Primary Nonrefluxing Megaureter: Does Ureter Diameter Really Matter?

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.

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.

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).

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.