Commentary on: Evaluation of the Effects of Silicone Implants on the Breast Parenchyma

This paper evaluates the changes in parenchyma volume after breast augmentation in a group of 23 patients who had subglandular implants and a control group of 10 patients without augmentation.¹ Breast volume was evaluated by magnetic resonance imaging (MRI) preoperatively, and at 6 months and 12 months postoperatively. The authors note that the breast volume decreased by a mean of 22% at 12 months and they state that the compression of the implant on the parenchyma may have caused atrophy from vascular compression and reduced blood flow.

My concerns are with both the accuracy of the technology and the idea that compression of an average-sized implant could actually cause decreased blood flow and atrophy of the breast parenchyma. Was the breast tissue just stretched like a thick elastic band and because it was spread out over the implant, was it somehow not incorporated or measured in the MRI?

The implants used were high-profile, textured (Silimed Maximum, Rio de Janeiro, Brazil) implants ranging between 225 to 335 mL placed in subglandular pockets.

The authors are to be praised in being careful to control variables by making sure that measurements were performed in each patient at the same time of the menses cycle and that patients were weighed each time to make sure that volume changes were not due to weight gain or loss. The authors were also careful to make sure that the same radiologist performed all the exams to avoid variation in the assessments.

Unfortunately, the technology may not be good enough to draw such conclusions. The authors of the current paper claim that 3-dimensional (3D) MRI images are accurate, but the reference articles showed significant spread in the actual numbers.^2,3 The authors of the current paper do not provide their actual numbers so we cannot determine the spread in the measurements. The scatter plots in Figure 3 of the most recent reference³ show significant variability between mastectomy specimen weights and MRI. This brings into question the accuracy of reaching any conclusions based on MRI volume measurements.

MRI images are taken with patients lying prone. The textured implants used in this study cause adherence between the implant and the surrounding tissue but the adherence also occurs between the implant and the chest wall, preventing the normal breast slide. Breasts are normally only loosely attached to the chest wall and one wonders whether the textured implants prevented some breast volume from being seen in the MRI. In an examination that is performed with the patient lying prone, the breast falls away from the chest wall.

The authors do state that the particular MRI used can take axial slices to make sure that all the parenchyma is included. Unfortunately, I do not think we have strongly accurate measurement systems, although they are improving. My experience, for example, with 3D photographic imaging is that the measurements are quite variable each time the software uses its own default landmarks. Although I have been told that “the data is the data”⁴ I cannot help believe that some data is still bad data. It all depends on the quality of the data that is entered and not just the software doing the analysis. I am not sure that we have technology that is accurate enough to make these conclusions.

It is a bit far-fetched to speculate that pressure from an implant causes decreased blood flow and therefore tissue atrophy. The human body can tolerate a significant amount of pressure before permanent changes occur. This paper is very interesting and further studies would be warranted, but the explanation of the results may instead lie within the limitations of the current technology.

At the present stage, I can only go by my clinical experience, which has shown that breasts tend to revert close to their original size as long as the implants were not overly large.

It would be ideal if we were able to measure breast volume with MRI before and after breast augmentation and again after implant removal. This of course would be difficult because numbers would be low but the authors might consider performing 3D MRIs on any future patients who ask for removal.

I would like to congratulate the authors on an interesting study that definitely has future potential. Although I do not believe that much of our technology is quite as accurate yet as we would like, papers such as this are helping us to advance our knowledge and understanding.

Disclosures

The author declared no potential conflicts of interest with respect to the research, authorship, and publication of this article.

Funding

The author received no financial support for the research, authorship, and publication of this article.

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