Botulinum Toxin A in Tissue Expander Breast Reconstruction: A Double-blinded Randomized Controlled Trial.

[UNLABELLED] Subpectoral tissue expander breast reconstruction is often associated with muscle spasms, pain, and discomfort during tissue expansion. In this study, we hypothesized that an intraoperative injection of botulinum toxin A (BTX-A) in the pectoralis major muscle reduces the pain associated with tissue expansion and improves women's physical well-being.

[METHODS] Between May 2012 and May 2017, women undergoing immediate subpectoral tissue expander breast reconstruction were randomized to administer 100 units of BTX-A or a placebo injection. A numeric pain intensity scale and the physical well-being scale of the BREAST-Q: Reconstruction Module were used to test our hypothesis. Data on postoperative oral narcotic consumption were not collected.

[RESULTS] Of the 131 women included in the analysis, 48% were randomized to placebo and 52% to BTX-A. The preoperative median pain intensity score was 0 [interquartile range (IQR), 0-1], and the median preoperative BREAST-Q score was 91 (IQR, 81-100). The median slopes for the change in pain intensity scores from baseline throughout tissue expansion for those randomized to placebo and BTX-A were -0.01 (IQR, -0.02 to 0.00) and -0.01 (IQR, -0.02 to 0.00), respectively ( = 0.55). The median slopes for the change in BREAST-Q scores from baseline throughout tissue expansion for those randomized to placebo and BTX-A were 0.04 (IQR, -0.17 to 0.14) and 0.02 (IQR, -0.06 to 0.13), respectively ( = 0.89).

[CONCLUSION] In this study, we found that an intraoperative intramuscular injection of 100 units of BTX-A in the pectoralis major muscle did not reduce postoperative pain and patient-reported physical well-being when compared with placebo.