Spontaneous resolution and the role of endoscopic surgery in the treatment of primary obstructive megaureter: a review of the literature

Submitted: 25 July 2023
Accepted: 4 December 2023
Published: 19 December 2023
Abstract Views: 454
PDF: 193
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The megaureter accounts for almost a quarter of all urinary tract dilations diagnosed in utero and is the second leading cause of hydronephrosis in newborns, following pyeloureteral junction obstruction. The current standard treatment for progressive or persistent, symptomatic primary obstructive megaureter is ureteral anti-reflux reimplantation, which can be associated with ureteral remodeling or plication. Due to the associated morbidity, postoperative recovery challenges, and the complications that may arise from the open surgical approach, there has been a natural inclination towards validating new minimally invasive techniques. This study reviews the literature, extracting data from three major international databases, from 1998 to 2022. Out of 1172 initially identified articles, only 52 were deemed eligible, analyzing 1764 patients and 1981 renal units. Results show that 65% of cases required surgical intervention, with minimally invasive techniques constituting 56% of these procedures. High-pressure endoscopic balloon dilation was the preferred endourologic technique. The degree of ureterohydronephrosis is considered one of the factors indicating the need for surgery. There is an inverse relationship between the diameter of the ureter and the likelihood of spontaneous resolution. Conditions such as renal hypoplasia, renal dysplasia, or ectopic ureteral insertion strongly indicate a poor prognosis. Endoscopic surgical techniques for treating primary obstructive megaureter can be definitive, firstline treatment options. In selected cases, they might be at least as effective and safe as the open approach, but with advantages like quicker recovery, fewer complications, shorter hospital stays, and reduced costs.

Isert S, Müller D, Thumfart J. Factors Associated With the Development of Chronic Kidney Disease in Children With Congenital Anomalies of the Kidney and Urinary Tract. Front Pediatr 2020;8:298. DOI: https://doi.org/10.3389/fped.2020.00298

Farrugia MK, Hitchcock R, Radford A, et al. British Association of Paediatric Urologists consensus statement on the managementof the primary obstructive megaureter. J Ped Urol 2014;10:26-33. DOI: https://doi.org/10.1016/j.jpurol.2013.09.018

Holcomb G, Murphy JP, Ostlie D. Ashcraft’s Pediatric Surgery, 6th Edition, Elsevier, 2014, p. 725 – 727.

Kang HJ, Lee HY, Jin MH, et al. Decreased interstitial cells of Cajal-like cells, possible cause of congenital refluxing megaureters: histopathologic differences in refluxing and obstructive megaureters. Urology 2009;74:318–23. DOI: https://doi.org/10.1016/j.urology.2009.02.062

Coran AG, Caldamone A, Adzick NS, et al. Pediatric Surgery, 7th Edition, Elsevier, p. 1497-1498.

Shafik A. Ureterovesical junction inhibitory reflex and vesicoureteral junction excitatory reflex: description of two reflexes and their role in the ureteric antireflux mechanism. Urol Res 1996;24:339–43. DOI: https://doi.org/10.1007/BF00389790

Khoury A, Bagli DJ. Reflux and megaureter. In: Wein AJ, Kavoussi LR, Novick AC, et al, editors. Campbell-Walsh Urology. 9th ed. Philadelphia: WB Saunders; 2007, p. 3468.

Ben-Meir D, McMullin N, Kimber C, et al. Reimplantation of obstructive megaureters with and without tailoring. J Ped Urol 2006;2:178-81. DOI: https://doi.org/10.1016/j.jpurol.2005.05.010

Arena F, Baldari S, Proietto F, et al. Conservative treatment in primary neonatal megaureter. J Prediatr Surg 1998;8:347-51. DOI: https://doi.org/10.1055/s-2008-1071230

Sheu JC, Chang PY, Wang NL, et al. Is surgery necessary for primary non-refluxing megaureter? Pediatr Surg Int 1998;13:501–3. DOI: https://doi.org/10.1007/s003830050383

Angulo JM, Arteaga R, Rodrıguez Alarcon J, Calvo MJ. Role of retrograde endoscopic dilatation with balloon and derivation using double pig-tail catheter as an initial treatment for vesicoureteral junction stenosis in children. Cir Pediatr 1998;11:15–18.

