Mandibular reconstruction in miniature pigs with prefabricated vascularized bone grafts using recombinant human osteogenic protein-1: a preliminary study

A new technique of prefabrication of vascularized bone grafts in the latissimus dorsi muscle of miniature pigs, using recombinant human osteogenic protein-1 (rhOP-1) and xenogenic bone mineral as a carrier, is presented. The grafts were used to reconstruct a mandible using microsurgical anastomosis of the thoracodorsal vessels of the flap with a branch of the external carotid artery and the external jugular vein. The technique provided enough bone to reconstruct a mandible. The bone marrow stayed viable after transplantation, demonstrated by fluorescence microscopy and scintigraphy. Compared with identical defects of the contralateral side, which were treated with directly applied rhOP-1/bone mineral, a significantly better result was obtained with the prefabrication technique. The prefabrication technique may provide a means to treat irradiated patients with bone grafts produced by osteoinductive proteins and has a potential to become a clinical alternative to conventional vascularized bone grafts.