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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_577_Библиотеки_им_академика_М_И_Перельмана
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Ultrasound-Assisted Liposuction (UAL)
https://t.me/medicina_free
withVASER Technology inBody
13
Contouring
AlbertoDi Giuseppe, WilliamW.Cimino,
andFedericoGiovagnoli
Contents
13.1 Introduction 157
13.2 Physical Principles 158
13.3 Cavitation (Bubble Mechanism) 158
13.4 Effects of UAL 159
13.5 How VASER Ultrasound Works 160
13.6 VASER Technology: The VASER System 160
13.7 VASER Technique 161
13.8 Infusion and Emulsication 162
13.9 Probe Selection 162
13.10 Aspiration 163
13.11 Tissue Selectivity 164
13.12 Skin Retraction: Endoscopic Evaluation 165
13.13 Autologous Fat Transfer with VASER Fat 167
13.14 Hematocrit 168
13.15 Optimizing Outcome 169
13.16 VASER Results 169
References 169
13.1 Introduction
Ultrasound-assisted liposculpture has developed as a modication of liposuction for body contouring and fat reduction.
The effect of sound waves in the subcutaneous tissues is to
emulsify the adiposities and, at the same time, preserve the
A. Di Giuseppe (*)
University of Padova, Padova, Italy
W. W. Cimino
University of Purdue, Louisville, CO, USA
e-mail: cimino@gidbio.com
F. Giovagnoli
University Vita-Salute San Raffaele, Milan, Italy
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2023
A. Di Giuseppe et al. (eds.), Fat Transfer in Plastic Surgery, https://doi.org/10.1007/978-3-031-10881-5_13
vessels and nerves. The technique relies on the surgical use
of ultrasonic energy, which allows the selective destruction
or emulsication of adipose tissue producing a “cream”
which is then aspirated. The procedure produces less edema
and bruising than traditional liposuction and allows a great
degree of skin retraction owing to “stimulation” of the dermis of the treated areas. Clinical application of ultrasoundassisted lipoculpturing is for primary lipodystrophy,
secondary cases, and difcult areas such as inner thigh, circumferential thigh, calf, ankle, neck, chin, arm, anks, and
abdomen.
There is little blood loss, and a greater volume of fat tissue can be removed in one session. Ultrasound- assisted
liposuction (UAL) can be used to treat obesity. This method
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A. Di Giuseppe et al.
has been applied to surgery of the breast for volume reduction of the adipose components in the fatty breast (mostly
in juvenile breast) and skin retraction after dermis stimulation for correction of minor degree ptosis. The main concept of this technique relies on the selective destruction of
mainly the uid fraction of the adipose tissue, which represents nearly 90% of all the adipose tissue volume. In contrast to traditional liposuction, which attacks and destroys
mechanically all the structures of the dermis, which may
have undesired side effects, UAL selectively destroys only
the target adiposities and spares the supporting structures
of the skin and dermis, such as vessels, nerves, collagenic
matrix, and elastic bers, thus conserving the elasticity of
the treated areas [1].
Suction-assisted lipoplasty (SAL) is generally regarded
as safe and effective with well-known and well-documented clinical results and potential complications. For
this method of lipoplasty the fundamental mechanism of
tissue removal is avulsion, that is, the fatty tissue is pulled
into a hollow suction cannula by vacuum and then avulsed
or torn by the movement of the cannula. Results and potential complications are a direct function of the avulsive/cutting process.
