THE USE OF RADIONUCLIDE ANGIOGRAPHY TO STUDY BLOOD-FLOW THROUGH ENDOTHELIAL-CELL SEEDED EXTRATHORACIC BYPASS GRAFTS IN THE DOG

Endothelial seeding of vascular grafts has been shown to decrease graf t thrombogenicity and prolong longevity when implanted in vivo. Previo us studies have utilized anatomic grafts to study endothelialization a nd healing, Anatomic thoracoabdominal grafts do not allow for sequenti al biopsy for evaluation of individual grafts nor do they approximate the environment for long bypass grafts used in limb salvage, This stud y evaluated the use of an extra-anatomic aortic bypass graft to assess the healing of endothelial cell seeded expanded polytetrafluoroethyle ne (ePTFE), Radionuclide angiography was used to evaluate graft patenc y and quantify blood flow through the graft, Dogs underwent placement of an extra-anatomic 60 cm long, 8 mm internal diameter, graft seeded with autologous endothelium. Grafts were biopsied from 2 weeks up to 1 year, Radionuclide studies were performed postimplantation and follow ing each graft biopsy, Graft placement and biopsies were well tolerate d in all dogs, Biopsied segments of graft allowed for sequential studi es of the healing of implanted grafts by scanning electron and light m icroscopy, Flow through the implanted graft was close to 50% of the to tal caudal abdominal aortic flow, No significant difference in graft f low was noted either between animals or over time.