Chapter 8 Ultrasound-assisted breast reduction
As is known, ultrasound energy was initially used by Zocchi1–6 to emulsify fat. A special instrument, composed of an ultrasound generator, a crystal piezoelectric transducer, and a titanium probe transmitter was utilized to target adipocyte cells. This new technology was first applied to body fat to emulsify only fat cells while sparing the other supporting vascular and connective components of the cutaneous vascular network. More recently, Goes,7 Zocchi,1–6 Benelli8 and di Giuseppe,9–12 have started to apply this technology to breast tissue to achieve breast reduction and correction of mild to medium-degree breast ptosis.
The ideal candidates for a breast reduction with ultrasound-assisted lipoplasty (UAL) are patients with juvenile breasts, which usually have fatty parenchyma, or patients with postmenopausal involution parenchyma, with good skin tone and elasticity present. Between 60 and 70% of women with large breasts are candidates for reduction with UAL. The preoperative assessment includes a mammographic study, breast clinical history, evaluation of breast ptosis, and evaluation of the consistency of breast parenchyma.
Preoperative mammograms (anteroposterior and lateral views), the so-called Ecklund view, are taken to evaluate the nature and consistency of the breast tissue (fibrotic, mixed or fatty parenchyma ), distribution of the fat, presence of calcifications, and areas of dysplasia or nodularity that might necessitate further studies (Fig. 8.1). The presence of fibroadenomas, calcifications, and other suspected or doubtful radiologic findings should be double-checked with ultrasound and a radiologist experienced in breast tissue resonance.
(A) A typical fatty breast. This patient is an ideal candidate for UAL. (B) Fibrotic glandular tissue is a contraindication for UAL .(C) Fibrotic mixed tissue. This patient is a candidate for UAL of the posterior upper and lower cone.
Furthermore, because the amount and distribution of the breast fat is variable, not all women are candidates for breast volume reduction with UAL. If fat and glandular tissue are mixed, penetration of the tissue may be impossible, as noted by Lejour13 and Lejour and Abboud.14 If the breast tissue is primarily glandular, the technique is not indicated.
In deeper and intermediate layers I expect a 1.5 : 1 ratio between infiltration and aspirate; in the superficial layer I normally infiltrate twice what I expect to extract (2 : 1 ratio). I use blunt infiltration cannulas, as described by Klein,15 15–20 cm long.
The operation begins with the introduction of the skin protector placed at the incision site, normally placed 1 cm below the inframammary crease. Another incision is normally placed at the axilla, at the same length.
A further incision is placed around the areola margin, and is utilized to address the superficial layers of the upper quadrants, if required. This skin port is designed to protect against friction injuries by the probe during its continuous movement.
The fatty breast is emulsified in the lateral and medial compartments, the upper quadrants and the inferior aspect of the periareolar area. All the periareolar area, where most of the glandular tissue is localized (5 cm circumference around the nipple–areola complex), is preserved.
The deep portion is also emulsified, allowing the breast mold to regain a natural shape through upward rotation, thus increasing the elevation from its initial position, taken from the midclavicular notch. Up to 4 cm of elevation is obtained after proper reduction and stimulation to allow skin retraction and correction of the ptosis.
Through these incisions the surgeon can reach all the breast tissues, working in a criss-cross manner. Recently, the ultrasound device software has been upgraded to provide the same degree of cavitation with less power, which reduces the risk of friction injury and burn at the entrance site; this even allows discontinuing the use of the skin protector.
With existing technology, a solid probe is more efficacious than a hollow probe for cavitation, which is the physical phenomenon that allows fat fragmentation and destruction. Moreover, the level of ultrasound energy conveyed by a hollow probe is limited, and consequently the level of the cavitations obtained in the tissue is diminished.
The Vaser system (Sound Surgical Technologies, Denver, CO, USA) provides different sizes and lengths of solid titanium probes (Box 8.1) expressly designed to fulfill all purposes in body contouring, as well as being capable of emulsification through the cavitation effect produced by the ultrasound energy. The piezoelectric transducer transforms electric energy into “vibration energy”, thus allowing the solid titanium probe to emulsify the target fat cells.
Four Different Probe Diameters are Actually Provided by the Manufacturers
The efficacy of these probes, which are narrower than the previous technologies available on the market, is connected to their design, as they are provided with rings (one, two, or three) at the tip of each probe. These rings have two special functions:
These options are not purely an academic difference: the energy and the wavelength of each probe is selected for the target tissue, avoiding unnecessary extra power and wasted energy, which is a potential cause of secondary unwanted complications (already seen with previous technologies).
In breast reduction with UAL the duration of the procedure varies depending on the volume of reduction, the type of tissue encountered, and the amount of skin retraction required. A breast with purely fatty tissue is easier to treat than one with mixed glandular tissue, in which fat cells are smaller, stronger, and denser (Fig. 8.5).
The author has started utilizing the Vaser ultrasound device with solid probes (2.9–3.7 mm wide). It delivers 50% of the ultrasound energy in comparison with the older Sculpture unit (SMEI, Casale Monferrato, Italy), which was used from 1990 to 2001, while emulsifying fatty tissue much more efficiently. Treatment of the target tissues starts with 10–15 minutes of ultrasound energy in fat tissue, which usually produces between 250 and 300 ml of emulsion.
The surgical planes, with good criss-cross tunneling and adequate undermining, are planned in the preoperative drawings. If large undermining is required for skin retraction, the superficial layers are treated initially. Then the deeper planes are reached, and more time is spent in thicker areas. Surgeons inexperienced in the procedure should be especially cautious when performing the technique, particularly in the subdermal planes.9–12,15–19
Together with UAL application to the fat layers, starting from the deeper layers and progressing to the more superficial ones, it is advisable to thin the superficial layer of the subcutaneous tissue of the upper and lower quadrants by using a different angle pattern, as in standard lipoplasty.20,21 This superficial undermining with low-frequency ultrasound energy helps to enhance the retraction of the breast skin and to redrape the breast skin to the newly shaped and reduced mammary cone (Fig. 8.6).
To facilitate these maneuvers, I often place a second tiny incision at the axilla, and (sometimes) at the areola border. This helps the superficial work of the probe. The undermining has to be complete, with full liberation of all adhesions within the deeper layers.
Vaser is selective, and does not interfere with the vascular network of the dermal tissue, if properly made. It divides the connective and supporting structures of the skin. Rudolph (1991)22 showed the great potential of the dermal layer in wound contracture. As much as the dermis is thinned, so much contraction will result, providing the tissue vascularization is preserved.
Tissues contract more easily, and when combined with the force of gravity, which helps the upward rotation of the gland (when decreased in weight), the final result is a greater contraction of the breast, with a superior antigravity effect.