Interstitial cystitis/bladder pain syndrome (IC/BPS) is currently defined as persistent or recurrent chronic pelvic pain, pressure or discomfort perceived to be related to the urinary bladder accompanied by at least one other urinary symptom such as an urgent need to void or urinary frequency according to ICS guideline. IC/BPS is a chronic disorder that has a significant negative impact on quality of life. Hydrodistention has been applied as a diagnostic and therapeutic tool in IC/BPS patients. Previous studies demonstrated effectiveness of bladder hydrodistention in the treatment of IC/BPS. However, reported outcomes of hydrodistention for IC/BPS have various response rates making it difficult to standardize its clinical utility. We aim to better characterize clinical features involved in the symptomatic response to bladder hydrodistention. Therefore, we investigate the relationship between bladder capacity under anesthesia and treatment effectiveness in patients with IC/BPS who had undergone therapeutic bladder hydrodistention.

We retrospectively reviewed medical records of female patients diagnosed with non-ulcerative IC/BPS who underwent bladder hydrodistention. Preoperative assessment with detailed history and physical examination were also documented. All patients received preoperative assessment with 3-day voiding diaries and videourodynamic study. Patients were excluded from study if they had a history of bladder, vaginal, uterine or ovarian cancer, spinal cord injury, or ketamine abuse. The O ́Leary – Sant Interstitial Cystitis Symptom Index (ICSI) and Interstitial Cystitis Problem Index (ICPI) questionnaires were administered to all patients prior to and one month after hydrodistention. Bladder capacity was measured during bladder hydrodistension under general anesthesia and large anesthetic bladder capacity was defined as a bladder volume of more than 650 ml.

Of 75 IC/BPS female patients enrolled in this study, mean age was 47.0 years (range 22 to 82). 33 (44%) patients were compatible with large anesthetic bladder capacity and 42 (56%) patients had small anesthetic bladder capacity. The evaluation of the individual items of the ICSI/ICPI questionnaires demonstrated that the improvement of subscore for bladder pain symptom (ICSI-Q4 : Have you experienced pain or burning in your bladder ?) after hydrodistention was significantly higher in patients with large anesthetic bladder capacity than those without (p = 0.04). The other subscores and total scores of the ICSI/ICPI questionnaires did not differ between the two groups. Patients with large anesthetic bladder capacity also had significantly larger median ± SE maximal voided volume recorded in the voiding diaries (265 ± 94.1 mL vs 200 ± 61.8 mL, p = 0.03). However, there was no significant difference in cystometric capacity between the patients with large anesthetic bladder capacity and those without. Similarly, the rate of positive KCL tests were not different between the two groups (84.6% vs 93.3%, p=0.4).

The present study retrospectively analyzed 75 female patients with non-ulcerative IC/BPS who underwent bladder hydrodistention. In the preoperative evaluation, Patients with large anesthetic bladder capacity (>650 ml) had larger maximal voided volume in 3-day voiding diaries. In the videourodynamic study, we found that there was no difference in cystometric capacity and the rate of positive KCL test between two groups. Compared ICSI/ICPI questionnaires prior to and one month after hydrodistention, the improvement of subscore for bladder pain symptom (ICSI-Q4) was significantly higher in patients with large anesthetic bladder capacity. The other subscores and total scores of the ICSI/ICPI questionnaires did not differ between the two groups. Large anesthetic bladder capacity is predictive of better response to hydrodistention in IC/BPS patients, especially improvement of pain or burning sensation.

The results of the present study suggest that hydrodistention is an effective treatment in patients suffering from IC/BPS. Patients with large anesthetic bladder capacity (>650 ml) are more likely to have bladder pain relief with hydrodistention alone.