Intradetrusor Botulinum Toxin A for OAB Via 1 Versus 10 Injections: A Randomized Clinical Trial

Intradetrusor (bladder) Botulinum toxin A (BTA or Botox®) is a well-established treatment for urinary urgency incontinence (UUI).[1,2] While this treatment's efficacy in comparison to alternative therapies including anticholinergic medications and sacral neuromodulation for treatment of UUI has been studied, the ideal number of injection sites within the bladder has not been well established. [3,4] Intradetrusor BTA injections are often completed as an office procedure while the patient is awake. Each injection site can cause discomfort for the patient during the procedure. Urinary tract infection and urinary retention are risks associated with this procedure and could potentially be related to number of injection sites. Currently, there is a lack of information in the literature regarding the optimal number of intravesical BTA injection sites.

Prior studies evaluated efficacy using 100u BTA spread across 20 injections sites, however current practices at local institutions safely use 10 injections sites based on studies showing similar effect and adverse event profiles between use of 10, 20, and 40 injection sites.[5,6] Research using animal models has shown diffuse distribution of BTA within the entire detrusor muscle after just a single BTA injection at one site.[7] This has been corroborated in human studies.[8] A recently published observational pilot study shows promise for single site intradetrusor Botox® injection as it reported a lower rate of urinary retention and similar durability.[9] Similar clinical efficacy with only one to three intravesical BTA injection[s] has also been reported.[10]

In this study, participants will be randomized to receive 100u BTA via intradetrusor injection at one injection site (experimental) versus 10 injection sites (control). Investigators hypothesize that one injection will have similar efficacy to multiple injections and potentially better tolerability and patient satisfaction, due to decreased procedure time and less pain, along with potential for lower adverse event rates, specifically urinary retention and urinary tract infections.

Inclusion criteria

• Female
• 18 years old or greater
• Diagnosis of overactive bladder (urinary urgency or frequency, OAB) or urinary urgency incontinence (UUI)

Exclusion criteria

• Have a diagnosis of neurogenic bladder
• Received intravesical botox injections within prior 6 months
• Current treatment with either: SNM, PTNS, or OAB medications - need wash out as below
• SNM - turn device off for at least 2 weeks prior to procedure, off during 3-month follow up window
• PTNS - no treatments within 2 weeks of start, none during 3-month post-procedure follow up window
• OAB meds - 2 week wash out period prior to injection, none during 3-month post-procedure follow up window
• Currently pregnant or trying to get pregnant
• Contraindications to Botox® - hypersensitivity to Botox®, inability to self-catheterize/refusal to have indwelling catheter
• Have a UTI (can enroll after treatment)
• Have urinary retention (PVR>150cc on two occasions)
• Do not speak English or Spanish