MATERIALS AND METHODS
Records were collected, and 1000 cases of truncal liposuction were analysed. Abdominoplasty
procedures were excluded. The following classification of aesthetic subunits of the
trunk was devised [[Figures 1]
[2]]
Figure 1: Aesthetic Subunits of Anterior abdomen
Figure 2: Aesthetic subunits of posterior trunk
-
Upper midline-overlying the linea alba from the xiphisternum to the umbilicus
-
Upper rectus-overlying the rectus muscles from lower costal margin to umbilicus on
each side
-
Lower rectus-single unit over both the recti from the umbilicus to the upper pubic
hairline
-
Lateral abdominal-overlying the oblique muscles, on either side of the recti from
the costal margin to the inguinal ligament, until the midlateral line. This was further
divided into two parts:
-
Pubic-below the pubic hairline
-
Lumbar-overly the lumbar muscles from the costal margin to the gluteal region, until
the paraspinous muscles posteriorly
-
Posterior midline-overlies the sacrum, spinous processes and the paraspinal muscles
-
Bra roll-above the lumbar unit, extending into the infraaxillary region.
This classification allows us to identify each aesthetic zone of the trunk. The pattern
of fat distribution and overlying skin quality varies in different zones. The underlying
musculoskeletal structure gives an aesthetically pleasing shape to the torso. This
shape gets altered with fat accumulation. While some patient with excess fat in all
the zones may still have aesthetically curved torso, others may lose the contour due
to irregular and uneven fat distribution pattern. Each zone has a characteristic shape
based on the underlying structure and overlying skin tone. Often, there is more volume
of fat deposited in the lower abdomen and lumbar region than upper abdominal zones.
The fat texture in upper zones is more fibrous and compact, hence has more risk of
irregularities following liposuction. The skin in the lower abdomen is loosely anchored
and skin sagging is more common in the lower abdomen.
Following this, a total of 2000 procedures were performed using the system from 2010
to 2018. All patients were evaluated with this classification. The subunits were marked
on patients preoperatively [[Figure 3]]. All cases were done under tumescent anaesthesia with intravenous sedation. Infiltration
was performed uniformly and symmetrically in all the zones. Zone 1 and Zone 2 have
tough fibrofatty tissue architecture; hence, it is more painful and tough to inject.
The risk of bleeding is more in upper abdominal zones. The lower abdomen has a loose
subscarpal fatty layer that allows easy infiltration and hence is less painful. The
posterior part of the trunk, particularly Zones 6 and 7 also have tough fibrofatty
tissue with dense deep adhesions. It requires thorough infiltration for adequate anaesthesia
and bloodless aspiration. A thorough and effective infiltration takes about 25–30
min.
Figure 3: (a) Marking of Aesthetic subunits of Anterior Trunk in a female for Body sculpting.
(b) Marking of Aesthetic subunits of Lateral Trunk in a female for body sculpting.
(c) Marking of Aesthetic subunits of Posterior Trunk in a female for body sculpting
Following infiltration ultrasonic emulsification is performed. Upper abdomen requires
more ultrasonic energy and time to emulsify than lower abdomen. A proper undermining
using ultrasonic device allows uniform skin retraction. Thorough emulsification helps
minimise bleeding, bruising, pain and allows good skin retraction. The average recommended
time is 1 min/100 ml of infiltrate [[Figure 4]].
Figure 4: Emulsified fat after ultrasonic liposuction
Then, liposuction was performed using 3 mm, 4 mm Mercedes type cannula. Zone 1 needs
thorough liposuction to achieve a nice midline groove. Zone 2 has tough, fibrous fat
and needs careful liposuction as there is a higher risk of accidental deeper injury
and a higher risk of lumpiness or skin irregularities. The cross tunnelling method
also helps prevent linear irregularities. The skin over this zone has tight adhesions
to underlying costal region and hence requires an adequate release for good retraction.
Zone 3 is easier to aspirate, but through deep and superficial liposuction is required
to achieve a good skin retraction. Zone 4a has tough, fibrous adhesion overlying the
costal region that requires proper undermining and release. Adequate deep fat extraction
in this zone gives a nice silhouette to the lateral part of the abdomen. Zone 4 b
has soft fat overlying oblique muscles and has two distinct layers above and below
the Scarpa's fascia.
A simultaneous liposuction for Zone 5 over the pubic zone is also important as the
patient may have a fat bulge if they gain weight postoperatively.
Zone 6 has two distinct layers of fat deep and superficial, deep fat is embedded in
the lumbar triangle and if not adequately removed the bulge may persist or recur with
weight gain. To achieve a highly desired lordotic lower back shape in women, both
these compartments must be treated.
