Videourodynamic characteristics of interstitial cystitis/bladder pain syndrome-The role of bladder outlet dysfunction in the pathophysiology

Abstract

Aims: To investigate the characteristics of videourodynamic study (VUDS) in females with interstitial cystitis/bladder pain syndrome (IC/BPS) focusing on the etiologies of bladder outlet dysfunction (BOD) and their associations with clinical and urodynamic parameters.

Methods: IC/BPS females with complete data on symptom assessment, VUDS, the potassium sensitivity test, and cystoscopic hydrodistention were reviewed retrospectively. Diagnoses of bladder dysfunction (hypersensitive bladder, HSB) and BOD including dysfunctional voiding (DV), poor relaxation of the external urethral sphincter (PRES), and bladder neck dysfunction (BND) were made by VUDS. The clinical and urodynamic parameters between patients with normal and abnormal VUDS diagnoses were analyzed.

Results: A total of 348 IC/BPS female patients (mean age 48.8 ± 13.5) were enrolled. HSB was found in 307 (88.2%) patients and BOD in 209 (60.1%). The causes of BOD included DV in 40 (11.5%), PRES in 168 (48.3%), and BND in 1 (0.3%). Patients with DV and BND had higher, and those with PRES had lower detrusor pressures at maximum flow rate (Q_max ) than those with normal tracings. For all BOD patients, univariate logistic regression revealed a significant positive correlation of disease duration and negative correlations of urodynamic volume parameters with BOD in IC/BPS patients. Multivariate logistic regression found a cut-off value of Q_max ≦ 11 mL/s predicted BOD in IC/BPS with a receiver operating characteristic area of 0.81 (sensitivity = 82.0%, specificity = 68.5%).

Conclusions: HSB and BOD are common findings on VUDS in IC/BPS females. BOD is associated with duration and hypersensitive bladder. A Q_max ≦ 11 mL/s predicts BOD in IC/BPS.

Keywords: bladder outlet dysfunction; interstitial cystitis; videourodynamic.