2024

Question 1

An eight-year-old boy has persistent urinary incontinence following newborn resection of PUV. This is most likely due to:
A.
detrusor overactivity.
B.
vesicoureteral reflux.
C.
poorly compliant bladder.
D.
incompetent bladder neck.
E.
damaged external urethral sphincter.

Answer 1

A. Urinary incontinence following PUV resection/ablation is common. Although, in some instances, this is secondary to surgical injury of the external urethral sphincter or bladder neck, the most common finding is bladder dysfunction. Three patterns of bladder dysfunction have been identified in boys with valves: myogenic failure, detrusor overactivity, and decreased compliance with a small bladder. In prepubertal boys with persistent incontinence, detrusor overactivity is the dominant pattern. Myogenic failure typically presents post-pubertally. Decreased compliance with reduced bladder capacity is seen less commonly. While decreased compliance may be seen initially, this typically improves after treatment of the valves and would be uncommon by age eight. VUR is unlikely to cause incontinence. An incompetent bladder neck is not commonly associated with PUV, and there is often bladder neck hypertrophy in these boys.

Question 2

A two-month-old uncircumcised boy with a sacral dimple undergoes evaluation of a febrile UTI. Ultrasound shows bilateral hydroureteronephrosis and a conus medullaris at the mid-aspect of L4. VCUG shows bilateral grade 4 VUR and a normal urethra. The next step is:

A.
CMG.
B.
cystoscopy.
C.
MAG-3 renal scan.
D.
circumcision.
E.
vesicostomy.

Answer 2

A. This infant may have a compromised urinary tract secondary to a neurogenic cause from a tethered spinal cord that must be considered. The conus normally ends above L3, and spinal ultrasound is a convenient and accurate screening method in the neonatal period. Given his low conus, a cystometrogram (CMG) would be important to measure compliance and capacity. Abnormal UDS findings might substantiate the presence of a clinically significant tethered cord. Circumcision is not mandatory. Vesicostomy at this point is premature, and cystoscopy is not necessary. In this case, the hydronephrosis may be related to the significant VUR and/or bladder dysfunction; a MAG-3 scan would not be indicated as the next step.