The
Inframammary Fold
The
dissection of the inframammary fold (IMF) is the key to breast implant surgery.
It is the most difficult and the most important area of dissection.
1.
The Dissection Procedure
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Fig.
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Through
any of the four incision sites the dissection of the pocket is rapid and easy
except for the IMF. The easy dissection can be done gently with the finger,
whether above or below the muscle. The finger dissection is gentle, and avoids
undue trauma to tissues.
Above
the muscle and beneath the breast there is a plane of loose areolar tissue with
a small amount of fat that easily allows separation of the breast from the
underlying pectoral muscle. With blunt or finger dissection superior to the
fifth rib and superficial to the pectoral fascia the dissection is easy and
bloodless.
Below
the muscle it is equally easy to lift the muscle off the ribs down to the 5th
and 6th where the pectoral muscle is firmly attached. This subpectoral plane
superior to the 5th rib is also free of bleeding and easy to dissect with blunt
gentle finger dissection.
Either
above or below the muscle the firm attachment and resistance to dissection begin
over the 5th rib. The IMF is usually located at the 5th or 6th rib. Here the
subcutaneous fat from the fifth through the 6th to the 7th ribs is less thick or
less in amount than above the 5th rib, where the breast tissue begins or below
the 6th and 7th ribs where the abdominal subcutaneous fat begins. You can feel
this on your own body whether male or female. And also notice as you feel
yourself how much more firmly attached the tissue is over the 5th - 7th ribs,
and how much more mobile the breast and subcutaneous tissues of the abdomen are
above and below this area.
The
breast implant surgeon finds how easy the pocket is to dissect above the 5th rib
and may insert the implant before giving special attention to the inframammary
fold. The implant will then be too high. The implant can be gradually lowered
with dissection of the inframammary fold even with the implant in place until it
is properly positioned and centered behind the nipple.
The
implant that is too high with the patient lying on the table may look like it is
in the proper position, and the fact that it is too high may not become obvious
until the patient is brought up to a sitting position.
The
dissection of the pocket except for the IMF is so easy it can be done with the
implant or a sizer, as has been shown with the umbilical approach, where the
implant or sizer is inserted and inflated and used to create the pocket.
This
gentle blunt dissection of the pocket is ideal. All dissection should be so
gentle and easy, but it is not. It is very difficult to dissect the IMF with the
finger. It is too tough. The attachment is the superficial pectoral, external
oblique, serratus anterior and rectus abdominus fascia extending into the
subcutaneous tissue and attaching to the deep dermis. In slender patients, there
can be little or no subcutaneous fat present.
Preserving
as much subcutaneous fat attached to the skin in the IMF dissection is
desirable. The tissues are thin in this area, and if the fat is not preserved
there may be little else but deep dermis in contact with the implant, causing
the implant to be more palpable and visible. Also, the fat attached to the skin
may partly protect from early capsule formation.
In
all of the drawings above only the fullness of the breast and the position of
the inframammary fold (IMF) has changed. The higher fold in 4 as compared to 1
gives the appearance of ptosis. And if the fold is lowered and the breast is
filled with an implant, the ptosis appearance and the ability to hold a pencil
disappears. If #8 has an implant compared to #5 or 6, the IMF is routinely
lowered to center the implant behind the nipple. Otherwise,
the implant would be too high.