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Hyaluronic Acid Copolymer in the Treatment of Vesico-Ureteric Reflux after Renal Transplantation
PEDIATRIC UROLOGY
267
Re: Risk of Renal Scarring in Children With a First Urinary Tract Infection: A Systematic Review N. Shaikh, A. L. Ewing, S. Bhatnagar and A. Hoberman Division of General Academic Pediatrics, Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania Pediatrics 2010; 126: 1084 –1091.
Background: To our knowledge, the risk of renal scarring in children with a urinary tract infection (UTI) has not been systematically studied. Objective: To review the prevalence of acute and chronic renal imaging abnormalities in children after an initial UTI. Methods: We searched Medline and Embase for English-, French-, and Spanish-language articles using the following terms: “Technetium (99m)Tc dimercaptosuccinic acid (DMSA),” “DMSA,” “dimercaptosuccinic,” “scintigra*,” “pyelonephritis,” and “urinary tract infection.” We included articles if they reported data on the prevalence of abnormalities on acute-phase (ⱕ15 days) or follow-up (⬎5 months) DMSA renal scans in children aged 0 to 18 years after an initial UTI. Two evaluators independently reviewed data from each article. Results: Of 1533 articles found by the search strategy, 325 full-text articles were reviewed; 33 studies met all inclusion criteria. Among children with an initial episode of UTI, 57% (95% confidence interval [CI]: 50 – 64) had changes consistent with acute pyelonephritis on the acute-phase DMSA renal scan and 15% (95% CI: 11–18) had evidence of renal scarring on the follow-up DMSA scan. Children with vesicoureteral reflux (VUR) were significantly more likely to develop pyelonephritis (relative risk [RR]: 1.5 [95% CI: 1.1–1.9]) and renal scarring (RR: 2.6 [95% CI: 1.7–3.9]) compared with children with no VUR. Children with VUR grades III or higher were more likely to develop scarring than children with lower grades of VUR (RR: 2.1 [95% CI: 1.4 –3.2]). Conclusions: The pooled prevalence values provided from this study provide a basis for an evidence-based approach to the management of children with this frequently occurring condition. Editorial Comment: The authors reviewed more than 1,533 articles, of which 33 described DMSA imaging immediately following the first urinary tract infection. Overall 57% of children had initial abnormalities on the scan, with 18% demonstrating persistent abnormalities at 5 months. Renal scarring was twice as likely to occur in children with grade III to V vesicoureteral reflux as in those with grades I and II reflux, suggesting a greater prevalence of renal dysplasia or a greater risk of renal scarring in patients with high grade VUR. This article supports a top-down approach to the treatment of urinary tract infection. In addition to identifying almost all of the children with high volume VUR, the DMSA scan also identifies children most likely to have persistent scarring. Some but not all of these children will have high volume VUR. While the prevalence of this scarring was more than twice as high in children with vesicoureteral reflux than without (41% vs 17%), voiding cystourethrography alone did not identify all children at risk for long-term scarring. I believe we will evolve to a system where the DMSA or a similar scan will be our first study and voiding cystourethrography will follow only in patients with long-term scarring. Surgery or possibly continuous antibiotic prophylaxis will follow for those with high volume VUR. What is still uncertain is what to do in patients with a positive DMSA scan and without VUR. Douglas A. Canning, M.D.
Re: Endoscopic Application of Dextranomer/Hyaluronic Acid Copolymer in the Treatment of Vesico-Ureteric Reflux after Renal Transplantation R. Pichler, A. Buttazzoni, P. Rehder, G. Bartsch, H. Steiner and J. Oswald Department of Urology, Medical University Innsbruck, Innsbruck, Austria BJU Int 2011; 107: 1967–1972.
