Defining imaging parameters to guide selection of cases for ureterocele surveillance

Selection criteria for surveillance in patients with ureteroceles are ill-defined.

To evaluate the outcomes of surveillance in patients meeting functional imaging criteria hypothesized to be associated with low rates of surveillance failure.

We performed a single institution retrospective cohort study of infants with ureterocele evaluated from 2015 to 2020. Patients were classified according to imaging criteria into group 1 (non-functional moieties or preserved function with prompt drainage) or group 2 (impaired function or drainage). The primary outcome was surveillance failure defined as urinary tract infection (UTI), new high-grade vesicoureteral reflux (VUR), new high-grade hydronephrosis or intervention for persistent high-grade VUR or hydronephrosis. Descriptive statistics and time-to-event analysis were performed.

Among 73 patients with a median follow-up interval of 2.7 years (IQR 1.4-4.8), 85% were diagnosed prenatally, and 62% were female. Collecting system duplication (74%) and high-grade hydronephrosis (71%) were common. Diuresis renography was performed in 61 patients (84%). Group 1 included 42 patients (57%) and group 2 included 31 (43%). Patients in group 1 were more likely to be male (50% v. 23%, p = 0.02) and have a non-duplex collecting system (28% v. 10%, p < 0.01). Thirty-five patients in group 1 (83%) and 13 in Group 2 (42%) underwent surveillance (48 total). Among Group 1 patients who underwent surveillance, 34% developed surveillance failure (12/35), 20% experienced UTI (7/35), and 14% underwent intervention (5/35); these outcome rates were not significantly different from Group 2. Three group 1 patients underwent intervention primarily for management of VUR while concern for obstructed infection drove intervention in two others. Group 1 patients with high-grade VUR on initial evaluation had significantly higher rates of surveillance failure (71% v. 25%, p = 0.03) and intervention (43% v. 7%, p = 0.04) compared to those with low-grade or absent VUR. Most failure events occurred within 2 years of initiating surveillance and group 1 was associated with lower risk of surveillance failure (HR 0.35, 95%CI 0.14-0.85, p = 0.02) and UTI (HR 0.30, 95%CI 0.10-0.89, p = 0.03).

Patients in group 1 had outcome rates on surveillance comparable to prior published studies. Few overall underwent intervention which was often for the management of VUR. High-grade VUR was associated with surveillance failure, even amongst patients meeting the proposed surveillance imaging parameters.

Imaging parameters supplemented by diuresis renography can aid clinical decision-making when selecting patients with ureteroceles for surveillance. VUR in duplex systems accounts for many outcomes in the identified group.

STUDY00000659.