Both interstitial cystitis/bladder pain syndrome (IC/BPS) and bladder outlet dysfunction (BOD) are common urinary disorders. A prior study demonstrated that approximate half of patients with IC/BPS had a coexisted BOD which may increase the severity of symptoms. However, the etiology of the coexisted BOD is not fully understood.
A recent online article of Neurourology and Urodynamics analyzed the etiology of BOD and related clinical and videourodynamic characteristics in 452 female patients with IC/BPS. In it, Dr. Kuo and his colleague found that the incidence of coexisted BOD was as high as 60.1%. In terms of the specific etiology, poor relaxation of the external urethral sphincter is the most common condition, accounting for 48.3% of patients, followed by dysfunctional voiding and bladder neck dysfunction based on the videourodynamic finding. In addition, authors further established a predictive cut-off value of Qmax ≦ 11 ml/s for BOD, with a sensitivity of 82.0% and specificity of 68.5%, in IC/BPS patients.
Although the causal relationship between BOD and IC/BPS is unclear, the high occurrence rate of BOD in IC/BPS patients may suggest a potential link between the two conditions. On one hand, long term BOD can cause the increase of detrusor collagen fibers and consequently induce detrusor overactivity which may exacerbate symptoms of IC/BPS. On the other hand, bladder inflammation may bring about the spasm of pelvic floor muscle and external urethral sphincter, resulting in BOD.
Since the diagnosis of female BOD remains a big issue and no universally accepted definition is available, the established cut off value from the study allows physicians and specialists to identify BOD in IC/BPS patients in an easy way.
Kuo YC, Kuo HC. Videourodynamic characteristics of interstitial cystitis/bladder pain syndrome-The role of bladder outlet dysfunction in the pathophysiology. Neurourol Urodyn. 2018 Mar 5. Epub ahead of print.
Article by Ran Pang on behalf of the Publications and Communications Committee