Won't Leak - There are two components to this
issue. One is whether the shell might break, and the other is whether
the gel will leak out if the shell does break. The shell is certainly
physically susceptible to breakage, but since most ruptures are
believed to occur along shell folds (they result in weakening of the
shell, much like a folded newspaper left in a drawer will crack along
its folds), it is expected that shell failures will occur less
frequently. In the largest series in the world, there has supposedly
been only one shell failure in several thousand implants done in
Sweden. If the shell is peeled off the implant, the cohesive gel
filler will maintain its shape. I have one that I did this to several
years ago, and it looks just the same as the day I did it. But, that
doesn't mean that in the warmth of the body, and with the forces that
act upon the implant, that the situation wouldn't be different.
Another issue is diffusion; though there is a layer of the implant
shell that decreases silicone diffusion, some microscopic diffusion of
silicone will always occur through the shell.
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MRI
of a cohesive implant shows anatomic shape, free from folds that are not
just visible and palpable, but worse, can be the site of shell failure. |
Capsular Contracture - The European experience
has been that firm scar tissue seems to occur less often with these
implants (capsular contracture.) It is not clear if this will be
maintained over time, or what the cause is. Some speculate that it is
related to there being less diffusion of silicone than with
non-cohesive fillers, while others believe it is due to the increased
firmness of the implant, which inhibits the body from contracting
around it. More time and study will be necessary before we know the
answer to this issue.
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Purported Disadvantages of Cohesive
Silicone Gel Breast Implants
Shape - It is listed here for the same reason that
it is listed as an advantage. Since it will impart its shape upon the
breast, the patient and surgeon had better be sure that they are choosing
an implant shape that they want the breast to have. While implant
selection certainly matters with old style silicone gel and saline
implants, since their shape so so affected by gravity and forces of the
breast, there is a great margin for error. This is not a problem per se,
but rather, this is an issue in which one must be aware of. For instance,
women preferring "Baywatch"-grapefruit looking breasts may find the
teardrop shape of this implant will not meet their expectations. I think
this problem becomes significant only in "disproportionate" augmentations,
situations in which the implant size chosen exceeds what is optimum for a
patient's soft tissues.
Feel - These implants do feel a little bit firmer
than old style silicone gel implants (though if the old ones get a
capsular contracture, they will feel firmer.some believe that the
cohesives are less likely to get such a contracture, but that is not yet
known.) How significant this is in a given patient depends upon how much
breast tissue they have relative to how large an implant will be chosen,
and how firm or loose their tissue feels. A rare patient will complain
about the firmness, but for most patients, particularly those getting
implants that are not oversized, this is not an issue.
Cost - These implants do cost significantly more
than saline, and several hundred dollars more per pair than old style
silicone gel implants. However, if part of the study, patients will be
reimbursed most of the implant cost over a period of ten years.
Incision Size - Since these implants are not
deformable, they cannot be squeezed through little incisions. Depending
upon the size of the implant, incision length must be between 4.5-5.5 cm.
It also can make insertion from around the areola difficult (I usually use
the underneath incision with the cohesive implants.) Armpit incision is
possible, but exceedingly difficult.
Rotation - These implants only come in anatomical
shapes, meaning that they project more on the bottom than they do on the
top. One of the risks of such a design is that if the implant rotates in
the body, it will create a distortion. Care is taken during pocket
dissection and insertion in order to minimize this. It is a very rare, but
very possible complication. The only way to fix it if it occurs is to
remove them and replace them with a round implant. Rotation is at greater
risk when the tissue is loose, for instance in a revision when a patient
wants to go smaller.
Gel Fracture - Since the gel is almost a solid, it
can actually crack. I have only seen this happen from excessive
manipulation of the implant outside of the body, but it can theoretically
occur in the body. No one knows if this can actually occur, or what the
consequences would be if it were to occur. My speculation is that it would
not be noticed, but the answer to this is not yet known.
History of Cohesive Silicone Gel Breast Implants
Cohesive Gel Breast Implants - General Info
Cohesive Silicone Gel FAQ
Mentor Core Gel Study for Silicone Gel Breast Implants
McGhan Cohesil Study Information for Cohesive Silicone Gel Breast Implants