VASER-assisted lipoplasty (VAL) presents a fundamental change in the treatment and subsequent removal of targeted fatty tissues. The fatty tissue is rst selectively
emulsied using ultrasonic frequency vibrations delivered
on a metal probe and then the emulsied tissues are removed
using a gentle, minimally avulsive aspiration process. The
VASER system's high selectivity for fatty tissue results in
decreased overall damage to the tissue matrix comprising
fat cells, vessels, nerves, structural tissues, and lymphatic
tissue. VAL uses ultrasonic frequency vibrations to emulsify
the fatty component of the tissue matrix but in a fundamentally different manner than earlier versions of ultrasonic
instrumentation for lipoplasty, namely, ultrasound-assisted
lipoplasty (UAL). The primary differences are that the
USER system delivers signicantly less power to the tissues
while simultaneously increasing fragmentation/emulsion
efciency compared with UAL devices and eliminating the
simultaneous aspiration feature of UAL devices [2, 3].
Ultrasonic energy was introduced to the plastic surgery
community in the form of UAL in the late 1980s and early
1990s [4–9]. UAL technology was characterized by largediameter (5-mm) ultrasonic cannulae, simultaneous aspiration and emulsion, continuous energy delivery, and
sharp-edged elements at the cannulae ends, usually associated with the suction pert holes. The UAL technique was
characterized by generally longer application times than
those of SAL owing to low-efciency ultrasonic cannulae
designs to create the emulsion and low- efciency aspiration
owing to the small (2-mm) suction lumens in the ultrasonic
cannulae. While both excellent results [10–15] and complications [16–21] were reported, there was no clear understanding of the causes for the excellent results or the
complications other than the unfortunate general assignment to “ultrasonic energy.” VASER technology uses ultrasonic frequency vibrations but delivers the energy to the
tissues in a substantially different manner than UAL. In
brief, VAL technology is characterized by small-diameter
probes (2.2–3.7-mm diameter), pulsed delivery of the ultrasonic energy, and grooved probe designs that provide energy
dissipation along the sides of the probes in addition to the
front face of the probes. The VAL technique is characterized
by procedure times similar to or shorter than typical SAL
procedure times and incision sizes comparable to those of
SAL.The amount of power delivered to the tissues and a
method of measure during the efciency of each probe
design (including other ultrasonic devices) are summarized
in the research published by Cimino [2].
13.2 Physical Principles
The standard acoustic spectrum comprises a wide range,
going from 1Hz (infra-sound) to 100Hz (audible sound),
to 10–100mHz (ultrasound), which is too high to be perceived by the human ear. This frequency spectrum has been
utilized in industrial application and medical application.
The audible sound range varies from 100 to 10,000Hz, and
the medical application range varies from 105 to 107Hz.
Ultrasound waves are the result of the transformation of
normal electric energy into high-frequency energy (over
16kHz). These waves are produced by high-power ultrasonic generators, which produce and transform the electric
energy into ultrasonic energy. The energy from the generator is transmitted to a piezoelectric quartz crystal or ceramic
transducer and then transformed into mechanical vibrations
that are amplied and transmitted. Other medical applications of ultrasound are dental cleaning, phacoemulsication for cataract surgery, diagnostic imaging, kidney calculi
fragmentation, and in neurosurgery.
13.3 Cavitation (Bubble Mechanism)
Cavitation can be dened as a peculiar activity induced by
the application of ultrasound waves in a liquid or liquid-like
material that contains bubbles or pockets of gas or vapor. The
consequences could be the production of stable or transient
13 Ultrasound-Assisted Liposuction (UAL) withVASER Technology inBody Contouring
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Fig. 13.1 Cavitation is the result of compression and rarefaction pressure. Photo taken from VASER Solta Medical User’s Guide [24]. Courtesy
of Bausch, ©2022 Bausch Health Companies Inc., All Rights Reserved
159
cavitation. In order to allow the cavitation to occur, the following conditions must be met:
1. Must have dissolved fat in the tissue.
2. Must have nucleation site at which microbubbles form.
3. Density/viscosity of the medium must not be very high.
Fatty tissues cavitate more easily than compact tissue, and
tumescent inltration makes cavitation easier. There is an
increase in the fragility of the target cell (adiposity), and the
acoustic intensity must exceed a threshold to cause the bubbles to grow. As a consequence of the cavitation phenomenon, implosion of bubbles results in cell disruption and fat
emulsication.
