Botulinum Toxin A (Botox) in Tissue Expander Breast Reconstruction
Status:
Completed
Trial end date:
2017-07-18
Target enrollment:
Participant gender:
Summary
Each year, the number of breast cancer survivors who choose post-mastectomy breast
reconstruction keeps rising. Among women who elect to pursue breast reconstruction,
approximately 75% will choose prosthetic breast reconstruction. Implant-based breast
reconstruction is frequently achieved in two-stages. The first stage consists of the
placement of a tissue expander after mastectomy. This is followed by a period of biweekly
tissue expansions that can last several months. In the second stage, the tissue expander is
removed in a surgical procedure and replaced with a permanent breast implant. Tissue
expansion is a well-established breast reconstruction technique characterized by high success
rates and high patient satisfaction. Despite the well-recognized advantages of this
successful breast reconstruction technique, the subpectoral placement of a tissue expander is
associated with significant pain and discomfort in the immediate post-operative period and
during the phase of tissue expansion. Pectoralis major muscle spasm is a frequently reported
problem during tissue expansion. Legeby et al. recently showed that women who underwent
prosthetic breast reconstruction had higher pain scores and took more analgesics that those
who did not choose post-mastectomy reconstruction.
In the past 10 years, publications on the use of botulinum toxin A (BTX-A) for pain relief in
a wide array of clinical conditions have increased tremendously. BTX-A is one of the
neurotoxins produced by Clostridium botulinum bacteria. By reversibly inhibiting
neurotransmitter release, BTX-A has both analgesic and paralytic properties. The analgesic
action of BTX-A was initially thought to be related to its effects on muscular contraction.
However, a recent in vitro study of embryonic rat dorsal neurons did confirm that BTX-A
inhibits release of substance P, a neurotransmitter associated with pain and inflammatory
reactions. The presence of analgesic properties of BTX-A is increasingly supported by several
clinical observations: pain relief with BTX-A injections has been reported for migraine
headaches, chronic pelvic, chronic tennis elbow, and post-operative pain control for lower
limb lengthening correction, among others.
This aspect has never been studied in breast cancer survivors who elect to pursue breast
reconstruction with tissue expanders. Furthermore, physical function outcomes are important
to consider with BTX-A use because the link between temporary muscle paralysis and
improvements in participation in daily activities is not a given.
The investigators propose to complete a double-blinded prospective randomized controlled
trial of women undergoing unilateral and bilateral mastectomies with immediate placement of
tissue expanders, to establish the efficacy and safety of BTX-A in alleviating pain and in
improving physical well-being during the expansion period.
Phase:
Phase 3
Details
Lead Sponsor:
Mayo Clinic
Collaborator:
Allergan
Treatments:
abobotulinumtoxinA Botulinum Toxins Botulinum Toxins, Type A incobotulinumtoxinA onabotulinumtoxinA