The pocket (placement) position of breast implants has been studied for many years. No single key fits every lock, and no single surgical procedure fits every patient. This holds true for all Plastic surgery procedures. As with many other Plastic surgery procedures, and as common sense would dictate, no single operation fits every patient. If multiple types of operations are available, and the same operation is performed on every patient irrespective of the patients specific anatomical situation, common sense would dictate that some patients will get a suboptimal result. The particular breast augmentation procedure should be chosen based on the patients specific anatomic situation, her goals and preferences, and because there is wide variation in breast shape and breast size one operation does not fit all patients.
Measuring breast plate thickness
The sub-glandular breast implant procedure is generally reserved for patients with a thick breast gland. In this procedure, the implant is placed between the breast gland and the chest muscle. The sub-glandular breast implant procedure has advantages in very active patients, especially those that participate in strenuous activities with the upper extremities, such as weight lifting.
The sub-glandular procedure (above the chest muscle) was the most commonly performed procedure thirty years ago. In this operation the breast implant is placed below the breast gland and above the chest muscles (pectoralis major muscle). The sub-glandular (above the chest muscle) procedure does not injure the pectoralis major (chest) muscle which is one of the largest muscles in the body. One study showed that partially sub-muscular (partially under the muscle) placement of breast implants resulted in a 20% loss of torque strength. Although the study was in breast cancer patients, inference (and common sense) for the cosmetic breast augmentation patient is strong. Common sense would indicate that if you (partially) cut a muscle the strength may decrease. Muscular action directly on the implant can be an advantage, and it can also be a disadvantage. One advantage of the sub-glandular (above the muscle) procedure is that there is no muscular activity directly on the implant. As a result, it is less likely that the breast implant will be displaced to an unfavorable position over time. In other words, with sub-glandular implant placement, it is more likely that the breast implant will remain in the same position that it was placed at the time of surgery. The potential disadvantage of the sub-glandular (above the chest muscle) procedure is the lack of muscular action that is thought to reduce problematic capsular contracture (breast firmness). If the breast implants are placed in the sub-glandular (above the muscle) pocket, the external massage can be performed by the patient as a substitute.
Partially Sub-Muscular Procedure
The sub-muscular procedure is more accurately called the “partially” sub-muscular procedure. The sub-muscular procedure is generally reserved for patients with a thin breast gland. In this procedure, the implant is placed between the chest muscle and the chest wall, and the implant is covered on the upper surface by muscle. This procedure has advantages in patients that have a very thin breast gland by placing more “soft tissue” over the top of the breast implant.
The partially sub-muscular (below the chest muscle) procedure places the breast implants partially under the chest (pectoralis major) muscle. The partially sub-muscular (below the chest muscle) procedure has been a source of confusion due to the often used terminology “under the muscle procedure”. The breast implants are placed under the muscle in this procedure, but only (approximately) the upper one half of the implant is covered by muscle (plus breast gland), and (approximately) one half of the lower breast is covered only by breast (gland) tissue. In other words, in the lower half (approximately) of the partially sub-muscular procedure the anatomic relationship is the same as the sub-glandular (above the muscle procedure). This procedure is more accurately called the partially sub-muscular (partially below the chest muscle) procedure to prevent confusion with the totally sub-muscular breast augmentation procedure. The partially sub-muscular (below the chest muscle) procedure by definition injures the pectoralis major (chest) muscle. Some surgeons feel that intentionally injuring a a very large normal muscle which could obviously affect its function (strength, range of motion, endurance) for an elective cosmetic surgery should not be taken lightly. As noted previously, one study confirmed this concern and showed a 20% torque strength loss. Common sense dictates that if injuring a large normally functioning muscle (pectoralis (chest) major) can be avoided by choosing another equally effective procedure, this may be the most prudent option. Because the pectoralis major (chest) muscle is injured (cut and or cauterized) during the partially sub-muscular (below the chest muscle) procedure, the recovery period is longer (6-8 weeks as compared to 1-2 weeks) when compared to the sub-glandular (above the muscle) procedure.
Advantages and Disadvantages
There are thought to be some advantages to the partially sub-muscular (below the chest muscle) procedure. In the partially sub-muscular (below the chest muscle) procedure, there is more natural soft tissue (breast gland and muscle) covering of the breast implant in the upper part of the breast compared to the sub-glandular (above the muscle) procedure. This gives a more natural appearance in the upper pole of the breast in thin patients (see the “pinch test” in subsequent section). Because the implant is below the pectoralis (chest) muscle, any contraction (flexion) of that muscle with arm movement will act directly on the implant. Because there is no muscle on (approximately) the lower half of the implant with the partially sub-muscular (below the chest muscle) procedure, there is no dynamic (active) resistance on the bottom half of the breast (no muscle coverage), and the implant can be displaced in that direction (down and outside). If this happens the implant can be malpositioned (in the wrong place). This unfavorable displacement of the breast implant can also cause asymmetry if one implant displaces more than the opposite side. It is thought that muscular action with the partially sub-muscular (below the chest muscle) procedure may reduce the chances of problematic capsule formation that results in increased breast firmness which is an advantage. As noted earlier, the muscular action with the partially sub-muscular (below the chest muscle) procedure also has a tendency to push the breast implants out from under the muscle to an anatomically unfavorable position. In some patients, the implant movement (displacement) is inconsequential, and in other patients the displacement may require additional surgery. Implant displacement is more likely to occur in extremely active patients and especially in weight lifters. Problematic implant displacement is also more likely to occur in extremely thin patients or that have a paucity of tissue or poor tissue integrity in the bottom outside area of the breast (next to the elbow when the arms are hanging in a standing position). This condition can be developmental or from aging, or from pregnancy. Severe implant displacement may require additional surgery called a capsulorrhaphy, which adjusts the capsule around the breast implant. Another problem with the partially sub-muscular (below the chest muscle) procedure is the so called “jumping breast” phenomenon. In some cases, when a patient that has had the partially sub-muscular (below the chest muscle) procedure moves her arms or flexes the pectoralis major (chest) muscle, the breast implants appear to “jump”. This can be very disconcerting to some patients. In addition, with this muscular action, the upper pole (top half) of the breast flattens and can ripple. This is a very unnatural appearance that commonly occurs with the partially sub-muscular (below the chest muscle) procedure when the chest muscle (pectoralis major) is flexed with arm movement, especially when wearing a low cut garment such as a evening gown or a bathing suit.