EDITORIAL COMMENT

Sacral neuromodulation (SNM) is recommended as a treatment option if conservative treatments either fail or lead to adverse events in patients with overactive bladder syndrome or non-obstructive urinary retention. Treatment success of these storage and voiding dysfunctions is evaluated in terms of improvement in micturition diaries, subjective patient evaluation, quality of life scores and symptom score questionnaires. In addition, treatment success in bladder dysfunctions is also evaluated with conventional urodynamic studies (UDS) and ambulatory UDS. This year, Drossaerts et al. have investigated 98 patients with lower urinary tract symptoms who underwent ambulatory UDS. All patients were already treated with SNM therapy. Success rate of SNM in patients with storage dysfunction was 70%, according to either conventional UDS or ambulatory UDS diagnosis. Based on conventional UDS, success rate of SNM in patients with hypocontractility was 67%, and in acontractile patients, 35%. According to ambulatory UDS diagnosis, success rates were 32% and 17%, respectively. The authors concluded that, in patients with storage dysfunction, conventional UDS predict the SNM treatment success as good as ambulatory UDS. However, conventional UDS overestimates the amount of patients diagnosed with hypocontractile or acontractile bladder. Thus, conventional UDS do not predict treatment success failure in those cases. In my opinion, as the authors emphasized in the paper, the recording of a detrusor contraction can easily be detected via ambulatory UDS, although it is not validated yet. An acontractile or hypocontractile bladder confirmed on ambulatory UDS is therefore definitely more reliable to be a real acontractile/hypocontractile bladder. For this reason, ambulatory UDS rather than conventional UDS should be preferred in the diagnosis of acontractile bladder. By this way, detrusor contractility dynamics might better be identified. In the next step, when we diagnosed acontractile/hypocontractile bladders via ambulatory UDS, we should not prefer SNM therapy as a treatment option. Because, as we see in the current study, success rates of 32% and 17% show treatment failure.