Crystallizing the Definition of Underactive Bladder Syndrome, a Common but Under‐recognized Clinical Entity

Abstract

Detrusor underactivity (DU) is an important contributor to lower urinary tract symptoms (LUTS). While DU has been defined in the literature in urodynamic terms, current definitions lack specific parameters. In addition, the clinical syndrome associated with and manifesting itself as DU, underactive bladder (UAB), has not been well defined in the literature. In the absence of a precise definition of UAB, it is difficult to appreciate the true nature and burden of this condition. We review the evidence regarding the epidemiology, pathogenesis, diagnosis, and treatment of DU and UAB and discuss the challenges in gathering data in the absence of precise definitions. DU may be idiopathic or caused by ageing, medications, or a number of causes of neurogenic, myogenic, or iatrogenic origin. Treatments are largely palliative due to a lack of curative options, and include watchful waiting, catheterization, medications, and surgical interventions. In light of the evidence available in the literature, we propose that a new symptom-based definition of UAB syndrome should be developed as a first step in furthering more standardized research. Further discussion on this proposed definition to reach expert consensus will enable researchers to gather more robust data, allowing greater insights into DU and UAB diagnosis and treatment.

Pathophysiological mechanisms in detrusor underactivity: Novel experimental findings

“…Other causes of DU include multisystem atrophy and iatrogenic lesions of the sacral cord, sacral nerve roots and pelvic nerves during surgical procedures (pelvic surgery) . An iatrogenic pelvic nerve injury UAB model in adult female rats showed a significant increase in cystometric bladder capacity, increased PVR, and reduced maximum voiding pressure and voiding efficiency 1 week after neuronal injury …”

Recent advances in the understanding and management of underactive bladder

“…No universally accepted definition currently exists for UAB. In addition, a variety of terms have been used in the literature to describe the condition, including DU, ‘non-obstructive voiding dysfunction’, ‘voiding dysfunction’, or ‘detrusor voiding insufficiency’, creating further confusion 4 .…”

Definition and symptoms of underactive bladder

“…Working back from this nonspecific definition of DU, a working symptomatic definition for UAB was derived by a consensus group at the 2014 International Consultation on Incontinence – Research Society as follows; “ The underactive bladder is a symptom complex suggestive of detrusor underactivity and is usually characterised by prolonged urination time with or without sensation of incomplete bladder emptying, usually with hesitancy, reduced sensation on filling, and a slow stream ” [ 3 ]. However, the need for further qualitative and quantitative research on which a symptomatic UAB definition may be based was increasingly recognised [ 3 4 19 ]. The latest symptomatic definition proposed by a Working Group set up by the ICS in 2016 is: “ Underactive bladder is characterised by a slow urinary stream, hesitancy and straining to void, with or without a feeling of incomplete bladder emptying and dribbling, often with storage symptoms ” [ 20 ].…”