Background: Tissue expander placement is a common means of reconstruction after mastectomy. Many patients report significant pain and discomfort with the tissue expansion process. Because placement is subpectoral, it was hypothesized that injection of the pectoralis muscle with botulinum toxin could decrease pain associated with tissue expanders.
Methods: A prospective, randomized, double-blinded controlled trial was used to evaluate the effects of intraoperative injection of 100 U of botulinum toxin into the pectoralis muscle on one side versus placebo on the contralateral side during immediate tissue expander reconstruction after bilateral mastectomy. Patients were enrolled in the study between October 2009 and February 2012. Preoperative and postoperative pain scores, number and volume of tissue expansion, and complications were recorded. The paired t test was used to compare preoperative to postoperative changes in pain between the botulinum toxin and placebo injections.
Results: Twenty-three patients were enrolled in the trial. There was no statistically significant difference between preoperative to postoperative changes in the pain scores on the botulinum toxin side compared to the control side at any time point postoperatively. All pain scores trended to zero over time.
Conclusions: Intraoperative injection of the pectoralis muscle with botulinum toxin is not an effective method to improve pain control in tissue expander reconstruction.