Avaliação dos efeitos do implante de silicone sobre o parênquima mamário e a musculatura peitoral maior

Abstract

Besides being a procedure with high level of patient s satisfaction, one of the main causes for reoperation after the procedure are related to contour deformities and changes in breast volume. Few objective data are available on postoperative volumetric analysis following breast augmentation. Breast parenchyma suffers microvascular changes when under mechanical compression, however, the muscle tissue is more susceptible to damage when subjected to pressure than other tissues, with little tolerance to mechanical compression. The aim of this study was to evaluate volume changes in the breast parenchyma and pectoralis major muscle after breast augmentation with the placement of silicone implants in the subglandular and submuscular planes. Fifty-eight women were randomly allocated either to the subglandular group (n = 24) or submuscular group (n = 24) and underwent breast augmentation in the subglandular or submuscular plane, respectively, or control group (n = 10) and received no intervention. Patients in the subglandular group performed volumetric analysis of the mammary gland and patients of submuscular and control groups, besides breast volumetry, also made pectoralis major muscle volumetry. Volumetric evaluation was performed preoperatively and on postoperative of six and twelve months through magnetic resonance. Only the submuscular group underwent assessment of muscle strength, through isokinetic testing, preoperatively and postoperative of three, six and 12 months. All patients were under oral contraceptive use and patients on the submuscular group remained away from physical activities for a period of two months postoperative. Twelve months after breast augmentation, only the subglandular group had a significant reduction in glandular volume (mean, 22.8%), while patients in the submuscular group showed significant reduction in muscle volume (mean, 49.80%). Isokinetic test showed muscle strength decrease in aduction, with no correlation with loss in volume. There was no muscle strength decrease in abduction. We concluded that subglandular breast augmentation causes breast parenchyma athropy, but not submuscular breast augmentation. In contrast, submuscular breast augmentation caused atrophy of the pectoralis major muscle, and reduction in muscle straight in aduction, after 12 months post operative that cannot be correlated with muscle atrophy and is probably related to the pectoralis major muscle detachment from its abdominal origin.