In order to produce this mechanism, a special titanium
probe attached to the piezoelectric transducer is able to
convert the ultrasonic energy into the tip of the probe with
100% of the energy translated into ultrasonic energy at the
tip of the probe. The cycle of ultrasound waves is passed
through the titanium probe and causes an alternation of
circular waves with nodal points of energy concentrated
along the probe and into its tip. All of the energy will be
concentrated in a perfectly functioning and efcient
system.
The bubble mechanism (cavitation) causes the formation
of bubbles of progressively increasing size in the fatty compartment. The alternation of positive and negative pressures,
with an expansion and contraction at a frequency corresponding to the ultrasonic wave, leads to the progressive
instability of the bubbles and microcavities already formed
until their nal explosion. Expansion and compression,
implosion and explosion, related to alternate cycles, are the
phenomena causing cavitation which leads to the nal
destruction of the target cells, the adiposity (Fig.13.1).
13.4 Eects ofUAL
The effects of UAL on adipose tissue are:
1. Micromechanical effect: The consequence of damage
produced by the direct action of the ultrasonic waves and
the organic intracellular molecules, which are violently
moved and displaced in the extracellular space with subsequent breaking up of macromolecules.
2. Cavitation effect: The cellular fragmentation from cavitation determines the diffusion of the lipid matrix (fatty
acids) of the adiposity into the inter cellular space where
a stable emulsion with interstitial uid and inltration
solution occurs. The formation of free radicals and the
denaturation of the lipoprotein components of the cellular
membranes may lead to a progressive lipolytic action,
which will partially continue even after the ultrasonic
treatment has ended.
3. Thermal effect: A hyperemic secondary mild effect is
associated with the friction action of the titanic ultrasonic
probe moving through the tissues. These effects are
restrained and negligible if the technique is properly
applied. Thermal effects do not cause any damage to
cells, structures, or uids involved and do not cause any
undesired biological reaction, especially at the protein
chain level (Figs.13.2 and 13.3).
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Fig. 13.2 The growth of the microbubbles to almost 200μm forces the
fat cell apart. As the microbubbles reach resonant size and collapse they
dislodge fat cells from the tissue matrix. Photo taken from VASER
Solta Medical User’s Guide [24]. Courtesy of Bausch, ©2022 Bausch
Health Companies Inc., All Rights Reserved
A. Di Giuseppe et al.
Fig. 13.4 VASER probe in action. Photo taken from VASER Solta
Medical User’s Guide [24]. Courtesy of Bausch, ©2022 Bausch Health
Companies Inc., All Rights Reserved
ing to further break up the fat into small clusters of cells.
Small groups of cells are ideal for fat transfer (Fig.13.4).
Fig. 13.3 Acoustic streaming is the result of powerful uid forces that
create swirling around the vibrating ultrasonic probe tip. This swirling
causes the fat cells that have been dislodged from the matrix to mix the
infusion uid creating the emulsion. Photo taken from VASER Solta
Medical User’s Guide [24]. Courtesy of Bausch, ©2022 Bausch Health
Companies Inc., All Rights Reserved
13.5 How VASER Ultrasound Works
There are millions of microscopic air bubbles in tumescent
solution. When the bubbles are exposed to ultrasound energy,
they expand and eventually collapse. These bubbles act as
miniature crowbars to force the fat cells apart. Once the fat is
loosened, it is mixed with the tumescent uid to form an
emulsion. Acoustic streaming causes intense localized swirl-
13.6 VASER Technology: TheVASER System
The technological advancements incorporated in VASER
technology are designed to deliver the absolute minimum
amount of vibratory energy to the tissues and still achieve the
desired emulsication/fragmentation of the fatty component
of the tissue matrix. These advancements include the use of
small-diameter solid probes in the range of 2.2–3.7 mm,
grooved probe designs to increase efciency, pulsed delivery
of the vibratory energy to reduce the average energy delivered, gentle aspiration cannulae designs to reduce tissue
avulsion while maintaining aspiration performance, and
rened instrumentation design with regard to size and weight
to provide more artistic use and movement (Fig.13.5).
