Voiding disorders as etiologic cofeature of overactive bladder syndrome. An observational study.

Background: Overactive bladder (OAB) is very common in the urological and gynecological practice. It is well known that the correlation between clinical features and urodynamics findings is often poor. In this observational study urodynamic findings of an OAB population have been retrospectively analyzed with the aim to identify a possible role of voiding disorders in the pathophysiology of OAB syndrome.
Methods: Urodynamics executed between January 2005 and December 2010 have been analyzed. Female patients presenting characteristics of OAB syndrome according to International Continence Society definition were identified. Urodynamic investigations have been carried out according to the good practice guidelines for urodynamics. The Blaivas-Groutz cut off for female urinary obstruction was to detect voiding disorders.
Results: According to the selection criteria 258 patients presenting OAB syndrome have been considered eligible to join the study. Eighty-one patients (30%) showed voiding difficulties: in 21 of them pressure-flow study was diagnostic for frank outlet obstruction, in 47 a mild form and 13 bladder sphincter pseudo-dyssynergia.
Conclusions: OAB syndrome can be related to voiding disorders mostly represented by a mild degree of obstruction. Such condition could trigger irritative symptoms. These clinical findings require an instrumental assessment represented by a pressure-flow analysis. This approach seems to be mandatory in patients refractory to drug therapy.