**3.2.3 Biomechanical properties**

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