The amount of energy delivered to the tissues by an ultrasonically vibrating probe is roughly proportional to the
square of the diameter of the ultrasonic probe or cannulae,
meaning that small reductions in diameter result in signicant reductions in delivered energy. Therefore, the design
objective is to utilize the smallest possible diameter probe
that accomplishes the desired emulsication in a reasonable
time. Generally speaking, probes smaller than about 2mm in
diameter are too exible to control (unless they are very
short), and probes larger than about 4mm in diameter present excessive amounts of energy to the tissues. The performance tradeoff is that these smaller diameter probes have
reduced contact area with the tissue and will therefore take
longer to achieve the desired emulsication. To increase the
efciency of the emulsication process and to decrease the
operative time, grooves have been added to the tips of the
13 Ultrasound-Assisted Liposuction (UAL) withVASER Technology inBody Contouring
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1
2
3
Fig. 13.6 VASER Grooved probes. Photo taken from VASER Solta
Medical User’s Guide [24]. Courtesy of Bausch, ©2022 Bausch Health
Companies Inc., All Rights Reserved
4
The advantage of VASER mode is that the peak energy is
delivered in a short burst (the on condition) and is strong
enough to emulsify fatty tissue, while the average energy
delivered over time is reduced compared with that for the con-
Fig. 13.5 VASER system includes: (1) ultrasound amplier (2) precision uid management system (3) VentX inltration and aspiration console (4) wireless foot switch system. Photo taken from VASER Solta
Medical User’s Guide [24]. Courtesy of Bausch, ©2022 Bausch Health
Companies Inc., All Rights Reserved
tinuous mode. VASER mode delivers around ten bursts per
second to the tissues, fast enough so that VASER mode is generally imperceptible to the surgeon and fast enough so that the
resultant on/off effect is uniform, smooth, and repeatable with
regard to emulsication of the tissue. If the burst rate is less
probes to provide additional emulsication zones. With this
grooved design, the tissue that contacts the sides of the
probes will be emulsied in addition to the emulsication
that occurs on the front surface of the probe, signicantly
increasing the emulsication efciency and decreasing opera
drive time.
Because the vibratory energy is dissipated from the sides of
the probe as well as the front surface of the probe, the energy
is less concentrated and results in a softer and more effective
emulsion of the fatty tissue. The number of grooves determines the relative partitioning of the vibratory energy. Four
than about ten times per second, then the on/off effect of the
device begins to present a timing issue to the surgeon with
regard to the forward and backward strokes of the device and
also tends to produce less consistent results because of the
physical spacing of the on periods in the tissue. Emulsied
fatty tissue is more easily removed with aspiration cannulae
than non-emulsied fatty tissue; therefore, only gentle aspiration is required. A series of emulsion cannulae, called the
VentX cannulae, were designed for efcient emulsion removal
and minimal trauma to the tissue matrix. The cannulae design
features are discussed in detail in the next section (Fig.13.6).
identical 3.7-mm probes were evaluated, having zero, one,
two, and three grooves. The results show that increasing the
number of grooves moves more energy to the sides of the
13.7 VASER Technique
probe. Note also that the overall power and efciency also rise,
meaning that the probes with more grooves are not only more
efcient but are also able to contact more tissue. The applicability of the different probe designs to different types of tissue
(soft to brous) is discussed in detail in the next section on the
VAL used in previous-generation UAL devices. The second
form is pulsed mode, a form where the vibratory energy is
delivered in short duration bursts, referred to as VASER mode.