Zone 7 has the ‘triangle of Venus’ inferiorly and midline depression overlying the
spinous process. It is ideal to completely remove fat in the Venus triangle and create
a midline groove if it is ill-defined. Zone 8, i.e., the bra roll area also needs
addressing as it is a common site of recurrence and exaggeration if patient continues
to gain weight.
During the procedure, the amount of infiltrate used, as well as the amount aspirated
was noted for each of the subunits [[Table 1]]. Zones also allow symmetrical and uniform aspiration. All the incision ports were
left open to drain. A compression dressing is applied for the first 24 h followed
by pressure garment. The first stage pressure garment was adviced for 4–6 weeks depending
on skin elasticity. A second stage pressure garment called ‘spanx’ was recommended
for 2–3 months. The foam was applied to different areas for additional compression.
Postoperatively, any asymmetries or complications were also documented using these
subunits. The follow-up protocol included schedules on day 2, day 5, 1 week, 3 weeks,
2 months, 4 months, 6 months, 1 year and 2 years. Every visit measurements was taken
and photography done.
Table 1
Intraoperative assessment of liposuction using subunits
|
Subunit
|
Infiltration (ml)
|
VASER energy
|
VASER duration (min)
|
Aspirate (ml)
|
|
I, II
|
500
|
80%
|
4
|
400
|
|
III
|
800
|
100%
|
8
|
700
|
|
IV (each side)
|
400
|
80%
|
3
|
250
|
|
V
|
100
|
80%
|
1
|
50
|
|
VI (each side)
|
400
|
80%
|
4
|
300
|
|
VII
|
100
|
80%
|
1
|
50
|
|
VIII (each side)
|
200
|
100%
|
2
|
150
|
|
Total
|
3500 ml
|
|
32
|
2450
|
RESULTS
Patients who were treated using this method of aesthetic subunits were satisfied with
their results. The results were assessed by physical examination, serial photographs,
measurements and patient satisfaction [[Figures 5]
[6]
[7]]. The use of these subunits enabled us to perform different degrees of liposuction
with different aims in each of the subunits which improved overall aesthetics. This
can be applied in all weight category patients who are fit for the liposuction procedure.
In more athletic individuals with good skin quality results are far superior. In moderately
overweight patients, good curvature can be achieved three-dimensionally. Use of the
subunits also had the following advantages:
Figure 5: (a) Anterior preoperative views of young female with body mass index 24. (b) Oblique
Preoperative views of Young female with body mass index 24. (c) Posterior Preoperative
views of Young female with body mass index 24. (d) 6 months Anterior Postoperative
views of same patient. (e) 6 months oblique Postoperative views of same patient. (f)
6 months Posterior Postoperative views of same patient. (g) 3 years anterior postoperative
of the same patient. (h) 3 years oblique Postoperative of the same patient. (i) 3
years posterior postoperative of the same patient
Figure 6: (a) Anterior preoperative views of young female patient with body mass index 26 for
body contouring, (b) Oblique preoperative views of young female patient with body
mass index 26 for body contouring, (c) Posterior preoperative views of young female
patient with body mass index 26 for body contouring, (d) Anterior Postoperative views
after 1 year, (e) Oblique Postoperative views after 1 year, (f) Posterior Postoperative
views after 1 year
Figure 7: (a) Anterior preoperative views of 54 years old patient with body mass index 32.
(b) Oblique Preoperative views of 54 years old patient with body mass index 32. (c)
Lateral Preoperative views of 54 years old patient with body mass index 32. (d) Anterior
Postoperative views after 6 months. (e) Oblique postoperative views after 6 months.
(f) Lateral Postoperative views after 6 months
-
Ease in planning
-
Ease in calculating infiltration required by subunit
-
Ease in calculating volume extracted from each subunit
-
Avoidance of errors-particularly asymmetry
-
Ease in follow-up.
Common complications in our series were skin unevenness in the upper abdomen, mild
asymmetry in the lower abdomen, visible scars and hyperpigmentation. There were no
incidences of seroma, skin loss, infection, etc.
DISCUSSION
The use of aesthetic subunits is well known in plastic surgery. Gonzales-Olloa designed
subunits of the face.[[4]] Scott Spear described subunits of the breast[[5]] and Mendieta described gluteal subunits.[[6]]
There have previously been a few attempts at devising an aesthetic classification
of the abdomen. The best known of these is that by Matarasso et al., which described seven subunits in females: upper abdomen, Lower abdomen, umbilicus,
flanks, mons, sacral area and bra roll. Moreover, 6 subunits in men: upper abdomen,
lower abdomen, umbilicus, flanks, mons sacral area.[[3]]
It was Mentz and Ersek who pointed out that traditional lipoplasty techniques fail
to achieve the desired results of abdominal contouring.[[7]
[8]] The Mentz technique of abdominal etching used differential lipoplasty to detail
abdominal musculature. However, it was designed for male bodybuilders and only the
anterior abdominal wall. In 2003, Hoyos presented a new technique of high definition
liposculpture.[[2]] This elevated the concept of etching to a three dimensional approach. It also integrated
the differing requirements of the male and female body. This became the gold standard
for abdominal contouring, and with its advent we found the Matarasso classification
lacking. Our system of aesthetic subunits of the trunk includes eight subunits, which
we will discuss under the headings of anatomy, procedure and precautions.
