Cohesive gel is a dense silicone polymer with unique characteristics. Cohesive gel implants retain their shape against gravity and deform less than saline or silicone gel implants when subjected to external pressure (Figure 1). These properties result in a more predictable breast shape with no wrinkles, less silicone bleed/gel migration, less capsular contraction, and, possibly, greater durability than other implant types ( Figure 2). From December 2000 to the present, I have used 83 cohesive gel implants: 54 in breast augmentation, 8 in implant replacement, and 21 in breast reconstruction. The Medical Devices Bureau of Statistics Canada controls and records the use of cohesive gel implants. Shaped and round cohesive gel devices are available in Canada, and approval in the United States may be given by 2004.

Cohesive gel implant, divided in half to expose the gel. Note the textured surface, as well as the cohesive gel’s stickiness and how the gel retains its shape.

A silicone gel, saline, and cohesive gel implant (right) are stacked together to demonstrate how only the cohesive gel implant maintains its shape against gravity, devoid of wrinkles.

The choice of implant is based on breast measurements, a concept that may at first be difficult to accept when one is accustomed to choosing implants by volume. The 3 measurements to consider are: The width of the breast, measured at the subareolar region; the height of the implant, measured from the inframammary fold to the upper limits of the breast tissue at the anterior axillary fold; and (3) the thickness of the skin and breast tissues (eg, in patients with thin skin and breast tissues I choose high-projection implants, but when breast tissue is substantial, I choose a low-projection implant).

In my experience, cohesive gel implants placed in the submammary space are most effective in lending an anatomic shape to the augmented breast. In my view, there is no advantage in placing these implants retropectorally because the implants are tapered, have a low incidence of capsular contracture, and do not create wrinkles in the upper quadrants, provided that the pocket is correctly dissected.

Augmentation mammoplasty with cohesive gel implants should conform to the patient’s chest and breast shape rather than to her volume preference. Full projection implants such as McGhan styles 410 LF, MF, and FF (Inamed Corp., Santa Barbara, CA) are recommended for patients with a thin skin envelope, small breasts, postlactation involution, breast atrophy, or thin skin such as that in a bodybuilder. These implants impart the most anatomic breast shape, and their tapered upper quadrants can be placed under the skin with little fear of rippling (Figure 3).

A, C, Preoperative views of a 38-year-old woman with small breasts and thin skin envelopes. B, D, Postoperative views after augmentation with McGhan style 410 LF 240 cohesive gel implants.

Implants with greater width than height, such as the Mentor Contoured Profile (Mentor, Santa Barbara, CA) or McGhan styles 410 ML, MM, MF, LL, LM, and LF are used for most breast augmentations, with the choice of projection (the second letter in the style descriptor) based on the amount of existing breast tissue (Figure 4).

A, C, Preoperative views of a 36-year-old woman with thick breast tissue. B, D, Postoperative views after augmentation with McGhan style MM 215 cohesive gel implants. For patients with thicker breast tissue, I choose McGhan style 410 with medium or low projection. Note how these implants shorten the nipple to sternal notch distance.

Implants with greater height than width (eg, McGhan styles FF, FM, and FL) are commonly selected for women with long, narrow chests. The final overriding decision is always based on existing breast measurements. Sometimes patients have a normal or wide chest but have measurements that dictate a higher implant (Figure 5). Round implants (eg, McGhan CML or Mentor Round) are inserted in women who request them because they prefer greater volume in the upper quadrant.

A, C, Preoperative views of a 42-year-old woman. B, D, Postoperative views after augmentation. The measurements dictate which implant to use. In this patient, the breast was higher than wide, so the selected implants are McGhan style 410 FM 270 cohesive gel.

Procedure

Begin by marking the perimeter of an area slightly larger than the implant. Mark a 5- to 7-cm incision on the proposed inframammary fold. In a patient with contracted lower quadrants, lower the fold 2 or 3 cm, take care to release it, and then tack the edge of the incision down to the fascia. I use a lipoplasty infiltration needle, inserted through an axillary crease, and about 500 mL of lipoplasty wetting solution. A combination of sharp and blunt dissection will easily create the pocket in the space that has been defined by the fluid.

After hemostasis, I introduce the wetted implant, taking care not to use excess force to insert it because it can fracture. A plastic sleeve facilitates introduction of the implant. It is important to pass a finger over and under the implant to ensure that no folds or creases occur, especially in the upper pole. Alignment dots on the shaped implants are helpful in preventing a rotational deformity. At this point, close the incision temporarily and sit the patient up on the operating table to ensure that the implant is well positioned, that the submammary folds are symmetric, and the nipple faces forward.

Close the incision with a first layer, stitching it into the fascia at the inframammary fold. These augmentations lift the nipple and areola, shortening the nipple to sternal notch distance. In some patients, mastopexies that have been planned will not be needed. The posterior breast adheres to the textured surface, and because of the firmer qualities of the cohesive gel it does not glide down when the patient is upright, thus maintaining the nipple at a higher position (Figure 4).

Replacement with cohesive-gel implants

I have noted in patients with long-term saline implants a certain degree of breast tissue atrophy. Patients with saline implants can achieve improvement in rippling, capsular contracture, or excessive upper pole fullness by having them replaced with shaped cohesive gel implants. In these patients, the cohesive gel implants impart a far better-shaped breast mound. I select the new implant using the measurements I have already described