A novel technique to overcome the visible implant contour throgh the thin skin, when performing the nasal brideg augmentation with silicone implant in Asians

1. Copyright © 2016 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
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Augmentation Rhinoplasty With Silicone Implant
Covered With Acellular Dermal Matrix
Man Koon Suh, MD,Ã
Kyo Ho Lee, MD,y
Aram Harijan, MD,z
Hyung-Gu Kim, PhD,§
and Euicheol C. Jeong, MD, PhDjjô
Background: Alloplastic materials are a mainstay in Asian rhino-
plasty. However, the outline of alloplastic implants can become
conspicuous over time in rhinoplasty patients, which is a significant
cause for revision. In revision rhinoplasty, alloplastic materials can
remain a viable and affordable option in Asian patients. The
acellular dermal matrices (ADM) are often used to interface
between the silicone material and the skin envelope. This study
assesses histologic changes following implantation of ADM-cov-
ered silicone material in rats.
Methods: To demonstrate differences at the histologic level,
silicone blocks with and without ADM were implanted in the
subcutaneous plane of 10 rats. These implants were harvested
after 9 weeks and examined histologically for capsule thickness
and myofibroblast activity.
Result: Intheinvivostudy,thepresenceofADMwasassociatedwith
significantly decreased capsule thickness and myofibroblast activity
around the implant and maintained the structure of ADM well.
Conclusion: The authors suggest that using the ADMs to cover
silicone implants can be an alternative method for decreasing the
visibility ofimplant contour,bythe prevention ofcapsularcontracture
and the addition of a soft tissue layer to the dorsal skin envelope.
Key Words: Acellular dermal matrix, alloplastic implant, Asian
rhinoplasty
(J Craniofac Surg 2016;00: 00–00)
In Asian rhinoplasty, dorsal augmentation is a popular method for
addressingthecharacteristicappearanceofalowprofileanddeficient
tip projection. The nasal skin envelope is known to be thicker among
Asian patients, and alloplastic implants are more frequently used than
among Caucasian patients.1–3
However, dorsal augmentation with an
alloplastic implant sometimes causes complications, such as infection,
contracture, mobile implant, deviation, visibility, transparency, and
nasal tip ulceration with associated extrusion.4
Of these complications, implant visibility is caused by the
obliteration of the dorsal esthetic lines, which is replaced by the
straight contour of the implant itself. Additionally, an extremely
thin envelope might be transparent enough to allow direct vision of
the implant and capsule color and texture beneath the skin. The
problem of implant visibility is more common in Caucasian
patients, but can also be observed in Asian patients with increasing
frequency. In addressing this problem, autogenous tissue is the most
popular and reasonable option in revision rhinoplasty. However,
alloplastic materials continue to be investigated and considered in
the setting of revision rhinoplasty.5,6
Among various materials,
silicone implants are frequently used for biological stability and
ease of carving to the appropriate configuration.1–4
The human
acellular dermal matrix (ADM) has also been used recently as the
wrapping material for diced cartilage graft and other alloplastic
implants.5–7
In this study, we characterize the utility of ADM in
minimizing capsule formation on the implant and adding a collagen
layer through an animal experiment.
MATERIALS AND METHODS
Animal and Implant Material
Throughout the course of this study, the authors followed the
‘‘Animal Research: Reporting In Vivo Experiments’’ guidelines.
Upon ethics approval from the committee on animal experimen-
tation at Boramae Medical Center (Study No 20130026), 10
Sprague Dawley rats were obtained (weight range 320–330 g).
The animals were an acclimation period of a week with unrestricted
access to water and feed.
Human cadaver ADM (Megaderm, L&C Bio, Seoul, Korea) was
obtained in a prepackaged form with 2 thickness, 0.7 and 1.5 mm.
Medical-grade thick silicone sheets of 3-mm thickness were
obtained, cut into 10 Â 10 mm2
, and sterilized in an aseptic package
prior to experimentation.
Implant Preparation
The study was designed such that each rat was implanted with
each 10 Â 10 mm2
of the following: silicone only, 0.7-mm ADM/
silicone, 1.5-mm ADM/silicone, and ADM only (1 layer of
3.0 mm). The ADM-silicone implants were prepared by cutting
respective ADM sheets into size and by suturing the ADM sheets to
silicone using 5-0 polypropylene sutures (Fig. 1A). The ADM-
containing implants were allowed to hydrate during the surgical
preparation of the rats.
