Reply: Role of Mitomycin C in Preventing Capsular Contracture in Implant-Based Reconstructive Breast Surgery
As stated in our article, all the actual evidence about different methods aiming to reduce capsular contracture following implant-based breast surgery derives from retrospective analyses or prospective studies without control groups. The study by Adams and colleagues about the use of triple-antibiotic irrigation2 presents very useful and interesting findings but, as the authors themselves admit, is limited by the absence of randomization or the presence of a control group. The authors compare their findings with capsular contracture rates deriving from Allergan and Mentor premarket approval studies,3,4 with all the possible biases deriving from comparing data deriving from patients with potentially different baseline characteristics and differently performed operations.
Breast pocket irrigation has been extensively studied and recommended for many years but was never investigated in a randomized setting and thus is far from being considered as a “standard of care.” Moreover, the specifics of this technique remain to be defined: many irrigation solutions have been proposed, but none of them has been proven to be significantly effective in reducing capsular contracture in a randomized trial.
In light of this evidence, it appears completely ethical to compare a new potentially effective method of capsular contracture reduction with the saline solution to obtain level I evidence about the usefulness of a new method (mitomycin C) for capsular contracture reduction and trying to eliminate all possible confounders.
We would strongly encourage that randomized trials be performed investigating the use of many other potentially effective methods (antibiotic solution as well) for capsular contracture reduction compared with saline solution to obtain data with a higher level of evidence about their real efficacy. Moreover, the National Cancer Institute of Milan Ethical Board approved this study in 2005 and, even though ethical conduct has evolved and changed throughout the years, we completely could not criticize the ethical choices of professionals working in this field.
According to the second consideration by Hassidim and colleagues, we refer to the data reported in a Cochrane Systematic Review about implant-based breast reconstruction,5 presenting capsular contracture rates deriving from randomized controlled trials comparing different types of implants for breast reconstruction and showing Baker grade III/IV capsular contracture rates up to 50 percent. In particular, the trial by Thuesen and colleagues comparing two-stage breast reconstruction with textured and smooth silicone-filled implants presents, respectively, demonstrated capsular contracture rates of 18 and 22 percent.6
Capsular contracture rates presented in our trial are 22.3 percent in the mitomycin C group and 24.2 percent in the control group, not significantly higher than those presented in other randomized controlled trials. Moreover, as presented in our article as a limitation of our study, the assessment of capsular contracture severity according to the Baker scale, even though it is the most commonly used scale, remains a subjective assessment method, and thus a significant bias in capsular contracture rate assessment between different studies could be attributable to the impact of subjective measurements as well.