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Updated: Apr 19, 2026

Transmesenteric Laparoscopic Pyeloplasty in Trendelenburg Position for Horseshoe Kidney with Hydronephrosis
Published on: July 8, 2025
Symptomatic versus asymptomatic pyeloplasties: A single institution review
Peter D Metcalfe1, Mark Assmus1, Darcie Kiddoo1
1Division of Pediatric Surgery, Stollery Children's Hospital, Edmonton, AB.
Insights
Most pyeloplasties for ureteropelvic junction obstruction (UPJO) were performed due to new symptoms, not solely based on prenatal screening. Current surveillance strategies may not fully prevent UPJO-related morbidity.
Area of Science:
- Pediatric Urology
- Nephrology
- Surgical Outcomes
Background:
- Historically, ureteropelvic junction obstruction (UPJO) diagnosis and treatment were symptom-driven.
- Prenatal ultrasonography now leads to early diagnosis, but optimal screening and intervention thresholds remain controversial and lack outcome-based evidence.
- This study investigates the indications for pyeloplasty in the era of widespread prenatal screening.
Purpose of the Study:
- To evaluate the primary indications for pyeloplasty in patients diagnosed with ureteropelvic junction obstruction (UPJO).
- To determine if widespread prenatal screening has reduced the incidence of symptomatic UPJO requiring pyeloplasty.
- To assess the effectiveness of current surveillance strategies for antenatally detected hydronephrosis.
Main Methods:
- Retrospective chart review of all pyeloplasties performed over 8 years at Stollery Children's Hospital.
- Patients categorized based on surgical indication: symptomatic versus asymptomatic.
- Analysis of preoperative renal scan function and postoperative recovery.
Main Results:
- 60% of pyeloplasties were performed for symptomatic ureteropelvic junction obstruction (UPJO).
- 12% of symptomatic patients had antenatally detected hydronephrosis that appeared to resolve spontaneously.
- Of 29 patients undergoing pyeloplasty, 8 experienced preoperative function loss, with only 50% recovering to 90% of original function.
Conclusions:
- Despite antenatal hydronephrosis surveillance, most pyeloplasties were performed for de novo symptoms.
- Current surveillance strategies may be insufficient to predict and prevent all UPJO-related morbidity.
- Further research is needed to refine UPJO management and improve surgical outcomes.
Introduction:
Historically, pyeloplasties have been performed after symptoms and radiographic confirmation of an ureteropelvic junction obstruction (UPJO). However, with prenatal ultrasonography, the approach to patients has fundamentally changed. Increasingly, patients are diagnosed and treated before the advent of morbidity, based on imaging findings alone. However, optimum screening strategies and thresholds for intervention vary significantly, are controversial, and are not founded on outcome-based evidence. We examined all pyeloplasties performed at our institution and reviewed their indication for surgery. We hypothesized that, despite ubiquitous screening for UPJO, most pyeloplasties had been performed secondary to symptoms and did not benefit from antenatal screening.
Methods:
A retrospective chart review was performed of all pyeloplasties performed at the Stollery Children's Hospital, Edmonton, Alberta, over the past 8 years. Patients were categorized according to indication for surgery: symptomatic or asymptomatic.
Results:
Most (60%) of our pyeloplasties were performed for symptomatic indications. Furthermore, 12% of these patients had antenatally detected hydronephrosis that was thought to have resolved spontaneously during follow-up. Of our symptomatic patients, 37% were undergoing surveillance with the expectation for spontaneous resolution. Of the 29 patients who underwent pyeloplasty, 8 suffered a preoperative loss of function on renal scans; however, only 50% returned to within 90% of their original function.
Conclusion:
Despite active surveillance of antenatally detected hydronephrosis, most pyeloplasties at our institution were performed for de-novo symptoms. We believe that this simple observation reinforces that our current surveillance strategies are unable to predict and eliminate all morbidity from UPJO.
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