The subject of chronic urinary retention (CUR) is of interest, as there is not even evidence that we need such a definition and we could probably live with the current definitions of acute urinary retention (AUR) and postvoid residual urine volume (PVR). The fine threshold between elevated PVR and CUR is unclear and is not necessarily linked to the presence of complications. Terminology is of utmost importance both in practice and research. The lack of a good definition of CUR makes epidemiological studies impossible. The current ICS definition: ‘a non-painful bladder, which remains palpable or percussable after the patient has passed urine. Such patients may be incontinent’. Is a remnant from a pre-ultrasound era and should probably be reconsidered.
We certainly need a consensus on ‘acute urinary retention’ because this is a condition that present in Emergency Rooms. We know how to define PVR, although we do not have a clear threshold beyond which the condition becomes problematic and it is associated with an increased risk of complications in the non-neurogenic adult male. From a clinical standpoint, we need to understand which patients may benefit from endoscopic relief of BOO and clinical studies suggest that an elevated PVR with a weak detrusor is associated with an increased risk of poor outcome after TURP. The clinical issue is in detrusor function, something that we usually quantify in terms of pressure rather than in the amount of work the muscle is able to perform. What we really need is a clinical translation of ‘bladder decompensation’, that is a measure in terms of muscle contractility. In patients with an elevated PVR, the clinical question is whether the detrusor muscle still functions or not. In cases of good contractility, surgery will restore normal voiding dynamics, in cases of a very week detrusor relief of BOO may not improve voiding function. From a teleological standpoint, AUR is a protective condition. In patients with benign prostatic obstruction, AUR may occur when the detrusor is still able to produce elevated pressure values, although these may be lower than those required to open the bladder neck and initiate voiding.
The mini review from Negro and Muir is of interest because it raises an important issue and hopefully will foster discussion on it.