Study design, materials and methods
Among 52 PBS/IC females who underwent HD, 32 patients who received the second HD due to symptom recurrence were included in the study. Clinical information of the patients such as age, duration suffered from the disease, preoperative functional bladder capacity (FBC), and the distended bladder volume during the first HD were investigated. Also, the period between the first and second HD and the volume difference between preoperative FBC and distended bladder volume during the first HD (ΔVolume_Bladder = Distended bladder volume during the first HD – Preoperative FBC) were calculated for the analysis. All investigated data were statistically analyzed by using simple and multiple linear regression test to find the factors affecting the period between the first and second HD in female PBS/IC patients.
Results
The mean values of age, duration of PBS/IC, preoperative FBC, and the distended bladder volume during the first HD are shown in the Table. The mean period between the first and second hydrodistension and the mean ΔVolume_Bladder was 9.63 ± 9.38 months and 273.50 ± 72.80 mL, respectively. Distended bladder volume during the first HD and ΔVolume_Bladder were the parameters that showed significant correlation with the period between the first and second HD (p = 0.003 and p <0.001, respectively) according to simple linear regression test. In multiple linear regression test, only ΔVolume_Bladder showed significant result with period between the first and second HD (p <0.001).
Interpretation of results
According to simple linear regression test, larger distended bladder volume during the first HD and ΔVolume_Bladder significantly elongated the period between the first and second HD. In multiple linear regression test, ΔVolume_Bladder was the only factor that significantly elongated the period between the first and second HD.