Zone 1 upper midline-overlying the linea alba from the xiphisternum to the umbilicus
Anatomy
This unit is a narrow unit overlying the linea alba, in between the recti. Anatomically, there are tight fibrous adhesions between the
skin and underlying rectus sheath. The groove is desirable by both men and women.
In an athletic individual, it is well defined, but as weight increases, the groove
disappears. The linea alba may also widen with diastasis of the recti in pregnancy and lead to an abnormally
complex contour.
Procedure
This area is targeted for heavy liposuction (superficial and deep) to create a groove
postoperatively.
Precautions
It is necessary to check for hernia sacs and divarication of recti. It is also important
to use caution while creating the groove to avoid inadvertent perforation, as well
as skin injury.
Zone 2 upper rectus-overlying the rectus muscles from lower costal margin to the umbilicus
Anatomy
The skin of this zone is more rigid and expands less than the lower abdomen. This
is evidenced by the fact that there usually are not many stretch marks in this zone.[[9]] The fat is also compact and well arranged. There are natural adhesions in men in
the form of horizontal transcriptions and in some athletic women as well. The skin
is firmly adhered to the costal margins near the origin of the rectus muscles. As
weight increases, there are the formation of folds and unnatural creases. Sometimes,
even in thin individual creases are formed in the upper abdomen, which can be referred
as ‘flexion creases’. Excessive fat accumulation may cause pannus formation in the
upper abdomen more often in women than men.
This region overlies the upper part of the rectus muscle. The recti have three tendinous
intersections which are responsible for the appearance of six packs-at or just above
the umbilicus, at the xiphoid, and midway between these two. These intersections may
be in line or asymmetrical.
Procedure
Liposuction here is tailored in men to create six packs in men if needed. In women,
the aim is to attain a concave shape. The lateral edge of this unit is targeted to
create a linea semilunaris.
Precautions
This area is prone to skin injury, both blunt as well as excessive energy usage, particularly
during groove creation. This area is also prone to contour irregularities in the hands
of beginners. Furthermore, creating the appearance of muscles in an overweight man
looks obviously fake and is referred to as the ‘ninja turtle’ man. There is also the
risk of skin loss in this zone, particularly if there is an additional complication
like seroma and overly tight fitting garment may aggravate it too.
Zone 3 lower rectus-single unit over both the recti from the umbilicus to the upper
pubic hairline
Anatomy
The skin here is prone to laxity and panniculus formation. The skin usually forms
a fold which stops at the inguinal region due to adhesions. The skin is poor quality
with extensive stretch marks and poor capacity for retracting.[[10]] In this region, the fat is divided by the scarpas fascia. That present below it
is loosely arranged with sparse fibrous tissue. That present above it is compact with
fibrous septae. The absence of posterior rectus sheath naturally gives a slightly
convex shape in the lower abdomen. Rectus muscle converges in the lower part to insert
on the pubic bones. The recti in this region are covered by the rectus sheath only
on its anterior surface. There may be a partial tendinous intersection in the region
of the arcuate line.
Procedure
During liposuction, it is preferable to maintain a slight bulge in this region.
Precautions
This area is also prone for skin injury. Moreover, special attention should be paid
to postoperative compression in this region, due to its propensity for skin laxity.[[11]] Seromas are also common here.[[12]]
Zone 4 lateral abdominal-overly the obliques, on either side of the recti from the
costal margin to the inguinal ligament, till the mid-lateral line
Anatomy
The skin is usually thicker in this region unless there is a very large volume of
fat accumulation. The skin is adherent in the region of the costal margin (Zone 4a)
and the iliac crest (4b). Adhesions in men in the iliac crest region are to be preserved
to avoid feminisation. In women, the mid-buttock area is responsible for a guitar
deformity and needs special attention. Flexion creases often form with fat accumulation
forming rolls or love handles that extend posteriorly.
Zone 4 overlies the oblique muscles of the abdomen and is bounded medially by Linea
semilunaris. Linea semilunaris is a tendinous intersection formed by the aponeurosis
of oblique muscles. The rectus muscle is thicker and has better support than the oblique
muscles that causes a sort of ‘ledge’ at the Linea semilunaris. Or in other words,
the musculofascial layer in this part is thinner than the central abdomen. There is
a differential layer of fat deposition in this unit with an excessive layer of deep
fatty tissue in the lower part (4b) and tougher fibrofatty tissue in the upper part
(4a) near the coastal region.
