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Acellular Dermis for Facial Soft Tissue Augmentation
Preliminary Report
Peter D. Costantino, MD;
Satish Govindaraj, MD;
David H. Hiltzik, BA;
Daniel Buchbinder, DMD, MD;
Mark L. Urken, MD
Arch Facial Plast Surg. 2001;3:38-43.
ABSTRACT
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Objective To evaluate the efficacy of acellular dermis as a viable alternative
for soft tissue augmentation in facial reconstruction.
Design A prospective, nonrandomized observational study consisting of 10 patients
who underwent soft tissue augmentation with acellular dermis.
Setting A tertiary care university medical center in an urban setting.
Patients Ten patients who had undergone soft tissue augmentation using acellular
dermis participated in this study. Postimplantation follow-up was 17 to 36
months.
Intervention The amount and location for placement of the acellular dermis was left
to the discretion of the surgeon. All implants were placed in the subdermal
tissues.
Main Outcome Measures The adequacy of acellular dermis for soft tissue augmentation was assessed
by subjective evaluation of implant volume persistence, postoperative complications,
and the restoration of normal contour.
Results Of 10 patients who underwent implantation, 9 had no complications and
1 had a recurrent sterile abscess or mucocele at the implantation site. A
22-month postimplantation tissue sampling of acellular dermis in a patient
with recurrent tumor revealed approximately 80% to 85% volume persistence.
Conclusion Preliminary experience with acellular dermis indicates that it shows
promise in soft tissue augmentation.
INTRODUCTION
FACIAL DEFORMITIES resulting from isolated soft tissue volume loss are
relatively common but difficult to correct. These defects most frequently
result from trauma, infection, or oncologic surgery, and their appropriate
reconstruction requires that the corrective "filling" material possess similar
mechanical characteristics as human soft tissue and skin. The spectrum of
implant materials suitable for facial soft tissue defect augmentation includes
local tissue transfer, regional vascularized flaps, microvascular tissue transfers,
and synthetic or semisynthetic biomaterials. Although local and regional flaps
bring vascularized soft tissue into the area requiring reconstruction, the
volume and composition of such tissue might be limited or inappropriate. This
is particularly true for patients who have undergone oncologic resection followed
by radiotherapy. In this situation, microvascular tissue transfer can solve
this problem but carries with it the disadvantage of technical complexity
and an increased risk of short-term flap failure. Until recently, synthetic
biomaterials have largely proven to be inadequate for isolated soft tissue
augmentation and have been used primarily as hard tissue alloplasts that simply
elevate the overlying soft tissue. This is particularly true for defects requiring
subdermal placement of the synthetic implant. Examples of such an implant
include silicone elastomer and porous high-density polyethylene. These materials
are frequently inappropriate for deformities resulting from isolated soft
tissue volume loss. Recently, use of expanded porous polytetrafluoroethylene
has gained popularity for isolated soft tissue augmentation and replacement.
Although useful, this synthetic polymer remains as a permanent nonvascularized
implant for the lifetime of the patient and carries with it the concurrent
risk of immediate or long-term infection or extrusion.
A relatively new material consisting of acellular cadaver dermis (AlloDerm;
LifeCell Corporation, The Woodlands, Tex) has become available in the past
few years for facial reconstructive applications that require isolated soft
tissue augmentation. Acellular dermis was originally developed for treatment
of full-thickness burns. Application of a thin layer of acellular dermis between
a debrided burn surface and a split-thickness skin graft results in decreased
contracture and improved durability of the skin graft.1-2
It also maintains a greater thickness compared with split-thickness skin graft
coverage alone. A secondary outgrowth of these findings observed in burn therapy
has been use of this material for soft tissue volume augmentation in a variety
of anatomical sites.3 When implanted within
a soft tissue pocket, the intact collagen matrix structure of the acellular
dermis is eventually ingrown and potentially replaced by the host's own tissue.
This implant replacement is coupled with maintenance of much of the original
augmented volume over time. Acellular dermis is currently approved by the
Food and Drug Administration for reconstructive applications in the head and
neck. This article describes our initial experience with 10 patients who underwent
isolated facial soft tissue defect augmentation using this material.
