I Thought I Saw a Retrocaval Ureter; Don’t Bite The Fish-hook Sign So Easily

Abstract

Abstract Purpose: To retrospectively evaluate the children who were suspected to have a retrocaval ureter during management for urinary tract dilation. Retrocaval ureter may be missed or misdiagnosed due to rare incidence. Fish-hook sign is a particular radiological sign that may indicate retrocaval ureter but sensitivity and specificity are not discussed previously. Materials And Methods: The children (n=12) in whom retrocaval ureter was considered in the differential diagnosis between 2016 and 2022 are enrolled in the study. The demographics of the patients, findings suggesting retrocaval ureter, evaluation process, management, and final diagnosis are retrospectively evaluated. Results: The final diagnosis was retrocaval ureter (n=3), ureteropelvic junction obstruction (n=7), and duplicated collecting system (n=2). A retrocaval ureter was confirmed or excluded by ultrasonography while there was a stent in the ureter in 6 patients and by laparoscopic exploration in the rest 6 patients. Three underwent surgery for RCU, 8 for uretero-pelvic junction obstruction, 1 for reflux and 1 ureterocele puncture. Discussion and Conclusion: Fish-hook sign is a rare conflicting finding that can be encountered on imaging studies. This uncommon finding needs confirmation or exclusion of a possible retrocaval ureter. Radiological evaluation (by ultrasonography or cross sectional studies) while there is a stent in the ureter is the most satisfactory way to confirm or exclude a retrocaval ureter. Alternatively, being aware of a possible retrocaval ureter and performing a little more extensive dissection may be necessary during surgery to confirm or exclude it. If available, laparoscopy may provide this goal in a minimal invasive manner with superior visualization .