The viability of revascularized calvarial bone graft in a pig model

This study compared the vascularity and resorption of calvarial bone flaps based on an undisturbed pedicle and on a previously (4 weeks) detached pedicle of the superficial fascia (galea) and periosteum and free calvarial bone grafts. Nine adult pigs were used, in three of which a silicone rubber compound was injected intravascularly immediately after the transfer confirmed the vascularity of both pedicled bone flaps. In six pigs, volume changes were assessed intraoperatively by a water displacement method and also 12 weeks postoperatively. Both pedicled bone flaps preserved their original volume, whereas free skull grafts showed approximately 50% of volume loss (p less than 0.001). Decalcified hematoxylin and eosin sections of the specimens obtained 12 weeks postoperatively showed a normal calvarial appearance in both pedicled bone flaps and extensive fibrous tissue infiltration into free grafts. It is suggested that a previous detachment of galea and periosteum does not interfere with the use of vascularized calvarial bone graft, which may provide a more predictable result than a free bone graft.