Onabotulinumtoxin A Injections for patients with pelvic floor dysfunction.

Objective: To review the current literature surrounding onabotulinum toxin A injections for patients with pelvic floor dysfunction and to demonstrate how to perform these injections.

Setting: Academic tertiary care hospital PARTICIPANTS: It is estimated that about 50-90% of patients with chronic pelvic pain have pain that originates from myofascial sources, including the pelvic floor muscles. In patients with pelvic floor dysfunction, management consists of pelvic floor physical therapy with the addition of pelvic floor trigger point injections with a local anesthetic as needed. We offer onabotulinum toxin A to individuals who require long-term repeat trigger point injections, have barriers to accessing monthly injections, or show no durable improvement.

Intervention: We demonstrate a comprehensive pelvic floor exam and techniques for administration of onabotulinum toxin A into pelvic floor muscles in individuals with pelvic floor dysfunction, as well as a demonstration on a live patient. We perform an exam while the patient is awake, either in clinic or at the time of the procedure, and examine the pubococcygeus, iliococcygeus, and obturator internus muscles to assess for hypertonicity and tenderness to palpation. Once sedation is initiated, 200 units of onabotulinum toxin A is then reconstituted with 20 mL of normal saline. The pudendal nerve kit allows for 1cm depth of penetration with the needle. Approximately 1-2 mL of onabotulinumtoxin A are injected sequentially in multiple locations along the above-mentioned pelvic floor muscles. Medication effects may last up to 3-6 months, with a reduction in pain scores starting at 6 weeks and lasting through 12 weeks based on published literature. Adverse effects may include constipation, urinary incontinence, urinary tract infections, fecal incontinence, or urinary retention.

Conclusions: Onabotulinumtoxin A may be helpful in patients with refractory pelvic floor dysfunction. We demonstrate how to perform these injections with a safe and reproducible technique.