Jm. Bellon et al., ARTERIAL AUTOGRAFTS AND PTFE VASCULAR MICROPROSTHESES - SIMILARITIES IN THE HEALING-PROCESS, European journal of vascular surgery, 8(6), 1994, pp. 694-702
A comparative study has been carried out dealing with the vascular hea
ling process in two experimental vascular graft models to determine th
e differences or similarities between the two. One of the models consi
sted of the use of arterial autografts and the other of the implantati
on of vascular microprostheses of polytetrafluoroethylene (PTFE). The
common iliac artery of female Sprague-Dawley rats was used. The length
of the grafts in both models was 5 mm. A microsurgical technique was
employed, and anticoagulant and antibiotic therapies were not used. Th
e results were studied using light microscopy, transmission and scanni
ng electron microscopies, autoradiography, and immunohistochemistry. A
patency of 100% was obtained in the arterial autographs, and 87.6% in
the PTFE implants. The histopathological findings were as follows: a)
the mechanisms of immediate postgrafting response were similar, with
marked presence of fibrin and platelet deposition in the form of a non
thrombogenic monolayer; b) a ''neoadventitia'' formed over the implant
in both models; c) the endothelialisation was complete in both types
of grafts 2 to 3 weeks after implantation; d) an intimal hyperplastic
response appeared in both, although at different times (in the first w
eek in the autografts and at one month with the PTFE); e) white cell a
ccumulation was significantly greater on the PTFE luminal surface than
on the autograft. The intimal hyperplasia was formed mainly by secret
ory myocytes in the autografts, while in the PTFE implants, fibrosis p
redominated.