Procedure
During liposuction, a concavity is created lateral to the recti to give an aesthetically
pleasing effect as well as highlight the recti. It is also important to break down
the fibrous tissue in the waistline as well as in any flexion creases. Higher energy
would be needed in the fibrous upper part (4a) of this region while the lower part
is easier (4b).
Precautions
Due to the relative weakness of the musculature in this region, it is prone to intraabdominal
perforation, particularly while moving from a convex to a concave area.[[13]
[14]] Similarly, one must be careful of intrathoracic perforation in the subcostal region.
There have been reports of major vascular injury while operating in this region, by
penetrating the iliac or femoral vessels. Failure to break down flexion creases will
lead to recurrence of rolls with weight gain.
Zone 5 pubic region-below the pubic hairline
Anatomy
It is also called as ‘mons pubis’ or pubic mound overlying the pubic bones. The area
consists of two layers of fat divided by the Scarpa's fascia. The youthful mons is
narrow with good skin tone. With age, the hair-bearing skin of pubic region has tendency
to sag with excess fat accumulation, and it covers the genitals in both men and women.
Procedure
Excess fat in this region should not be neglected during liposuction.
Precautions
This area is often neglected during liposuction, with the result that any excessive
fat here becomes more pronounced following the surgery.
Zone 6 lumbar-overly the lumbar muscles from the costal margin to the gluteal region,
till the paraspinous muscles posteriorly
Anatomy
The skin is quite thick in this region and very rarely has stretch marks. It has a
good chance of contraction after liposuction. Fat deposition in this region obliterates
the lumbar triangle and is generally in an oblique fashion. It has two compartments
of fat deposits, superficial and deep. The deeper lies in the femoral triangle region.
The lumbar region consists of the superior and an inferior lumbar triangle. The inferior
triangle is more superficial and is a weak area with excessive fat accumulation. It
is bounded by the latissimus Dorsi muscle, external oblique and iliac crest. Excess
fat accumulation causes a distinct bulge referred to as ‘love handles’ or flanks.
It also obliterates the dimple overlying the posterior superior iliac spine.
Hernias are known to occur in this region warranting extra precaution during liposuction
procedure. Often, in massive weight loss patients, a bulge is persistent in this region
due to musculofascial laxity.
Procedure
Particular importance is to be paid to the love handles, as well as breaking down
zones of fibrosis on either side to redrape the skin and create the waistline.
Precautions
The lumbar triangles are areas of weakness in an otherwise strong region. Attention
should be paid to avoid inadvertent perforation. Aggressive superficial liposuction
can permanently damage the dermal vasculature causing a mottled appearance.[[15]] Unequal liposuction of the love handles can cause postoperative asymmetry.
Zone 7 posterior midline unit-overlies the spinous processes and the paraspinal muscles
Anatomy
Skin is adherent over the spinous processes and posterior iliac spine forming a midline
groove and dimples. There is often a typical fat deposit inferiorly called the sacral
pad which obliterates the curve posteriorly. It is also called as ‘triangle of Venus’.
Procedure
Liposuction is performed mostly over the presacral region to improve the contour of
the buttock in women. Some patents may require liposuction of midline if the groove
is absent. It is important to leave some fat in the paraspinous region to aesthetically
highlight the muscles.
Precautions
As it is a tough fibrous area, more force is needed which can cause injury to the
skin or spinous processes.
Zone 8 Bra roll-above the lumbar unit, extending into the infraaxillary region
This region is of fat deposition, which extends from the lower margin of the breast
posteriorly. The skin here is thick, and the fat is tough. It overhangs the subcostal
region forming a flexion crease. Some patients may have multiple folds.
Procedure
This region is often overlooked, with the result that it stands out postoperatively,
or it obliterates the waistline. Creases in between or below rolls need to be broken
down to present recurrence.
Precautions
While operating this region in supine position, there is a risk of injury to latissimus
Dorsi and its vascular pedicle as it forms the posterior axillary fold that falls
flat on the table and the cannula may inadvertently enter the anterior surface of
this muscle.
We used this system in 2000 cases and were able to achieve uniformly good results.
Our success with this classification validates its use. The system was used in the
following manner:
Preoperative
Intraoperative
-
To calculate the tumescent fluid requirement
-
To calculate aspirate by region
-
To compare both sides and avoid asymmetry
-
To calculate ultrasonic energy usage bilaterally.
Postoperative
-
To evaluate and report results
-
To identify complications or fat residues by zone
-
To track recurrence of fat with future weight gain
-
We found the system of liposuction to be uniformly applicable and greatly improved
our performance.
