Importance of Considering the Duplex Collecting System During Routine Endourological Procedures: A Case Report

We report the case of a 58-year-old woman who initially presented to the emergency department with intermittent nausea, vomiting, and left upper quadrant abdominal pain for six days. As part of the abdominal pain workup in the emergency department, contrast-enhanced abdominopelvic CT and laboratory assessment were performed, which were consistent with pyelonephritis secondary to a distal ureteral stone. Interestingly, while the imaging failed to detect any significant anatomic variation, a duplicated collecting system was diagnosed during ureteral stent placement. Recognition of this anomaly was crucial for successful patient management. Awareness of anatomic variants is essential during endourological procedures, as diagnostic imaging may not reliably detect them.