The following guidelines cover safe and effective use and
application of the VASER system for VAL including the
infusion, emulsication, and aspiration phases. Probe selec-
tion for the various types of tissues (guideline 4) is discussed
in detail following the 11 guidelines for infusion and emul-
sion. Aspiration is discussed after the section on probe
selection.
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A. Di Giuseppe et al.
13.8 Infusion andEmulsication
1. Infusion. Use sufcient and appropriate amounts of wet-
ting solution. Make sure that the wetting solution is uniformly and evenly distributed in the intended
fragmentation volume. A gentle rmness and fullness in
the targeted area are desirable. Allow sufcient time for
vasoconstrictive requirements (usually at least 10min
minimum for 1:1000000 concentrations). Apply wetting
solution slightly beyond the marked boundaries and in
all potential port locations. If you cannot achieve a sufcient distribution of uid, then do not use the VASER
system in that location. The targeted ratio of wetting
solution into total aspirate out is approximately 1.5:1. If
more than a 2:1 ratio is used, the VASER system begins
to lose efciency owing to the presence of excessive
uid. If less than a 1:1 ratio is used, then there will not
be enough uid to easily form an emulsion.
2. Incision protection. Skin ports are designed to protect
the incision edges during the fragmentation phase with
minimal incision size (approximately 4-mm incision)
and also protect the incision edges during the suction
phase. The skin ports should go in easily; otherwise, the
incision is too small, or the port is hooked on the underside of the dermis.
3. Skin protection. Use a towel (wet or dry) to cover the
skin near the skin port. This protects the skin in the accidental situation where the probe is levered into any
exposed skin near the skin port. This is especially important across the lower abdomen when working in the
upper abdomen and near creases (buttocks). Note: A
single towel layer will not protect the skin from prolonged contact with the vibrating probe or if the probe is
levered strongly into the skin through the towel. If prolonged contact or strong levering is unavoidable, use a
triple-folded towel to ensure skin protection.
4. Probe selection. Use the correct probe. Adjust the setting
so that the probe moves smoothly through the tissue. If
the probe is dragging or struggling, then all of the energy
will be used to penetrate the tissue, and very little emulsion will occur. In this case, move the amplitude up a
notch or two. If this does not solve the problem, switch
to a probe designed for more brous tissues.
5. Probe movement. Keep the probe moving at all times.
Move it smoothly at a speed that the tissue and amplitude setting will allow without excessive pushing. Do
not let the probe sit (vibrate) in one location. A speed
just slightly slower than standard suction cannula movement is appropriate.
6. Torquing. Do not torque the probe! Move the probe in
and out like spokes of a wheel, do not lever (torque) the
probe sideways or up and down. The skin protector
should not be used as a fulcrum. Torquing will lever the
probe into the skin protector so that frictional rubbing
can cause heat build-up in the skin protector.
7. Application time and surgical end points. Look for a loss
of resistance to probe movement in all areas of the
intended fragmentation volume as the primary indicator
of the surgical end point. Initial application times can be
based on 1min of ultrasonic application (continuous or
VASER mode) for every 200 mL of wetting solution
infused at a site. This guideline usually results in only
partial emulsication of the target volume. With experience, application times can rise to 1 min for every
100mL of wetting solution. This guideline results in a
more complete emulsication of the target volume.
(These times are only suggestions; your requirements
will be dictated by many factors that cannot be covered
in this short space.) Special note: For the upper abdomen, use 1 min of ultrasonic application for every
200 mL of wetting solution infused until experience
allows otherwise.
8. End-hits. Prevent end-hits or punching into the dermis
from below. Place incisions so that probe movement is
generally parallel to the skin. Do not try to go around
tight corners – this may result in potential an end-hit or
torquing of the probe.
9. Cross-tunneling. Cross-tunneling is highly desirable for
more uniform fragmentation and to improve the subsequent aspiration performance.
10. Free air vibration. Keep the tip of the probe inside the
patient at all times. Do not vibrate the probes in free air,
or they may be subject to cracking.
