Histologic Analysis of Acellular Dermal Matrix in the Treatment of Anal Fistula in an Animal Model
ABSTRACT Human acellular dermal matrix (ADM) has been used successfully for the treatment of severe burns, ureter support, and abdominal wall reconstruction. This study was designed to evaluate the mechanism of ADM in the closure of anal fistula in an experimental porcine model.
The fistula-in-ano model was created in the porcine model and treated with ADM in 14 animals. Fistula specimens were obtained at hours 12 and 24 and on days 3, 7, 14, 28, 60. Hematoxylin and eosin staining, Masson trichrome staining, and immunohistochemical staining for alpha smooth muscle actin and matrix metalloproteinase 9 were performed.
The cell density increased from hour 12 to day 7 and decreased from day 7 to day 28 (p < 0.001). Mature vessels stained with alpha smooth muscle actin were identified at day 7. Alpha smooth muscle actin-positive myofibroblasts were found in clusters at the edge of the ADM at day 7. The density of vessels (p < 0.001) and myofibroblasts (p < 0.001) increased from day 7 to day 14. The density of matrix metalloproteinase 9 increased from hour 12 to day 7 and decreased from day 14 to day 60 (p < 0.001). Partially organized bundles of muscle were found by day 60.
We suggest that ADM is a reasonable new option for closure of anal fistulas. Anal fistulas begin to heal as early as 12 hours, and day 7 may be an important time point to judge whether the fistula healed preliminarily or not. The ability of ADM to become vascularized and remodeled by autologous cells may be advantageous for anal fistula healing.
- SourceAvailable from: Chen Huang
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- "Such a scaffold must demonstrate several critical features for potential utility in vivo, including mechanical integrity, biocompatibility, slow biodegradation, and transparency. An acellular dermal matrix (ADM) is a commercially available tissue graft derived from donated human skin  . ADM has been widely used since 1992 for various reconstructive surgeries, such as in cases of severe burns, recurrent hernias, abdominal wounds, and oculoplastic applications        . "
ABSTRACT: The aim of this study was to analyze the viability of using an acellular dermal matrix (ADM) as a reinforcement material for peripheral corneal thinning disease. The complete removal of cell components was confirmed by hematoxylin and eosin (H&E) and 4',6-diamidino-2-phenylindole (DAPI) staining. Transmission electron microscopy determined that the stromal structure was well preserved. Uniaxial tests revealed that the ADM had strong mechanical properties. After being implanted into rabbit cornea the ADM showed no sign of rejection and even achieved good transparency 24weeks post-surgery. H&E staining demonstrated that keratocytes grew in the ADM and the ADM-cornea interface became blurry. Picrosirius red staining revealed great changes of collagen in the ADM. Uniaxial testing of the reinforced cornea showed better mechanical strength than the normal rabbit cornea, but this did not exhibit statistical significance. These results suggest that ADM is a worthy candidate for future exploration as a reinforcement material for peripheral corneal thinning problems.Acta biomaterialia 05/2012; 8(9):3326-32. DOI:10.1016/j.actbio.2012.05.004 · 5.68 Impact Factor
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ABSTRACT: Abstract We report on a clinicopathologic study in an animal model of treatment with a new bioabsorbable polymer plug (BAPP). Over a 2-week period, 6 porcine models, which each had 4 anal fistulae, were created using Blake drains. The pigs were divided into 2 groups: the BAPP-treatment group (n = 12 fistulae) and the control group (n = 12 fistulae). Two weeks later, the pigs were humanely killed, and the perianal sites were excised and examined with gross and pathologic studies. Each fistula in the BAPP group was completely cured. In the pathologic study, the treatment sites had little disarray, few defects in the muscular layer, and small numbers of inflammatory cells. The control group had a significantly greater number of inflammatory cells and microabscesses than the BAPP group. The newly developed BAPP reduced the infection and induced good healing in anal fistulae. The BAPP may be a useful new device for the clinical treatment of anal fistulae.International surgery 05/2013; 98(2):122-128. DOI:10.9738/CC180 · 0.25 Impact Factor
Article: Anorectal abscess and fistula.[Show abstract] [Hide abstract]
ABSTRACT: Anorectal abscesses and fistula-in-ano represent different stages along the continuum of a common pathogenic spectrum. The abscess represents the acute inflammatory event while the fistula is representative of the chronic process.Medical times 04/1955; 83(3):289-91. DOI:10.1007/978-1-4419-1584-9_13