To assess intralevator botulinum toxin type A (Botox) injections for refractory myofascial pelvic pain with short tight pelvic floor.
Retrospective cohort study of all women with intralevator Botox injection (100–300 Units) from 2005 through 2010 for refractory myofascial pelvic pain. Primary outcomes were self-reported pain on palpation and symptom improvement. Secondary outcomes included postinjection complications and a second injection. Pain was assessed during digital palpation of the pelvic floor muscles using a scale of 0 to 10, with 10 being the worst possible pain. Follow-up occurred at less than 6 weeks after injection and again at 6 weeks or more. Data are presented as median (interquartile range) or proportion.
Thirty-one patients met eligibility criteria; 2 patients were lostto follow-up and excluded. The median age was 55.0 years (38.0–62.0 years). Before Botox injection, the median pain score was 9.5 (8.0–10.0). Twenty-nine patients (93.5%) returned for the first follow-up visit; 79.3% reported improvement in pain, whereas 20.7% reported no improvement. The median pain with levator palpation was significantly lower than before injection (P<0.0001). Eighteen women (58.0%) had a second follow-up visit with a median pain score that remained lower than before injection (P<0.0001). Fifteen (51.7%) women elected to have a second Botox injection; the median time to the second injection was 4.0 months (3.0–7.0 months). Three (10.3%) women developed de novo urinary retention, 2 patients (6.9%) reported fecal incontinence, and 3 patients (10.3%) reported constipation and/or rectal pain; all adverse effects resolved spontaneously.
Intralevator injection of Botox demonstrates effectiveness in women with refractory myofascial pelvic pain with few self-limiting adverse effects.