Role of spinning top urethra in dysfunctional voiding

Abstract

Objective. The role of spinning top urethra (STU) in children with dysfunctional voiding was evaluated retrospectively. Material and methods. From 1995 to 2002, the records of 154 children with dysfunctional voiding were reviewed retrospectively. Of the children 110 (71%) were girls and 44 (29%) were boys (mean age 8 years, range 4–14). All children were neurologically normal and no exhibited physical signs of occult spinal dysraphism. Patients were divided into two groups according to their width of proximal urethra: group I had STU and the group II had normal urethral width. The groups were compared with each other for gender, voiding symptoms, urinary tract infection (UTI), vesicoureteral reflux (VUR) and urodynamic observations. Results. There were 84 children (mean age 8.3 ± 2.2 years, range 4–14) in group I and 70 (mean age 8.0 ± 2.1 years, range 4–14) in group II; no significant age difference was found between the two groups (p = 0.4674). Group I consisted of 66 (71%) girls and 18 (29%) boys and group II 44 (63%) girls and 26 (37%) boys. STU was observed more in girls than boys in group I (p = 0.0316). UTI was observed in 57 patients (68%) in group I and 34 (49%) in group II (p = 0.0154). Mean duration of symptoms was 42 ± 24 months (range 6–118) and 39 ± 23 (range 3–120) months in groups I and II, respectively (p = 0.6302). Postvoid residual urine (PVR) more than 10% of expected bladder capacity was detected in 15 patients (18%) in group I and seven (10%) in group II. No association was found between the meaningful PVR and STU (p = 0.1653). The presence of detrusor overactivity during filling was observed in 54 patients (64%) in group I and 42 (60%) in group II (p = 0.4676). Diminished bladder compliance (< 10 ml/cmH₂O) was detected in 34 patients (40%) in group I and 17 (24%) in group II (p = 0.0335). The mean voiding pressure was measured as 56 ± 29 cmH₂O in group I, which was significantly higher than in group II (49 ± 25 cmH₂O) (p = 0.0373). The mean flow rate during the emptying phase of urodynamics was 16 ± 8 and 15 ± 6 ml/s in groups I and II, respectively (not significant, p = 0.2686). VUR was detected in 16 patients (19%) in group I and two (3%) in group II (p = 0.0018). Conclusions. STU was related to recurrent UTIs, VUR, poor bladder compliance and more serious functional urinary obstruction. Furthermore, STU may be a consequence of a neurogenic maturation defect in detrusor–sphincter coordination resembling that of urofacial syndrome, because development of this situation was found to be independent of the duration of symptoms.

Key Words::

• Dysfunctional voiding
• spinning top urethra
• urinary tract infection
• vesicoureteral reflux
• videourodynamics

Acknowledgement

This study is supported by a grant from Akdeniz University Scientific Research Project Administration Division.