Urethral pressure variation: a neglected contributing factor in patients with overactive bladder syndrome?

ABSTRACT Objective To study urethral pressure variations during the whole filling phase among different groups of patients. Material and Methods We investigated 79 consecutive patients from January 2011 to June 2012. All patients were recruited within our routine practice in our continence clinic and were evaluated with urodynamic exam according to the standards of the International Continence Society (ICS) with an additional continuous measurement of the urethral pressure profile (cUPP) that was done in a supine position. Patients with genital prolapse >grade I, as well as patients with impaired cognitive function or neurogenic disorders were excluded. Bacteriuria at the time of investigation was excluded by urine analysis. Urethral pressure changes higher than 15cmH2O were considered as ‘urethral instability’. Results From 79 investigated patients, 29 were clinically diagnosed with OAB syndrome, 19 with stress urinary incontinence (SUI) and 31 with mixed (OAB and SUI) incontinence. The prevalence of ‘urethral instability’ as defined in this study was 54.4% (43/79). The mean Δp in patients with OAB (36.5cmH2O) was significantly higher (p<0.05) than in groups with pure stress (14.9cmH2O) and mixed urinary incontinence (19.3cmH2O). Conclusions Etiology of ‘urethral instability’ is unknown, but high prevalence among patients with overactive bladder syndrome, especially concomitant with detrusor activity can raise a fair question and direct further diagnostic as well as treatment efforts.

Use of near infrared spectroscopy as an alternative to videourodynamics to detect detrusor overactivity in women with the overactive bladder syndrome.

OBJECTIVE: To evaluate near infrared spectroscopy as a noninvasive alternative to cystometry for detecting detrusor overactivity in women with overactive bladder (OAB). Although cystometry is considered the "gold standard" investigation for the lower urinary tract, it is invasive. Recently, a noninvasive form of assessment of the lower urinary tract has been introduced using near infrared spectroscopy. METHODS: This was a prospective pilot study. Women with symptoms of OAB, referred to a tertiary referral one-stop urodynamics clinic were studied. A urodynamic diagnosis was made according to the International Continence Society guidelines. The near infrared spectroscopy monitoring results were analyzed by an independent near infrared spectroscopy Clinical Research Assessor. Both the urodynamics and near infrared spectroscopy assessors reported whether detrusor overactivity was present. Primary outcome measurement was the performance of near infrared spectroscopy as a new diagnostic test. We evaluated the performance of this by calculating the sensitivity and specificity. The clinical usefulness of near infrared spectroscopy was evaluated using positive and negative predictive values. RESULTS: One hundred patients were recruited of whom 95 had traces that could be interpreted. Thirty-one patients were found to have detrusor overactivity on cystometry. Twenty-five of these patients (26%) had detrusor overactivity on near infrared spectroscopy analysis. In 6% of these cases, no near infrared spectroscopy changes identified as suggestive of detrusor overactivity were seen. No detrusor overactivity was detected by cystometry in 64 patients, and in 19% of cases by near infrared spectroscopy. Forty-six patients (48%) had near infrared spectroscopy monitoring events identified as detrusor overactivity but no cystometry changes diagnostic of detrusor overactivity. CONCLUSION: The results of our study suggest that near infrared spectroscopy is an unreliable method for detecting detrusor overactivity in women with OAB symptoms.