Rapid Responses to:

PRACTICE: Brian Buckley and Adrian M Grant What is the most effective management of neurogenic bladder dysfunction? BMJ 2009; 338: b659 [Full text]

Rapid Responses: Submit a response to this article

Rapid Responses published:

Bladder stimulation for neurogenic bladder

Martin S Knapp   (8 April 2009)

Bladder stimulation for neurogenic bladder 8 April 2009
Martin S Knapp, retired/part-time nephrologist melbourne, 3079, Australia Send response to journal: Re: Bladder stimulation for neurogenic bladder	The review of management of neurogenic bladder (April 4, 2009) makes depressing reading, concluding that there is little but uncertainty to guide clinicians managing this difficult but not uncommon problem. The focus on the lack of quality in the randomised trials published has obscured the probability that alternative research methodology does provide useful direction. The authors fail to review one important alternative to intermittent bladder catheterisation - bladder stimulation (1). In an earlier review in 1996 in your journal, just prior to the publication of positive results from bladder stimulation, Hunt(2) stated that: “A bladder that retains a large volume of residual urine soon fills to capacity, causing frequency, urgency, nocturia, or incontinence. Urinary stasis leads to urinary tract infections and calculi. By eliminating residual urine, intermittent catheterisation enables the bladder to function more effectively as a reservoir, relieves symptoms, and reduces the incidence of symptomatic urinary infections." If that statement is accepted trials of management should use residual urine as a surrogate marker of efficacy, even if in an ideal world those trials would be randomised and have death, kidney failure and symptomatic urinary infections as end-points. In an individual patient any management strategy without complications that decreases residual urine from values above 100ml to values well below 100ml could be regarded as a success for that patient, even if randomised controlled trials have not yet established its merits to a "significant" level of probability in hetrogeneous populations of individuals also with neurogenic bladders . The widespread use of intermittent catheterisation to achieve low residual volumes is based on that logic and I agree with the authors that many trials, eg with a no treatment arm, would now be unethical. In the future Buckley and Grant anticipate that "more robust guidelines will still need to depend on “empirical evidence and carefully planned observational research”. It was disappointing to me that the authors did not review the use of suprapubic bladder stimulation among the alternatives considered. This technique evaluated at the Queen’s Square Hospital, London was well documented at that hospital in a prospective, but non-randomized, study (1): “The study involved 36 patients, comprising 29 with multiple sclerosis (MS), four with multiple system atrophy (MSA), one with radiation myelitis and two with neurological disease of uncertain aetiology. The device improved the symptoms in 25 of 36 patients (70%) and reduced the post-voiding residual (PVR) from a mean (standard deviation) of 175 (78) mL to 68 (32) mL. There were no complications and most patients complied well. The authors concluded that suprapubic vibration is an effective means of emptying the neurogenic bladder ...... and that the device may be a useful alternative to clean intermittent self -catheterization.” The Queen's Square Bladder Stimulator (©Malem Medical)was introduced to clinical units and patients in Australia in 1998 on the basis of the Queen's Square trial. I consider that bladder stimulation is still not sufficiently often considered as an alternative to intermittent catheterization, or other active intervention in patients with neurogenic bladder dysfunction. Suprapubic stimulation has also been observed to be very effective in some bladder conditions with bladder emptying difficulties resistant to other strategies. Supra-pubic bladder stimulation is non-invasive and should be used when there is neurogenic bladder with residual urine as an alternative to intermittent catheterization unless residual bladder volumes cannot be kept below 100ml (or some other arbitrary number selected by the treating clinician) with stimulation. A trial of stimulation may be merited even when there are high residual volumes as if these can be reduced without intermittent catheterization there may be less infections and there will certainly be less expense. I agree with the review that it is unfortunate that there were never randomised controlled trials carried out to adequately contrast intermittent catheterization and no active treatment. The non-invasive method of bladder stimulation and the various surgically invasive alternatives mentioned in this review should now be contrasted in trials with intermittent catheterisation, at least in relation to their ability to reduce bladder emptying volumes and the frequency of infections. When ethically justified, eg when there is no residual urine, a group with no intervention should also be included. The effect of bladder stimulation can be evaluated in clinical practice using a within patient cross-over eg contrasting with no treatment or/and with intermittent catheterisation, using residual bladder volume to guide management. With careful design, a series of patients studied with a cross-over design could make a useful contribution to future reviews prepared on this topic and be available long before any RCT - which would require large numbers due to the hetrogeneous patient population. The reasonable certainty is that a low or zero residual urine in neurogenic bladders is a desirable objective. The uncertainty over management is greatest when this cannot be achieved. 1. P Dasgupta, C Haslam, R Goodwin, and CJ Fowler.The 'Queen Square bladder stimulator': a device for assisting emptying of the neurogenic bladder. Br J Urol, 1997;80(2): 234-7. 2. Hunt GM, Oakeshott P, Whitaker RH. Intermittent catheterisation: simple, safe, and effective but underused. BMJ 1996;312:103-107 Competing interests: I import and distribute the Queen's Square Stimulator and other Malem devices in Australia.