In vivo h-VEGF165 gene transfer improves early endothelialisation and patency in synthetic vascular grafts.
OBJECTIVE
Small-diameter synthetic vascular graft performance is inferior to autologous vein grafts. This study tested the hypotheses that local in vivo administration of plasmids encoding for human vascular endothelial growth factor (VEGF), or co-administration of plasmids encoding for human vascular endothelial growth factor/plasmids encoding for fibroblast growth factor-2 in the tissues surrounding a porous synthetic vascular graft would enhance graft endothelialisation and, consecutively, graft patency.


METHODS
First, optimal gene for small-diameter synthetic graft endothelialisation was studied in rat abdominal aorta model (n=132): plasmids encoding for human vascular endothelial growth factor; co-administration of plasmids encoding for human vascular endothelial growth factor/plasmids encoding for fibroblast growth factor-2; or control plasmids were injected around 60 microm ePTFE graft. Second, optimal small-diameter synthetic graft design for endothelialisation was explored in rabbit abdominal aorta model (n=90). Various ePTFE grafts or pre-clotted polyester grafts were used with/without plasmids encoding for human vascular endothelial growth factor. Third, clinically used medium-size synthetic grafts were investigated with/without plasmids encoding for human vascular endothelial growth factor in dog carotid (n=20) and femoral arteries (n=15). Endothelialisation was assessed in midgraft area with scanning electron microscopy.


RESULTS
In rats, plasmids encoding for human vascular endothelial growth factor enhanced endothelialisation; whereas co-administration of plasmids encoding for human vascular endothelial growth factor/plasmids encoding for fibroblast growth factor-2 had worst outcome at 1 week (NS), 2 weeks (P=0.01) and 4 weeks (P=0.02). In rabbits, pre-clotted polyester grafts had a trend for faster endothelialisation than ePTFE grafts (P=0.08); whereas plasmids encoding for human vascular endothelial growth factor enhanced endothelialisation compared to controls at 2 weeks (P=0.06), however, the effect reversed at 4 weeks (P=0.03). In dogs, synthetic graft patency was improved by plasmids encoding for human vascular endothelial growth factor in femoral position (P=0.103); whereas all carotid grafts were patent at 6 weeks.


CONCLUSIONS
Thus, these data suggested that endothelialisation was fastest in pre-clotted polyester grafts; and that local application of plasmids encoding for human vascular endothelial growth factor had a potential to improve early endothelialisation and patency in synthetic vascular grafts.
Lahtinen
Mika
M
Department of Surgical Sciences, Uppsala University Hospital, Uppsala, Sweden. mika.lahtinen@medsci.uu.se
Blomberg
Pontus
P
Baliulis
Giedrius
G
Carlsson
Fredrik
F
Khamis
Harry
H
Zemgulis
Vitas
V
D000818:Animals; D001807:Blood Vessel Prosthesis; D004285:Dogs; D004730:Endothelium, Vascular / Q000502:physiology / Q000648:ultrastructure; D016222:Fibroblast Growth Factor 2 / Q000235:genetics / Q000502:physiology; D015870:Gene Expression; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D006083:Graft Occlusion, Vascular / Q000517:prevention & control*; D006801:Humans; D018919:Neovascularization, Physiologic; D010957:Plasmids; D011091:Polyesters; D011817:Rabbits; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D013045:Species Specificity; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000502:physiology*; D014654:Vascular Patency / Q000502:physiology*
D011091:Polyesters; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D016222:Fibroblast Growth Factor 2