Implantation and Harvest
The rats were anaesthetized by the intraperitoneal injection of
a mixture containing 20 mg/kg of Zoletil (Virbac, France) and
2 mg/kg of Rompun (Bayer Korea Corp, Seoul, Korea). The back
was shaved and subsequently washed with povidone–iodine
From the ÃJW Plastic Surgery Center; yCBK Plastic Surgery Clinic; zWell
Plastic Surgery Clinic, Seoul; §L&C BIO Co/R&D Center, Seongnam;
jjDepartment of Plastic Surgery, SMG-SNU Boramae Medical Center;
and ôDepartment of Plastic and Reconstructive Surgery, College of
Medicine, Seoul National University, Seoul, Korea.
Received June 14, 2016.
Accepted for publication August 27, 2016.
Address correspondence and reprint requests to Euicheol C. Jeong, MD,
PhD, Department of Plastic Surgery, SMG-SNU Boramae Medical
Center, 5 Gil 20, Boramae-Road, Dongjak-gu, Seoul 07061, Korea;
E-mail: ecjeong@me.com
H-GK is the Director of the Research Institute in L&C Bio Co. ECJ has
received research grant support from L&C Bio Co. The remaining
authors report no conflicts of interest.
Copyright # 2016 by Mutaz B. Habal, MD
ISSN: 1049-2275
DOI: 10.1097/SCS.0000000000003225
ORIGINAL ARTICLE
The Journal of Craniofacial Surgery Volume 00, Number 00, Month 2016 1

2. Copyright © 2016 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
CE: A.B.; SCS-16-0858; Total nos of Pages: 4;
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solution. Four subcutaneous pockets were created with the
following designation: A and B for the right and left upper
back and C and D for the right and left lower area (Fig. 1B).
Each of the pockets was made through a respective 2-cm
incision. Care was taken not to allow communication between
these spaces.
In pocket A, the silicone implant without ADM was placed. The
0.7- and 1.5-mm ADM/silicone implants were placed into pockets
B and C, respectively. The orientation was such that the exposed
silicone surface was in contact with the wound bed and the ADM
surface toward the skin. In pocket D, the ADM-only implant was
placed. Incisions were closed with 5-0 nylon sutures.
At 9 weeks after implant placement, the animals were eutha-
nized. The dorsal skin was raised as a single flap in the caudal-to-
cranial direction (Fig. 1C). Each implant was harvested with a
surrounding layer of connective tissue and individually fixed in 10%
formalin solution (Fig. 1D).
Histological Examination
Formalin-fixed specimens were cut into 4-mm-thick sections
and treated with hematoxylin and eosin (HE) and a-smooth
muscle stains. The tissues were examined at 100Â magnification
for HE samples and at 400Â for the smooth muscle stains. The
histologic slides were then presented to a pathologist who was
blinded to the nature of each specimen and who was asked to
determine the capsule thickness and myofibroblast activity.
The capsule thickness was measured from each of the HE
samples except the 3-mm ADM-only specimen from microscope
reticles calibrated with a 0.01-mm-stage micrometer slide. Myofi-
broblast activity was graded by the intensity of the a-smooth muscle
stains. A total lack of staining was graded as 0; sparse staining as 1;
mild staining as 2; moderate staining as 3; and intense staining as 4.
Both of these findings were measured or evaluated in 3 separate
locations in each sample and reported as an average value.
Statistical Analysis
The in vivo study of the animals, capsule thickness, and myofi-
broblast activity were expressed as mean Æ standard deviation.
Statistical analysis was performed with 1-way ANOVA and paired
t-tests. All statistical analyses were performed using GraphPad
PRISM 6.0f (GraphPad Software, La Jolla, CA). P-values of
0.05 were considered statistically significant.
RESULTS
During the 9-week duration between implantation and harvest, 1
animal expired without any signs of infection. The implants
detached easily from the surrounding tissue with the implant shape
entirely preserved.
On microscopic examination, in pockets A, B, and C, the
specimens contained a layer of omnidirectional dermal-like fibers
beneath the subcutaneous tissues and had indirect contact with the
implant. The former layer corresponded to the ADM that was placed
on the implant, but there was a thin additional layer of wavy,
parallel arrays of collagen fibers abutting the implant beneath the
ADM, suggesting that a capsule had formed at the layer in close
proximity to the implant. The mean thickness was 197.3 Æ 28.5 mm
in pocket A, 97.8 Æ 17.2 mm in pocket B, and 90.8 Æ 16.2 mm in
pocket C (Table 1; Fig. 2). The capsules of pocket B and C were
significantly thinner compared with that of pocket A (control) (1-
way ANOVA test, P 0.0001). However, the thickness of the
capsule did not differ significantly between pockets B and C (paired
t-test, P ¼ 0.4371). When the extent of myofibroblasts in the
capsule was compared according to histopathologic findings, the
results showed an average of 3.8 Æ 0.4 in pocket A, 1.9 Æ 0.6 in B,
and 1.2 Æ 0.7 in C (Table 2; Fig. 3). These results indicate that the
ADM-layered implant had significantly low myofibroblast activity
(1-way ANOVA test, P 0.0001), which is a pathologic cell of a
hypertrophic scar or capsular contracture, but no statistically sig-
nificant difference was observed between pockets B and C, either
(paired t-test, P ¼ 0.0805). In pocket D, we did not find the capsule
around ADM.
