The preservation of minor pectoralis muscle in axillary dissection for breast cancer: functional and cosmetic evaluation.

We have evaluated, in two groups of 50 patients each submitted to axillary dissection for breast cancer (10 mastectomies and 90 conservative procedures), the advantage of the preservation of the minor pectoralis muscle. This muscle was preserved in one group and removed in the other. Whereas in the immediate postoperative period complications (shoulder pain, functional impairment, quantity or duration of serum drainage from the axilla) were the same in the two groups, at longer follow-up (more than 6 months after surgery) the patients whose pectoralis minor muscle was preserved showed a reduction in the incidence of partial atrophy and fibrosis of the pectoralis major muscle. Patients treated with conservation of the pectoralis minor muscle showed this atrophy in 6% of cases vs 54% observed in the other patients. This fact may be related to disruption of the pectoral nerves, which are in close contact with the pectoralis minor during their course from the brachial plexus to the pectoralis major muscle.