In her February article on interstitial cystitis (“The generalist’s guide to interstitial cystitis”), Dr. Christine LaSala called cystoscopy with hydrodistention the “gold standard” for diagnosis, but also observed that “the need for this procedure is under debate.” She does mention the potassium sensitivity test, but her remarks about it are slightly negative, despite the fact that it had only a 4% false-positive rate among controls in the study she cited.1
Many sources now consider cystoscopy with hydrodistention the previous gold standard and point out that it is of limited benefit or uncommonly used. How do you explain this discrepancy?
Mark Tomsho, MD
- Parsons CL, Dell J, Stanford EJ, Bullen M, Kahn BS, Willems JJ. The prevalence of interstitial cystitis in gynecologic patients with pelvic pain, as detected by intravesical potassium sensitivity. Am J Obstet Gynecol. 2002;187:1395-1400.
Dr. LaSala responds:
Potassium sensitivity test hurts—a lot!
Cystoscopy with hydrodistention under anesthesia remains a viable option in diagnosing interstitial cystitis. It rules out an intravesical source for irritative bladder symptoms (eg, neoplasms, foreign bodies). if a generalist’s office is unable to perform the potassium sensitivity test (due to staffing or reimbursement problems), cystoscopy under hydrodistention is reasonable.
Frankly, the potassium sensitivity test can be quite uncomfortable for the woman and can make for a very angry and upset patient. I’ve experienced an angry reaction a couple of times, which is why I choose not to do the test in my office. It isn’t fair to warn a patient that it may hurt a lot, and then hurt her!
I also feel that a picture “paints a thousand words,” and I find it very helpful for the patient and her family or partner to actually see what an affected bladder looks like. It may help her justify the painful or aggravating symptoms she has experienced.
My point: Although cystoscopy under anesthesia may be controversial in some quarters, it is acceptable and valuable. I choose to perform it on almost all my patients.