Ureteric wall thickness as a novel predictor for failed retrograde ureteric stent placement

Area of Science:

• Urology
• Interventional Radiology
• Nephrology

Background:

• Identifying predictors of failed retrograde ureteric stent (FRS) placement is crucial for managing obstructing ureteric calculi.
• Ureteric wall thickness (UWT) measured by computed tomography (CT) shows potential in predicting outcomes for various urological procedures.

Purpose of the Study:

• To identify predictors of failed retrograde ureteric stent (FRS) placement in patients with obstructing ureteric stones.
• To evaluate the role of ureteric wall thickness (UWT) in predicting FRS placement failure.

Main Methods:

• Retrospective case-control study comparing successful retrograde stent (SRS) insertions with failed placements requiring nephrostomy tube (NT) insertion.
• Data collected from administrative and prospective databases (2013-2019), including patient demographics, clinical, and stone characteristics.
• Statistical analysis using univariate and multivariate logistic regression, with manual imaging review.

Main Results:

• Analysis included 109 patients (34 FRS, 75 SRS); sepsis was the most common indication for stent insertion (79%).
• Multivariate analysis revealed acute kidney injury (AKI) as the primary indication for stent insertion (OR 9.16) and UWT (OR 0.34) as significant predictors of FRS placement.
• Optimal UWT cutoff for predicting FRS placement was 3.2 mm, with 60.6% sensitivity and 83.3% specificity.

Conclusions:

• Elevated UWT and AKI as an indication for urgent urinary decompression predict FRS placement failure in obstructing ureteric stones.
• Patients with these predictive factors may benefit from upfront nephrostomy tube insertion instead of retrograde stent placement.