Thank you for your question. Breast asymmetry is very common, particularly size asymmetry. If you are looking to decrease the asymmetry from one breast to another, then you have several options.
1) You can reduce the larger breast with liposuction or a traditional breast reduction technique
2) You can enlarge the smaller one with fat grafting or an implant
3) You can enlarge both but use different size implants
4) A lift procedure may also be needed to help address differences in shape, nipple position and areolar size.
Some additional considerations would have be made depending on the degree of asymmetry that is attributed to your pectus excavatum.
I would visit with a board certified plastic surgeon to discuss your options in more detail.
Without an exam it is very difficult to say how complex the repair would be to try to match the two breasts more accurately.
Breast Asymmetry and correction with pectus
SEE VIDEO BELOW FOR BREAST ASYMMETRY WITH PECTUS:
It is likely that your breast asymmetry would be improved but not necessarily corrected. It is important to realize that diminished asymmetry is a more realisttic goal as opposed to achieving perfect symmetry.
Breast Implants for breast asymmetry and Pectus Excavatum
Very good question but it has a few issues that need to be addressed.
Breast asymmetry is THE NORM - not an exception. While we try to correct breast asymmetry as much as possible (using different fill in saline breast implants), we rarely succeed in getting perfectly symmetrical breasts. I suspect that the odds of perfect symmetry would be lower in your case where the chest wall is deformed. To get a chance at symmetry, you may need placement of a computer generated customized implant which would essentially correct the Pectus Excavatum and create a symmetrical plateau for the implants to sit on.
As regards your choice of implant - I seriously disagree. While you focused on the old studies purporting a much lesser rate of capsular contraction rate with textured implants you overlooked the facts that - Textured implants ripple more than smooth implants and leak much faster than smooth implants. Moreover, saline implants are not only heavier but also ripple more than silicone filled breast implants. If you wanted an implant that would demonstrate its ripples more than any other and leak sooner than all of them - the textured saline implant is your implant. A much better choice would be a smooth silicone gel implant ESPECIALLY with a thin breast coverage situation.
Finally, while a trans axillary approach is feasible, nothing beats the accuracy of a periareolar access and the re-usability, over and over, of its largely inconspicuous scar.
Breast implants to correct asymmetry
First, please realize that nobody is completely symmetrical. Secondly, with a pectus excavatum, you have a bony chest wall abnormality that is often asymmetrical. This would put your implants on uneven ground and would make true symmetry impossible. Also, capsular contractures should be the least of your concerns as they are rare and using a textured saline implant in a thin patient will be so wrinkly and ripply that you won't like the result even if the symmetry is adequate.
What you should do is either post some photos of yourself or see several experienced plastic surgeons and get their advice. It sounds like you have "decided" what you want ie. incision, implant etc. What you should do is ask an expert what they would recommend instead of telling them technically what to do.
There are only two ways to correct asymmetry. One is to make the larger breast smaller and the other, is to make the smaller one larger. Usually, however, something is done to each breast in order to make them as symmetric as possible. With careful measurement and meticulous technique, we can usually obtain significantly improved symmetry. With Pectus, the breast tissue may not be the problem, however. Frequently the problem is that one side of the chest is more prominent than the other due to asymmetries of the rib cage. If this is the problem, then a limited width breast implant may not provide complete symmetry. You may need a custom implant to bring the entire chest forward. If there is also a difference in the volume of the breasts, then this will have to be addressed also. For thin people like you, I like the anatomic implant. Right now, the only way this implant comes is in saline. The FDA is supposedly on the verge of releasing this implant in silicone, which would be ideal for you. This implant, by necessity, is textured. This markedly does reduce the incidence of capsular contracture.
Symmetry and implant coverage in thin women
You raise a number of questions so let's take them one at a time. First, no one can promise perfect symmetry but if there is a big size difference and you don't want the larger one reduced then implants are the way to go. Secondly, the type of implant makes a difference in how natural they feel and look especially in thin women; most are going to be happier with silicone rather than saline. Third, if coverage is an issue, there are some options such as Strattice or Alloderm grafts that can be helpful (www.renewingyou.com). Additionally, fat grafts around the implants or between them for the pectus can also be very successful.