Botulinum Toxin Injections for Neurogenic Detrusor Overactivity Technique

Updated: Mar 06, 2019
  • Author: Pamela I Ellsworth, MD; Chief Editor: Edward David Kim, MD, FACS  more...
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Approach Consideration

Intradetrusor injection of botulinum toxin A may be performed via rigid or flexible cystoscopy, depending on the urologist’s preference and the patient’s sensory level. Before injections are initiated, the injection needle should be filled (primed) with approximately 1 mL of reconstituted onabotulinumtoxinA to remove any air (the exact volume will depend on the needle used). Sufficient saline should be instilled into the bladder to achieve adequate visualization for the injections, but overdistention should be avoided.

The needle is inserted into the detrusor muscle to a depth of approximately 2 mm. A total of 30 injections (each containing 1 mL, or approximately 67 U of botulinum toxin A), equally spaced about 1 cm apart, are made into the dome, posterior, and right and left lateral walls of the bladder; the trigone is spared (see the image below). The bladder is then emptied, and the patient is observed for at least 30 minutes after injection.

Injection sites using minimally invasive outpatien Injection sites using minimally invasive outpatient technique. Flexible cystoscope with superfine 27-gauge disposable needle is used to inject onabotulinumtoxinA (BOTOX; Allergan, Irvine, CA) into bladder while avoiding trigone. At equally spaced points, 30 distinct injections, each containing 1 mL, are introduced

Kuo described a suburothelial technique that uses a rigid cystoscope and a 23-gauge injection needle. [2] In this approach, the needle is inserted into the submucosal space, and the botulinum toxin A solution is injected to form a ballooning of the bladder mucosa.

Reinjection may be performed when the clinical effect of the previous injection decreases, but no sooner than 12 weeks after the preceding bladder injection.



In 3 randomized, controlled trials, the most common adverse event (AE) of intradetrusor injection of botulinum toxin A was increased postvoid residual, which may necessitate clean intermittent catheterization. Thus, patients should be counseled about the potential need for clean intermittent self-catheterization (CIC).

A placebo-controlled study reported that the overall incidence of least 1 AE in treated patients was not significantly different from that in the placebo group. [4] The more frequently reported AEs across the studies were urinary tract infection and mild hematuria.

A dose-ranging study including both neurogenic detrusor overactivity (NDO) and idiopathic detrusor overactivity (IDO) patients reported that patients who received 100 U of botulinum toxin A had a significantly smaller postvoid residual urine volume than patients who received 150 U or 100 U at 1 month. [2] One study reported a mild case of asthenia after injection of botulinum toxin A 300 U, which persisted for 10 days. [5]