PATIENTS AND METHODS
This preliminary study consists of 10 patients who underwent soft tissue
augmentation using acellular dermis at a tertiary care medical center in an
urban setting. Because this material is approved for this application by the
Food and Drug Administration, investigational review board approval was not
required. Patients were specifically counseled as to the risks and benefits
of using acellular dermis and cadaveric grafts. Other reconstructive options
were offered to the patient, including autogenous vascularized tissue, autogenous
nonvascularized tissue, and a synthetic biomaterial (Gore-Tex; Gore Corp,
Dallas, Tex). The patient population consisted of the first 10 individuals
(age, 34-74 years; 7 women and 3 men) who consented to acellular dermis as
their preferred method of augmentation. These individuals all had isolated
soft tissue volume deficits resulting in facial deformity. No additional inclusion
or exclusion criteria were used beyond the requirements that the patients
be aged 18 years or older, capable of providing their own informed consent,
and sufficiently healthy to safely undergo the proposed reconstructive procedure.
Eight of the defects resulted from oncologic resection, 1 from penetrating
trauma, and 1 from congenital deformity. Three patients had previously received
full-course radiotherapy to the region and 2 had soft tissue deficits resulting
from local or microvascular flap failure.
Outcome evaluation was done with respect to restoration of facial contour,
presence of postoperative complications, and implant volume maintenance. Restoration
of facial contour and postoperative complications were assessed by comparison
of preoperative and postoperative photographs and clinical evaluation, respectively.
Photographs were evaluated by the surgeon and the patient. Because of the
difficulty in accurately assessing volume after implantation, this variable
was evaluated by the persistent restoration of facial contour at follow-up
and in greater detail in one patient who necessitated resection of previously
implanted acellular dermis secondary to tumor recurrence at an adjacent site.
This enabled direct visualization of the implanted material. A detailed review
of 2 patients is included in the "Results" section.
RESULTS
Postimplantation follow-up ranged from 17 to 36 months. Of 10 patients
who underwent implantation, 9 had no complications and 1 had a recurrent delayed
sterile abscess or mucocele near the implantation site. The specifics of this
patient's postoperative course are reviewed later in this article. Although
not statistically evaluated, restoration of facial contour was achieved in
9 of 10 patients in the region(s) of acellular dermis implantation. In addition,
volume maintenance based on clinical evaluation of soft tissue augmentation
persistence at postoperative follow-up visits was good to excellent in all
patients. In no patient did reformation of the preoperative soft tissue defect
occur.
PATIENT 1
A 67-year-old woman was diagnosed as having a mucoepidermoid carcinoma
of the parotid gland involving the right mandible. She originally underwent
an extensive skull base resection that resulted in transposition of the temporalis
muscle coupled with a total parotidectomy, sacrifice of the right facial nerve,
and a right posterior segment mandibulectomy. Her immediate reconstruction
consisted of a scapular microvascular free tissue transfer. Postoperative
ischemia in the skin flap portion of the scapula transfer (the parascapular
flap) resulted in substantial soft tissue volume loss in the right temporal
fossa and right side of the face lateral to the scapular skeletal reconstruction
(Figure 1A). After resection, she
received full-course radiotherapy to the entire region.
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Figure 1. A, Preoperative photograph of
a patient with substantial volume loss in the right temporal fossa and right
submalar region. B, Intraoperative photograph of the same patient shows a
sheet of 3-cm x 7-cm x 1-mm acellular dermis placed over the region
under which it will be applied in a subdermal soft tissue pocket. C, The same
patient 20 months after surgery has maintenance of soft tissue volume restoration
in the submalar region. The temporal fossa was augmented with hydroxyapatite
cement (BoneSource).
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The patient wanted reconstruction of the temporal and facial defects
on the right side. Hydroxyapatite cement (BoneSource; Howmedica Leibinger,
Dallas) was chosen to augment volume loss in the temporal fossa, whereas 3
sheets of 3-cm x 7-cm x 1-mm acellular dermis was chosen to augment
soft tissue loss lateral to the scapular reconstruction below the zygoma (Figure 1B). During the surgical procedure,
a static facial suspension of the right side of the upper lip and oral commissure
was also performed using acellular dermis as a suspensory material. Additional
procedures included scar revision over her neck, right lateral canthoplasty,
and implantation of a conchal cartilage graft to the right side of the lower
lid to correct her ectropion and excessive scleral show. The acellular dermis
was implanted through a modified rhytidectomy incision coupled with a melolabial
incision for upper lip suspension. The patient tolerated the procedure well
20 months after implantation (Figure 1C).
