**3.2.2 Graft biocompatibility**

SIS is made by a way that all cells responsible for an eventual immune response are removed, but the ECM and natural growth factors are left intact. It contains collagen, growth factors TGF-beta and FGF-2 **(Wiedemann and Otto, 2004)**. Many clinical trials and histopathological studies support the fact that the SIS graft has excellent biocompatibility as evidenced by lack of significant immunological reaction, foreign body reaction, and chronic inflammatory reaction (figure 8). In addition, the SIS sling is well known for its strength,

biologic implants were introduced in an effort to reduce the local complications associated

Biological xenograft is a mammalian extracellular matrix (ECM) composed of laminin, fibrinectin, elastin, and collagen. Tissue sources from which xenografts are chosen include: porcine (small intestine, dermis), bovine (pericardium, fetal, dermis) and equine**.** Collagen based implants can either be cross-linked or not. Cross-linking protects the implant against degradation by collagenases, so that they remain intact very long, if not ever. At present, most xenogenic materials are from porcine source and it is the most commonly used, as bovine material became less acceptable. Production is strictly controlled by Food and Drug Administration (FDA) guidelines, which include knowledge of the animal herd, vaccination status, feed source, abattoir approval and bovine spongiform encephalopathy clearance

We will discuss below the role of Small intestinal submucosal (SIS) graft as a futuristic

SIS xenograft is an acellular, nonimmunogenic, biodegradable, biocompatible, collagen matrix manufactured from porcine small intestinal submucosa, which could induce native

SIS graft has gained popularity in the field of urogynecology and reconstructive surgery. Promising results have been reported with the use of SIS as a bladder and urethral substitute material in animals **(Kropp, 1998a; Kropp et al, 1998b; Chen, Yoo and Atala, 1999).** Also, SIS has been used in humans undergoing urogenital procedures such as cystoplasties, ureteral reconstructions, penile chordee, and even urethral reconstruction for hypospadias and strictures **(Dedecker et al, 2005; Atala et al, 1999; Le Roux, 2005; Kassaby et al, 2003; Sharma and Secrest, 2003; Liatsikos et al, 2001).** In the field of urinary incontinence, SIS has been used with encouraging results in treatment of postprostatectomy incontinence **(Jones et al, 2005a),** neuropathic incontinence **(Misseri et al, 2005),** and SUI **(Wiedemann and Otto, 2004; Rutner et al, 2003; Jones et al, 2005b; Farahat et al, 2009).** Practical concerns regarding the use of the SIS implant in clinical practice: The first practical concern is related to the graft biocompatibility and how the tissue would react to the implant. The second practical concern is related to the biomechanical properties of the SIS

SIS is made by a way that all cells responsible for an eventual immune response are removed, but the ECM and natural growth factors are left intact. It contains collagen, growth factors TGF-beta and FGF-2 **(Wiedemann and Otto, 2004)**. Many clinical trials and histopathological studies support the fact that the SIS graft has excellent biocompatibility as evidenced by lack of significant immunological reaction, foreign body reaction, and chronic inflammatory reaction (figure 8). In addition, the SIS sling is well known for its strength,

biodegradable implant to substitute synthetic slings in the treatment of female SUI.

with synthetic materials without compromising the surgical results.

**(Deprest et al, 2006).**

**3.2 Small intestinal submucosal (SIS) graft** 

sling and its suitability for curing SUI **(Farahat et al, 2009).**

tissue regeneration in various organs.

**3.2.1 Clinical applications of SIS** 

**3.2.2 Graft biocompatibility**

durability, and resistance to infection **(Badylak, 2004; Jankowski, et al, 2004; Wiedemann and Otto, 2004; Rutner et al, 2003).**

Fig. 8. First histopathological results for SIS pubovaginal slings show: submucosal biopsy with A) minimal SIS residues (red arrows) - B) minimal chronic inflammatory infiltration **(Wiedemann and Otto, 2004)**.
