Hydrodistention, in simple terms, is the overfilling of the bladder
with water. Physicians perform hydrodistention for various reasons,
including determining a patients bladder capacity, and "stretching" the
bladder walls so that they may be closely examined for hemorrhages, a
hallmark of IC. Hydrodistention in and of itself may reduce the pain and
discomfort of IC and therefore is diagnostic as well as therapeutic.
Once the cystoscopic examination has been performed and urine obtained
for cytologic study, the bladder is distended. Many IC patients report
improvement for 3 to 6 months, and the procedure may be repeated.
How Does Hydrodistention Work?
Hydrodistention was first advocated for use in the management of IC in
1930. It is believed that the distention of the bladder wall produces a
type of sensory denervation, providing temporary abatement of pain.
Also, it may stimulate production of bladder surface mucin to further
protect the bladder wall. Hydrodistention is performed by filling the
patients bladder to 80 cm water pressure for 8 minutes, at which point
the bladder is drained and re-filled. A portion of the effluent is often
blood-tinged. Re-inspection of the bladder will reveal the pin-point
hemorrhages (the hallmark finding in IC patients) that develop
throughout the bladder after distention.