What is intrinsic sphincter deficiency (ISD) and its treatment?

• A. ISD is poor urethral closure independent of support; may require bulking agents, urethral inserts, pessaries, or sling with careful consideration.
• B. ISD is caused by bladder overactivity in all patients.
• C. ISD is worsened by pelvic floor strengthening.
• D. ISD is only seen after pelvic organ prolapse repair.

Answer: (A)

Intrinsic sphincter deficiency means the urethral sphincter itself isn’t able to close adequately, so continence isn’t about supporting structures but about the sphincter’s closing pressure being too low. Treatments focus on increasing urethral closure or providing mechanical support to the urethra: bulking agents raise the urethral walls to improve coaptation, urethral inserts act as spacers to prevent leakage, pessaries can support the pelvic area to improve urethral resistance, and a sling may be considered in some cases but requires careful selection because it relies on the surrounding tissues for closure and can carry risks like retention. The other statements aren’t correct because ISD isn’t caused by bladder overactivity (that’s detrusor overactivity), pelvic floor strengthening doesn’t worsen ISD in a predictable way and isn’t the primary fix, and ISD is not limited to occurring after prolapse repair.