DISCUSSION
In Asian patients, silicone implants are widely used in rhinoplasty
because the material is biologically stable, resistant to degradation,
easy to carve, and convenient to remove in the patient with revision
rhinoplasty.1–4
A significant shortcoming of implants is that implant visibility
via obliteration of the dorsal esthetic line and translucency of skin in
those patients with thinner envelope.4,8–10
This is very common
among Caucasian patients with inherently thin skin, and is observed
with frequency even in Asian patients in whom the skin envelope
has been thinned. This phenomenon is caused by host inflammatory
FIGURE 1. (A) Preparation of an acellular dermal matrix (Megaderm, LC Bio,
Seoul, Korea)-covered silicone implant. (B) The implants are inserted into 4
separate subcutaneous pockets on the dorsum of each rat, as described in the
‘‘Methods’’ section. (C) Each implant was loosely adhered to the panniculus
carnosus layer without gross changes at the 9th week. (D) En-block excision of
each implant at 9th week.
TABLE 1. Thickness of Capsular Fibers Surrounding Silicone Implants
Silicone Implants
Test Animal No ADM 0.7-mm ADM 1.5-mm ADM
1 210 103 85
2 253 116 100
3 217 85 75
4 187 100 113
5 213 83 116
6 167 90 86
7 183 123 67
8 163 70 85
9 183 110 90
Mean 197.3 Æ 28.5 97.8 Æ 17.2 90.8 Æ 16.2
All measurements are in micrometers (mm).
ADM, acellular dermal matrix.
Suh et al The Journal of Craniofacial Surgery Volume 00, Number 00, Month 2016
2 # 2016 Mutaz B. Habal, MD

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response to the foreign body and formation of scarring around the
implant, leading to a thick capsule, including calcification and a
thinning innate dorsal tissue envelope of the nose around the
implant.8–10
To correct this visibility of the silicone implant, the best solution
in the revision surgery is to use autogenous tissues for dorsal
augmentation.4,7,8
However, the use of autologous tissue presents
its own limitations in various situations. For one, autologous
sources of tissue may not provide sufficient volume of graft material
needed for dorsal augmentation in Asian patients (eg, auricular
cartilage, septal cartilage, or dermofat graft). The use of autogenous
rib cartilage necessitates a second operative donor site on the torso,
which is shunned among Asian patients. Absorption and warping
are additional issues to consider.4,5
In specific patients, the alloplastic implants are still used in the
revision rhinoplasty.5–8,10
In using an alloplastic implant in the
revision, there are several options. Generally, the implant material
and/or style should be changed. For example, solid silicone
implants are switched with soft implants such as Gore-Tex, and
high-profile L-shape implants are changed to low-profile I-shape
implants.8–11
Removing the capsule surrounding the implant is
inevitable in revision rhinoplasty, which aggravates the problem of
dorsal tissue envelope already being too thin. To counter this
problem, some surgeons use implants in conjunction with auto-
logous tissue, such as temporoparietal fascia and/or pieces of
cartilage to achieve a smooth implant profile by adding a
layer.12–14
However, debates still exist over the long-term dura-
bility of used alloplastic implants in rhinoplasty related to the
biologic response.
ADM is produced from human cadaveric skin. The cellular and
immunogenic components of the skin are removed, leaving behind
the basement membrane and cellular matrix. Studies have shown
that this matrix acts as scaffolding, which leads to cellular integ-
ration into the surrounding tissue.15
In rhinoplasty, it is used for
adding height to the nasal dorsum, camouflaging minor irregula-
rities, and thickening the nasal dorsal skin.16
Gordon et al7
used
ADM as a framework material for wrapping diced cartilage in
various saddle nose deformity with few complication and accep-
table results. The clinical characteristic of ADM would be
beneficial for making a smooth profile implant, as with the auto-
logous dermis or fascia, and ADM has already been used in this
manner.5–7
In the experience of authors, clinical outcomes were
also favorable (Figs. 4 and 5). Among various operations involving
alloplastic implants, using ADM to partially cover implant or tissue
expender has become very popular in reconstructive breast surgery.
