Abstract
There are strong demands for innovative anti-thrombogenic materials, such as carbon,
because of their necessity in fabricating artificial organs and progressive surgical
vascular prostheses. Serial platelet deposition, surface topography, and patency were
evaluated in control standard (N 45) and carbon-lined (N 45), small diameter (4 mm
inner diameter) polytetrafluoroethylene grafts implanted in the abdominal aortic replacement
in rabbits. A pilot study of 80 animals—40 carbon-lined (CL) and 40 standard (ST)
grafts were used to develop microsurgical techniques. The 2-hour graft patency (Doppler
and angiographic studies) showed better patency rate in the CL group (93% vs 80%).
In 10 animals (5 ST and 5 CL grafts) the platelet deposition on each prostheses was
quantitated by means of Indium 111 labeled platelets in a dual, isotope-platelet imaging
technique. Platelet deposition on ST grafts 2 hours after insertion was significantly
higher than on the CL grafts (6.60 ± 1.98 × 103 platelets/mm2 vs 0.82 ± 0.25 × 103 platelets/mm2; p < 0.05). Light microscopy evaluation of explanted ST midgrafts sections, including
both anastomoses, indicated platelet-fibrin deposition (PFD) in nearly all prostheses,
whereas only 13% of the CL grafts exhibited PFD (chi-square: 61.117; p < 0.001). Gammacamera imaging allowed scintiphotos of the grafts and cinetic acquisition.
We conclude that carbon-lining decreases platelet accumulation and improves patency
in small-diameter PTFE grafts in the acute phase.
