Primary Nonrefluxing Megaureter: Does Ureter Diameter Really Matter?

A BSTRACT Purpose: A ureter diameter exceeding 6 mm is termed megaureter. This study aimed to evaluate the clinical features of primary non-refluxing megaureter (PNMU) and the importance of ureteral diameter in its management. Methods: Clinical, radiological, and operative findings and long-term outcomes of PNMU followed or operated on between 2011 and 2023 were evaluated retrospectively. Patients with vesicoureteral reflux, a history of lower urinary tract pathology or surgery, and a follow-up <18 months were excluded. Results: Among 32 patients (12.5% female, 87.5% male), 50% were diagnosed prenatally. Twenty-six patients had unilateral, six had bilateral megaureters. Over a mean follow-up of 94.3 ± 53.4 months, 37.5% were managed conservatively, 62.5% required intervention. Nine underwent open surgery, 11 underwent double-J-stenting. Median operation age was comparable between surgical groups ( P > 0.05) but significantly lower in patients with urinary tract infection ( P : 0.007). Ureteral diameter decreased from 10.4 mm (range: 6.2–24.2) to 6.9 mm (range: 0–17) in conservatively managed cases, from 11 mm (range: 8–24.2) to 9 mm (range: 0–19) in double-J-stent group, and from 9.7 mm (range: 6.2–18.8) to 4.3 mm (range: 0–13) in the open surgery group ( P > 0.05). No significant difference was observed among the peak measured ureter diameters in the conservatively managed group (median: 12 mm, range: 9–33), preoperative ureter diameters in the double-J-stent group (median: 12.5 mm, range: 8.8–17), and open surgery group (median: 14 mm, range: 8–31) ( P > 0.05). Conclusion: Ureteral diameter has limited importance in PNMU management. Conservative management may be an option even in advanced dilatations. Postoperative ureteral dilatation may persist at varying levels and durations.