Drs. Donfrancesco et al.1 report that their patients feel that three-dimensional simulation is very accurate. Notably, the authors themselves do not make this claim. Nevertheless, they promote this method as a revolutionary office tool. Is it time to invest in such a system?
Methodologic issues merit comment. The authors do not provide the number of patients selected for this analysis compared with the total number of breast augmentations performed. The time frame of the study is not reported either. What percentage of women did not return for follow-up photographs and surveys at 6 months? The inclusion rate (ideally ≥80 percent)2 is needed to determine whether the reported experience is likely to be representative of all patients. In comparing conversion rates, the authors reference a series of 151 consecutive patients consulted without this imaging method. This group would have served nicely as a control to assess any possible benefit in implant sizing. Why did the investigators forego this opportunity?
A crucial consideration is the measuring device.3 Instead of taking measurements, the authors survey a panel of plastic surgeons and nurses who compared nonstandardized photographs with simulations. These observers opined that the images were equivalent in only 18.7 percent of the cases studied. There were numerous dissimilar findings, reported in 36 categories, which the authors candidly enumerate.1 The simulations were particularly unreliable in predicting the appearance of the cleavage area.1 In 28.6 percent of cases, the simulations appeared better than the actual results, a liability that the authors recognize as a “challenge.” They incautiously (from a medicolegal perspective) comment that, in patients with suboptimal characteristics such as asymmetry and ptosis, the simulated image can appear “deceitfully good.”1 The authors claim that “seeing what the breasts will appear like with several types of implants” is a benefit, but they present no data comparing simulations by implant type (all were McGhan Style 410 implants).
Lack of accuracy of simulations is not surprising. The authors point out that “there exist no validated instruments at present designed to evaluate the similarity of three-dimensional images and the actual operated breasts that address specific mammometric parameters.” To correlate with actual breast shape changes after augmentation, a standardized measurement system with well-defined parameters is needed. Such a system is now available4 and has been used successfully in two-dimensional frontal and lateral renderings of breast measurement data.5 (Although the authors’ system uses a three-dimensional reconstruction, the images themselves are two-dimensional.) Next, real measurement data are needed.5 By entering this information, a database may be constructed and used to inform the simulations.
We know from measurements that the inframammary crease6 and lower pole level descend after breast augmentation.5 The breast area, upper pole projection, breast projection, and lower pole width increase; the nipple level is unchanged; and the areola width increases approximately 1 cm.5 The simulations show some of these changes, with magnitudes that differ from actual results, but not others (e.g., simulations do not depict areola widening) (Fig. 1).
Photographic standardization is mandatory. The postoperative photograph shown in the authors’ Figure 4 is 19 percent magnified compared with the simulation. These images may be easily matched for size and orientation using the basic measurement functions contained in the same Canfield software used by the investigators. When this difference is corrected, the simulated breast size appears larger than the actual postoperative breast size (Fig. 1). Ideally, the authors would also standardize arm positioning. It is difficult to exactly match the degree of rotation, making oblique images of less value.4 Lateral images, not used by the authors, are best for measuring breast area, breast projection, upper pole projection, and nipple level.4
The authors conclude1 that “if they could go back in time they [patients] would choose the same implant again.” However, 19 percent of their patients reported that they would have preferred a different implant size, usually larger, despite having undergone three-dimensional analysis. Other studies using preoperative breast measurements and bra inserts to gauge implant size report patient size dissatisfaction in the range of 16 to 20 percent.7,8 Evidently, the simulations do not improve the reliability of implant sizing.
Practical measures to improve the quality of evidence include (1) reporting the inclusion rate, (2) photographic standardization, (3) an objective measuring device,4 and (4) a control group.3 In fact, all of these desirable methodologies were available to these researchers and would have enabled a level II study with greater reliability and possibly different conclusions.
The authors conclude that three-dimensional imaging is a useful tool for improving their “conversion rate.” From a scientific standpoint, the conversion rate is irrelevant. Should plastic surgeons be encouraged to purchase tools that patients perceive as advantageous but are of no proven value? Three-dimensional imaging may be in our future (or maybe not if television broadcasting is any indication). If real patient data are entered with frontal and lateral references, it may be possible to develop a system that can truly simulate surgical changes and relate them to implant size (shape may be more of a challenge). If successful, such a system would improve on perceived value and represent a real advance. In the meantime, perhaps plastic surgeons are best advised to show patients actual before-and-after photographs of women with similar breast characteristics and candidly inform them that computer simulations cannot yet accurately predict surgical changes of the breasts, particularly when there is a degree of breast sagging, and their actual result is likely to differ from a simulation.
The author has no financial interest to declare in relation to the content of this communication. This study received no outside funding.
Eric Swanson, M.D.
11413 Ash Street
Leawood, Kan. 66211
1. Donfrancesco A, Montemurro P, Hedén P. Three-dimensional simulated images in breast augmentation surgery: An investigation of patients’ satisfaction and the correlation between prediction and actual outcome. Plast Reconstr Surg. 2013;132:810–822; discussion 823–825
2. Sackett DL, Straus SE, Richardson WS, Rosenberg W, Haynes RB. Therapy. Evidence-Based Medicine: How to Practice and Teach EBM. 20002nd ed New York Churchill Livingstone:105–154
3. Swanson E. Levels of evidence in cosmetic surgery: Analysis and recommendations using a new CLEAR classification. Plast Reconstr Surg Global Open. 2013;1:e66
4. Swanson E. A measurement system for evaluation of shape changes and proportions after cosmetic breast surgery. Plast Reconstr Surg. 2012;129:982–992 discussion 993
5. Swanson E. Prospective photographic measurement study of 196 cases of breast augmentation, mastopexy, augmentation/mastopexy, and breast reduction. Plast Reconstr Surg. 2013;131:802e–819e
6. Swanson E. Photometric evaluation of inframammary crease level after cosmetic breast surgery. Aesthet Surg J. 2010;30:832–837
7. Hidalgo DA, Spector JA. Preoperative sizing in breast augmentation. Plast Reconstr Surg. 2010;125:1781–1787
8. Adams WP Jr. The process of breast augmentation: Four sequential steps for optimizing outcomes for patients. Plast Reconstr Surg. 2008;122:1892–1900
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