Objective: To evaluate the success of endoscopic dextranomer/hyaluronic acid copolymer (DHAC) application in the treatment of patients with recurrent urinary tract infections (UTIs) and vesicoureteric reflux (VUR) into the transplanted graft after renal transplantation. Patients and Methods: Between January 2008 and April 2009, 19 patients with recurrent UTIs presented VUR proven by
268
PEDIATRIC UROLOGY
voiding cystourethrography. To correct VUR of the transplanted ureter, DHAC was injected endoscopically using hydrodistention technique. Pre- and postoperative serum creatinine levels, the number of pre- and postoperative UTIs, postoperative complications and reflux resolution rate were recorded. The mean follow-up was 6.5 months. Results: The average number of UTIs was reduced significantly from 4.89 (range 2–14) to 1.31 (range 0 – 4) on pre- and postoperative follow-up, respectively, of 6 months (P ⬍ 0.001). The success rate increased from 57.9% after the first injection to 78.9% after the second injection. The remaining four patients with residual VUR received long-term low dose antibiotic prophylaxis. In total, two (10.5%) patients developed increasing creatinine levels postoperatively as a result of distal ureteral obstruction, and temporary urinary drainage was necessary in both patients. Conclusions: DHAC appears to be an efficient and minimal invasive method for treating VUR after renal transplantation with respect to short-term success. Further investigation with a larger group of patients and longer follow-up is needed to evaluate the prolonged effect, as well as any potential side effects. Editorial Comment: The authors report a series of 19 patients who underwent endoscopic correction with dextranomer/hyaluronic acid copolymer for vesicoureteral reflux after renal transplantation. Not only was treatment successful in the majority of patients, but there was a consistent and significant improvement in the frequency of pretreatment vs posttreatment urinary tract infections. Our results following dextranomer/hyaluronic acid injection for vesicoureteral reflux following transplantation are not nearly as good. We have not endeavored to create a long submucosal ureteral tunnel because we are more concerned about ureteral obstruction than reflux at transplantation. The ureters in this series were implanted with a robust tunnel on the dorsal wall of the bladder rather than on the dome or sidewall. This approach results in a longer intramural passage of the ureter, resulting in a better platform through which to place the implant, and probably explains the good results. Douglas A. Canning, M.D.
267
Re: Risk of Renal Scarring in Children With a First Urinary Tract Infection: A Systematic Review N. Shaikh, A. L. Ewing, S. Bhatnagar and A. Hoberman Division of General Academic Pediatrics, Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania Pediatrics 2010; 126: 1084 –1091.
Background: To our knowledge, the risk of renal scarring in children with a urinary tract infection (UTI) has not been systematically studied. Objective: To review the prevalence of acute and chronic renal imaging abnormalities in children after an initial UTI. Methods: We searched Medline and Embase for English-, French-, and Spanish-language articles using the following terms: “Technetium (99m)Tc dimercaptosuccinic acid (DMSA),” “DMSA,” “dimercaptosuccinic,” “scintigra*,” “pyelonephritis,” and “urinary tract infection.” We included articles if they reported data on the prevalence of abnormalities on acute-phase (ⱕ15 days) or follow-up (⬎5 months) DMSA renal scans in children aged 0 to 18 years after an initial UTI. Two evaluators independently reviewed data from each article. Results: Of 1533 articles found by the search strategy, 325 full-text articles were reviewed; 33 studies met all inclusion criteria. Among children with an initial episode of UTI, 57% (95% confidence interval [CI]: 50 – 64) had changes consistent with acute pyelonephritis on the acute-phase DMSA renal scan and 15% (95% CI: 11–18) had evidence of renal scarring on the follow-up DMSA scan. Children with vesicoureteral reflux (VUR) were significantly more likely to develop pyelonephritis (relative risk [RR]: 1.5 [95% CI: 1.1–1.9]) and renal scarring (RR: 2.6 [95% CI: 1.7–3.9]) compared with children with no VUR. Children with VUR grades III or higher were more likely to develop scarring than children with lower grades of VUR (RR: 2.1 [95% CI: 1.4 –3.2]). Conclusions: The pooled prevalence values provided from this study