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

Overview

Patients with either overactive bladder (OAB) or urgency urinary incontinence (UUI) with be randomized (like a flip of a coin) to receive 100 units of bladder Botox® at either one injection site or ten injection sites. Efficacy and patient satisfaction will be measured by questionnaires.

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.