4872 Unraveling the Risk Factors of Seroma and Breast Augmentation: Closing the Circle

Friday, May 6, 2011
Marcos Sforza, MD1, Katarina Andjelkov, MD2 and Renato Zaccheddu, MD2, (1)UNIFESO School of Medicine, Birmingham, United Kingdom, (2)Private Practice, Birmingham, United Kingdom

Unraveling The Risk Factors Of Seroma And Breast Augmentation: Closing The Circle.


Silicone breast implants have been widely used in the United States and throughout the world for almost five decades. Meanwhile, there has also been a growing concern about the safety of these devices, with regard to both local complications and possible systemic effects.

 A large body of scientific literature has been published addressing a possible association between silicone implants and systemic pathologies, mainly breast cancer. Recent studies have documented a significant incidence of local complications and side effects from breast implants. It has also been determined that a relatively large proportion of implant patients require revisional surgery.

Capsula contracture and hematomas are the most frequent complications leading to revision surgeon. Early seroma (first 12 weeks) appears as frequent as 2% of the cases in some series. However, it has been unprecedented for most scientific literatures to recount and specify the risk factors which contribute to developing seroma after breast enlargement surgery. Nevertheless, seroma is always adressed to patients as a possible complication without accounting for the underlying factors rendering this problem even more likely. As surgeons we feel obligated to allude to risk factors intuitively regarded as been detrimental, however there is a short coming in our scientific literature referring to such factors more explicitly.


The authors analyzed 538 patients who had bilateral breast augmentation with silicone cohesive gel implants in a period of 12 months. The procedures were performed by the same surgical team, with the same brand of implants (Eurosilicone, France), same equipment (Valleylab diatherm, US), same hospital facilities and same surgical technique. For the purpose of analyzing the data the authors isolated 5 possible variable risk factors: patients age, BMI, smoking habit, implants pocket and size of the implants. The data were analysed using odds which mainly signifies how many times the probability of developing seroma is higher than the probability of not developing seroma. Since the outcome of seroma is relatively small, the odds and risk of seroma will be close, however,  using odds provides more coherent statistical analysis. For the purpose of this preliminary assessment both the BMI and size of implant factors were used as  category variables (divided into several groups) and as binary variables (divided into two groups).


Using simple logistic regression with smoking and pocket treated as binary variables, while implant size, BMI and age treated as category variables, we found that smoking, implant size, BMI and pocket have positive effect  while age has negative effect on developing seroma. However, at 5% significance level, we found that only smoking and implant size affect the seroma development. Smokers face 30 times the risk of developing seroma than non smokers and increasing the implant size bigger than  350cc increases the risk of seroma by 7 times.  Using BMI and implant size as binary variable, we found that smoking, BMI, implant size and pocket are all significant contributing positively to seroma development. In this model smoking, BMI and breast implant size are all significant risk factors, where smoking increases the odds of developing seroma by 32 times, BMI increases by 27 times, breast implant by 9 times and pocket increases the odds of developing seroma by 7 times. Age only slightly increases the odds but at non significant level. The analysis reveals that these factors might influence seroma development. As Figure 1 illustrates, implant size bigger than 350cc and smoking increase the risk of seroma manifold. Indeed, almost 30% of those who smoke and have bigger than 350cc implant have developed seroma. Finally, taking BMI into account seems to further increase the risk of seroma. From the 4 smoking patients with high BMI and large breast implant 3 have developed seroma .  Amongst those who smoke and have high BMI and large breast implant 75% have developed seroma. On the other hand, those 182 patients who do not smoke and have lower BMI and smaller breast implant none has developed seroma which translates into a risk difference of 75%.

Figure 1 - The graph bellow illustrates the odds ratio for developing seroma according to smoking and implants size.


In this restrospective cohort study, we found strong evidence that smoking is associated with seroma development in patients after breast enlargement surgery. We have also found moderate evidence that patients with bigger breast implants or with higher BMI are more likely to suffer from seroma (Figure 2). Thus, these results could provide us with a vital weapon of knowledge to protect our patients not to sustain such complications.

Figure 2 – The graph bellow illustrates the odds ratio for developing seroma according to the risk factors

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