Small case series suggests botulinum toxin affords major pain relief in endometriosis.(Gynecology)

TORONTO -- Patients with endometriosis that is unresponsive to surgical and medical treatment may get relief from intravaginal injections with botulinum toxin, according to a case series from the National Institutes of Health.

"We saw an impressive period of relief beyond what we would expect," said Dr. Melissa Merideth, an ob.gyn. with the Office of Rare Diseases at the National Human Genome Research Institute, an arm of the National Institutes of Health.

The study, which she reported in a poster at the annual meeting of the Society for Gynecologic Investigation, involved three women with chronic pelvic pain that persisted after laparoscopic excision of their endometriosis. Upon physical examination, all the women had palpable spasm of their pelvic floor muscles, Dr. Merideth said in an interview.

Because botulinum toxin relaxes muscle spasm and has been effective in the treatment of headache and myofascial pain, her group decided to test its effect on pelvic floor muscle spasm, she said.

"We felt the pelvic floor spasm was a component of their pain, and we wanted to see how addressing that would affect their other pain symptoms," she said.

Working in an office setting in conjunction with a neurologist, a gynecologist injected a total dose of 100 U of botulinum type A toxin (reconstituted with 4 cc of preservative-free saline) trans-vaginally into between three and six injection sites in the women's levator ani musclesat sites of palpable spasm. The women were premedicated with Valium and the procedure was done using electromyorgraphic guidance and lidocaine cream at each injection site. Five ...