11. Dry application. Do not reapply the VASER probe after
a site has been aspirated (the site is dry).
13.9 Probe Selection
One of the most critical understandings necessary for successful VAL is the proper choice of the probe for the tissue
type, tissue volume, and anatomical location. The key elements are (1) the diameter of the probe and (2) the number of
grooves located at the tip of the probe. The smaller-diameter
2.9-mm probes all have three grooves for maximum ef-
ciency and can be used on tissue from soft to brous because
of their small diameter. The 3.7-mm probes may have one
groove, two grooves, or three grooves and should be selected
based on the tissue type and intended application. Tissue
type ranges from very soft to very brous in ve grades as
shown in Table 13.1. The probe design and appropriate
amplitude settings for each tissue type are shown. Table13.1
shows additional guidelines for the selection and use of the
various probes.
13 Ultrasound-Assisted Liposuction (UAL) withVASER Technology inBody Contouring
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Table 13.1 Tissue type, VASER-probe selection, mode and amplitude setting. Photo taken from VASER Solta Medical User’s Guide. Courtesy
of Bausch, ©2022 Bausch Health Companies Inc., All Rights Reserved
Continuous
Tissue type
Very soft Ye s Yes 60–80 70–80 70–80 –
Soft Yes Yes 60–80 70–90 70–90 70–80
Medium Ye s Ye s 70–90 80–90 80–90 70–90
Fibrous Yes 2.9mm
Very
brous
mode?
Yes No 80–90 – – 80–90
VASER
mode?
only
2.9mm, 3-groove
(any length)
80–90 – 80–90 80–90
3.7mm, 3-groove
(any length)
3.7mm, 2-groove
(any length)
3.7mm, 1-groove
(any length)
163
1. Do not vibrate the probes in free air. Always keep the tip
of the probe, at least the distal 1–2cm, in contact with
tissue or uids and inside the patient and skin port before
initiating vibration. Vibrating the probes in free air can
lead to cracking of the probe owing to unintended transverse vibrations.
2. The 3.7-mm probes are intended for rapid debulking and
contouring of medium to large volumes of soft to brous
tissue.
3. The 2.9-mm probes are intended for debulking and
ne contouring smaller volumes of soft to extremely
brous tissue, sensitive areas, and more supercial
work.
4. General volume considerations. If a single anatomical
site is expected to yield less than about 500mL, then consider using the 2.9-mm probes. If the expected volume
(single anatomical site) is estimated to be between 500
and 1000 mL, then consider using either the 2.9-mm
probes or the 3.7mm probes, depending on how brous
the tissue is and the nature of the anatomical site. If the
expected volume is over 1000 mL (single anatomical
site), consider using the 3.7-mm probes.
For a given diameter, probes with more grooves (rings)
fragment tissue more efciently but do not penetrate brous
tissues as easily because a signicant amount of the vibratory energy is coupled from the sides of the probe as opposed
to the front surface. Therefore, for a given diameter, probes
with fewer grooves (rings) are more appropriate for brous
tissues. If the tissue is too brous for a selected 3.7-mm
probe design, select a probe with fewer rings. For comparison purposes, a three-ring 3.7-mm probe distributes approximately 58% of its energy from the sides and 42% from the
front surface. A two-ring 3.7-mm probe distributes approximately 45% of its energy from the sides and 55% from the
front surface. A one-ring 3.7-mm probe distributes approximately 35% of its energy from the sides and 65% from the
front surface.
Smaller-diameter probes will penetrate brous tissues
more easily than larger-diameter probes, irrespective of the
number if rings. The 2.9-mm diameter probes all have three
rings because their smaller diameter allows penetration of
even the most brous tissues with three rings.
