This is the filling of the bladder with fluid under anesthesia.
How is hydrodistention performed? The bladder is filled with sterile water until the fluid level starts backing up in the tubing. The bag is held 6-8 inch above the belly level to maintain a pressure head of 60-80 mm Hg. This maximal bladder capacity is noted and the bladder distention is held for 3 to 5 minutes. The bladder is then emptied and filled a second time. Sometimes, during the refill, Hunner ulcers (star-like scar tissue), petechial hemorrhages or glomerulations (significant redness) may be seen. A steroid may be injected under the Hunner’s ulcers.
How does hydrodistention work? Under anesthesia, the bladder is filled past the sensory threshold of the C fibers and this may reset the nerves. Also, the GAG layer of the bladder may regenerate and thereby insulate the C (pain) nerve fibers from getting exposed to the urine.
Who is a good candidate for hydrodistention? Though anyone could benefit from this, it is typically useful in women who have reduced bladder capacity as noted on the urinary voiding diaries. Therefore, it is very important to keep the urinary diaries.
How often does this need to be repeated? Individuals experiencing improvement in symptoms for greater than 6 months are candidates for repeat procedures.
What are the possible complications of this procedure? Complications are rare. Some patients may experience difficulty in emptying their bladder after this procedure and may need a catheter for a short time ( <1%). Rupture/tearing of the bladder is very rare and unlikely to happen at the low pressure distention that is now used for this procedure. We have never seen a bladder rupture.