A case of Late Occlusion of Femoro-Post Tibial PTFE Graft due to Ectopic Bone Formation

ABSTRACT

The ectopic bone formation is a condition in which mature lamellar bone is formed in tissues that do not normally ossify, which was first described by Riedel in 1883. It has been observed at sites of chronic infection, hemorrhage, fibrous scarring or contracture. The pathophysiology of ectopic bone formation is not clearly identified but has complex and multifaceted causes, which resulted to differentiate the non-circulating pluripotent mesenchymal cells to osteoblastic stem cells. The local environment conditions of trauma, disruption of soft tissues and periostium, bone debris, hematoma, damaged muscle, uncommitted fibroblasts are suspected to be one of the causes of this condition. Comparing to simple soft tissue calcification, the ectopic bone has all the morphologic and biochemical characteristics of orthotopic bone, which is subjected to turnover and even has the ability for bone marrow formation. A case of late occlusion in a femoro-post. tibial PTFE graft about 5 months after vascular reconstruction due to ectotopic bone formation, which is confirmed by pathology around the graft is presented. After excision of the ectopic bone around the inflow vascular anastomosis site with re-vascularization, the patient was free from the ischemic leg symptoms. We reported a case of occlusion of vascular anastomosis site by ectopic bone formation with review of literature.