General recommendations: Use the 3.7-mm two-groove
probes for most applications, 70–90% amplitude. Use the
3.7-mm three-groove probes for larger volumes of very soft
tissue (70–90% amplitude) or the 3.7-mm one-groove probes
for more brous tissues (70–90% amplitude). Use the 2.9mm three-groove probes for smaller volumes, sensitive
areas, ne contouring, or very brous tissues (60–80%
amplitude). Ninety percent amplitude may be used with any
2.9- or 3.7-mm probe, but consider selecting a probe more
appropriate for the “brousness” of the tissue if 90% amplitude is required for smooth, gliding motion. Use continuous
mode for general use, if tissues are quite brous, or for
higher-speed fragmentation. Use VASER mode for more
delicate work, softer tissues, or for ner sculpting. VASER
mode may be used for general use when probe selection is
appropriate (Table13.1).
13.10 Aspiration
Once a fatty area has been emulsied the next step is to
remove the emulsied tissues and uids using aspiration.
In theory and in practice, almost any type of aspiration
cannula will sufce. However, aggressive suction of an
area treated with the VASER system is generally not
required and will result in excessive trauma to the tissue
matrix. Once appropriately treated with the VASER system the fatty tissue is largely in uid form and does not
require high-vacuum aggressive avulsion for removal. A
gentle aspiration is sufcient and expedient and will result
in decreased trauma to the tissue matrix. For this purpose,
a gentle aspiration cannula, called Vent cannula, were
developed to complement the emulsication of the VASER
system. VentX cannula employ smaller port sizes for a
selected cannula diameter than more traditional cannula
and are less traumatic than traditional cannulae. The
largely uid emulsied tissues are re moved, while the tissue matrix is maintained. The port size (slot width and
length) and the cannula diameter determine the application
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of the cannula, the speed of the cannula, and the aggressiveness of the cannula. The VentX cannulae use port sizes
that maximize tissue and uid removal speed while reducing suction trauma by balancing the total area of the ports
with the cross-sectional area of the cannula. Port sizes
with areas larger than the cross-sectional area of the cannula lumen, as in most traditional cannula designs, are
unnecessarily traumatic.
The recommended approach to the selection of a Vent X
cannula is to use a diameter one size larger than you would
normally use because the port sizes on the VentX cannulae
are smaller than those found on traditional suction cannula.
The cannula descriptions that follow should help with cannula selection. The 4.6-mm SST-6 pattern is designed for
rapid emulsion removal and debulking with small ports for
reduced suction trauma. The port size on this cannula la is
slightly smaller than the port size on a traditional 3.7-mm
Mercedes cannula. The 3.7-mm SST-6 pattern is designed
for general debulking and shaping with less suction trauma
than a standard 3.7-mm Mercedes cannula. The port size on
this cannula is slightly smaller than the port size on a traditional 3.0-mm Mercedes cannula. The 3.0-mm SST-6 pattern
is designed for nishing and feathering, or slightly slower
but less-traumatic debulking. The port size on this cannula is
slightly smaller than the port size on a traditional 2.4-mm
Mercedes cannula. In addition to smaller port sizes, these
cannulae also include a precision continuously vented handle that creates a means by which the suction tube is continuously cleared during the aspiration process. This continuous
venting has been named the VentX effect and decreases the
available vacuum at the cannula by approximately 0.25–
0.50in. Hg. The VentX effect signicantly increases the efciency of aspiration when large amounts of uid/tissue are in
the suction tube. The suction tube will always appear to be
empty because the VentX effect continually and rapidly empties the suction tube even when the cannula remains inserted
in the patient. The VentX effect does not have a strong impact
on suction performance during the nal feathering and nishing steps because very little tissue/uid is in the suction
tube.
13.11 Tissue Selectivity
The VASER system spares the tissue matrix, removing primarily the fatty component, producing smooth, predictable
results (Figs.13.7 and 13.8).
A. Di Giuseppe et al.
Fig. 13.7 Post ultrasound treatment
Fig. 13.8 Post aspiration
Fatty tissue is broken apart, and cells are suspended in
inltration uid. Connective tissue is left intact after adipose
tissue has been removed.
