject only 1 side for unilateral primary reflux we could have contralateral reflux. The reason is that there is no distortion of the trigone from the surgical technique but there is impairment. Dr. Ross Decter. Your report supports my theory that there is no primary vesicoureteral reflux. Sillen has shown us that reflux in newborns is basically pressure driven. We know that reflux occurs in children as they start toilet training, and we see those who have secondary reflux, whether it results from bladder outlet obstruction or anatomic abnormalities. You have shown us that there really is no contralateral reflux that occurs when you operate for an obstructive process of the ureter. That process does not have associated bladder dysfunction and the operation does not cause contralateral reflux in your experience. I would submit to you that this suggests that reflux is a bladder or pressure phenomenon. Doctor Caione. I agree with you. Megaureter is associated with normal bladder function and reflux is not primary. Dr. Barry Kogan. Do you have data on bladder dysfunction in the 2 groups? Doctor Caione. All children were normal in the study group, with no dysfunctional voiding. The primary reflux group was also considered normal, as we avoided operating on the dysfunctional bladder. We know that normal voiding is not completely normal in patients with reflux.
Vol. 164, 1061–1063, September 2000 Printed in U.S.A.
IS PRIMARY OBSTRUCTIVE MEGAURETER REPAIR AT RISK FOR CONTRALATERAL REFLUX? PAOLO CAIONE, NICOLA CAPOZZA, LAURA ASILI, ALBERTO LAIS
AND
ENNIO MATARAZZO
From the Division of Pediatric Urology, Department of Surgery, “Bambino Gesu`” Children’s Hospital, Research Institute, Rome, Italy
ABSTRACT
Purpose: Contralateral vesicoureteral reflux occurs after successful unilateral reflux repair in a significant proportion of patients without correlation to the surgical approach. Unilateral congenital obstructive megaureter was compared to primary vesicoureteral reflux with regard to the risk of onset of contralateral reflux after unilateral ureteral reimplantation. Materials and Methods: Unilateral congenital obstructive megaureter was diagnosed in 58 consecutive patients 2 to 10 years old (mean age 3.2). Cross-trigonal ureteroneocystostomy was performed in 57 cases and longitudinal ureteral reimplantation, according to the PolitanoLeadbetter technique was done in 1. Longitudinal tapering according to Hendren was performed in 44 ureters, and the Kalicinski folding was used to repair 11 ureters. All patients underwent serial renal ultrasound, diethylenetetraminepentaacetic acid nuclear scan, excretory urogram and voiding cystourethrogram. The control group was composed of 98 age matched children with unilateral vesicoureteral reflux who underwent unilateral reimplantation with or without tapering. Fisher’s exact test and Student’s t test were used for statistical analysis. Results: Followup ranged from 1 to 5 years. All patients in both groups underwent a voiding cystourethrogram at 6 months, and renal ultrasound at 3, 6 and 12 months postoperatively. Grade 2 reflux developed in 1 study group patient after contralateral Kalicinski ureteral folding and cross-trigonal reimplantation (1.7%). In the control group new onset contralateral reflux developed in 11 cases (11.2%). The difference was statistically significant (p ⬍0.005, Fisher’s exact test p ⫽ 0.033). Conclusions: Ureteral reimplantation for unilateral congenital obstructive megaureter is not correlated with the development of contralateral reflux. The occurrence of contralateral reflux after successful unilateral reflux repair is high (11.2%), and is not correlated with age, sex and technique of reimplantation or tapering. These results support the hypothesis that the functional anatomy of the trigone is preserved in congenital obstructive megaureter but is impaired on both sides in cases of unilateral vesicoureteral reflux. The surgical management of unilateral primary vesicoureteral reflux and congenital obstructive megaureter should be differentiated based on these results. KEY WORDS: ureter; bladder, replantation; vesico-ureteral reflux; ureteral obstruction
The onset of de novo contralateral reflux after successful unilateral repair of primary vesicoureteral reflux occurs in 10% to 27% of cases.1–5 The development of postoperative contralateral reflux is independent of age, sex, and technique of reimplantation and ureteral tapering, and involves intravesical, extravesical and endoscopic approaches.5, 6 To date no attention has been paid to congenital obstructive megaureter in regard to the occurrence of contralateral reflux after unilateral reimplantation with or without ureteral tapering. We performed a retrospective longitudinal study comparing unilateral congenital obstructive megaureter with unilateral primary vesicoureteral reflux treated with similar surgical procedures. MATERIALS AND METHODS
