Experimental study of adventitial collagen cross-linking by glutaraldehyde reducing intimal hyperplasia of vein graft / 中华胸心血管外科杂志

ABSTRACT

Objective:To evaluate the validity of adventitial collagen cross-linking by glutaraldehyde(GA) to reduce intimal hyperplasia of vein graft in a rabbit carotid artery bypass graft model.Methods:Harvesting 36 segments of the external jugular vein and 6 segments of the internal carotid artery with 3 cm length from the New Zealand white rabbits. The veins were randomly divided into 6 groups and underwent adventitial collagen cross-linking by 0.3% glutaraldehyde for 0 min, 1 min, 2 min, 3 min, 4 min, and 5 min, respectively. All vessel segments were subjected to biomechanical tests and pathological tests. Carotid artery bypass graft models were established in 24 New Zealand white rabbits including crosslinked group(n=12) and non-crosslinked group(n=12). The vein grafts were obtained for pathological examination 4 weeks after models feeding, and the intimal hyperplasia of vein graft was evaluated.Results:Adventitial cross-linking increased fiber density of adventitia significantly, and increased the stiffness of the veins as the time of cross-linking increased. And in the high strain region(strain ratio 1.4-1.8), the mechanical curve of veins receiving 3min cross-linking was similar to that of the carotid artery. The patent rate of the vein grafts of rabbit models was 100% after 4 weeks. Comparing with non-crosslinked group, the intimal and medial thickness of vein grafts in crosslinked group were reduced remarkably[(78.83±9.02)μm vs.(140.19±19.90)μm, (43.75±5.05)μm vs.(58.35 ± 8.61) μm, P<0.01). Conclusion:Adventitial collagen cross-linking by GA can enhance the mechanical strength of the jugular vein, and reduce the intimal hyperplasia of the jugular vein grafts in rabbit models.