**3. Use of biodegradable materials**

#### **3.1 Introduction**

The perfect implant material currently is not available yet, but in general surgery there is now a consensus, that low weight, large pore (macroporus), monofilament synthetic materials are preferable. However, still serious local complications (e.g. erosion and infection) may occur and related to an increased foreign body reaction. Subsequently,

Futuristic Concept in Management

**and Otto, 2004; Rutner et al, 2003).**

**(Wiedemann and Otto, 2004)**.

**3.2.3 Biomechanical properties** 

anti-incontinence surgery **(Jankowski et al, 2004).** 

**3.2.4 Outcome of the SIS Sling** 

of Female SUI: Permanent Repair Without Permanent Material 305

durability, and resistance to infection **(Badylak, 2004; Jankowski, et al, 2004; Wiedemann** 

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

SIS is degraded in 4 to 12 weeks by a "constructive" remodeling process that replaces the graft gradually by host connective tissue **(Clarke et al, 1996; Prevel et al, 1995).** Tensiometric strength initially decreases down to 45% 10 days after implantation, but by 1 month it is identical to that of the native tissue **(Badylak et al, 2001).** The task of the SIS sling is mainly to act as a scaffold that allows in-growth and structural organization of the native host tissue. The implant actively supports connective and epithelial tissue ingrowth and differentiation, as well as deposition, organization, and maturation of ECM components that characterize site-specific tissue remodeling. This phenomenon has been called *smart tissue remodeling* **(Badylak, 1993)** and it is important to note that the balance between implant degradation and host incorporation results in a dynamic implant strength response. The strength of the SIS sling is expected to be the net result between SIS degradation and tissue regeneration. Degradation rates that are too rapid or reconstruction rates that are too slow can result in transient minimum strengths that are below the critical threshold. Supposedly, this carries increased risk of recurrence of incontinence symptoms after an initial successful

The suitability of the SIS sling is better reflected by the clinical outcome. In terms of clinical efficacy in correction of SUI, the results of different studies showed that SIS was able to

Rutner et al, reported in their work utilizing SIS as a pubovaginal slings in the treatment of female SUI that all patients had minimal local reactions and pelvic pain; no cases of erosion

provide a strong suburethral support and durable clinical results (table 7).

biologic implants were introduced in an effort to reduce the local complications associated with synthetic materials without compromising the surgical results.

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

We will discuss below the role of Small intestinal submucosal (SIS) graft as a futuristic biodegradable implant to substitute synthetic slings in the treatment of female SUI.
