Breast augmentation is a surgical procedure that increases the volume of the breasts through the insertion of prosthetic implants. Implants range in volume from 90 to 900 millilitres and also come in different shapes. They have either saline or silicone filling, smooth or textured silicone or textured polyurethane envelopes.The breast augmentation procedure involves the surgical placement of a saline or silicone gel-filled implant in each breast to push the breast tissue forward.
Silicone vs saline implants
Silicone gel-filled implants are designed to mimic natural breast tissue, and are the most commonly used implants in Australia. They have an outer silicone shell encasing a firm, cohesive gel that offers a more natural feel. Their cohesive consistency means gel-filled implants retain their shape better than saline-filled implants. If ruptured, the risk of dispersal is lessened in gel-filled implants than with saline, though some doctors are wary as ruptures can be left undetected for longer periods of time. Reassuringly, silicone is regularly used in medical devices and is regarded as one of the most compatible materials for implanting into the body.
Because silicone gel is manufactured into the implant before surgery, the incision sites must be slightly longer than those required for saline implants, which can be filled through valves once inside the breast pocket. The length of incision will depend on the size of the implant.
Saline-filled implants have an outer shell of silicone, but are filled with a medical grade saltwater solution to create a waterbed-like feel. This feel can be moderately adjusted by changing the volume of fill, but saline implants will remain firmer to touch than their silicone filled counterparts. If implant rupture occurs the body will absorb the saline solution; a rupture will be noticeable immediately and a slow leak will be noticeable within days. Saline implants have a higher risk of visible folds and ripples compared to silicone filled implants.
Saline implants can be filled through a valve during surgery, after the implant is situated in the breast pocket. Because of this, the incision site is generally smaller than that needed for silicone implants. The valve also means the amount of fill can be adjusted after surgery, which is not possible with silicone gel implants. Alternatively, saline implants can be pre-filled to a fixed volume during manufacture, which eliminates the need for a valve and filling during surgery.
Round vs teardrop implants
Round implants: When the patient is upright, a round implant can assume a defined, round shape or a teardrop-like contour, depending on its fill. Round implants come in smooth and textured shells, and will usually lend more upper pole fullness than anatomically shaped implants.
Anatomical (teardrop) implants: With a fuller lower pole, these implants more closely resemble the natural shape of a breast. Their design gives them greater projection in relation to the size of the base, making them particularly suitable for women with little breast tissue.
A precise degree of accuracy is needed when positioning anatomical implants and if they shift after surgery the shape of the breast may be noticeably distorted. To reduce this risk, anatomical implants will always have a textured surface to enable adherence to surrounding tissue. Despite this, movement after surgery may still occur and it is best to see a surgeon experienced with these types of implants.
Smooth vs textured implants
Acclaimed for their natural movement and feel, smooth-shelled implants are relatively easy to insert and have a thinner shell than textured implants. Smooth shelled implants have an increased risk of capsular contracture (hardening of the breast), which is a common reason for revision surgery.
A textured implant surface means the implant will cling to surrounding tissue and limit the friction between the implant and breast pocket. This will reduce the chance of capsular contracture and can prevent implant movement after surgery. Many surgeons also believe a textured surface grants them greater control over the breast’s ultimate shape.
The polyurethane foam coated implant provides a texture specifically designed to reduce rates of capsular contracture. The foam coating means the collagen fibres around the implant do not line up, and are less likely to slide over each other and contract. Instead, the fibres assemble in a circular pattern around the foam and are unable to form a hardened capsule. There are some differences in the administration of foam-coated implants, for example the pocket size generally needs to be bigger than usual. Polyurethane foam coated implants gained approval for use in Australia in 2008; they have been used in South America and Europe since the 1970s.
Implant placement
Similar to choosing texture and shape, deciding upon implant placement is a balancing act with benefits and drawbacks for each option. Typically, there are three placement possibilities: subglandular, submuscular and dual plane.
Subglandular: This pocket resembles the plane of normal breast tissue and sits in front of the pectoral muscle, underneath the breast tissue. Sometimes a thin membrane on top of the muscle, the fascia, will cover the implant and this is called subfascial placement.
An implant positioned in front of the muscle is best suited to patients who have adequate breast tissue, as this natural tissue will hide the defined implant edges. Subglandular breast implants may be more conspicuous in women with little breast tissue, little body fat and thin skin. With subglandular implants there is often a pronounced ‘roundness’ to the breasts, though the implant tends to move more naturally in this position.
Because the chest muscles are not disturbed during surgery, the procedure is typically faster and will usually result in a shorter, more comfortable recovery period than with submuscular (under the muscle) placement. Any rippling of the implant will be more noticeable in subglandular placements and some studies have reported an increase of capsular contracture rate when implants are placed over the muscle.
