Value of Dynamic Renal Scintigraphy in Suggesting Congenital Midureteral Stricture: A Case Series and Literature Review.

This study aims to discuss the role of dynamic renal scintigraphy (DRS) in diagnosing congenital midureteral stricture (CMUS) as a rare and challenging condition in children, often confused with ureteropelvic junction obstruction (UPJO), leading to inadequate management. We retrospectively analyzed DRS data from 133 cases of hydronephrosis from 2015 to 2023, including 3 CMUS and 15 UPJO by Crossing Vessels (CV). Preoperative protocol involved ultrasound and DRS. We adhered to the paediatric protocol of the European Association of Nuclear Medicine, only radiotracer selection depended on availability. Surgery was indicated based on symptoms, obstruction on DRS, and reduced renal function. Ureteral stricture was considered congenital if no extrinsic compression was found. We excluded non operated patients and those with missing data. Proximal ureteral retention on DRS was observed in one case with complete stricture in lumbar ureter (case1), absent in a case with ipsilateral UPJO (case 2), and equivocal findings were noted with incomplete stricture in the pelvic ureter (case 3). Ureteral stasis was consistently absent in all 130 cases of PUJO including 15 cas of CV. CMUS diagnosis was confirmed intraoperatively in all 3 cases. Lumbotomy allowed surgical access in 2 cases but was unsuitable in one. Outcomes were favorable in 3 patients. Often requested for hydronephrosis, DRS can provide additional information suggesting CMUS. However, ureteral retention on DRS may not always be present, particularly in cases of incomplete stenosis or associated uropathies.