provide a basis for an evidence-based approach to the management of children with this frequently occurring condition. Editorial Comment: The authors reviewed more than 1,533 articles, of which 33 described DMSA imaging immediately following the first urinary tract infection. Overall 57% of children had initial abnormalities on the scan, with 18% demonstrating persistent abnormalities at 5 months. Renal scarring was twice as likely to occur in children with grade III to V vesicoureteral reflux as in those with grades I and II reflux, suggesting a greater prevalence of renal dysplasia or a greater risk of renal scarring in patients with high grade VUR. This article supports a top-down approach to the treatment of urinary tract infection. In addition to identifying almost all of the children with high volume VUR, the DMSA scan also identifies children most likely to have persistent scarring. Some but not all of these children will have high volume VUR. While the prevalence of this scarring was more than twice as high in children with vesicoureteral reflux than without (41% vs 17%), voiding cystourethrography alone did not identify all children at risk for long-term scarring. I believe we will evolve to a system where the DMSA or a similar scan will be our first study and voiding cystourethrography will follow only in patients with long-term scarring. Surgery or possibly continuous antibiotic prophylaxis will follow for those with high volume VUR. What is still uncertain is what to do in patients with a positive DMSA scan and without VUR. Douglas A. Canning, M.D.
Re: Endoscopic Application of Dextranomer/Hyaluronic Acid Copolymer in the Treatment of Vesico-Ureteric Reflux after Renal Transplantation R. Pichler, A. Buttazzoni, P. Rehder, G. Bartsch, H. Steiner and J. Oswald Department of Urology, Medical University Innsbruck, Innsbruck, Austria BJU Int 2011; 107: 1967–1972.
Objective: To evaluate the success of endoscopic dextranomer/hyaluronic acid copolymer (DHAC) application in the treatment of patients with recurrent urinary tract infections (UTIs) and vesicoureteric reflux (VUR) into the transplanted graft after renal transplantation. Patients and Methods: Between January 2008 and April 2009, 19 patients with recurrent UTIs presented VUR proven by
268
PEDIATRIC UROLOGY
voiding cystourethrography. To correct VUR of the transplanted ureter, DHAC was injected endoscopically using hydrodistention technique. Pre- and postoperative serum creatinine levels, the number of pre- and postoperative UTIs, postoperative complications and reflux resolution rate were recorded. The mean follow-up was 6.5 months. Results: The average number of UTIs was reduced significantly from 4.89 (range 2–14) to 1.31 (range 0 – 4) on pre- and postoperative follow-up, respectively, of 6 months (P ⬍ 0.001). The success rate increased from 57.9% after the first injection to 78.9% after the second injection. The remaining four patients with residual VUR received long-term low dose antibiotic prophylaxis. In total, two (10.5%) patients developed increasing creatinine levels postoperatively as a result of distal ureteral obstruction, and temporary urinary drainage was necessary in both patients. Conclusions: DHAC appears to be an efficient and minimal invasive method for treating VUR after renal transplantation with respect to short-term success. Further investigation with a larger group of patients and longer follow-up is needed to evaluate the prolonged effect, as well as any potential side effects. Editorial Comment: The authors report a series of 19 patients who underwent endoscopic correction with dextranomer/hyaluronic acid copolymer for vesicoureteral reflux after renal transplantation. Not only was treatment successful in the majority of patients, but there was a consistent and significant improvement in the frequency of pretreatment vs posttreatment urinary tract infections. Our results following dextranomer/hyaluronic acid injection for vesicoureteral reflux following transplantation are not nearly as good. We have not endeavored to create a long submucosal ureteral tunnel because we are more concerned about ureteral obstruction than reflux at transplantation. The ureters in this series were implanted with a robust tunnel on the dorsal wall of the bladder rather than on the dome or sidewall. This approach results in a longer intramural passage of the ureter, resulting in a better platform through which to place the implant, and probably explains the good results. Douglas A. Canning, M.D.