In-Situ Vascular Regeneration by Host Cells of Acellular Human Saphenous Vein Implanted in Porcine Carotid Artery

Small vascular graft engineering may help reduce early vein graft failure. We assessed the feasibility, safety, and in vivo vascular regeneration potential of the decellularised human saphenous vein (D-hSV) with and without pre-seeding with porcine endothelial-like cells (ELCs) following grafting in porcine carotid artery (CA). A total of 14 pigs received CA grafting of control D-hSVs (n = 7) or D-hSVs seeded with ELCs (SD-hSV; n = 7). Ultrasound vascular Doppler was undertaken before and after grafting, and at 4 weeks. Outcome measures included patency, intimal thickening (IT), in situ vascular regeneration, endothelial cell (EC) coverage, neo-angiogenesis, mesenchymal-EC transition, and contractile cells. All animals reached the predefined culling point in good health, with no feasibility/safety concerns. Mild graft dilatation occurred at 4 weeks vs. baseline, with no difference between groups. In total, 9/14 grafts (64.3%) remained patent at 4 weeks (4/7 (57.1%) vs. 5/7 (71.4%) in the D-hSV and SD-hSV groups, respectively). IT increased from 17.1 ± 4.7% at baseline to 54.1 ± 12.2% at 4 weeks. Vascular regeneration occurred in all patent grafts with EC coverage, an increase in collagen and elastin, vimentin, SM-MHC-11, and calponin, with no difference between groups. The D-hSV for arterial vascular grafting is feasible and safe and associated with signs of in situ vascular regeneration by host cells at 4 weeks. Pre-seeding with ELCs did not add benefits.