Title: Revascularization of Human Acellular Dermis Matrix when used for Ventral Hernia
Repair – A Rabbit Model
Authors: Nathan G. Menon MD, Eduardo D. Rodriguez DDS, MD, Nelson H. Goldberg MD,
Ronald P Silverman MD.
Division of Plastic Surgery,
University of Maryland, School of Medicine
Introduction:
In general, the first choice in reconstructing extensive abdominal wall defects involves the use of
prosthetic material. Prosthetic materials such as expanded polytetrafluoroethylene (GoreTex )
while frequently used, do not get revascularized and hence its use is limited to applications at
low risk for infection. Previous work in the rabbit model has shown that autologous
thoracodorsal fascia when used for abdominal wall reconstruction becomes revascularized,
retains its cellular architecture, and resists infection better than prosthetic material1. Clinically,
autologous tensor fascia lata has confirmed our laboratory findings. Despite clinical success in
abdominal wall reconstruction with autologous tensor fascia lata, donor site morbidity remains
problematic. One study over a ten-year period reports a 30% donor site complication rate, largely
consiting of seromas and hematomas2. Therefore, a prosthetic material that supports vascular ingrowth would be a useful reconstructive option and would not involve the use of a donor site nor
subject the patient to the relatively high complication rate.
This study investigates if human acellular dermis (AlloDerm) supports vascular in-growth when
used to reconstruct full thickness abdominal wall defects in the rabbit model. AlloDerm®
(manufactured by Life Cell Corporation, Woodlands, TX) is an acellular dermal matrix
processed by a proprietary protocol from human cadaver skin. The epidermis of the cadaver skin
is separated from the dermis using a high ionic-strength solution, which uncouples the bond
between the two layers; the cells in the dermis remain undamaged by this process. The dermal
cells are then removed from the dermis using sodium deoxycholate and the material is then
freeze-dried. The end-product of the protocol results in a biomaterial containing components of
types IV and VII collagen, elastin, and laminin, which are undamaged within the residual dermal
matrix3. This material has already shown to be efficacious in the treatment of full thickness
burns4, as a substrate material for oral resurfacing and periodontics5. Furthermore AlloDerm®
has shown promise as a soft tissue filler in plastic surgery6 and is used as a viable option for
dural replacement in neurosurgical cases where autogenous tissues are either unavailable or
insufficient for proper reconstruction7. If it can be conclusively shown that AlloDerm®
revascularizes similar to fascial autograft, then abdominal wall reconstruction can be
accomplished without the need for a donor site. A material that revascularizes when used as an
implant would be an useful reconstructive option especially in patients with large ventral hernias
who are at high risk for postoperative infection.
Methods:
A full-thickness abdominal wall defect was created in 25 rabbits. This defect was repaired (1) in
Group A with an Alloderm patch (n = 10 rabbits), (2) in Group B with a GoreTex patch (n =
10 rabbits), and (3) in Group C with primary closure using a continuous non-absorbable #0
Prolene® suture (n = 5 rabbits). The defect measured 3cm x 7cm in groups A and B whereas the
defect in Group C measured 0.5cm x 7cm.
After 30 days the following endpoints were evaluated: (a) the incidence of herniation (b) the size
of repaired patch at harvest in Groups A and B, (c) the presence of intra-abdominal adhesions (d)
the breaking strength of the patch–fascia interface (with the suture removed), and (e) assessment
of vascular in-growth into the patch by fluorescein-dye infusion and histological analysis.
Results:
There was no incidence of herniation in any of the rabbits in the three groups. The size of the
patch was unchanged in all rabbits except for 2 rabbits in the Alloderm group (20%) but the
increase in size was not statistically significant when compared to the GoreTex group (p >
0.05). Visceral adhesions to the patch were found in all the GoreTex group rabbits, but no such
adhesions were present in the other two groups.
There was no significant difference between the mean breaking strength of the Alloderm-fascial
interface (288.6 N/mm2  97.1 SD) and that of the GoreTex-fascial interface (337.0 N/mm2 
141.2 SD). The mean breaking strength of the primary closure group with the suture removed
(521.2 N/mm2  223 SD) was not only higher but also statistically different from both the
Alloderm and GoreTex groups (p < 0.05). Infusion with flourescein dye and histological
analysis revealed vascular in-growth into the Alloderm patch but not the GoreTex patch.
Conclusions:
This study demonstrates that human acellular dermis (Alloderm) functions at least as
effectively as GoreTex in ventral hernia repair with fewer adhesions at one-month post
operation in the rabbit model. Alloderm supports vascular in-growth within thirty days when
used to reconstruct full thickness abdominal wall defects. A material that becomes vascularized
holds much promise in patients with large ventral hernias who are at high risk for infection. A
longer-term study in a larger animal model is certainly warranted.
References:
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abdominal reconstruction in experimental animal defects. Plast. Reconst Surg. 97:801-806,
1996.
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Fascia versus synthetic patch abdominal reconstruction in experimental animal defects. Plast.
Recons Surg. 108: 2086-2087, 2001.
3. Eppley BL. Revascularization of Acellular Human Dermis (Alloderm) in Subcutaneous
Implantation, Aesthetic Surgery Journal – July/August 2000
4. Wainwright DJ, Madden M, Luterman L. Clinical evaluation of an acellular dermal matrix in
full thickness burns. J Burn Care Rehabil 1996. 17: 124-136
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tissue. Practical Pariodontic and Aesthetic Dentistry (PPAD). 3: 14-21, 1996.
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for soft-tissue augmentation. Aesthetic Surg Q. 16: 196-201, 1996.
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review of the literature. Head & Neck, Dec 2000 765-771.