In our in vivo study, the ADM-covered silicone developed rela-
tively little of the parallel, wavy collagen fibers—the histologic
finding of capsular formation. More superficial than this capsular
fiber, the specimens contained a layer of omnidirectional dermal-
like fibers typical of ADM. Such histological features have been
reported in past studies in which ADM was found to be incorporated
by the host tissue with evidence of cellular repopulation and
revascularization.17,18
The presence of ADM was also associated with a significantly
lower density of myofibroblasts, which corresponds with clinical
FIGURE 2. Hematoxylin and eosin staining of the capsule at Â100. (A) The thick
capsule in the silicone-only specimen, Pocket A. (B) Capsule in the 0.7-mm-thick
ADM layered silicone implant, pocket B. (C) Capsule in the 1.5-mm-thick ADM-
layered silicone implant, pocket C. (D) No capsule in the 3-mm ADM-only
specimen, Pocket D. The omnidirectional appearance of the collagen layer is
characteristic of ADM. Dense fibrous capsule is less thick in the ADM-layered
implant. ADM, acellular dermal matrix.
FIGURE 3. The extent of myofibroblasts, a-smooth muscle actin staining at
Â400. (A) The thick capsule in silicone showed strong staining, score 4, Pocket
A. (B) The capsule in the 0.7-mm-thick ADM-layered silicone implant showed
less staining than A, score 2. (C) Capsule in the 1.5-mm-thick ADM-layered
silicone implant showed weaker staining, score 1, pocket C. (D) No capsules in
the 3-mm ADM-only specimen were stained, Pocket D. ADM, acellular dermal
matrix.
TABLE 2. Histologic Grading for Myofibroblasts
Silicone Implants
Test Animal No ADM 0.7-mm ADM 1.5-mm ADM
1 4 2 1
2 3 2 0
3 4 3 1
4 4 2 2
5 4 1 2
6 3 2 2
7 4 2 1
8 4 2 1
9 4 1 1
Mean 3.8 Æ 0.4 1.9 Æ 0.6 1.2 Æ 0.7
The intensity of a-smooth muscle actin served as a representation of myofibroblast
activity. 0: Complete lack of staining, 1: sparse staining, 2: mild staining, 3: moderate
staining, and 4: intense staining.
ADM, acellular dermal matrix.
The Journal of Craniofacial Surgery Volume 00, Number 00, Month 2016 Silicone Nasal Implant With ADM
# 2016 Mutaz B. Habal, MD 3

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reports regarding the decreased rates of hypertrophic scarring and
capsular contracture when ADMs are used in conjunction with
silicone implants. The results of our experiment are in general
agreement with a primate model of ADM-covered tissue expander,
in which the presence of ADM was found to significantly decrease
the amount of capsular fibers around the tissue expander.18
How-
ever, the authors found that the thickness of ADM did not cause any
difference in capsular thickness or myofibroblastic activity.
This study shifts the burden of proof back to the clinical arena to
determine whether such histologic changes are significantly associ-
ated with implant visibility from the thick capsule and thin dorsal
skin envelope in rhinoplasty. The authors believe that ADM would
be beneficial in conjunction with silicone implants as well as other
alloplastic implants. In primary rhinoplasty operations, this con-
struct would decrease the possibility of unnatural implant visibility
in the long-term period when compared to that of alloplastic implant
alone. However, additional expenses for the ADM material should
be considered.
CONCLUSION
When the silicone implant is used for rhinoplasty, the concomitant
use of ADM has the potential to decrease the implant visibility,
especially for patients with thin skin envelops. In our study, the
presence of ADM was associated with significant decreases in
capsule thickness as well as in myofibroblast activity compared
with silicone-only implantation. Better outcomes with low compli-
cation incidence are expected in follow-up observations.
ACKNOWLEDGMENT
The authors thank Dr Sohee Oh for statistical analysis in the
preparation of this manuscript.
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FIGURE 5. A 52-year-old woman who reported a noticeable and visible nasal
implant caused by previous silicone augmentation rhinoplasty. A 4-mm-thick
boat-shaped silicone implant and the surrounding capsule were removed. The
new silicone implant, which had a similar profile to the previous one, covered with
acellular dermal matrix was used in the revision rhinoplasty. (A, B) Preoperative
frontal and lateral views; (C, D) postoperative frontal and lateral views 1 year later.
She underwent additional blepharoplasty before the revision rhinoplasty.
FIGURE 4. (A) The ADM (Megaderm, LC Bio, Seoul, Korea) (above) and the
carved silicone implant (below); size of the ADM is 0.7 mm  5 cm  1.2 cm. (B)
The silicone implant was fixed with ADM using absorbable sutures, which will be
used in the rhinoplasty. ADM, acellular dermal matrix.
Suh et al The Journal of Craniofacial Surgery Volume 00, Number 00, Month 2016
4 # 2016 Mutaz B. Habal, MD