Capsular contracture, an exaggerated hardening of the tissue around a foreign body, continues to be one of the most stubborn issues to stomp out with breast augmentation and reconstruction surgery. It's also been one of the most difficult things to study in a way that's useful because of a relative lack of a clear understanding of why it happens.
Forming a capsule is a normal physiologic process. It happens around everything your body doesn't recognize as "self" when it's implanted and is mediated by a well established interaction among signaling proteins on cell surfaces and your bodies immune system cells. When this process goes haywire, you get thickening and shortening of the capsule which can become painful and distort the shape of the breast.
There's a couple things we know clearly cause high rates of hard capsules with breast implants:
Forming a capsule is a normal physiologic process. It happens around everything your body doesn't recognize as "self" when it's implanted and is mediated by a well established interaction among signaling proteins on cell surfaces and your bodies immune system cells. When this process goes haywire, you get thickening and shortening of the capsule which can become painful and distort the shape of the breast.
There's a couple things we know clearly cause high rates of hard capsules with breast implants:
- post-operative hematoma
- infection around an implant
- a history of breast irradiation
- older silicone devices (1970's-19080's) with high rates of "gel bleed"
- rupture of silicone implants
What's more complex is trying to "reverse engineer" how to prevent capsules. Suggestions to reduce high grade capsule rates have included:
- textured implant surfaces
- placement of the implant underneath the pectoralis muscle
- polyurethane-coated implants
- antibiotic irrigation of the implants during insertion
- the use of contemporary "4th generation" implants with thicker "low bleed" shells and more cohesive fillers
- saline implants
The data on textured implants and position of the implant relative to the muscle have been somewhat mixed. At this point it's hard to definitively say that either make much difference long-term. Polyurethane foam works very well, but it's use in the US is likely DOA in the long-term due to liability issues over a (now debunked)risk of breast cancer. Antibiotic irrigation works well in the short-term, but it's not clear that it could affect capsular contracture years out from surgery.
It's been very interesting to see the performance of the "5th generation" silicone devices in published studies. These are the "gummy bear" implants which are semi-rigid and textured. Whether it's a synergistic effect or what is not clear, but these implants have dramatically lower rates of capsular issues almost a decade out. These devices appear to offer an improved solution to capsular (and rupture) issues and hopefully the FDA will give the green light sometime in 2008 for their US debut.
So what else do we have to offer?
There's a class of drugs used to treat asthma called leukotriene inhibitors (LTI) that has shown some promise in prevention or treatment. The two most common LTI's are Accolate and Singulair. Accolate has a small potential for liver problems and has mostly been avoided in favor of Singulair. Singulair was in the news as it's been alleged to cause suicidal ideation by people suing Merck. (How you prove a negative here is anyone's guess, but call me the skeptic.)
Anyway the genesis of this post was a study I saw in a European journal showing dramatic inhibition of capsule thickening in an animal model using zafirlukast (aka Accolate) which you can see view here). This is the first basic science model I've seen actually showing this idea of LTI's can work. This information gives us another option to discuss in the high risk capsule former which is good!
Rob
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