Current concepts of the acontractile bladder Marc Colaco* , Nadir I. Osman † , Ahmet Karakec ß i ‡ , Walter Artibani § , Karl-Erik Andersson* and Gopal H. Badlani* *Wake Forest School of Medicine, Winston-Salem, NC, USA, † Academic Urology Unit, Royal Hallamshire Hospital, Sheffield, UK, ‡ Firat University Medical School, Elazig, Turkey, and § Urologic Clinic, University Hospital, Ospedale Policlinico, Azienda Ospedaliera Universitaria Integrata, Verona, Italy The acontractile bladder (AcB) is a urodynamic-based diagnosis wherein the bladder is unable to demonstrate any contraction during a pressure flow study. Although it is often grouped with underactive bladder, it is a unique phenomenon and should be investigated independently. The purpose of the present review was to examine the current literature on AcB regarding its pathology, diagnosis, current management guidelines, and future developments. We performed a review of the PubMed database, classifying the evidence for AcB pathology, diagnosis, treatment, and potential future treatments. Over the 67 years covered in our review period, 42 studies were identified that met our criteria. Studies were largely poor quality and mainly consisted of retrospective review or animal models. The underlying pathology of AcB is variable with both neurological and myogenic aetiologies. Treatment is largely tailored for renal preservation and reduction of infection. Although future developments may allow more functional restorative treatments, current treatments mainly focus on bladder drainage. AcB is a unique and understudied bladder phenomenon. Treatment is largely based on symptoms and presentation. While cellular therapy and neuromodulation may hold promise, further research is needed into the underlying neuro-urological pathophysiology of this disease so that we may better develop future treatments. Keywords acontractile detrusor, acontractile bladder, underactive bladder, detrusor areflexia, urodynamic evaluation Introduction According to ICS definition from 2002: ‘Acontractile detrusor is one that cannot be demonstrated to contract during urodynamic studies’ [1]. This definition was revised 2010 to: ‘the detrusor cannot contract during urodynamic studies resulting in prolonged bladder emptying within a normal time span’ [2]. This finding is a separate finding from detrusor underactivity (DU): ‘detrusor contraction of reduced strength and/or duration, resulting in prolonged bladder emptying and/or a failure to achieve complete bladder emptying within a normal time span’. Whilst presentations are similar, evidence suggests that these are two distinct entities rather than a single, progressive spectrum [3]. Regardless, these urodynamic diagnoses are generally grouped together under the clinical diagnosis of ‘underactive bladder’ (UAB). Acontractile detrusor occurs in ~5–17% of patients with LUTS. While the presentation may be uniform, the underlying aetiology of acontractile detrusor may be due a wide range of metabolic, infectious, autoimmune, congenital, and degenerative changes that affect the myogenic or neurogenic properties of the bladder. Acontractile detrusor may also be the result of paruresis: the inability to initiate a contraction whilst being observed. As such psychosocial stressors may distract from the true underlying presentation and underlying pathology. Differentiation between aetiologies thus requires an understanding of the nuances of this presentation including differences in symptoms, patient history, and physical data to formulate the correct diagnosis. Furthermore, although treatment options are currently limited, new developments will potentially allow us to treat the different categories with pathology specific solutions in the near future. The purpose of the present review was to examine the current literature regarding acontractile detrusor and its pathology, diagnosis, current management guidelines, and possible future developments. This was to discover if the acontractile detrusor, as demonstrated by conventional urodynamic study (UDS), can be separated from DU. Furthermore, we examine that from a pathophysiological point of view an acontractile detrusor is only one potential cause of an acontractile bladder (AcB), as the lack of detrusor contraction during urodynamic studies may not be caused by the myogenic failure of detrusor muscle to contract. We thus suggest that the term acontractile detrusor is replaced by acontractile bladder, covering urodynamic diagnosis, symptoms, and underlying pathophysiology. This is important, particularly within the ageing population, where this is likely to be an increasingly prevalent clinical problem. Evidence Acquisition The PubMed database was searched for all English manuscripts pertaining to AcB from 1 January 1950 to 1 © 2018 The Authors BJU International © 2018 BJU International | doi:10.1111/bju.14236 BJU Int 2018; 122: 195–202 Published by John Wiley & Sons Ltd. www.bjui.org wileyonlinelibrary.com Review