RESUMEN
INTRODUCTION AND HYPOTHESIS: There is significant variability in technique for cystodistension and an international discrepancy in the role in its treatment of bladder pain syndrome (BPS). The authors evaluate the evidence base for the use of cystodistension for BPS with particular reference to patient-related outcomes. METHODS: In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analysis statement, a prospective search and evaluation protocol was prepared and registered with the PROSPERO database (ID CRD42017053710). A review of the literature was performed using the search terms cystodistension and hydrodistension of the bladder using the PubMed database on 6 October 2016. RESULTS: A total of 59 papers were reviewed, but only 17 studies contained original data available for analysis from 1975 to 2016. Ten studies evaluated the outcome of cystodistension in a single arm design or used cystodistension as the control for evaluating adjunctive treatments. Seven studies evaluated cystodistension in combination with other agents or therapies. The best symptomatic responses reported a subjective improvement in 56% of men with moderate to severe prostatitis and 57% in patients with "inflammatory cystitis" respectively. There were no studies that employed a validated outcome measure, neither a questionnaire nor an analogue scale, to assess the effect of cystodistension alone. CONCLUSIONS: Cystodistension is increasingly popular, despite a weak evidence base by current standards. The quality of available evidence falls below the level that would be expected of a new intervention. This review highlights the need for cystodistension to be further investigated with randomised control trials.