Unilateral congenital obstructive megaureter was diagnosed in 58 consecutive patients 2 to 10 years old (mean age 3.2) during the last 5 years. All patients underwent preoperative serial renal ultrasound, diethylenetetraminepentaacetic acid nuclear scan, excretory urogram and at least 1 voiding cystourethrogram to rule out vesicoureteral reflux. Crosstrigonal ureteroneocystostomy was performed in 57 cases and longitudinal ureteral reimplantation, according to the Politano-Leadbetter technique was done in 1. A dilated distal
ureter was tapered in 54 cases. Longitudinal tapering according to Hendren7 was performed in 44 ureters, and the Kalicinski folding8 was used to repair 11 ureters. No tapering was required in 3 ureters. The control group included 98 patients 1 to 12 years old (mean age 2.9) with unilateral primary reflux ranging from grade 2 to 5 according to the International Reflux Classification. Grade 3 and 4 reflux was present in 85 cases. Preoperative evaluation included renal ultrasound, dimercaptosuccinic acid scan and at least 2 voiding cystourethrograms. The second voiding cystourethrogram was performed 1 year after a trial of antimicrobial prophylaxis. Contralateral vesicoureteral reflux was not recognized in any patient. All patients underwent ipsilateral antireflux surgery, including cross-trigonal ureteroneocystostomy in 86, longitudinal Politano-Leadbetter reimplantation in 8 and Glenn-Anderson trigonal advancement in 4. Longitudinal modeling of wide ureters was performed in 21 cases, including ureteral tapering in 13 and ureteral folding in 8. Preoperative cystoscopy was not performed and there was no history consistent with dysfunctional voiding in either group. Postoperative followup included serial renal ultrasound at 3, 6 and 12 months, voiding cystourethrogram every 6 months and nuclear renal scan at 1 year. All procedures were performed by the same pediatric urology staff. Statistical
1061
1062
PRIMARY OBSTRUCTIVE MEGAURETER REPAIR
analysis was performed with chi-square and Fisher’s exact tests. RESULTS
Followup ranged from 1 to 5 years in the control and study groups. Contralateral reflux developed postoperatively in 1 of the 58 patients with congenital obstructive megaureter (1.7%). This patient was a 3-year-old boy who had undergone Kalicinski longitudinal folding for a grossly dilated left ureter and cross-trigonal left ureteroneocystostomy. The postoperative voiding cystourethrogram showed right grade 2 vesicoureteral reflux that was successfully treated with the endoscopic subureteral injection of cross-linked collagen.9 New onset vesicoureteral reflux developed in the ureter opposite the reimplantation site in 11 of the 98 control group cases (11.2%). Contralateral reflux was grade 2 in 6 cases and grade 3 in 5 (see table). No postoperative ipsilateral vesicoureteral reflux was detected in the congenital obstructive megaureter group, and 2 cases of reflux, which was grade 2 in 1 and grade 3 in 1, occurred in the control group. The occurrence of contralateral de novo reflux was significantly different between the 2 groups (p ⬍0.005, Fisher’s exact test p ⫽ 0.033). DISCUSSION
Congenital obstructive megaureter or primary obstructive megaureter refers to large ureters with intrinsic obstruction of the ureterovesical junction or more frequently in the nearby ureteral segment. Congenital distal ureteral stricture, ureteral valves or more often a distal adynamic segment has been reported to cause congenital obstructive megaureter.10 Histological studies using light microscopy and electron microscopy have predominantly shown hypoplasia and atrophy of the ureteral muscle, and an increased amount of collagen between muscle cells with abnormal cellto-cell contact.11–13 As a consequence ureteral peristalsis is disrupted and noneffective.14 Congenital obstructive megaureter affects more males and the left ureter, and is unilateral in approximately 75% of cases.10 Surgical correction of congenital obstructive megaureter should be reserved for cases with proved obstruction of ureteral urinary flow by excretory urography or diethylenetetraminepentaacetic acid/mercaptoacetyltriglycine renal nuclear scan. Specific surgical indications include progressive loss of parenchymal function, significant delayed washout, increasing upper tract dilatation and/or symptomatic megaureter (urinary tract infections, stone disease, persistent flank pain and hematuria). In 1969 Hendren developed the tapering technique of wide ureters7 and in 1977 Kalicinski et al proposed a simplified technique of ureteral modeling with longitudinal folding of the ureteral wall.8 The tapered megaureter is suitable for
Contralateral vesicoureteral reflux after unilateral reimplantation No. Study Group (congenital obstructive megaureter) Total cases Lt. ureter Rt. ureter Cross-trigonal reimplantation Longitudinal Politano-Leadbetter repair Glenn-Anderson advancement Ureteral tapering (Hendren) Ureteral folding (Kalicinski) No ureteral modeling New contralat. reflux (%) Ipsilat. persistent reflux *Reflux was grade 2 in 6 cases and grade 3
58 42 16 57 1 – 47 11 3 1 (1.7%) – in 5.
