Figure 13.

Radial Laser holes creating ingrowth permissible spaces in vascular grafts. (A) Laser holes in polyurethane grafts and (B) a decellularized arterial allograft. The clear-cut edges without tissue trauma are typical for very short-waved lasers (330). Trans-mural tissue ingrowth from the adventitia after 3 months of carotid interposition grafting in sheep. In spite of dense fully transmural tissue ingrowth through the laser perforation the decellularized allograft tissue surrounding the laser hole remained acellular (B1). Vimentin positive fibroblasts were restricted to the laser channel (B2). Within the laser hole, neovascularization was restricted to the outer half as capillary sprouting did not reach the graft lumen (von Willebrand staining) (B3). From (331, 332) and (329) with permission.