Gimpel C, Masioniene L, Djakovic N, et al. Complications and long-term outcome of primary obstructive megaureter in childhood. Pediatr Nephrol 2010;25:1679-86. DOI: https://doi.org/10.1007/s00467-010-1523-0

Im YJ, Jung HJ, Lee YS, et al. Impact of ectopic insertion on treatment outcome of primary non-refluxing megaureter. Urology 2013;81:402-6. DOI: https://doi.org/10.1016/j.urology.2012.11.038

Drlik M, Flogelova H, Martin K. Isolated low initial differential renal function in patients with primary non-refluxing megaureter should not be considered an indication for early surgery: A multicentric study. J Ped Urol 2016;12:231.e1-e4. DOI: https://doi.org/10.1016/j.jpurol.2016.05.025

Di Renzo D, Aguiar L, Cascini V, et al. Long-term followup of primary nonrefluxing megaureter. J Urol 2013;190:1021-6. DOI: https://doi.org/10.1016/j.juro.2013.03.008

Sidhu G, Beyene J, Rosenblum ND. Outcome of isolated antenatal hydronephrosis: a systematic review and meta-analysis. Pediatr Nephrol 2006;21:218-24. DOI: https://doi.org/10.1007/s00467-005-2100-9

Dekirmendjian A, Braga LH. Primary Non-refluxing Megaureter: Analysis of Risk Factors for Spontaneous Resolution and Surgical Intervention. Front Pediatr 2019;7:126. DOI: https://doi.org/10.3389/fped.2019.00126

Lima M, Manzoni G. Pediatric Urology. Contemporary strategies from fetal life to adolescence. Springer-Verlag; 2015. DOI: https://doi.org/10.1007/978-88-470-5693-0

Arena S, Magno C, Montalto AS, et al. Long-term follow-up of neonatally diagnosed primary megaureter: Rate and predictors of spontaneous resolution, Scand J Urol Nephrol 2012;46:201–7. DOI: https://doi.org/10.3109/00365599.2012.662695

Chertin B, Pollack A, Koulikov D, et al. Long-term follow up of antenatally diagnosed megaureters. J Ped Urol 2008;4:188-1. DOI: https://doi.org/10.1016/j.jpurol.2007.11.013

Garcia-Aparicio L, Blazquez-Gomez E, Martin O, et al. Use of high-pressure balloon dilatation of the ureterovesical junction instead of ureteral reimplantation to treat primary obstructive megaureter: Is it justified? J Ped Urol 2013;9:1229-3. DOI: https://doi.org/10.1016/j.jpurol.2013.05.019

Torino G, Roberti A, Brandigi E. High-pressure balloon dilatation for the treatment of primary obstructive megaureter: is it the first line of treatment in children and infants? Swiss Med Wkly 2021;151:w20513. DOI: https://doi.org/10.4414/smw.2021.20513

Romero RM, Angulo JM, Parente A, et al. Primary obstructive megaureter: the role of high pressure balloon dilation. J Endourol 2014;28:517-23. DOI: https://doi.org/10.1089/end.2013.0210

Destro F, Selvaggio G, Marinoni F. High-pressure balloon dilatation in children: our results in 30 patients with POM and the implications of the cystoscopic evaluation. Pediatr Med Chir 2020;42:1-5. DOI: https://doi.org/10.4081/pmc.2020.214

Casal Beloy I, Argibay S, García González M, et al. Endoscopic balloon dilatation in primary obstructive megaureter: long-term results. J Pediatr Urol 2018;14:167.e1-e5.