No. Control Group (primary vesicoureteral reflux) 98 46 52 86 8 4 13 8 – 11 (11.2%)* 3
effective ureteroneocystostomy using standard ureterovesical reimplantation techniques. The results are good with a success rate of 90% to 95% regardless of the ureteroneocystostomy techniques.15 In our experience results of ureteral reimplantation for primary vesicoureteral reflux have been satisfactory,16 and we have achieved similar results with surgical repair of obstructive unilateral congenital obstructive megaureter. The effects on the contralateral ureter differ grossly after surgical repair for congenital obstructive megaureter than for unilateral primary vesicoureteral reflux. The incidence of newly diagnosed contralateral reflux postoperatively for unilateral primary reflux is significant. Warren et al reported the development of contralateral reflux in 15% to 20% of patients after unilateral reimplantation.1 Parrott and Woodard,2 and more recently Diamond et al4 confirmed that these data do not seem to be influenced by intravesical repair, extravesical repair or endoscopic treatment. Diamond et al reported that high grade vesicoureteral reflux and a duplex system were important risk factors for contralateral reflux.4 In our series we found an overall 11.2% incidence of de novo contralateral reflux without a statistically significant difference between surgical technique or grade of reflux.17 We proposed a simple and effective solution, contralateral ureteral meatal advancement, to prevent postoperative de novo contralateral reflux.17 This procedure is easy to perform during ipsilateral reimplantation, allows marginal invasiveness and prevents contralateral reflux. Contralateral ureteral meatal advancement avoids systematic standard bilateral surgery in all cases of unilateral vesicoureteral reflux2 or the “wait and see” approach. Our results indicate that vesicoureteral reimplantation for unilateral primary congenital obstructive megaureter does not cause de novo contralateral reflux in a significant number of cases. We only observed 1 case of grade 2 contralateral reflux in a 3-year-old child who had undergone ureteral folding and cross-trigonal ureteroneocystostomy. This unique onset of contralateral postoperative reflux is difficult to explain but we postulate that trigone distortion secondary to the cross-trigonal reimplantation was a predominant factor. This newly developed reflux was successfully treated with endoscopic subureteral injection of bovine cross-linked collagen. Our results indicate that congenital obstructive megaureter is different than primary vesicoureteral reflux, and the occurrence rate of secondary contralateral reflux is significantly higher in cases of primary reflux independent of age, sex and repair technique. Of our 98 control group patients 11 (11.2%) had contralateral postoperative reflux despite close attention to detect any sign of bilateral involvement before performing unilateral reimplantation. Two main hypotheses have been proposed with regard to the pathophysiology of contralateral reflux after primary vesicoureteral reflux repair. Iatrogenic distortion of the contralateral trigone has been described as a result of ipsilateral surgical correction6 but it does not explain the onset of contralateral reflux also reported after endoscopic treatment. Similarly, elimination of the pop-off valve mechanism as a result of surgical correction of the refluxing ureter has been advocated4 but we equally observed development of secondary contralateral reflux regardless of primary reflux grade. Our results confirm the hypothesis that the functional anatomy of the trigone is normal in cases of primary nonrefluxing megaureter, whereas the ureterovesical junctions appear bilaterally impaired in cases of vesicoureteral reflux. Thus, contralateral reflux is unlikely to occur after congenital obstructive megaureter repairs. In cases of primary vesicoureteral reflux contralateral reflux is probably a result of primitive trigonal impairment, which is associated with the weakness of both ureterovesical junctions rather than the effect of bladder fiber distortion during ureteral reimplantation or elimination of the pop-off valve mechanism.
