Neurourology and Urodynamics 30:723–728 (2011) Detrusor Underactivity: A Plea for New Approaches to a Common Bladder Dysfunction G.A. van Koeveringe, MD, PHD 1, ∗ B. Vahabi, PHD 2 K.E. Andersson, MD, PHD 3 R. Kirschner-Herrmans, MD, PHD 4 and M. Oelke, MD, PHD 5 1 Department of Urology and Pelvic care Center Maastricht, Maastricht University Medical Centre, Maastricht, The Netherlands 2 Department of Urology, Bristol Urological Institute, Southmead Hospital, Bristol, UK 3 Wake Forest Institute for Regenerative Medicine, Wake Forest University School of Medicine, Winston Salem, North Carolina, USA 4 Continence Centre, Aachen Medical University, Aachen, Germany 5 Department of Urology, Hannover Medical School, Hannover, Germany Aims: Detrusor underactivity (DU) is defined by the International Continence Society as a contraction of reduced strength and/or duration resulting in prolonged or incomplete emptying of the bladder but has yet received only little attention. The purpose of this report is to summarize the ICI-RS meeting in Bristol in 2010 exploring current knowledge on DU and outline directions for future research. Methods: A think tank discussion was held and the summary of discussions was presented to all ICI-RS participants. This report is based on the final discussions. Results: The under- standing of the pathophysiology, epidemiology, assessment, and treatment of DU remains rudimentary. DU is defined by pressure-flow analysis but no consensus exists regarding which of the available formulae should be used for quantifica- tion of detrusor work. DU is likely to be multifactorial. Aging causes a decay in detrusor activity but other concomitant causes, either myogenic or neurogenic, may aggravate the problem resulting in decrease of detrusor contractility. No effective pharmacotherapy for the condition exists. Only a few surgical therapeutic strategies have been explored, such as neuromodulation and skeletal muscle myoplasties. Consequently, the management of affected individuals remains unsatisfactory. Conclusions: Future directions recommended by the ICI-RS panel include assessment of pathogenesis by developing novel animal models in addition to new non-invasive tests allowing longitudinal trials. Furthermore, optimizing the existing evaluation algorithms to support standard testing for DU and further epidemiological studies to quantify the size of the problem are required for the development of future treatment modalities. Neurourol. Urodynam. 30:723–728, 2011. © 2011 Wiley-Liss, Inc. Key words: bladder outlet obstruction; detrusor contractility; detrusor underactivity; non-obstructive voiding dysfunc- tion; underactive bladder; urinary retention INTRODUCTION Detrusor underactivity (DU) has yet received only little sci- entific attention. This is illustrated by a Medline search for publications between 1980 and 2010 using the terms “detrusor underactivity” and “underactive bladder” that revealed 93 and 80 publications, respectively, resulting in a total of 165 different articles during the last 30 years. In contrast, “detrusor overac- tivity” and “overactive bladder/OAB” had as many as 1,223 and 2,688 hits, respectively. The incidence and prevalence of a condition is highly dependent on both definition and available diagnostic tests. The availability of treatment modalities greatly determines the need for a thorough diagnostic work-up and vice-versa. Improved tests and treatment options will eventually lead to a higher degree of differentiation within the general condition. Until recently, the only available treatments for DU had been clean intermittent catheterization or drug therapy. Drugs, especially directly or indirectly acting parasympathomimetics, remain contentious due to low efficacy and high prevalence of side-effects. 1 During the past decade, new treatment modalities have become available, such as neuromodulation, neurostim- ulation, or latissimus dorsi muscle transposition. The focus on bladder reconstruction using tissue engineering warrants more research with regard to the mechanisms of detrusor control and contractility. The purpose of this report, based on discussions during the 2nd ICI-RS meeting in Bristol in June 2010, is to critically sum- marize and structure the current knowledge of DU and outline suggestions for future research. METHODS Step 1 An outline for a think tank discussion was prepared by the two chairmen (G.vK. and M.O.) based on a literature review. The topic: “Detrusor underactivity” or “underactive bladder” was discussed by the participants of the think tank with regard to etiology, pathophysiology, epidemiology, assessment, and treatment. Conflict of interest: none. Christopher Chapple led the review process. Abbreviations used: BOO, bladder outlet obstruction; DU, detrusor underactivity; ICI-RS, International Consultation on Incontinence—Research Society; ICS, Interna- tional Continence Society; PG, prostaglandin; UAB, underactive bladder. ∗ Correspondence to: G.A. van Koeveringe MD, PhD, FEBU, Department of Urol- ogy, Maastricht University Medical Centre, PO Box 5800 6202 AZ Maastricht, The Netherlands. E-mail: g.van.koeveringe@mumc.nl Received 6 February 2011; Accepted 9 February 2011 Published online 15 June 2011 in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/nau.21097 © 2011 Wiley-Liss, Inc.