VIABILITY OF VASCULARIZED BONE GRAFT FROM THE ILIAC CREST USING THE ILIAC BRANCH OF THE ILIOLUMBAR ARTERY: EXPERIMENTAL STUDY ON RATS

Objective: Through an experimental model, our aim was to create inferences about the viability of vascularized bone grafts from the iliac crest in rats and investigate their histological features. Methods: Twenty-one rats were used, divided into two groups: the first consisted of animals that were subjected to the technique of vascularized bone graft pedicled onto the iliac branch of the iliolumbar artery; the second (control group) underwent the same procedure as performed on the first group, with the addition of ligation of the vascular pedicle. The viability of the bone grafts was observed for three weeks, by means of direct observation of the graft, histology and immunohistochemistry. Results: All the vascularized grafts evaluated in the first week showed viability according to direct observation, histology and immunohistochemistry. However, in the second and third weeks, direct observation showed that 75% of the grafts were unviable, while histological analysis and immunohistochemistry showed that 50% were unviable. Conclusions: Some grafts that are designed to be vascularized became unviable and began to behave like non-vascularized grafts under direct observation and histology. Despite the possibility of failure, use of vascularized bone grafts should be encouraged, because descriptive histology shows greater cell density in the medullary bone portion, and osteocytes that function better regarding deposition of bone matrix, with preservation of the intraosseous vascular network.