Breast Implants on Pigs

Subclinical (Biofilm) Infection Causes Capsular Contracture in a Porcine Model following Augmentation Mammaplasty, Tamboto, Vickery and Deva, Plastic and Reconstructive Surgery, September 2010.


In the past four decades, since the introduction of silicone breast implants, capsular contraction has been the most common complication, accounting for the majority of remedial surgery. Capsular contraction is the tightening and/or thickening of the capsule surrounding the implant causing excessive firmness and distortion of the breast shape. There is growing evidence that this problem is associated with subclinical infection of the mammary implants as a biofilm of bacterial cells forms on the polymer surface.

The Experiment

To investigate this relationship, six adult female pigs were implanted with up to nine miniature, gel-filled, silicone mammary implants. Each implant was 2cm in diameter and weighed 1.7g.

Prior to insertion, submammary pockets were created using blunt dissection and were inoculated with varying doses of staphylococcus epidermidis (for infected teats) or saline (for control teats). The solutions were allowed to distribute evenly within the pockets before the implants were placed and the wounds closed.

The implants were left in for an average of 13 weeks while the pigs were monitored for signs of infection. The pigs were then killed and the implants removed for laboratory analysis.


The implants inoculated with staphylococcus epidermidis showed a fivefold increase in risk of forming biofilm and a fourfold increase in the risk of developing contracture. None of the pigs showed any sign of clinical infection.

The authors surprisingly state that there was already evidence (as far back as 1981) staphylococcus was the most commonly isolated organism from bacteriologic cultures of contracted capsules.

Further the authors of the publications refer to research by Adams that reported an in vitro study in 2000 and a prospective clinical trial supported the use of antibiotic pocket irrigation for reducing capsular contracture.

So why did the authors develop a pig model of subclinical infection and biofilm formation to further investigate what was already known?

See what Antidote Europe Director Andre Menache has to say about Europes recent disaster concerning silicon breast implants.

What can you do?

Write to the University of NSW to ask why they conducted such wasteful research:

Write to the University of Sydney Animal Ethics Committee who approved this study asking them how it had been justified:

Research Integrity Office

Level 6, Jane Foss Russell Building – G02
City Road, Darlington Campus
The University of Sydney




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