Outlet Obstruction in Women

Abstract

Female voiding requires co-ordinated bladder contraction and outlet relaxation. Failure of the outlet to accommodate urine fl ow can occur in various circumstances in women. This chapter describes the diverse nature of the problem and its management, along with some of the limitations in the evidence base which make this a challenging clinical problem. Of these, one of the most important is the recognition that impairment of bladder contractility is common in older women [ 1 ] and this could cause overdiagnosis of bladder outlet obstruction (BOO). BOO may be asymptomatic, cause voiding LUTS, or complete obstruction resulting in inability to void (acute urinary retention-which is usually painful emergency). However, assessing the bladder contractility is diffi cult in women, and this hinders decisionmaking regarding diagnosis of BOO. Until the ability to agree defi nitions, and subsequently approaches to diagnosis, management of BOO in women will remain a clinical challenge.Retention in women results from a diverse set of conditions, which makes research into its epidemiology diffi cult. Most studies are small case series, or case reports with unusual causes. Part of the diffi culty in estimating prevalence rates of obstruction relates to the fact that unlike for men, there are no universally accepted or standardised criteria for diagnosing the condition in women. Voiding symptoms have been shown to have a poor predictive value for diagnosing female voiding dysfunction, rarely exist in isolation and often occur in association with storagerelated symptoms [ 2 -4 ]. The true prevalence of BOO in women is unknown, but estimates from large retrospective studies range from 3 to 8 % [ 3 -6 ]. A Scandinavian study revealed an incidence of AUR in women of seven per 100,000 population per year [ 7 ]. Defi ning Urinary ObstructionBOO can be diagnosed on the basis of urodynamic studies, as in men (see Chap. 4 ). BOO has been defi ned as detrusor pressure of 60 cm of water (cm H 2 O) or more, with a peak urine fl ow rate of less than 15 mL/s, though this was derived from measurements in a small number of women [ 8 ]. Another study derived criteria from evaluation of the videourodynamic studies of 261 women for non-neurogenic voiding function and defined BOO as radiographic evidence of obstruction between the bladder neck and the distal urethra in the presence of a