Assessment of lower urinary tract function in children with Down syndrome

BACKGROUND

Despite the fact that functional lower urinary tract symptoms are common among people with Down syndrome (DS), their voiding function has not been studied precisely. Our goal was to assess the lower urinary tract functions in DS.

METHODS

Fifty-five DS children aged 5-15 years old and 35 age-matched control children were evaluated by ultrasonography and uroflowmetry.

RESULTS

Eleven (20%) DS children had no uresiesthesia, 21 (38%) were urinated under guidance, nine (16%) urinated fewer than three times a day, two (4%) urinated more than 10 times a day, three (5%) used diapers, and 26 (47%) had urinary incontinence. Seven (13%), 15 (27%), and 10 (18%) DS children had weak, prolonged and intermittent urination, respectively, and seven (13%) had urination with straining. In contrast, none of the control subjects had urinary problems. In the uroflowmetrical analysis, 10 (18%), 20 (37%), 11 (20%) and five (9%) DS children showed "bell-shaped," "plateau," "staccato" and "interrupted" patterns, respectively; the remaining nine (16%) could not be analyzed. In contrast, 21 (60%), one (3%), four (11%), three (9%) and two (6%) control subjects showed bell-shaped, tower-shaped, plateau, staccato and interrupted patterns, respectively; the remaining four (11%) could not be analyzed. Residual urine was demonstrated in four (7%) DS children and one (3%) control child.

CONCLUSIONS

Lower urinary tract symptoms and abnormal uroflowmetry findings, which can lead to further progressive renal and urinary disorders, are common in DS children. Therefore, lower urinary tract functions should be assessed at the life-long regular medical check-ups for subjects with DS.

Long-term urethral function measured by uroflowmetry after hypospadias surgery: comparison with an age matched control

PURPOSE

Long-term outcomes of hypospadias surgery, particularly urinary function, have not been examined thoroughly. Uroflowmetry can be used to evaluate long-term functional outcomes by assessing flow shape and the rate of micturition. We assessed urethral function using uroflowmetry in adolescents after undergoing hypospadias repair in infancy and compared this with age matched controls.

MATERIALS AND METHODS

After human research ethics committee approval (HREC 28111A), 17 boys 13 to 15 years old with no history of urological or neurological disorders underwent uroflowmetry (65 separate voids) to determine standard values for boys of this age. Then 60 boys age 13 to 15 years who had undergone treatment for hypospadias in early infancy were seen for long-term followup and underwent uroflow assessment.

RESULTS

Standard urinary flow rates were established in the 13 to 15-year-old control group and represented on a nomogram. In the boys who underwent hypospadias surgery the urine flow rates were significantly lower compared to the control nomogram (p <0.0001), with half the patients having uroflow rates below 1 SD from the control mean but without symptoms. Boys with significant preoperative chordee were more likely to have poorer urinary flow (p <0.04). A poor urinary flow rate also was significantly associated with post-void residual bladder volume (p <0.03). There was no correlation with original meatal location, number of operations, presence of postoperative complications, current anatomy and lower urinary tract symptoms (eg post-void dribble, hesitancy, incontinence).

CONCLUSIONS

At long-term followup after hypospadias surgery urinary flow rates were significantly lower compared to age matched controls but still fell within the normal range. In the hypospadias cohort there was no significant association with lower urinary tract symptoms and poor urinary flow. Detection of poor urinary flow may indicate incomplete bladder emptying. The presence of severe chordee preoperatively is a significant risk factor for poor urinary flow rates on long-term followup.