At 22 months, she developed a recurrence in the mandible that required resection
of the previous augmentation site. This additional resection permitted biopsy
of the previously placed acellular dermis (Figure 2, Figure 3, and Figure 4). Gross inspection and subjective
evaluation based on knowledge of the original dimensions of the previously
implanted acellular dermis revealed an approximately 85% volume persistence.
Histological analysis revealed fibrovascular host tissue ingrowth and a well-integrated
acellular dermis-host tissue interface with no evidence of tumor in the implant
(Figure 5).
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Figure 2. The biopsy site for the acellular
dermis is outlined in blue ink.
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Figure 3. The portion of skin outlined in
blue ink in Figure 2 has been inverted to demonstrate the implanted acellular
dermis. The instrument in the photograph points to the preserved layers of
acellular dermis implanted 22 months earlier. Note that the sheets of acellular
dermis have been well integrated into the surrounding host tissue.
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Figure 4. Resected specimen 22 months after
implantation. Arrows indicate the 3 preserved layers of acellular dermis in
the biopsy specimen. A significant degree of the implant sheet thickness has
been maintained despite implantation being performed more than 1 years
earlier.
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Figure 5. Histological analysis of resected
acellular dermis demonstrates host tissue fibrovascular ingrowth. The individual
sheets of acellular dermis can be seen, with absence of an inflammatory response.
Arrows indicate the sheets of AlloDerm. Areas stained black represent the
elastic fibers within the sheets of acellular dermis (Verhoeff elastic tissue
stain, low magnification [x40]).
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PATIENT 2
A 43-year-old woman was born with Clippel-Fiel syndrome. She underwent
multiple craniofacial skeletal procedures in the past that resulted in extensive
innerconnected dental bridgework. She wanted correction of her facial asymmetry
and of the bilateral soft tissue irregularities of her lower face. She did
not want any further craniofacial skeletal surgery because this would involve
substantial revisions to her well-functioning dentition.
Her treatment consisted of placement of bilateral malar-submalar high-density
porous polyethylene (Medpor; Porex Corp, Atlanta, Ga) implants, coupled with
placement of a hard tissue replacement implant on her right side. All implants
were placed through intraoral incisions and served to balance her asymmetrical
facial skeletal structure. Soft tissue contour irregularities of the lower
face were then addressed through application of acellular dermis through a
modified rhytidectomy approach bilaterally. Several layered sheets of the
material were sutured together and inserted on the right side. Single sheets
of acellular dermis were implanted on the left side. The implantation sites
were drained with small Penrose drains for 48 hours after implantation. This
patient's preoperative and postoperative facial contour 17 months after implantation
is shown in Figure 6. There was
improvement in the soft tissue contour irregularities lateral to the oral
commissure in the lower third of the face.
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Figure 6. A, Preoperative photograph of
patient 2. B, Same patient 17 months after surgery. The soft tissue irregularities
of the lower face were addressed through application of acellular dermis.
The implants were placed using a modified rhytidectomy approach.
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COMMENT
This limited series demonstrates the utility of acellular dermis for
soft tissue augmentation and replacement within the face. All of the patients,
except 2, underwent reconstruction secondarily, after oncologic resection.
The acellular dermis was applied to isolated soft tissue defects, alone or
in conjunction with other reconstructive techniques or biomaterials. Three
of 10 patients had been exposed to full-course radiotherapy before implantation
of acellular dermis. Despite the suboptimal implantation environment and the
aesthetically challenging nature of most of these defects, the acellular dermis
was infection resistant; showed no potential for initial or delayed extrusion;
and, more than 6 months after implantation, maintained a degree of softness
comparable to the tactile characteristics of the surrounding native tissue.
We believe that this performance is the direct result of the basic properties,
composition, and architecture of acellular dermis. These properties result
from a tissue processing technique that removes all cellular components from
the cadaveric graft material, along with all major histocompatability complex
class I and II antigens. The processing technique achieves this without disrupting
the normal microarchitecture of the collagen bundles within the dermis. The
elastic components and the basement membrane structure (including the laminins)
are also preserved.4 We believe that preservation
of the basal lamina layer is vital in early vascularization of these processed
grafts. The architecture of acellular dermis provides a scaffold into which
the patient's own fibroblasts can grow and eventually repopulate the augmented
region. The graft material is then fully incorporated by the host's own fibrovascular
tissue until it is indistinguishable from the surrounding natural dermal matrix.
