NEUROUROLOGY & FEMALE UROLOGY

Urodynamic characteristics of mixed urinary incontinence and idiopathic urge urinary incontinence
Chou EC, Blaivas JG, Chou LW, Flisser AJ, Panagopoulos G
Department of Urology, School of Medicine, China Medical University, Taichung, Taiwan
Neurourol Urodyn. 2008; 27: 376-8

• Purpose: To evaluate and compare the clinical and urodynamic findings in patients with either mixed urinary incontinence (MUI) or simple urge urinary incontinence (UUI).
• Materials and Methods: A series of 100 consecutive female patients with MUI and UUI were identified from a database. Patients with neurogenic bladder, fistula, urethral diverticulum, prior urologic surgery or known urinary tract obstruction were excluded. All patients were classified according to the urodynamic classification of overactive bladder of Flisser et al. and all patients underwent history, physical examination, validated incontinence questionnaire, 24-hour voiding diary, 24-hour pad test, video urodynamic study (VUDS), and cystoscopy.
• Results: A significantly higher proportion of patients with UUI exhibited detrusor overactivity at VUDS, (67% of the patients with UUI vs. 24% of the MUI, P < 0.05). Patients with UUI had fewer episodes of incontinence (6.7 vs. 4.2, P < 0.05) with slightly less objective urine loss (24-hour pad test 94 gm vs. 128 g of loss, P < 0.05) and voided at higher pressures (p(det) at Q(max) 21.4 vs. 15.6 cm H2O, P < 0.05). Patients in both groups had functional and urodynamic bladder capacities that were not statistically different.
• Conclusions: Women with UUI were more likely to exhibit detrusor overactivity but experienced fewer episodes of incontinence and less urinary loss when compared with women who had MUI. The “urge incontinence” component of MUI appears to be different than that of UUI, and suggests that urge incontinence may be overdiagnosed in patients with SUI who misinterpret their fear of leaking (because of SUI) for urge incontinence. Neurourol. Urodynam. 27:376-378, 2008. (c) 2008 Wiley-Liss, Inc.
  
  
• Editorial Comment
  A straightforward report from leaders in the field comparing the urodynamic characteristics and variables of patients suffering from stress urinary incontinence combined with urinary urge incontinence versus those plagued with urinary urge incontinence alone. The authors started with 100 patients in the study population then parsed the group down to a total of 72 patients: 45 patients with mixed urinary incontinence versus 27 patients with urinary urge incontinence alone (patients were excluded from the original 100 if they had a neurogenic bladder, urinary fistula, urethral diverticulum, prior urologic surgery, or known infravesical outlet obstruction). The patient’s overactive bladder was classified by the criteria of Flisser et al. (1). Significant differences were noted upon analysis with regards to the presence of absence of detrusor overactivity, episodes of urinary incontinence for 24 hour period, voiding pressure, functional bladder capacity, as well as severity of urinary incontinence on a 24 hour pad test.
  A well written paper with an excellent discussion on urinary urge incontinence in patients with and without stress urinary incontinence. The presentation does raise an excellent point with regards to the presence of urinary urge incontinence in patients classified with mixed urinary incontinence: are these patients really suffering from urge episode or do they just void often to minimize bladder volume and potential leakage episodes? This paper is an appropriate companion to the other reviewed article in this month’s journal to engender thought on urinary urge incontinence and its role in anti-incontinence surgery success rates.

Reference
Flisser AJ, Walmsley K, Blaivas JG: Urodynamic classification of patients with symptoms of overactive bladder. J Urol. 2003; 169: 529-33; discussion 533-4.

Steven P. Petrou, M.D
Associate Professor of Urology
Chief of Surgery, St. Luke’s Hospital
Associate Dean, Mayo School of Graduate Medical Education
Jacksonville, Florida, USA
E-mail: petrou.steven@mayo.edu