Sk. Williams et al., MICROVASCULAR ENDOTHELIAL-CELL SODDING OF EPTFE VASCULAR GRAFTS - IMPROVED PATENCY AND STABILITY OF THE CELLULAR LINING, Journal of biomedical materials research, 28(2), 1994, pp. 203-212
Small diameter (<6 mm) synthetic vascular grafts fail at a clinically
unacceptable rate due in large part to their inherent thrombogenicity.
The development of a new cellular lining on synthetic vascular grafts
would most likely improve the patency rates observed for these grafts
in small diameter positions. We have evaluated the use of endothelial
cell transplantation to accelerate the formation of a cell lining usi
ng microvascular endothelial cells derived from canine falciform ligam
ent fat. This source of fat is histologically similar to human liposuc
tion fat and was isolated using a collagenase digestion technique iden
tical to methods used for human liposuction fat microvessel endothelia
l cell isolation. The isolated fat endothelial cells were sodded onto
4 mm ePTFE grafts using pressure to force the cells onto the luminal s
urface. This pressure sodding method permitted cell deposition in less
then 3 min. Sodded and control (non-cell-treated) grafts were implant
ed as interpositional paired grafts using end-to-end anastomoses in th
e carotid arteries of mixed breed dogs. Each dog therefore received a
sodded graft on one side and 9 control graft on the contralateral side
. After 12 weeks of implantation all control grafts were occluded whil
e 86% of the cell-sodded grafts remained patent. Statistical evaluatio
n of the data revealed a significant improvement in patency of cell so
dded grafts (McNemar's chi(2) P =.02). Morphological evaluation of gra
fts explanted at 5, 12, 26, and 52 weeks following implantation reveal
ed the presence of a cell lining on sodded grafts which remained stabl
e for a period of at least one year. This new cell lining exhibited mo
rphologic characteristics of a nonthrombogenic endothelial cell lining
. The development of this new intima, evaluated 5 weeks-1 year after i
mplantation, was not associated with a progressive intimal hyperplasia
. From these data we conclude that microvessel endothelial cells deriv
ed from canine falciform ligament fat can be rapidly isolated using an
operating room compatible method. Cell deposition on synthetic grafts
is subsequently accelerated using a pressure sodding technique. A cel
lular Lining forms on the inner surface and is associated with a stati
stically significant improvement in the function of sodded grafts in a
canine carotid artery model. (C) 1994 John Wiley and Sons, Inc.