This repopulation and replacement allows acellular dermis to become vascularized
early in the postimplantation period ( 5 days) and makes possible the potential
preservation of much of the augmented volume within the reconstruction site.
It is unlikely that all of the volume of the original implant will remain
permanently, but we estimate that a significant volume of the acellular dermis
is likely to persist based on its composition and architecture. Our single
biopsy specimen of acellular dermis 22 months after implantation in a radiated
field tends to support this opinion. It is logical to assume that additional
volume contraction will occur when multiple sheets of acellular dermis are
stacked in the soft tissue pocket. As fibrovascular tissue fills the spaces
between sheets of acellular dermis, settling and contraction should be expected.
It is probable that the greater the number of sheets combined as a single
multilaminar implant, the greater the percentage of volume contracture (compared
with the original composite implant thickness). Only an appropriate experimental
animal study using species-specific acellular dermis, coupled with several
years of clinical experience, will adequately quantify the degree of volume
loss over time.
A key attribute of acellular dermis is the preservation of an intact
collagen fibril microarchitecture. This is not the case with other processed
(injectable) collagen preparations such as bovine or autogenous collagen.
These other collagen implants contain damaged collagen strands in an amorphous
orientation that elicit a macrophage response leading to substantial or complete
resorption. The intact collagen fibril microarchitecture of acellular dermis
coupled with the intact dermal macroarchitecture establish a matrix that is
repopulated by fibrovascular tissue with a minimum amount of implant collagen
degradation and potentially greater implant volume maintenance over time.
The single complication in this initial series consisted of recurrent
episodes of either infection or mucocele formation at the reconstructed neopyriform
aperture of a patient who underwent reconstruction after removal of an intranasal
adenoid cystic carcinoma. The reconstruction site included the entire pyriform
aperture, along with the nasal and maxillary bone adjacent to the medial canthus
and nasolabial fold. Other materials simultaneously implanted in this area
included titanium plates and split-thickness calvarial bone grafts. Recurrent
episodes of inflammation resulted after the patient began blowing her nose
6 weeks after surgery. We suspect that mucus secretions or mucosa became invaginated
within the newly layered tissue planes of the pyriform aperture, resulting
in recurrent episodes of inflammation. Multiple aspiration cultures from this
area did not yield any organisms, although scant mucoid fluid could be periodically
aspirated from the area. These episodes were treated symptomatically with
antibiotics and finally resolved approximately 4 months after they began.
The patient shows moderate volume loss in those previously inflamed areas.
None of the other patients demonstrated any complications resulting from use
of this material. Subjective evaluation demonstrated good to excellent volume
maintenance in all patients without defect reformation over time. In general,
the acellular dermis maintained a soft texture after implantation. Increased
firmness was observed for approximately 4 to 6 months after implantation in
almost every patient. This firmness abated and the augmented region became
more pliable more than 6 months after implantation. None of the patients demonstrated
any skin color changes or episodes of recurrent edema suggestive of a chronic
inflammatory response, other than the previously mentioned patient.
Limitations of the present study are the small sample size and the degree
of experience the surgeons possess in handling and applying acellular dermis
as a soft tissue augmentation device. These factors might have played a role
in the positive outcomes seen in this study. In addition, certain limitations
in the application of acellular dermis should be addressed. First and foremost,
definitive volume maintenance studies have not been performed, to our knowledge,
using acellular dermis to objectively determine the degree of soft tissue
augmentation that persists over time. Although the limited results seen in
this study are promising, further evaluation is necessary before clinicians
can definitively convey to patients the long-term expectations of this material.
The cost of acellular dermis has been a perceived deterrent of using this
material; however, when one compares the additional operative time and postoperative
morbidity associated with using autogenous tissue, acellular dermis might
be a more cost-effective method of soft tissue augmentation in the head and
neck.
When this material is compared with other reconstructive implants, we
believe that acellular dermis has demonstrated significant potential. The
only other material appropriate for subdermal reconstruction of the soft tissue
defects included in this limited series is vascularized tissue transfer. Most
of these patients did not have adequate local tissue for transfer and therefore
would have required a pedicled or microvascular transfer. We did not believe
that any of the previously radiated patients would be appropriate for nonvascularized
autogenous grafts. None of these patients were willing to undergo pretreatment
with hyperbaric oxygen before reconstruction. In light of these limitations
and suboptimal conditions, the acellular dermis performed well in most regards.
With respect to synthetic biomaterials for the reconstructive applications
described in this series, we would not consider any to have been appropriate.