Submuscular: This is where the implant is placed underneath the pectoralis muscle after some release of inferior muscle attachments. This placement will camouflage the implant edges and can create a natural looking contour at the top of the breasts, particularly in those patients with little natural breast tissue. This placement reportedly reduces the risk of capsular contracture, though when the pectoral muscles are contracted the implant is squashed and may noticeably move upwards or outwards. The breast tissue can also drop away from the implant; a complaint termed the ‘snoopy’ deformity, which is more common with this placement.
Because the muscles are interfered with in submuscular placement, the recovery period may be longer with greater post-operative discomfort. The implants may initially sit high in the chest and take time to ‘drop’ to their designated position. The submuscular placement will reduce the appearance of folds and ripples.
Dual plane: Here, the implant is placed partially beneath the pectoral muscle in the upper pole, while the lower half of the implant falls in the subglandular plane. This placement will camouflage upper implant edges and provide full projection in the lower pole, suited to women with a high degree of sag or an accentuated breast fold. It will reduce the defined ‘roundness’ usually associated with subglandular implants and will offer a natural breast contour. The submuscular component will also reduce the appearance of folds and ripples. This placement involves complex surgery and procedure errors could result in visible deformities when the pectoral muscles are contracted.
Implant incision sites
The incision site will determine the visibility of scars and is generally decided based upon personal preference. Understandably, the patient will have her own ideas about the positioning of scars and a surgery she is comfortable with. Also, the surgeon will usually have a preference based on visibility offered, amount of control possible and experience using a particular incision site.
Inframammary: This is the most common incision for breast implant placement and it is made in the inframammary fold, or the crease under the breast. There are different techniques for determining the position of this fold on an augmented breast, which can be particularly difficult in patients with little breast tissue. Experienced surgeons can place the incision so the scar is hidden within the inframammary crease and not visible when wearing a bikini top.
The surgeon will create a pocket for the breast implant situated behind the nipple and slide the implant up through the incision. This incision site allows for subglandular, submuscular and dual plane placement. Its close proximity to the implant pocket offers the surgeon high visibility and greater control over placement and bleeding.
Periareolar: Here, the incision is made on the border of the areolar – the area of darker skin surrounding the nipple. The incision should be at the junction of the areolar and lighter breast tissue, where the scar will be least visible. Again, the proximity to the breast pocket will afford the surgeon heightened visibility and control, making it possible to easily and accurately place the prostheses in different positions.
This is the only incision to cut through breast tissue and ducts and, because of this, sensitivity in the nipple may be affected. Erroneous procedures or healing complications could result in noticeable scarring, as the incision is in the centre of the breast.
Transaxillary: From the armpit to the breast, the incision is made in the armpit fold and a channel is created to deliver the implant to the breast pocket. This may be performed with an endoscope to provide visibility. The greatest advantage to this incision site is that no scars are left on the breast, while the lack of tension in the armpit fold generally allows for efficient healing.
Because the incision site is such a distance from the breast, visibility in creating the breast pocket is restricted. There is a higher incidence of the implant being positioned too high and a greater risk of breast asymmetry after surgery. If capsular contracture occurs, an additional incision will be necessary for treatment.
Transumbilical: Quite an uncommon incision site, the transumbilical or navel (TUBA) incision is made on the rim of the navel. Again, an endoscope is used to create a tunnel and provide visibility to the breast. Once the pocket is created in the breast, the implants are moved through the tunnel, from the navel into the breast area. This incision site is only used for saline implants, as they can be filled after insertion. The remote proximity to the breast means visibility is reduced and surgeons have limited control over bleeding in the pocket and implant positioning. In the case of capsular contracture or complication, further surgery will demand another incision site.
What happens during a breast augmentation?
The patient is anesthetised, either with general anaesthetic or twilight sedation, and the chest area is cleaned and marked up with guidelines by the surgeon. Then the surgeon makes an incision that enables them to lift the breast tissue to create a pocket above or below the pectoral muscle for the implant. Depending on a patient’s anatomy, breast condition and other factors, the implant can be inserted through four different incision sites according to the patient and doctor’s choice of which will work best and takes into account where the residual scarring will be located.
After making an incision, the surgeon cuts a channel through the tissue to the final location of the implant. Having created the path, the surgeon then separates tissue and/or muscle to make the implant pocket. Surgeons create the pocket to receive the breast implant using one of two methods: blunt or electrocautery dissection. With blunt dissection, a curved, blunt steel instrument or the doctor’s index finger is used to separate tissue to create the pocket. While blunt dissection can cause bleeding and trauma, it is fast and effective.
Electrocautery dissection employs electrical current to cut tissue and coagulate bleeding vessels at the same time, resulting in greater visibility and consequently greater accuracy for surgeons. Because using electrocautery dissection causes less bleeding and tissue trauma, it can shorten recovery time. The implant is inserted through the incision and strategically positioned by the surgeon.The incision is closed with sutures or surgical glue and covered with tape, which helps the tissues adhere. In some cases additional dressings may be applied or a surgical bra may need to be worn.
