Journal time for 2016! The January issue of Plastic and Reconstructive Surgery Journal had an article, “Volumetric Evaluation of the Mammary Gland and Pectoralis Major Muscle following Subglandular and Submuscular Breast Augmentation.” (Too much for early January to digest?) In English, they are looking at the thickness and volume of your natural tissue- your breast tissue and your muscle thickness- after we place breast implants.
I like the idea of this study. I describe to patients their natural breast tissue is like a comforter covering their implant. And just like the comforter on your bed, the thicker it is, the less you see and feel what is beneath it. And also just like your comforter, with time the thickness thins. This is why you don’t see wrinkles and ripples right after augmentation. It is frequently something seen years down the road, as the tissue has thinned.
STUDY: This was a prospective study of 58 women, where they were randomly placed in the subglandular group (implant in front of the muscle), or submuscular group. There was a control group who had no intervention. Volumetric MRI was done at 6 and 12 months after surgery. The volumes were checked at a specific time in the menstrual cycle (to avoid hormonal changes). All women were 18-30, BMI 19-25, and on contraceptives. Any women with history of pregnancy, breast feeding, obesity, smoking, cancer, and other factors were excluded. Implant volume ranged from 225-335.
FINDINGS: After one year,
- Only the sublandular group had reduction in breast volume (23%)
- Only the submuscular group had reduction in muscle volume (50%)
Looking at the data more in depth, at 6 months you see there was loss of breast volume in both groups, but the volume loss was 16.6% lower in the submuscular group. There was a regain in breast volume in both groups at 1 year, but the subglandular group still had statistically significant breast volume loss. Why see the loss at 6 months and then the volume regain by 1 year? They theorize the tissue accommodates, and the breast remodels. Why does it persist in the subglandular group? They theorize there is atrophy of the breast tissue due to direct vascular compression and reduced blood flow.
Looking at the muscle findings, they state muscle is more susceptible to injury when under constant pressure. They think there may be some atrophy of the muscle due to release of the muscle during implant insertion.
So what do I think?
I think it is interesting. There was a study which showed implant removal caused an increase in the volume of natural tissue as measured by the VECTRA 3D imaging system. That study indicated the pressure of the implant compressed the natural breast tissue, and the breast tissue expanded about 15% when the implant was removed. I don’t recall they differentiated between placement of the implant.
This study eliminated many variables. As with all things, there are other variables not identified. What was the profile of implant? thickness of overlying tissue? Every patient varies. A 300cc implant on a thin petite woman is not the same as a 300cc implant on a taller, more muscular woman. And the changes would not be the same.