PRIMARY OBSTRUCTIVE MEGAURETER REPAIR CONCLUSIONS
Based on these results and the pathophysiology of secondary vesicoureteral reflux, management of the contralateral ureter should be differentiated when treating congenital obstructive megaureter and primary vesicoureteral reflux. In cases of reflux bilateral involvement must be carefully ruled out and contralateral ureteral meatal advancement should be routinely performed to prevent contralateral reflux.17 In cases of primary unilateral congenital obstructive megaureter no surgery of a normal appearing, opposite ureter is warranted. REFERENCES
1. Warren, M. M., Kelalis, P. P. and Stickler, G. B.: Unilateral ureteroneocystostomy: the fate of contralateral ureter. J Urol, 107: 466, 1972 2. Parrott, T. S. and Woodard, J. R.: Reflux in opposite ureter after successful correction of unilateral vesicoureteral reflux. Urology, 7: 276, 1976 3. Ahmed, S. and Tan, H.: Complications of transverse advancement ureteral reimplantation. J Urol, 127: 970, 1982 4. Diamond, D. A., Rabinovitz, R., Hoenig, D. M. et al: The mechanism of new onset contralateral reflux following unilateral ureteroneocystostomy. J Urol, part 2, 156: 665, 1996 5. Hoenig, D. M., Diamond, D. A., Rabinovitz, R. et al: Contralateral reflux after unilateral ureteral reimplantation. J Urol, 156: 196, 1996 6. Kumar, R. and Puri, P.: Newly diagnosed contralateral reflux following successful unilateral endoscopic correction. Is it due to “pop-off valve” mechanism? Pediatrics, part 2, 98: 617, abstract 56, 1996
1063
7. Hendren, W. H.: Operative repair of megaureter in children. J Urol, 101: 491, 1969 8. Kalicinski, Z. H., Kansy, J., Kotarbinska, B., et al: Surgery of megaureters. Modification of Hendren’s operation. J Pediatr Surg, 12: 183, 1977 9. Caione, P., Capozza, N., Nappo, S. et al: Vesico-ureteral reflux in children: update on diagnosis and treatment. Acta Urol Ital, 11: 397, 1997 10. Noe, H. N.: The wide ureter. In: Adult and Pediatric Urology. Edited by J. Y. Gillenwater, J. T. Grayhack, S. S. Howards et al. Chicago: Year Book Medical Publishers, Inc., chapt. 49, p. 1653, 1987 11. McLaughlin, A. P., III, Pfister, R. C. and Leadbetter, W. F.: The pathophysiology of primary megaloureter. J Urol, 109: 805, 1973 12. Pagano, F. and Passerini, G.: Primary obstructed megaureter. Br J Urol, 49: 469, 1977 13. Tokunaka, S., Koyanagi, T., Tsuji, I. et al: Histopathology of the nonrefluxing megaureter: a clue to its pathogenesis. J Urol, 127: 238, 1982 14. Sripathi, V., King, P. A., Thompson, M. R. et al: Primary obstructive megaureter. J Pediatr Surg, 26: 826, 1991 15. Parrott, T. S., Woodard, J. R. and Wolpert, J. J.: Ureteral tailoring: a comparison of wedge resection with infolding. J Urol, 144: 328, 1990 16. Caione, P., Capozza, N., De Gennaro, M. et al: Il reflusso vescicoureterale: quale spazio per la chirurgia oggi? Ital J Pediatr, 16: 372, 1990 17. Caione, P., Capozza, N., Lais, A. et al: Contralateral ureteral meatal advancement in unilateral antireflux surgery. J Urol, 158: 1216, 1997
DISCUSSION
Dr. Mark Zaontz. You made a comment that despite all of the different techniques you used with the unilateral reimplantations you had a fairly high rate of contralateral reflux recurrence. In what percentage of those cases did reflux resolve spontaneously? We presented a paper here 2 years ago using the extravesical technique and, while we had a small percentage of contralateral reflux, by just simply observing these patients the reflux usually resolved. Dr. Paolo Caione. Regarding contralateral reflux, in the literature there is no technique that is free of the this complication, including extravesical detrusorrhaphy. Contralateral reflux can disappear but not always and sometimes we have to do something. We used to treat it endoscopically if the reflux did not resolve spontaneously within 2 or 3 years. If we open the bladder for intravesical reimplantation, we advance the contralateral orifice. We have had no complications with this technique and no contralateral defects. It is very simple and easy. Dr. Peter Frey. You mentioned that contralateral reflux is managed initially with endoscopic treatment but you did not show us any results. In our series contralateral reflux occurred initially in less than 3% of the cases and it was of low grade. Doctor Caione. Our presentation was not on contralateral reflux, but on megaureters, and our message was not to touch the trigone in the congenital, primary obstructive megaureter. This is different from what we see in cases of unilateral or bilateral primary reflux. If we inject only 1 side for unilateral primary reflux we could have contralateral reflux. The reason is that there is no distortion of the trigone from the surgical technique but there is impairment. Dr. Ross Decter. Your report supports my theory that there is no primary vesicoureteral reflux. Sillen has shown us that reflux in newborns is basically pressure driven. We know that reflux occurs in children as they start toilet training, and we see those who have secondary reflux, whether it results from bladder outlet obstruction or anatomic abnormalities. You have shown us that there really is no contralateral reflux that occurs when you operate for an obstructive process of the ureter. That process does not have associated bladder dysfunction and the operation does not cause contralateral reflux in your experience. I would submit to you that this suggests that reflux is a bladder or pressure phenomenon. Doctor Caione. I agree with you. Megaureter is associated with normal bladder function and reflux is not primary. Dr. Barry Kogan. Do you have data on bladder dysfunction in the 2 groups? Doctor Caione. All children were normal in the study group, with no dysfunctional voiding. The primary reflux group was also considered normal, as we avoided operating on the dysfunctional bladder. We know that normal voiding is not completely normal in patients with reflux.