A STUDY OF BONE AND VASCULAR CHANGE IN FABRICATING THE NEO-OSSEOUS FLAP USING ILIAC BONE AND INFERIOR EPIGASTRIC VESSEL

Kim, Woon Gyu; Lee, Jong Ho; Kim, Jong Won

Abstract

Generally fabrication of neovascularized bone flap are produced by snadwiching vessels between bone segment with the optimal size and shape for the recipient sites. When these flaps are transferred to the recipient site, they are again isolated from the surrounding soft tissues, resulting not only decrease in the blood flow to bone segments by sacrifices of peripheral blood circulation due to elevation of flap, but also possible changes of shape of osseous flap by bone resorption. To overcome these disadvantage, it may be considerable to block bone segment off from the surrounding soft tissue. Purpose of this study are observed time-dependent changes of blood flow, vascularity and histologic finding of bone flaps using the autogenous bone and local vessel implantation. The results are compared with bone flap which had not been blocked off from surrounding soft tissues. Neovascularized bone flap were fabricated in 90 Sprague-Dawley rats using autogenous iliac bone and superficial inferior epigastric vessels. The experimental flaps were wrapped with silastic sheets to block neovascularization from surrounding soft tissues, and the control flaps were left unwrapped. The degree of bone formation, vascularity and blood flow were then assessed at 1, 2, 4, 6 and 8 weeks after flap fabrication, using a histological examination, microangiogram, corrosion cast study and radioactive microspheres. When fabricating a neovascularized bone flap using the autogenous iliac bone and the superficial inferior epigastric vessels, the physico-histological organization, vascularity and blood flow of neovascularized flaps were same or superior for wrapped than for unwrapped bone segments until the 4th week after grafting. This means that the period of neovascularization can be lengthened by the 4th weeks in the fabrication of bone segments, which can be blocked off from surrounding soft tissues. For these reasons, blocked bone flap fabrication can be considered to be superior to the conventional method.