Fat cell structures are affected most by cavitation because
the tumescent uid containing the microbubbles can inltrate between the cells.
Other tissues, such as blood vessels, muscles, fascia, and
nerve bundles, have tighter interstitial cell junctions preventing the microbubbles from getting in between the cells.
Thus ultrasound action is uniquely tissue selective.
Ultrasound does not cavitate fat cells; it cavitates microbubbles in the tumescent uid, inltrated among the fat cells.
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13.12 Skin Retraction: Endoscopic
Evaluation
The application of the ultrasonic probe must be in the subdermal area in order to induce postoperative skin retraction.
The duration of the procedure and the amount of energy
required to liquefy the excess fat vary with the character of
the tissue, the volume of the planned reduction, and the type
of lipodystrophy. Hypertrophic lipodystrophy is easier to
treat the mixed lipodystrophy or hyperplastic lipodystrophy.
Less energy is required when the adiposity container has
large volumes of uid compared with tissues that are rm,
and the fat content and the ratio of tissue to are less. For
instance, in the treatment of inner thigh application of ultrasonic energy set at 65% power for 10–12min is required to
obtain a volumetric reduction of 250mL and to give good
skin stimulation. Clinical experience is helpful in establishing the time of application of the ultrasonic energy. The
author applies up to 1 h of ultrasonic energy to defat the
abdomen. The number and the location of access incisions
also vary according to the treatment site. For the abdomen,
usually, only a 2-cm suprapubic incision is required for
good radial energy application. The addition of two 3-mm
incisions in the upper lateral sides of the abdomen allows
the removal of only the emulsion with a traditional small
Teon-covered cannula connected to a low-pressure (0.3
atm) vacuum. For the buttocks and lateral and posterior
sides of the thighs, two 2cm incisions located in the middle
portion of the infragluteal fold on each side are utilized.
Tazi and Schean [22] introduced endoscopic evaluation of
ultrasound-assisted liposculpture. The author began using this
method with a Storz endoscopic system and camera. The
tumescent technique was used in the inner thigh area and the
abdomen. The instrument was placed in the supercial layer of
the subcutaneous fat veried by needle depth. subcutaneous
fat veried by needle depth. UAL was performed with crisscross tunnels, recording the technique by video. An adjacent
area was treated with standard liposuction. The results were:
1. Standard liposuction appears to be a more aggressive
technique, with mechanical destruction of the subcutaneous tissue, including vessels, nerves, and supporting
structures.
2. Ultrasonic liposculpting is a gentler, selective method,
which is aggressive only in the fatty compartment of the
body, sparing vessels, nerves, and elastic supporting
bers. Alterations in the tissue resulting from the use of
SAL are a thickened der mal undersurface, markedly
thickened vertical collagenous bers, intact lymphatic
vessels, and intact blood vessels.
Schean and Tazi [22] hypothesized that this horizontal
and vertical thickening and shortening of the collagen in the
dermis and ligamentous bers is responsible for the remarkable skin tightening. The closer to the skin and the more
complete the removal of fat from the immediate subdural
space, the greater the skin-tightening effect. Although infrequent, signicant complications such as thermal burns and
skin necrosis are possible (Figs.13.9 and 13.10).
Measuring skin retraction is very difcult, apart from
clinical evidence. A new technique of developed- invisible,
UV-activated micro-dot tatooc can help measure the skin
retraction of each area of the patient skin (Figs.13.11 and
13.12).
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A. Di Giuseppe et al.
Fig. 13.9 Supercial fat treatment and tissue remodelling with elastic
retraction: selective fatty tissue emulsication of the supercial layer,
helps to expose and denude the elastic and connective structures of the
subcutaneous tissues, by doing that in a safe way, as sparing vessels and
nerves, tissue retraction capabilities are amplied
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