Correlates of Positive Response to Therapeutic Hydrodistension in Interstitial Cystitis/Bladder Pain Syndrome

The objective of this study was to assess the duration and clinical correlates of positive response in interstitial cystitis/bladder pain syndrome patients undergoing therapeutic bladder hydrodistension (HOD) or HOD with electrofulguration (for those with Hunner lesions).

One hundred and twenty four women were enrolled in this prospective IRB-approved study. Participants answered a set of validated questionnaires at intake including chronic overlapping pain conditions (COPCs), brief pain index (BPI), and IC/BPS symptomatic questionnaires. These were repeated at 1, 2-, 3-, 6-, and 12-months posttreatment, together with a global response assessment (GRA). The primary outcome measure was the GRA score. A secondary analysis of patients who were strong responders to treatment was used to identify clinical correlates of positive response.

At 1-month post-HOD, 62 patients (53.9%) were responders (i.e., reported persistent positive response to treatment). Further, 21/49 (42.9%) respondents continued to report a positive response at 12 months. Logistic regression analyses identified several correlates of strong response to therapy including absence of Huynner lesions (odds ratio (OR) = 3.629), lack of diagnosis of fibromyalgia (OR = 0.31), lower number of total sites of pain on BPI pain map (OR = 0.91), fewer total number of COPCs (OR = 0.36), and lower complex medical symptom inventory scale (CMSI; OR = 0.91). After false discovery rate correction, only the CMSI remained statistically significant.

Therapeutic hydrodistension results in a clinically meaningful and sustained improvement in associated symptoms and pain for many patients. However, having higher scores on markers of a widespread pain/non-bladder centric phenotype was associated with a lower treatment success rate.