Bujons A, Saldana L, Caffaratti J, et al. Can endoscopic balloon dilation for primary obstructive megaureter be effective in a long-term follow-up? J Pediatr Urol 2015;11:37.e1-37.e6. DOI: https://doi.org/10.1016/j.jpurol.2014.09.005

Kassite I, Petel MR, Chaussy Y, et al. High pressure balloon dilatation of primary obstructive megaureter in children: A multicenter study. Front Pediatr 2018;6. DOI: https://doi.org/10.3389/fped.2018.00329

Ortiz R, Parente A, Perez-Egido, et al. Long-term outcomes in primary obstructive megaureter treated by endoscopic balloon dilation. Experience after 100 cases. Front Pediatr 2018;6. DOI: https://doi.org/10.3389/fped.2018.00275

Chiarenza SF, Bleve C, Zolpi E, et al. Endoscopic balloon dilatation of primary obstructive megaureter: method standardization and predictive prognostic factors. Pediatr Med Chir 2019;41:25-28. DOI: https://doi.org/10.4081/pmc.2019.219

Torino G, Collura G, Mele E, et al. Severe Primary Obstructive Megaureter in the First Year of Life: Preliminary Experience With Endoscopic Balloon Dilation. J Endourol 2012;26:325-9. DOI: https://doi.org/10.1089/end.2011.0399

Capozza N, Torino G, Nappo S, et al. Primary Obstructive Megaureter in Infants: Our Experience with Endoscopic Balloon Dilation and Cutting Balloon Ureterotomy, J Endourol 2015;29:1-5. DOI: https://doi.org/10.1089/end.2013.0665

Shirazi M, Natami M, Hekmati P, et al. Result of Endoureterotomy in the Management of Primary Obstructive Megaureter in the First Year of Life: Preliminary Report. J Endourol 2014;28:79-83. DOI: https://doi.org/10.1089/end.2013.0098

Casal Beloy I, Somoza Argibay I, García González M, et al. Endoscopic balloon dilatation in primary obstructive megaureter: long-term results, J Pediatr Urol 2017;14:167.e1-e5. DOI: https://doi.org/10.1016/j.jpurol.2017.10.016

Garcia‑Aparicio L, Blazquez‑Gomez E, De Haro I, et al. Postoperative vesicoureteral reflux after high‑pressure balloon dilation of the ureterovesical junction in primary obstructive megaureter. Incidence, management and predisposing factors. World J Urol 2015;33:2103-6. DOI: https://doi.org/10.1007/s00345-015-1565-9

Di Renzo D, Persico A, Di Nicola M, et al. Conservative management of primary non-refluxing megaureter during the first year of life: A longitudinal observational study. J Pediatr Urol 2015;11:226.e1-e6. DOI: https://doi.org/10.1016/j.jpurol.2015.05.007

Braga LH, D’Cruz J, Rickard M, et al. The fate of primary nonrefluxing megaureter: a prospective outcome analysis of the rate of urinary tract infections, surgical indications and time to resolution. J Urology 2016;195:1300-5. DOI: https://doi.org/10.1016/j.juro.2015.11.049

Awad K, Woodward MN, Shalaby MS. Long-term outcome of JJ stent insertion for primary obstructive megaureter in children. J Pediatr Urol 2019;15:66.e1-e5. DOI: https://doi.org/10.1016/j.jpurol.2018.09.011

Farrugia MK, Steinbrecher HA, Malone PS. The utilization of stents in the management of primary obstructive megaureters requiring intervention before 1 year of age. J Pediatr Urol 2011;7:198-202. DOI: https://doi.org/10.1016/j.jpurol.2010.04.015

Castagnetti M, Cimador M, Sergio M, De Grazia E. Double-J stent insertion across vesicoureteral junction—is it a valuable initial approach in neonates and infants with severe primary nonrefluxing megaureter? Urology 2006;68:870-5. DOI: https://doi.org/10.1016/j.urology.2006.05.052

Christman MS, Kasturi S, Lambert SM, et al. Endoscopic management and the role of double stenting for primary obstructive megaureters. J Urology 2012;187:1018-23. DOI: https://doi.org/10.1016/j.juro.2011.10.168

Isac, G. V., Danila, G. M., & Ionescu, S. N. (2023). Spontaneous resolution and the role of endoscopic surgery in the treatment of primary obstructive megaureter: a review of the literature. La Pediatria Medica E Chirurgica, 45(2). https://doi.org/10.4081/pmc.2023.327


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