De-novo generation of vascularized tissue using different configurations of vascular pedicles in perforated and closed chambers

Growing three-dimensional tissue within a chamber requires vigorous angiogenesis initiated by, for example, an arteriovenous fistula or a ligated vascular pedicle. Growth may also be enhanced by contact with the external environment. In this study tissue growth in a rat model, vascularized via an arteriovenous loop (AV Loop) or ligated pedicle, was compared in chambers that were either closed or perforated. Chambers were harvested at 4 weeks and tissue volume and histology compared. In perforated chambers, more tissue were generated using the ligated pedicle (0.75 ml+/-0.04) than the AV Loop (0.59 ml+/-0.01). Perforated chambers generated larger volumes of tissue than closed chambers because they encouraged tissue ingrowth through the perforations. Both vessel configurations supported tissue growth but, interestingly, the ligated pedicle resulted in significantly more tissue in the perforated chambers.