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A Mouse Model to Evaluate the Long-Term Structural and Functional Outcomes after the Reversal of Prolonged Unilateral Ureteric Obstruction
Published on: July 18, 2025
Complications and long-term outcome of primary obstructive megaureter in childhood
Charlotte Gimpel1, Liuda Masioniene, Nenad Djakovic
1Center for Child and Adolescent Medicine, University Hospital Freiburg, Freiburg, Germany.
Insights
Conservative management is effective for primary obstructive megaureters (POM) in children. Antibiotic prophylaxis significantly reduces urinary tract infections (UTIs) in infants, improving outcomes.
Area of Science:
- Pediatric Urology
- Nephrology
- Surgical Innovation
Background:
- Primary obstructive megaureters (POM) affect 49 children, with a higher incidence in boys and on the left side.
- The 2001 German consensus guidelines recommend a conservative approach for POM management.
Purpose of the Study:
- To assess the clinical outcomes of children with POM treated conservatively.
- To evaluate the efficacy of antibiotic prophylaxis in reducing urinary tract infections (UTIs).
Main Methods:
- Retrospective analysis of 56 primary obstructive megaureters (POM) in 49 children.
- Assessment of conservative treatment, surgical intervention, complication rates, and spontaneous regression.
- Evaluation of antibiotic prophylaxis impact on UTI incidence.
Main Results:
- 77% of POM cases were managed conservatively, with 9 requiring later surgery.
- Urinary tract infections (UTIs) were common (1.3/patient), but 55% less frequent with prophylactic antibiotics in infants.
- Spontaneous regression observed in 80% of non-obstructive cases and <20% of obstructive cases. Megaureters <8.5 mm regressed, none >15 mm.
- Poor outcomes were linked to congenital kidney hypoplasia rather than obstruction severity.
Conclusions:
- Conservative treatment yields favorable long-term outcomes for primary obstructive megaureters (POM).
- Antibiotic prophylaxis is crucial for reducing UTIs in infants with POM.
- Congenital kidney hypoplasia is a stronger predictor of adverse outcomes than the degree of obstruction.
Abstract:
We assessed the clinical outcome of 49 children with 56 primary obstructive megaureters (POM) treated with the primarily conservative approach recommended by the 2001 German consensus guidelines. POM occurred more often in boys (71%) and on the left side (67%). Forty-three POM (77%) were treated conservatively. Four kidneys underwent immediate surgery and nine of 52 kidneys managed primarily conservatively worsened subsequently, requiring surgery. Urinary tract infections (UTI) were the most common complication (mean 1.3 per patient), with frequent hospital admission (45%). During the first year of life, the incidence of UTIs was 55% less during prophylactic antibiotic treatment (0.94 vs.0.42 UTIs per year, p < 0.05). Spontaneous regression occurred in 80% of POMs with dilated non-obstructive renogram, but in <20% with intermediate or relevant obstruction. All megaureters with <8.5 mm sonographic diameter regressed, but none over 15 mm. Eight patients had a poor outcome (partial kidney function <40% (n = 6), renal atrophy (n = 3)), but in seven of the patients, these findings were already present postnatally. In summary, the long-term outcome of POM appears favorable with mainly conservative treatment. UTI as the most common complication was 55% lower with antibiotic prophylaxis in infants. Adverse outcome was more closely related to congenital kidney hypoplasia than to degree of obstruction.
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