Previous exposure to radiotherapy eliminated the use of silicone elastomer
implants in that subset of patients. For several patients, silicone elastomer
and porous high-density polyethylene would not have been appropriate choices
because of the requirement of subdermal implantation or placement near the
nasal cavity mucosa resulting in a high risk of infection or extrusion. Only
expanded polytetrafluoroethylene (Gore-Tex) could have been used for some
of these reconstructions.5-8
Our experience with Gore-Tex in a previously irradiated field has demonstrated
at least a 50% incidence of chronic edema and erythema in the skin over the
implantation site. We do not believe that use of Gore-Tex would have been
appropriate for any of the previously radiated patients presented in this
limited series.
In summary, for a new material, acellular dermis has performed remarkably
well in our hands for the reconstruction of difficult, isolated soft tissue
defects. This material is fully vascularized and becomes incorporated by the
host so that it is eventually transformed into living tissue. This is the
key advantage that acellular dermis has over synthetic implants. It is likely,
based on its intact collagen microstructure and preserved dermal matrix macroarchitecture,
that a significant volume of the implant will persist permanently. It is unlikely
that the entire original implant volume will remain permanently, and it is
logical that the increased layering of acellular dermis will result in greater
volume loss relative to single-layer or bilayer implantation because of compaction
over time. Only additional animal testing and simultaneous clinical experience
will fully answer these questions. In any event, acellular dermis possesses
short- and long-term advantages over current synthetic polymer and processed
collagen implants. It also has advantages over autogenous nonvascularized
grafts (as well as several potential disadvantages). It is up to the surgeon,
in detailed consultation with the prospective patient, to select the appropriate
defect for which the advantages of this new material outweigh its potential
shortcomings in light of the other autogenous or synthetic reconstructive
materials currently available. Acellular dermis seems to represent a "next
step" in tissue engineering as it relates to the soft tissues of the craniofacial
region and potentially elsewhere in the body.
AUTHOR INFORMATION
Accepted for publication May 24, 2000.
Reprints: Peter D. Costantino, MD, Department of Otolaryngology,
Box 1189, The Mount Sinai Medical Center, 1 Gustave L. Levy Pl, New York,
NY 10029.
From the Departments of Otolaryngology (Drs Costantino, Govindaraj,
and Urken and Mr Hiltzik) and Oral and Maxillofacial Surgery (Drs Costantino
and Buchbinder), The Mount Sinai Medical Center, New York, NY. Dr Costantino
is a consultant to LifeCell Corporation, The Woodlands, Tex, and Stryker Leibinger
Inc, Kalamazoo, Mich, and receives research funding from these companies as
well. None of the other authors have a financial interest in either of these
companies.
REFERENCES
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1. Wainwright D, Madden M, Luterman A, et al. Clinical evaluation of an acellular allograft dermal matrix in full-thickness
burns. J Burn Care Rehabil. 1996;17:124-136.
PUBMED
2. Wainwright DJ. Use of an acellular allograft dermal matrix (AlloDerm) in the management
of full-thickness burns. Burns. 1995;21:243-248.
FULL TEXT
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ISI
| PUBMED
3. Jones FR, Schwartz BM, Silverstein P. Use of a nonimmunogenic acellular dermal allograft for soft tissue
augmentation: a preliminary report. Aesthetic Surg Q. 1996;16:196-201.
4. Livesey SA, Herndon DN, Holyoak MA, Atkinson YH, Nag A. Transplanted acellular allograft dermal matrix: potential as a template
for the reconstruction of viable dermis. Transplantation. 1995;60:1-9.
ISI
| PUBMED
5. Schoenrock LD, Chernoff WG. Subcutaneous implantation of Gore-Tex for facial reconstruction. Otolaryngol Clin North Am. 1995;28:325-340.
ISI
| PUBMED
6. Lassus C. A surgical solution to the deep nasal labial fold. Plast Reconstr Surg. 1996;97:1473-1478.
ISI
| PUBMED
7. Biel MA. Gore-Tex graft midfacial suspension and upper eyelid gold-weight implantation
in the rehabilitation of the paralyzed face. Laryngoscope. 1995;105:876-879.
ISI
| PUBMED
8. Conrad K, MacDonald MR. Wide polytef (Gore-Tex) implants in lip augmentation and nasolabial
groove correction. Arch Otolaryngol Head Neck Surg. 1996;122:664-670.
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